Weather Satellites: Planning for the Geostationary Operational
Environmental Satellite Program Needs More Attention (Chapter Report,
03/13/97, GAO/AIMD-97-37).
Pursuant to a congressional request, GAO reviewed the National Oceanic
and Atmospheric Administration's (NOAA) management of the Geostationary
Operational Environmental Satellite (GOES) Program, focusing on: (1)
NOAA's strategy for procuring satellites in the GOES continuation
series; (2) what steps NOAA should be taking now to prepare for the next
generation series of satellites; and (3) whether the potential exists
for improving the system and reducing costs in the long term.
GAO noted that: (1) based on the best available analysis, the potential
for a gap in geostationary satellite coverage will be significant in the
early years of the next century if procurement of new satellites does
not begin soon; (2) to prevent this problem, NOAA plans to competitively
procure two to four continuation series spacecraft that will carry the
same meteorological instruments as the current spacecraft and
incorporate modest technical improvements; (3) the satellites are
planned for launch beginning in 2002; (4) given the importance of
maintaining continuous geostationary weather coverage, NOAA's plans are
reasonable; (5) however, there are inherent difficulties in determining
exactly when and how many of the continuation series spacecraft will be
needed; (6) despite these difficulties, GAO identified several specific
shortcomings in NOAA's spacecraft planning process that, if remedied,
could improve planning in the future; (7) based on the President's
fiscal year (FY) 1998 budget, NOAA does not plan to begin a follow-on
GOES program until FY 2003 at the earliest; (8) given that the
opportunity now exists to consider alternatives for a follow-on system,
current usage of GOES data by weather forecasters suggests that a
reexamination of the GOES satellite architecture is warranted; (9)
before a decision can be made about what kind of follow-on satellite
system to build, an updated analysis of user needs must be completed;
(10) several new approaches and technologies for geostationary satellite
meteorology have been suggested in recent years by government, academic,
and industry experts, however, identifying and evaluating the full range
of options will require thorough engineering analysis; (11) in addition,
past NOAA experience shows that developing new technologies is done most
efficiently as a separate line of effort, outside of the operational
satellite program; (12) such an effort would benefit from greater
collaboration with the National Aeronautics and Space Administration,
whose expertise and support have, in the past, significantly contributed
to the development of NOAA's weather satellite systems; (13) the longer
that NOAA continues without actively considering other options for a
future system, the more it risks having to procure additional
continuation series satellites, because the availability date for a
fully developed new satellite system will slip farther into the future;*
--------------------------- Indexing Terms -----------------------------
REPORTNUM: AIMD-97-37
TITLE: Weather Satellites: Planning for the Geostationary
Operational Environmental Satellite Program Needs More
Attention
DATE: 03/13/97
SUBJECT: Geosynchronous satellites
Weather forecasting
Federal procurement
Planning
Interagency relations
Research and development contracts
Earth sciences data systems
Cost control
Aerospace engineering
IDENTIFIER: NOAA Geostationary Operational Environmental Satellite
NOAA/NASA GOES-Next Satellite Program
NWS Modernization Program
NASA Operational Satellite Improvement Program
Atlas Launch Vehicle
NOAA GOES I-M Product Assurance Plan
NWS Advanced Weather Interactive Processing System
NASA Geostationary Advanced Technology Environmental System
NOAA Polar Orbiting Weather Satellite System
NOAA Television Infrared Observation Satellite
NASA Applications Technology Satellite
High Resolution Infrared Radiometer
Advanced Very High Resolution Radiometer
NASA New Millennium Program
NASA Earth System Science Pathfinder Program
NASA Advanced Geostationary Studies Program
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Cover
================================================================ COVER
Report to the Chairman, Subcommittee on Energy and Environment,
Committee on Science, House of Representatives
March 1997
WEATHER SATELLITES - PLANNING FOR
THE GEOSTATIONARY SATELLITE
PROGRAM NEEDS MORE ATTENTION
GAO/AIMD-97-37
Weather Satellites
(511611)
Abbreviations
=============================================================== ABBREV
ATS - Applications Technology Satellite
AVHRR - Advanced Very High Resolution Radiometer
GAO - General Accounting Office
GATES - Geostationary Advanced Technology Environmental System
GOES - Geostationary Operational Environmental Satellite
GPS - Global Positioning System
GPS/MET - Global Positioning System/Meteorology
MIT - Massachusetts Institute of Technology
NASA - National Aeronautics and Space Administration
NESDIS - National Environmental Satellite, Data, and Information
Service
NOAA - National Oceanic and Atmospheric Administration
NWS - National Weather Service
OSIP - Operational Satellite Improvement Program
TIROS - Television and Infrared Observational Satellite
Letter
=============================================================== LETTER
B-275996
March 13, 1997
The Honorable Ken Calvert
Chairman
Subcommittee on Energy and Environment
Committee on Science
House of Representatives
Dear Mr. Chairman:
This report responds to your predecessor's request that we review the
National Oceanic and Atmospheric Administration's (NOAA) management
of the Geostationary Operational Environmental Satellite (GOES)
Program. Specifically, we were asked to assess (1) the agency's
strategy for procuring satellites in the GOES continuation series,
(2) what steps the agency should be taking now to prepare for the
next generation series of satellites, and (3) whether the potential
exists for improving the system and reducing costs in the long term.
The report recommends that the NOAA Administrator take certain steps
to improve the agency's planning for future systems.
We are sending copies of this report to the Ranking Minority Member
of your Subcommittee; the Chairmen and Ranking Minority Members of
the House Committee on Science; the Senate Committee on Commerce,
Science, and Transportation; the House and Senate Committees on
Appropriations; the House Committee on Government Reform and
Oversight; and the Senate Committee on Governmental Affairs. We are
also sending copies to the Secretary of Commerce and the
Administrator of NOAA. Copies will also be made available to others
upon request.
If you have any questions concerning this report, please call me at
(202) 512-6240. Other major contributors are listed in appendix II.
Sincerely yours,
Jack L. Brock, Jr.
Director, Defense Information and
Financial Management Systems
EXECUTIVE SUMMARY
============================================================ Chapter 0
PURPOSE
---------------------------------------------------------- Chapter 0:1
The National Oceanic and Atmospheric Administration (NOAA) is in the
process of planning the procurement of new Geostationary Operational
Environmental Satellites (GOES) to replace the current series of
satellites, which will begin to reach the end of their useful lives
in approximately 2002. NOAA plans to buy a continuation series of
two to four satellites that will be very similar to the current
series in their capabilities and operations to fill the potential gap
in satellite coverage that could occur beginning in 2002. Beyond the
potential gap in coverage, NOAA has not yet decided whether to
continue procuring the same type of satellites or consider new
designs for a next generation system.
In fiscal year 1998, NOAA plans to spend over $240 million for
development and operations costs associated with the GOES system.
Given that the NOAA budget is expected to be constrained in the
coming years, the Chairman of the House Committee on Science,
Subcommittee on Energy and Environment, requested that GAO assess (1)
the agency's strategy for procuring continuation series satellites,
(2) what steps the agency should be taking now to prepare for the
next generation series of satellites, and (3) whether the potential
exists for improving the system and reducing costs in the long term.
BACKGROUND
---------------------------------------------------------- Chapter 0:2
The GOES system, which has been operational since 1975, plays a
critical role in weather forecasting. The continuous availability of
GOES data is vital to the success of the National Weather Service's
(NWS) approximately $4.5 billion systems modernization program. GOES
satellites are uniquely positioned to observe the development of
hazardous weather, such as hurricanes and severe thunderstorms, and
track their movement and intensity so that major losses of property
and life can be reduced or avoided. GOES satellites have two primary
meteorological instruments: an imager and a sounder. The imager
collects digital images of portions of the earth's surface from
radiation that is sensed at five different wavelengths. The sounder
is mechanically similar but sensitive to a broader range of spectral
wavelengths, which allows it to measure natural variables, such as
temperature and humidity, at different levels of the atmosphere.
NOAA's operational strategy calls for two GOES satellites to be
active at all times--one satellite to observe the Atlantic Ocean and
eastern half of the United States, and the other to observe the
Pacific Ocean and the western part of the country. Two GOES
satellites are currently in orbit--GOES-8 covering the east and
GOES-9 in the west. These satellites were launched in 1994 and 1995,
respectively.
Even though satellites in the GOES series have been operational for
over 20 years, only one major design change has been implemented.
The first generation design, used on GOES-1 through GOES-7, was
developed experimentally by the National Aeronautics and Space
Administration (NASA) and subsequently came to be relied upon for the
operational system. The second generation, called GOES-Next,
represents a complete redesign of the spacecraft and its instruments
that allows for the collection of substantially more and better
weather data. The GOES-Next series includes the two currently
operational satellites, GOES-8 and GOES-9, plus three additional
spacecraft that are in different stages of production. Development
of this second generation experienced severe technical problems, cost
overruns, and schedule delays. For example, NOAA's estimate of the
overall development cost for GOES-Next grew from $640 million in 1986
to $2.0 billion in 1996. Also, a nearly 5-year schedule slip in the
launch of the first GOES-Next satellite left NOAA at one point in
real danger of temporarily losing geostationary satellite data
coverage, although no gap in coverage ever actually occurred. GAO
reported in 1991 that design complexity, inadequate management of the
program by NOAA and NASA (NOAA's agent for the procurement), and poor
contractor performance all contributed to the cost, schedule, and
technical problems experienced by GOES-Next.\1
Although some technical problems remain, the first two of these
satellites are now producing useful, high quality weather data daily.
--------------------
\1 Weather Satellites: Action Needed to Resolve Status of the U.S.
Geostationary Satellite Program (GAO/NSIAD-91-252, July 1991), p. 3.
RESULTS IN BRIEF
---------------------------------------------------------- Chapter 0:3
Based on the best available analysis, the potential for a gap in
geostationary satellite coverage will be significant in the early
years of the next century if procurement of new satellites does not
begin soon. To prevent this problem, NOAA plans to competitively
procure two to four continuation series spacecraft that will carry
the same meteorological instruments as the current spacecraft and
incorporate modest technical improvements. The satellites are
planned for launch beginning in 2002. Given the importance of
maintaining continuous geostationary weather coverage, NOAA's plans
are reasonable. However, there are inherent difficulties in
determining exactly when and how many of the continuation series
spacecraft will be needed. Despite these difficulties, GAO
identified several specific shortcomings in NOAA's spacecraft
planning process that, if remedied, could improve planning in the
future. They include unclear policies for replacing partially failed
satellites and backing up launches.
Also, NOAA has no formal program underway to develop a new spacecraft
series to follow the continuation series. Based on the President's
fiscal year 1998 budget, NOAA does not plan to begin a follow-on GOES
program until fiscal year 2003 at the earliest. Given that the
opportunity now exists to consider alternatives for a follow-on
system, current usage of GOES data by weather forecasters suggests
that a reexamination of the GOES satellite architecture is warranted.
Although requirements have not been formally updated since the
GOES-Next satellite series was developed, usage of GOES data has
continued to evolve. The current satellite design hosts two
meteorological instruments that are devoted to a range of
capabilities, some of which are increasing in importance to weather
forecasters and others of which remain largely experimental. Before
a decision can be made about what kind of follow-on satellite system
to build, an updated analysis of user needs must be completed.
Several new approaches and technologies for geostationary satellite
meteorology have been suggested in recent years by government,
academic, and industry experts. Some of these options may offer the
potential for reducing system costs and improving performance in the
long term. Examples include moving to an architecture of smaller
satellites as well as incorporating various spacecraft and instrument
technologies that were not available for the previous spacecraft
generation. However, identifying and evaluating the full range of
options will require thorough engineering analysis. In addition,
past NOAA experience shows that developing new technologies is done
most efficiently as a separate line of effort, outside of the
operational satellite program. Such an effort would benefit from
greater collaboration with NASA, whose expertise and support have, in
the past, significantly contributed to the development of NOAA's
weather satellite systems.
The longer that NOAA continues without actively considering other
options for a future system, the more it risks having to procure
additional continuation series satellites, because the availability
date for a fully developed new satellite system will slip farther
into the future. The potential advantages of advanced technologies
and small satellite constellations as well as questions about
changing user requirements suggest that alternatives to the present
architecture should be seriously considered.
PRINCIPAL FINDINGS
---------------------------------------------------------- Chapter 0:4
ISSUES IN NOAA'S PLANNING TO
ENSURE CONTINUOUS GOES
COVERAGE
-------------------------------------------------------- Chapter 0:4.1
Based on the best available analysis, the potential for a gap in
geostationary satellite weather coverage will be significant in the
early years of the next century if procurement of new satellites does
not begin soon. Although three satellites in the current series are
still in production and scheduled for launch over the next 5 years,
designing and producing an entirely new spacecraft would take much
longer--approximately 10 years, according to aerospace experts.
Accordingly, NOAA plans to procure a continuation series of at least
two spacecraft that will carry the same meteorological instruments as
the current spacecraft and incorporate only limited technical
improvements. NOAA expects this approach to allow for development of
the continuation series satellites within 5 years.
Calculating the quantity and need dates for the continuation series
satellites is a complex process involving factors that cannot be
precisely defined. Although NOAA has determined that it will need
the first continuation series satellite in 2002, the actual date that
a replacement satellite is launched may be different. A major risk
for any satellite program is the chance that a spacecraft launch will
fail, necessitating that future planned launches be moved up to try
to compensate for the lost spacecraft. Unexpected component failures
on operational satellites--such as GOES-8 and GOES-9 have recently
experienced--can also advance the need dates for future satellites.
Conversely, a string of successful launches and robust, long-lived
satellites can significantly delay the need for new satellites. Once
a change in needs is identified, scheduling a new launch may be
constrained by the unavailability of flight-ready replacement
spacecraft, launch vehicles and facilities, or funding to support a
launch. Given these risks and uncertainties, NOAA's procurement
strategy, which calls for two continuation series spacecraft to be
built but includes separate options to build two additional
spacecraft, provides a reasonable degree of flexibility to cope with
unexpected schedule changes.
We identified several shortcomings in NOAA's spacecraft planning
process that, if remedied, could lead to better planning in the
future. First, the need for the continuation series arose because
planning for a follow-on series has been repeatedly deferred since it
was first attempted in 1989. Second, NOAA's official policy for
replacing satellites that experience partial failures is unclear,
increasing the uncertainty about when replacements will be needed.
Third, NOAA does not have a consistent policy for providing backup in
the event of a launch failure. Timely initiation of follow-on
planning combined with clearer, more consistent policies for
replacing partially failed spacecraft and backing up launches would
provide better assurance of meeting future needs with minimal risk.
NOAA IS UNPREPARED TO
DEVELOP A NEXT GENERATION
GOES SYSTEM
-------------------------------------------------------- Chapter 0:4.2
In addition to procuring satellites to prevent a gap in coverage,
NOAA needs to begin planning for a follow-on program of GOES
satellites if it is to avoid continuing to procure additional
continuation series satellites in the future. Although several
preliminary efforts have been made to study the feasibility of making
incremental enhancements to the current meteorological instrument
designs, NOAA has no formal program underway to develop a follow-on
series. Based on the President's fiscal year 1998 budget, NOAA does
not plan to begin a follow-on GOES program until fiscal year 2003 at
the earliest.
Current usage of GOES data by weather forecasters suggests that a
reexamination of the GOES satellite architecture is warranted.
Although requirements have not been formally updated since the
GOES-Next satellite series was developed, usage of GOES data has
continued to evolve. The current satellite design hosts two
meteorological instruments that are devoted to a range of
capabilities, some of which are increasing in importance to weather
forecasters and others of which remain largely experimental.
According to NOAA, limited experience with GOES-Next data makes it
difficult to precisely determine which capabilities will be of most
value to users in the future. Before a decision can be made about
what kind of follow-on satellite system to build, an updated analysis
of user needs must be completed.
Once user needs are determined and requirements established, a full
range of potential architectural solutions needs to be identified and
evaluated. Several new approaches and technologies for geostationary
satellite meteorology have been suggested in recent years by
government, academic, and industry experts. Some of these options
may offer the potential for reducing system costs and improving
performance in the long term. Examples include moving to an
architecture of smaller satellites as well as incorporating various
spacecraft and instrument technologies that were not available for
the previous spacecraft generation. NOAA officials involved in GOES
acquisition and development agree that these options need to be
considered, given that the follow-on GOES program will be subject to
cost constraints.
Identifying and evaluating options will require thorough engineering
analysis. In addition, past NOAA experience shows that developing
new technologies is done most efficiently as a separate line of
effort, outside of the operational satellite program. Such an effort
would benefit from greater collaboration with NASA, whose expertise
and support have, in the past, significantly contributed to the
development of NOAA's weather satellite systems.
MATTERS FOR CONGRESSIONAL
CONSIDERATION
---------------------------------------------------------- Chapter 0:5
Given that options may exist for NOAA to develop a significantly
improved follow-on GOES system, the Congress may wish to closely
examine the costs and benefits of different approaches for the
timing, funding, and scope of the follow-on program. Further, the
Congress may also wish to examine NASA's potential role in working
with NOAA to support the needs of geostationary weather satellites
within NASA's advanced spacecraft technology programs.
RECOMMENDATIONS
---------------------------------------------------------- Chapter 0:6
GAO recommends that the NOAA Administrator ensure that the National
Environmental Satellite, Data, and Information Service (NESDIS)
clarifies certain of its GOES planning policies. Further, GAO
recommends that the Administrator prepare a formal analysis of the
costs and benefits of several alternatives for the timing, funding,
and scope of the follow-on program. This analysis should be provided
to the Congress for its use in considering options for the future of
the GOES program. Details of our recommendations are included in
chapters 2 and 3.
AGENCY COMMENTS AND OUR
EVALUATION
---------------------------------------------------------- Chapter 0:7
GAO requested comments on a draft of this report from the Secretary
of Commerce. The Secretary provided written comments, which are
discussed in chapters 2 and 3 and are reprinted in appendix I. The
Secretary concurred with GAO's recommendation that certain of its
GOES planning policies be clarified. However, the Secretary did not
concur with GAO's recommendations that the NOAA Administrator
reconsider the agency's decision to defer the follow-on program and
prepare a formal analysis of options for such a program. The draft
that GAO provided to Commerce was based on its fiscal year 1997
budget, which showed that a GOES follow-on program would begin in
2000. However, the fiscal year 1998 budget request, released since
then, shows no follow-on program beginning through 2002. In
discussions with GAO, NOAA officials confirmed that a follow-on
program is currently not planned until 2003 at the earliest.
As stated in the report, GAO believes that continued deferral of the
follow-on program is risky because it forgoes the opportunity to
identify and develop a potentially more effective and economical
architecture. Furthermore, the longer that NOAA continues without
actively considering other options for a future system, the more it
risks having to procure additional continuation series satellites,
because the availability date for a fully developed new satellite
system will slip farther into the future.
INTRODUCTION
============================================================ Chapter 1
BACKGROUND
---------------------------------------------------------- Chapter 1:1
The GOES satellite system, which has been operational since 1975,
plays a critical role in weather forecasting. The continuous
availability of GOES data is vital to the success of NWS'
approximately $4.5 billion systems modernization program. GOES is
one of two weather satellite systems operated by NOAA; the other is a
system of polar-orbiting satellites.\1 Unlike the polar satellites,
geostationary weather satellites are placed into a special orbit that
allows them to continuously maintain the same view of the earth's
surface.\2 Thus, they are uniquely positioned to observe the
development of hazardous weather, such as hurricanes and severe
thunderstorms, and track their movement and intensity so that major
losses of property and life can be reduced or avoided. Further, the
unique ability of geostationary satellites to provide broad,
continuously updated coverage of atmospheric conditions over land as
well as oceans is very important to NOAA's weather forecasting
operations.\3
NOAA's operating strategy calls for two GOES satellites to be active
at all times--one satellite to observe the Atlantic Ocean and the
eastern half of the U.S., and the other to observe the Pacific Ocean
and the western part of the country. Figure 1.1 shows the coverage
provided by two GOES satellites.
Figure 1.1: GOES Satellite
Coverage
(See figure in printed
edition.)
Source: NOAA.
GOES satellites have two primary instruments for collecting weather
data: an imager and a sounder. The imager is akin to a camera; it
collects data in the form of digital images of the earth or some part
of it, based on radiation that is sensed at five different spectral
wavelengths or "channels," including four in the infrared range and
one that corresponds to visible light. Forecasters use animated
sequences of imager data to track the development of various weather
phenomena. The sounder is mechanically similar to the imager but
receives data much more slowly and is sensitive to a broader range of
spectral wavelengths. The sounder's sensitivity to 19 different
channels allows it to collect data on a number of natural variables,
such as temperature and humidity, and attribute those measurements to
specific levels of the earth's atmosphere. The data from both the
imager and sounder are relayed to a ground station at Wallops Island,
Virginia, which processes the data to make them usable by weather
forecasters. Then the data are retransmitted back up to the GOES
satellites, which broadcast them to the weather forecasting
community.
NOAA has never been directly responsible for the design and
development of any of its meteorological satellites. Instead, the
agency has relied on NASA's expertise in spacecraft design and
development. After NOAA defines user requirements for its satellite
systems, it turns them over to NASA to contract with industry to
design and develop satellites that meet NOAA's needs. NASA launches
and tests the satellites, which are subsequently turned over to NOAA
to operate. Beginning in the 1970s, NASA had a formal ongoing
program, called the Operational Satellite Improvement Program (OSIP),
to develop and demonstrate experimental versions of advanced
meteorological satellites and instruments. Successful designs from
the OSIP program were often incorporated into NOAA's operational
satellite systems. OSIP was terminated in 1981 due to budgetary
constraints at NASA. However, NASA continues to act as the
procurement agent for NOAA's weather satellites.
--------------------
\1 Polar satellites are launched on a roughly north-south trajectory
that takes them over the polar regions of the earth. As the earth
turns beneath them, polar satellites observe a different portion of
the earth's surface during each orbit. Thus they can provide
observations of the weather over any given location, such as the
United States, only infrequently.
\2 Geostationary orbits are located approximately 22,300 miles out in
space. In contrast, polar satellites orbit at an altitude of about
500 miles.
\3 GOES satellites carry out other secondary missions as well, such
as monitoring conditions in the space environment around the earth,
relaying data from remote surface-based instruments to NOAA's command
and data acquisition stations, and relaying distress signals from
aircraft or marine vessels to search and rescue ground stations.
GOES SATELLITE DEVELOPMENT
HISTORY
---------------------------------------------------------- Chapter 1:2
Even though GOES satellites have been operational for over 20 years,
only one major design change has been implemented. The first
generation design was developed and operated experimentally by NASA
in the 1960s and early 1970s and subsequently became the basis for
the first operational satellites, GOES-1 through GOES-7. Figure 1.2
is an illustration of the first generation design. This series of
satellites was "spin-stabilized," meaning that the satellites slowly
spun while in orbit to maintain a stable position with respect to the
earth. While these satellites operated effectively, they had
technical limitations that NOAA wished to eventually overcome. The
imager and the sounder on these satellites\4 shared the same
telescopic viewing apparatus and could not collect data at the same
time. Further, because the satellite was spinning, it had to collect
data very slowly, capturing one narrow band of data each time that
its field-of-view swung past the earth.\5 A complete set of sounding
data, for example, took 2 to 3 hours to collect.
Figure 1.2: GOES 4-7 Satellite
Design
(See figure in printed
edition.)
Source: NASA.
(See figure in printed
edition.)
Legend:
EPS - Electrical Power System
HEPAD - High Energy Proton and
Alpha Detector
UHF - Ultra High Frequency
VAS - Visible and Infrared Spin
Scan Radiometer (VISSR)
Atmospheric Sounder
(See figure in printed
edition.)
In 1982, the National Weather Service (NWS) within NOAA sponsored a
review of what new technologies were available and what additional
missions could be performed by a new generation of geostationary
satellites. The review was supported by NOAA's National
Environmental Satellite, Data and Information Service (NESDIS) as
well as by NASA's Goddard Space Flight Center and industry
representatives. Based on input from these sources, requirements for
a new generation spacecraft were developed.
The new spacecraft design, called GOES-Next, was a significant
departure from the first generation GOES. For example, GOES-Next was
to be "body-stabilized." This meant that the satellite would hold a
fixed position in orbit relative to the earth, allowing for
continuous meteorological observations. Instead of maintaining
stability by spinning, the satellite would preserve its fixed
position by continuously making small adjustments in the rotation of
internal momentum wheels or by firing small thrusters to compensate
for drift. Further, the imager and sounder would be completely
separate, so that they could function simultaneously and
independently. These and other enhancements meant that the GOES-Next
satellites would be able to collect significantly better quality data
more quickly than the older series of satellites. However, the
improvements would be made at the expense of a heavier and more
complex spacecraft. Figure 1.3 is an illustration of the GOES-Next
design.
Figure 1.3: GOES-Next
Satellite Design
(See figure in printed
edition.)
Source: NASA.
(See figure in printed
edition.)
Legend:
SAR - Search and Rescue
T&C - Telemetry and Command
UHF - Ultra High Frequency
(See figure in printed
edition.)
--------------------
\4 A sounder was first added to the existing satellite design as an
experiment on GOES-4. Sounders have flown on all subsequent GOES
satellites.
\5 At a geostationary orbit, the earth would fill only 23 degrees (6
percent) of the satellite's 360 degree rotational view.
GOES-NEXT DEVELOPMENT PROBLEMS
---------------------------------------------------------- Chapter 1:3
Although GOES-Next represented a complete redesign of NOAA's
geostationary satellite system, satellite industry observers told us
that the technical risks involved in developing GOES-Next appeared in
the early 1980s to be manageable. Polar-orbiting meteorological
spacecraft had already evolved from spin-stabilized to
body-stabilized designs, and the GOES-Next builder, Ford Aerospace,\6
had already built a body-stabilized geostationary meteorological
satellite for India. Furthermore, the instrument manufacturer, ITT
Corporation, had proposed designs that were closely based on
successful imagers and sounders it was building for NOAA's
polar-orbiting satellites. On this basis, NOAA did not authorize and
NASA did not require engineering analysis prior to GOES-Next
development work.
Despite the spacecraft and instrument design heritage, the GOES-Next
program experienced severe technical problems, massive cost overruns,
and dangerous schedule delays. Technical issues that had seemed
straightforward when the spacecraft design was being conceptualized
proved to be substantially more difficult to implement. For example,
the original design did not sufficiently take into consideration the
harshness of geostationary orbit, which is subject to large daily
temperature variations that can stress and warp ordinary materials.
Accordingly, the scan mirrors on the instruments had to be completely
redesigned using other materials. It was also discovered that it
would be very difficult to establish the fine pointing necessary to
meet requirements for accurately mapping the satellite's detailed
images to their exact position on earth.\7
These and other problems led to an increase of over 200 percent in
NOAA's estimate of the overall development cost of the GOES-Next
program--from $640 million in 1986 to $2.0 billion in 1996. Also,
the first launch of a GOES-Next satellite, which had been planned for
July 1989, did not occur until April 1994. This nearly 5-year
schedule slip left NOAA in real danger of temporarily losing
geostationary satellite data coverage. Fortunately, due to the
exceptional robustness of the last remaining first-generation
satellite, GOES-7, as well as the use of a borrowed European
satellite, NOAA was able to avoid a gap in coverage. GAO reported in
1991 that design complexity, inadequate management of the program by
NASA and NOAA, and poor contractor performance all contributed to the
cost, schedule, and technical problems experienced by the GOES-Next
program.\8 Although some technical problems remain, the first two of
these satellites, GOES-8 and GOES-9, are now producing useful, high
quality weather data daily.
The GOES-Next contract with Space Systems/Loral is for five
spacecraft, designated GOES-I through GOES-M.\9 Once the first two in
the series, GOES-I and GOES-J, were successfully launched and placed
in orbit, they were redesignated GOES-8 and GOES-9 respectively. The
other three spacecraft in the GOES-Next series, GOES-K, GOES-L, and
GOES-M, are in various stages of production. The GOES-K spacecraft
has been completed and is scheduled for launch in April 1997. If
GOES-8 and GOES-9 are still operational then, GOES-K will be stored
at a central location in orbit and activated when either of its two
predecessors fails. GOES-M and GOES-L are planned to be launched in
2000 and 2002, respectively. GOES-M, which has a stronger frame than
the other satellites in the series, will be launched ahead of GOES-L
in order to accommodate a new and heavier secondary instrument for
measuring the space environment, called the Solar X-ray Imager.
--------------------
\6 Now called Space Systems/Loral.
\7 The process of establishing the satellite's exact position and
maintaining it through a series of images continues to pose problems
for NOAA even as the GOES-Next satellites have become operational.
\8 Weather Satellites: Action Needed to Resolve Status of the U.S.
Geostationary Satellite Program (GAO/NSIAD-91-252), July 24, 1991, p.
3.
\9 Weather satellites are given an alphabetic designation until they
are launched; they are then assigned a number in the series.
OBJECTIVES, SCOPE, AND
METHODOLOGY
---------------------------------------------------------- Chapter 1:4
In February 1996, the House Committee on Science, Subcommittee on
Energy and Environment, requested that we review NOAA's management of
the GOES Program. On the basis of subsequent discussions with
subcommittee staff, our specific objectives were to assess: (1) the
agency's strategy for procuring continuation series satellites, (2)
what steps the agency should be taking now to prepare for the next
generation series of satellites, and (3) whether the potential exists
for improving the system and reducing costs in the long term.
To meet our objectives, we reviewed NOAA and NASA documents regarding
GOES historical background, current status, mission operations,
spacecraft and instrument improvements, ground systems, future
procurement strategies, and proposed technology infusion. We
reviewed NASA documents regarding the GOES Project and proposed
technology infusion. We reviewed NOAA cost and budget documents and
NASA Program Operating Plans. In addition to discussing these issues
with agency officials from NOAA and NASA, we met with a broad range
of representatives from academia and industry. Staff also attended a
3-day conference on "GOES-8 and Beyond," sponsored by the
International Society for Optical Engineering.
Specifically, with regard to the continuation series procurement
strategy, we obtained and analyzed information from NOAA and NASA
satellite acquisition officials. We discussed our analysis and
obtained additional information from industry representatives of:
-- Hughes Space and Communications Company, El Segundo, California;
-- Lockheed Martin Corporation, Sunnyvale, California; and
-- Space Systems/Loral, Palo Alto, California.
Regarding what steps the agency should be taking now to prepare for
the next generation series of satellites, we obtained information
from researchers and other officials at a range of NOAA and NASA
facilities, including:
-- NOAA System Acquisition Office, Silver Spring, Maryland;
-- NOAA NESDIS GOES Program Office, Suitland, Maryland;
-- NOAA NESDIS Cooperative Institute for Meteorological Satellite
Studies, Madison, Wisconsin;
-- NOAA NESDIS Cooperative Institute for Research in the
Atmosphere, Ft. Collins, Colorado;
-- NOAA NWS Headquarters, Silver Spring, Maryland;
-- NOAA NWS Weather Forecast Offices in Sullivan, Wisconsin;
Denver, Colorado; and Pueblo, Colorado;
-- NOAA Forecast Systems Laboratory, Boulder, Colorado;
-- NWS Cooperative Program for Operational Meteorology, Education,
and Training, Boulder, Colorado; and
-- NASA GOES Project Office, Goddard Space Flight Center,
Greenbelt, Maryland.
Regarding the potential for improving the GOES system while reducing
costs in the long run, we began by obtaining information from NOAA
and NASA officials at the sites listed above. We analyzed this
information and sought additional input from representatives of
industry and academia, including:
-- Aerospace Corporation, El Segundo, California;
-- Applied Physics Laboratory, Johns Hopkins University, Laurel,
Maryland;
-- Ball Aerospace & Technologies Corporation, Boulder, Colorado;
-- Hughes Space and Communications Company, El Segundo, California;
-- Lockheed Martin Corporation, Sunnyvale, California;
-- MITRE Corporation, McLean, Virginia;
-- National Research Council, Washington, D.C.;
-- Northrop Grumman Corporation, Baltimore, Maryland;
-- Space Systems/Loral, Palo Alto, California;
-- TRW Space and Electronics Group, Redondo Beach, California; and
-- University Corporation for Atmospheric Research, Boulder,
Colorado.
We were unable to perform a detailed audit of the cost of the
continuation series and next generation satellites because cost
information was unavailable. A budget figure of $2.2 billion for a
program to build four spacecraft had been estimated within NOAA for
the fiscal year 1997 budget. However, during our audit, NOAA
restructured the program and its procurement strategy on two
different occasions, each of which resulted in different cost
estimates. At the time we concluded our review, NOAA's System
Acquisition Office, which will manage the continuation series
procurement, did not have an official estimate for the overall cost
of the program.
We conducted our review from March 1996 through February 1997, in
accordance with generally accepted government auditing standards. We
requested written comments on a draft of this report from the
Secretary of Commerce. The Secretary provided us with written
comments that are discussed in chapters 2 and 3 and are reprinted in
appendix I.
ISSUES IN NOAA'S PLANNING TO
ENSURE CONTINUOUS GOES COVERAGE
============================================================ Chapter 2
Based on the best available analysis, the potential for a gap in
geostationary satellite weather coverage will be significant in the
early years of the next century if procurement of new satellites does
not begin soon. Although three satellites in the current series are
still in production and scheduled for launch over the next 5 years,
designing and producing an entirely new spacecraft would take much
longer--approximately 10 years, according to aerospace experts.
Accordingly, NOAA plans to procure at least two "continuation
series"\1 spacecraft that will carry the same meteorological
instruments as the current spacecraft and incorporate only limited
technical improvements. NOAA expects this approach to allow for
development of the new spacecraft within 5 years.
Calculating the quantity and need dates for the continuation series
is a complex process involving factors that cannot be precisely
defined. Although NOAA has determined that it will need the first
continuation series satellite in 2002, the actual date that a
replacement satellite is launched may be different. According to
NOAA officials, a major risk for any satellite program is the chance
that a spacecraft launch will fail, necessitating that future planned
launches be moved up to try to compensate for the lost spacecraft.
Unexpected component failures on operational satellites--such as
GOES-8 and GOES-9 have recently experienced--can also advance the
need dates for future satellites. Conversely, a string of successful
launches and robust, long-lived satellites can significantly delay
the need for new satellites. Once a change in needs is identified,
scheduling a new launch may be constrained by the unavailability of
flight-ready replacement spacecraft, launch vehicles and facilities,
or funding to support a launch. Given these risks and uncertainties,
NOAA's procurement strategy, which calls for two continuation series
spacecraft to be built but includes separate options to build two
additional spacecraft, provides a reasonable degree of flexibility to
cope with unexpected schedule changes.
We identified several shortcomings in NOAA's spacecraft planning
process that, if remedied, could lead to better planning in the
future. First, the need for the continuation series arose because
planning for a follow-on series has been repeatedly deferred since it
was first attempted in 1989. Second, NOAA's official policy for
replacing satellites that experience partial failures is unclear,
increasing the uncertainty about when replacements will be needed.
Third, NOAA does not have a consistent policy for providing backup in
the event of a launch failure. More consistent policies for
replacing partially failed spacecraft and backing up launches would
provide better assurance of meeting future needs with minimal risk.
--------------------
\1 NOAA does not have an official name for this series of satellites.
During our audit, NOAA officials originally referred to the series as
"clones." Later, after revising their procurement strategy, they
referred to them as "gap fillers." In comments on a draft of the
report, the Department of Commerce objected to the use of the term
"gap fillers." Accordingly, we have adopted the phrase "continuation
series" for our final report.
NOAA'S STRATEGY FOR PROCURING
THE CONTINUATION SERIES
---------------------------------------------------------- Chapter 2:1
In order to procure continuation series spacecraft quickly, NOAA
plans to minimize design changes from the current series. The same
meteorological instruments as the current series will be used, and
the spacecraft itself (called the spacecraft "bus") will be very
similar. According to government and industry officials, limiting
the amount of new design work should make an accelerated procurement
feasible. NOAA, working through NASA, its procurement agent, has
already negotiated a contract with the instrument manufacturer, ITT
Corporation, to deliver up to four additional sets of GOES imagers
and sounders to be flown on the continuation series satellites. NOAA
and NASA also plan to soon issue a Request for Proposals for two to
four spacecraft busses and expect several manufacturers to submit
bids. In most cases, bids are likely to be based on modified
versions of standard spacecraft busses that manufacturers have
developed to satisfy commercial needs for geostationary
communications satellites. NOAA and NASA plan to negotiate a firm
fixed-price contract with the winner of the spacecraft bus
competition.
Although the instruments on the continuation series spacecraft will
be identical to those currently in use, the spacecraft busses will
not. The current spacecraft bus, which was designed by Space
Systems/Loral in the mid 1980s, has never been able to fully meet
NOAA's original GOES-Next specifications for spacecraft pointing.
Designing the spacecraft to point very precisely at the earth and
maintain that precise orientation is important because it allows the
data collected by the instruments, especially the imager, to be
mapped very accurately to their exact location on the surface of the
earth. Because the GOES-Next spacecraft has been unable to achieve
the originally required precision, extra work routinely needs to be
done by spacecraft operators to correct for errors in mapping GOES
data to its proper position over the earth's surface. According to
NASA and NOAA officials, improvements in pointing accuracy made in
commercial spacecraft busses since the time that the GOES-Next design
was finalized will better meet original GOES-Next specifications and
are expected to be incorporated into the continuation series
spacecraft.
Other, relatively minor improvements are expected in the spacecraft
busses as well. For example, an improved power system, based on more
recent battery technology, should reduce certain brief observation
gaps that occur periodically with the current design.
NOAA considered several other approaches before arriving at its
current procurement strategy. Originally, NOAA intended to procure
four or five additional "clones" of the current spacecraft from Loral
on a sole-source basis. The clones would have been largely identical
to the current spacecraft, using new parts only in cases where
original parts were no longer available. However NASA and NOAA
officials jointly concluded that the government would not be
justified in avoiding a competitive procurement, and this strategy
was dropped. NOAA then considered buying just one or two clones from
Loral, to be followed by a competitive procurement for a continuation
series. In September 1996, we reported that significant cost savings
were not expected from the sole-source clone procurement and that
requirements for a follow-on system had not been determined.\2
Because of concerns raised by ourselves and others, NOAA eventually
also abandoned this second strategy.
NOAA's current strategy has advantages over earlier approaches that
involved buying clones of the GOES-Next spacecraft. As discussed
above, procuring a new spacecraft bus will allow NOAA to take
advantage of technical improvements that have already been developed
for commercial customers, such as greater pointing accuracy and a
more capable power subsystem. In addition, use of a competitively
awarded, firm fixed-price contract can be expected to help control or
reduce costs.
While moving to a fully competitive procurement approach for the
continuation series, NOAA is also planning to reserve the option to
obtain an additional satellite in the current series in the event
that one is needed before the first satellite in the continuation
series can be completed. To do this, NOAA and NASA are negotiating a
"warranty option" as an extension to the current contract with Space
Systems/Loral. Under this arrangement, NASA will contract with Loral
to procure necessary long-lead time parts so that it is ready to
build an extra spacecraft of the current type, if such a spacecraft
is needed due to (1) the premature failure of either GOES-8 or
GOES-9, which were designed to last 5 years each, or (2) a launch
failure of the GOES-K spacecraft in April 1997. Should either of
these occur, NOAA plans to advance the launches of GOES-L and GOES-M
and subsequently launch the warranty spacecraft to ensure continuity
until the first continuation series spacecraft is available. NOAA
and NASA will determine by mid-1998 whether to exercise this warranty
option and complete construction of the additional spacecraft.
NOAA does not yet know what the continuation series will cost. A
budget figure of $2.2 billion for a program to build four spacecraft
had been estimated within NOAA for the fiscal year 1997 budget.
However, as discussed above, NOAA restructured the program and its
procurement strategy on two different occasions, each of which
resulted in different cost estimates. At the time we concluded our
review, NOAA's System Acquisition Office, which will manage the
continuation series procurement, did not have an official estimate
for the overall cost of the program.
--------------------
\2 NOAA Satellites (GAO/AIMD-96-141R, September 13, 1996).
DIFFICULTIES IN DETERMINING
WHEN AND HOW MANY CONTINUATION
SERIES SATELLITES WILL BE
NEEDED
---------------------------------------------------------- Chapter 2:2
Calculating the quantity and need dates for the continuation series
satellites is a complex process involving factors that cannot be
precisely defined. Although NOAA has determined that it will need
the first one in 2002, the actual date that a replacement satellite
is launched may be different. Figure 2.1 shows NOAA's planned GOES
launch schedule. A major risk for any satellite program is the
chance that a spacecraft launch will fail, necessitating that future
planned launches be moved up to try to compensate for the lost
spacecraft. Unexpected component failures on operational
satellites--such as GOES-8 and GOES-9 have recently experienced--can
also advance the need dates for future satellites. Conversely, a
string of successful launches and robust, long-lived satellites can
significantly delay the need for new satellites. Once a change in
needs is identified, scheduling a new launch may be constrained by
the unavailability of flight-ready replacement spacecraft, launch
vehicles and facilities, or funding to support a launch. Given these
risks and uncertainties, NOAA's procurement strategy, which calls for
two spacecraft to be built but includes separate options to build two
additional spacecraft, provides a reasonable degree of flexibility to
cope with unexpected schedule changes.
Figure 2.1: Planned GOES
Launch Schedule
(See figure in printed
edition.)
Source: NOAA.
The risk of launch failure is significant in any spacecraft program.
NOAA and NASA officials have told us that a failure rate of one in
five launches is a reasonable estimate for the GOES program. NOAA
has factored this risk into its launch schedule by designating the
GOES-L launch in 2002 as a "planned failure." GOES-L will be the
fifth and last in the current (GOES-Next) series. Because NOAA
assumes for planning purposes that the GOES-L launch will fail, it is
planning to have the next spacecraft (the first in the continuation
series) ready for launch at the same time. NOAA officials told us
that it is especially important to plan for the next spacecraft to be
available at the same time as GOES-L is launched because it will be
the first in a new series and may be vulnerable to schedule delays
because of development problems. Conservatively scheduling its
launch at the same time as GOES-L is one way to try to compensate for
the risk of development delays. However, the success of other
launches, especially the launch of GOES-K in April 1997, will also be
of critical importance. If the GOES-K launch were to fail, NOAA
could risk a gap in coverage between 1998 and 2000. NOAA GOES
program officials told us that if this situation were to occur, they
would attempt to move up the GOES-L or GOES-M launches to reduce the
length of the coverage gap.
Unexpected component failures are another source of risk to the
launch schedule. GOES-8 and GOES-9, for example, are now expected to
operate for only 3 years, due to several technical problems that were
unforeseen when they were launched. The two satellites were launched
in April 1994 and May 1995, respectively, and had been designed to
last 5 years each. The most serious of the technical problems is a
tendency of the motor windings within the satellites' meteorological
instruments to break due to thermal stress.\3
Each of the satellite's two instruments has a primary and a backup
motor winding. If both windings fail, the instrument cannot operate.
The 3-year lifetime for GOES-8 and GOES-9 was determined in mid 1996
after one winding (out of a total of four) had already failed on each
spacecraft. If the revised predictions for the lifetimes of GOES-8
and GOES-9 are accurate, NOAA runs the risk of having only one
operational satellite (GOES-K, assuming it is successfully launched
in April 1997) between 1998 and 2000. As described above for launch
failures, if this situation were to occur, NOAA officials would
attempt to move up the GOES-L or GOES-M launches to reduce the length
of the coverage gap. They would also likely exercise the warranty
option on the GOES-Next contract to ensure continuity until the first
continuation series satellite were available.
Although it is possible to move up scheduled launches, NOAA officials
say that it is difficult to do so for several reasons. First, the
spacecraft itself must be ready for launch at the earlier date, which
may not be practical if integration and ground testing have not been
completed well in advance of the previously anticipated launch date.
Second, only a limited number of commercial launch opportunities
(usually six) are available each year for the Atlas launch vehicle
that GOES spacecraft are designed to use.\4 Most, if not all, of
those launch opportunities are reserved far in advance. In order to
move a launch forward, NOAA officials need to be able to find another
scheduled launch that can be deferred and replaced by the GOES
spacecraft. Third, it may be difficult to move a launch forward from
one fiscal year to another because funding may not be available to
support a launch. NOAA officials told us that a GOES launch costs
approximately $25 million (not including the cost of the Atlas IIA
launch vehicle itself, which is approximately $80 to 90 million).
Because of the many uncertainties in its planned launch schedule,
NOAA has not made a final determination of how many satellites in the
continuation series it will procure. The possibility of exercising
the warranty option on the current GOES-Next contract, in addition to
the chance that the existing satellites will last longer than 3 years
and that none of the planned launches will fail, are all factors that
could delay the need date for the first continuation series
spacecraft, either singly or in combination. Conversely, NOAA's
current predictions for satellite lifetimes and launch failures could
hold true, in which case the first continuation series spacecraft
would be needed in 2002.
The number of continuation series satellites needed also depends on
when the potential for a coverage gap ends. The potential gap will
end whenever the first of a new, follow-on series of satellites is
available for deployment. As stated earlier, government and industry
aerospace experts agree that it takes approximately 10 years to
develop a new spacecraft system. If work were begun in 1998, the
first spacecraft in a new GOES series would, therefore, be ready in
about 2008 and could be launched as the GOES-Q spacecraft. (See
figure 2.1.) Under this scenario, three continuation series
satellites would be needed (GOES-N, -O, and -P). If satellites in
the current series last longer than NOAA expects, or the expected
launch failure does not occur, NOAA's schedule could easily slip one
or two years for the later launches. In that situation, only two
continuation series satellites might be needed.
NOAA's planned continuation series contract will be for two
spacecraft with two separate options for one additional spacecraft
each. Thus, as few as two or as many as four spacecraft may be
procured through this contract. Given the uncertainties in the
launch schedule, NOAA's flexible procurement strategy is reasonable.
--------------------
\3 Other technical problems have arisen as well. Some of GOES-8's
electronic components have been damaged by electrostatic discharge,
prompting the installation of additional shielding on the rest of the
GOES-Next spacecraft. GOES-8 also experienced a failure within its
attitude stabilization system, which is being compensated for through
redundant components.
\4 NOAA's policy is to use commercial launch services wherever
possible.
SHORTCOMINGS IN NOAA'S PLANNING
PROCESS
---------------------------------------------------------- Chapter 2:3
We identified several shortcomings in NOAA's spacecraft planning
process that, if remedied, could lead to better planning in the
future. First, the need for the continuation series exists now only
because planning for a follow-on series has been repeatedly deferred
since it was first attempted in 1989. Second, NOAA's official policy
for replacing satellites that experience partial failures is unclear,
increasing the uncertainty about when replacements will be needed.
Third, NOAA does not have a consistent policy for providing backup in
the event of a launch failure. Timely initiation of follow-on
planning combined with clearer, more consistent policies for
replacing partially failed spacecraft and backing up launches would
provide better assurance of meeting future needs with minimal risk.
FOLLOW-ON PLANNING HAS BEEN
DEFERRED
-------------------------------------------------------- Chapter 2:3.1
NOAA officials have recognized for many years that a follow-on
program to GOES-Next would have to be started early in order to avoid
facing a potential gap in coverage. In 1989, NOAA commissioned a
working group to identify requirements for a follow-on system. A
list of requirements was developed and turned over to NASA in May
1989 for an assessment of architectural options for a follow-on GOES
program. Specifically, NOAA asked that NASA examine options for
modifying the GOES-Next system to improve efficiency, reduce costs,
and satisfy the new requirements. In response, NASA examined a range
of three architectural options and presented its results in October
1990. NASA's final report indicated that the study had been very
limited, both by resources\5 and by the restriction of only looking
at modifications to the GOES-Next architecture. NASA recommended
that a more thorough study be conducted and that development work be
immediately begun on the more challenging technical features of its
design options. However, no further resources were committed to this
line of effort.
Since 1990, NOAA officials involved in the GOES program have made
several attempts to initiate a follow-on program but have not
received agency approval to move forward. An internal presentation
delivered in March 1993 proposed studying a number of alternative
approaches to the current GOES architecture, including flying
low-cost weather cameras as secondary payloads on non-NOAA
geostationary satellites. The presentation stressed the need to
begin a formal study phase in fiscal year 1996 in order to have
sufficient time to develop and implement a new architecture by 2008.
Another presentation made in April 1995 also urged that engineering
studies be conducted early in order to meet tight time frames. Both
the 1993 and 1995 presentations assumed that several additional
spacecraft in the GOES-Next series would be procured before the first
follow-on satellite would be ready in 2008. Program officials told
us that, faced with budget constraints, NOAA did not act on any of
the recommendations of these studies.
--------------------
\5 NOAA and NASA estimates for the cost of a thorough study ranged
from $3 to $6 million; however, NASA received only $1.56 million to
conduct the study.
SATELLITE REPLACEMENT POLICY
IS UNCLEAR
-------------------------------------------------------- Chapter 2:3.2
NOAA's official policy for replacing partially failed satellites is
unclear. The stated policy has been to launch and activate a
replacement satellite if either of the two primary meteorological
instruments (the imager or the sounder) fails on either of the two
operational spacecraft. However, according to NASA and NOAA
officials, it is not certain that a replacement would actually be
launched in the event of a sounder failure, since sounder data is
less critical than imager data. (Use of sounder data is discussed at
greater length in chapter 3.) Also, no official criteria exist for
launching a replacement satellite if other partial failures were to
occur. For instance, a detector failure in a satellite's imager
could reduce the number of channels that it uses to collect data.
Such a reduction may or may not be cause to replace the satellite.
NOAA officials told us that they prefer to exercise judgement on a
case-by-case basis as specific failures occur. However, the lack of
explicit criteria for replacement makes it more difficult to forecast
how soon new satellites are most likely to be needed.
LAUNCH BACKUP POLICY IS
ARBITRARY
-------------------------------------------------------- Chapter 2:3.3
As discussed above, all spacecraft programs have to address the risk
of launch failure. However, NOAA's approach of designating certain
launches as "planned failures" and providing backup spacecraft for
only those launches is arbitrary, because NOAA does not know in
advance which launches will actually fail. In other words, the risk
of a launch failure is no greater for the "planned failure" than for
any of the other launches, which do not have specifically designated
backups. Although NOAA's approach is effective in putting an extra
spacecraft into the production stream to compensate for a launch
failure, it is ineffective in providing backup for each launch. An
alternative approach would be to schedule each launch to be backed up
by the next spacecraft in the production stream. Such an approach
would not require procurement of any additional spacecraft or launch
vehicles and would enhance NOAA's ability to compensate for launch
failures by planning to have spacecraft always available for backup
launches.
According to NOAA satellite acquisition officials, the GOES program
originally included the concept of maintaining an on-orbit spare in
addition to the two operational satellites. The spare would be
maintained in a central position and then moved either east or west
to replace the first operational satellite that failed. As soon as
possible after the on-orbit spare was activated, a new spare would be
launched. If both GOES-8 and GOES-9 are still operating in April
1997 when GOES-K is launched, it will be put into on-orbit storage in
the central location for up to 2 years. However, aside from this
particular case, NOAA has not decided to move to this method of
backup. Among aerospace experts, on-orbit storage of satellites is
controversial. Although the practice can reduce the risk of a break
in satellite coverage, other risks are incurred in the process of
storing a spacecraft in orbit that could reduce its capabilities once
it is activated. For example, a satellite stored in orbit would be
susceptible to the possibility of radiation damage that it would not
face if it were stored on the ground. In our opinion, further
analysis of this strategy is necessary before it is adopted on an
ongoing basis.
CONCLUSIONS
---------------------------------------------------------- Chapter 2:4
Given the importance of maintaining continuous geostationary weather
coverage, NOAA's decision to immediately begin procuring two to four
continuation series spacecraft through a competitively bid, firm
fixed-price contract is reasonable. The planned procurement has been
designed to be flexible enough to deal with the uncertainties of
determining exactly how many satellites to buy and when they need to
be available. However, the continuation series became necessary
because a follow-on program had been repeatedly deferred since 1989.
Such a program must be initiated soon if the number of continuation
series satellites is to be kept to a minimum. Clarifying official
policies for replacing partially failed spacecraft and backing up
planned launches could improve program planning for the future.
RECOMMENDATIONS
---------------------------------------------------------- Chapter 2:5
We recommend that the NOAA Administrator ensure that the National
Environmental Satellite, Data, and Information Service (NESDIS) (1)
clarifies official criteria for activating replacement spacecraft in
the event of a failure of an operational GOES satellite or any of its
instruments or subsystems and (2) reexamines the agency's strategy
for anticipating possible launch failures and considers scheduling
backups for all future launches.
AGENCY COMMENTS AND OUR
EVALUATION
---------------------------------------------------------- Chapter 2:6
The Secretary of Commerce concurred with the recommendations that
appear in this chapter but objected to our use of the term "gap
filler" to refer to the GOES-N, O, P, and Q satellites in the draft
report. Accordingly, we have used the term "continuation series" to
refer to these satellites in the final report.
NOAA IS UNPREPARED TO DEVELOP A
NEXT GENERATION GOES SYSTEM
============================================================ Chapter 3
In addition to procuring satellites to prevent a gap in coverage,
NOAA needs to begin planning for a follow-on program of GOES
satellites if it is to avoid continuing to procure additional
continuation series spacecraft in the future. Although several
preliminary efforts have been made to study the feasibility of making
incremental enhancements to the current meteorological instrument
designs, NOAA has no formal program underway to develop a follow-on
series. Based on the President's fiscal year 1998 budget, NOAA does
not plan to begin a follow-on GOES program until fiscal year 2003 at
the earliest.
Current usage of GOES data by weather forecasters suggests that a
reexamination of the GOES satellite architecture is warranted.
Although requirements have not been formally updated since the
GOES-Next satellite series was developed, usage of GOES data has
continued to evolve. The current satellite design hosts two
meteorological instruments that are devoted to a range of
capabilities, some of which are increasing in importance to weather
forecasters and others of which remain largely experimental.
According to NOAA, limited experience with GOES-Next data makes it
difficult to precisely determine which capabilities will be of most
value to users in the future. Before a decision can be made about
what kind of follow-on satellite system to build, an updated analysis
of user needs is necessary.
Once user needs are determined and requirements established, a full
range of potential architectural solutions needs to be identified and
evaluated. Several new approaches and technologies for geostationary
satellite meteorology have been suggested in recent years by
government, academic, and industry experts. Some of these options
may offer the potential for reducing system costs and improving
performance in the long-term. Examples include moving to an
architecture of smaller satellites as well as incorporating various
spacecraft and instrument technologies that were not available for
the previous spacecraft generation. NOAA officials involved in GOES
acquisition and development agree that these options need to be
considered, given that the follow-on GOES program will be subject to
cost constraints.
Identifying and evaluating options will require thorough engineering
analysis. In addition, past NOAA experience shows that developing
new technologies is done most efficiently as a separate line of
effort, outside of the operational satellite program. Such an effort
would benefit from greater collaboration with NASA, whose expertise
and support have, in the past, significantly contributed to the
development of NOAA's weather satellite systems. NOAA and NASA are
both likely to find it difficult to fund extensive engineering
analysis or technology demonstration projects.
NOAA HAS STUDIED ONLY
INCREMENTAL ENHANCEMENTS TO THE
CURRENT ARCHITECTURE
---------------------------------------------------------- Chapter 3:1
Based on the President's fiscal year 1998 budget, NOAA does not plan
to begin a follow-on GOES program until fiscal year 2003 at the
earliest. Agency officials told us that, lacking a formal follow-on
program, NOAA's primary ongoing efforts related to future planning
for the GOES system are described in the GOES I-M Product Assurance
Plan. Most of the plan addresses efforts to assess and improve the
utilization of data from the current GOES satellites in order to
maximize the return on the investment made in developing GOES-Next.
The plan also discusses goals and potential capabilities for a
follow-on system, concentrating on proposed incremental improvements
to the current system, including enhancements to both the imager and
sounder. The plan also suggests the need for additional instruments.
However, none of these possible improvements has yet been funded for
production.
In accordance with the plan, NOAA funded some research at the
Massachusetts Institute of Technology's (MIT) Lincoln Laboratory and
at ITT, the current manufacturer of the imager and sounder, to test
potential incremental enhancements to both instruments. One possible
enhancement would change the way the GOES sounder processes the
radiance signal it receives from the earth, allowing that signal to
be divided into a much greater number of discrete spectral bands.
The larger number of bands would allow extrapolation of more
information about the temperature, humidity, and pressure of the
atmosphere over a given spot on the earth's surface. The device that
would do this spectral separation, called an interferometer, was
originally designed and demonstrated on aircraft flights in the mid
1980s. Although NOAA spent several million dollars for engineering
studies of the interferometer at MIT Lincoln Laboratory and at ITT,
it recently decided not to continue development of the device.
The second potential enhancement would change the configuration of
the imager to speed up its operation. However, a faster imager would
produce a larger data stream than the current space-to-ground
communications system can handle. Because it would necessitate
changes in other systems, this enhancement has also not been approved
by NOAA.
The GOES I-M Assurance Plan also suggests the possible need for two
new instruments, a lightning mapper and a microwave sounder, in the
next-generation system. The lightning mapper could improve severe
weather monitoring, while the microwave sounder would allow sounder
data to be collected through cloud cover, which the current sounder
cannot do. No engineering analysis has yet been done on the
lightning mapper. NOAA commissioned a preliminary engineering study
of the microwave sounder from MIT's Lincoln Laboratory, which is due
in March 1997.
USES OF GOES DATA ARE EVOLVING
---------------------------------------------------------- Chapter 3:2
NOAA is not yet in a position to make decisions about what kind of
follow-on satellite system to build because its future needs are not
yet well understood. NOAA has not conducted a formal revision or
update of user requirements since 1989. However, recent positive
experience with GOES-8 and GOES-9 has led to increasing demands for
imager data. Data from the GOES sounders, on the other hand, is in
less demand because it has seen little operational use. Changing the
follow-on GOES architecture to facilitate greater collection of
imager data and deemphasize sounder data might better serve user
needs.
OFFICIAL USER REQUIREMENTS
HAVE NOT BEEN UPDATED
-------------------------------------------------------- Chapter 3:2.1
Current GOES user requirements were established in 1983 and have not
been formally revised since 1989. In 1994, just after the launch of
the first of the GOES-Next satellites, a NWS draft document
identified potential requirements for a next-generation GOES system.
However, this document was never finalized because NOAA officials
wanted to wait for the chance to evaluate the utility of the enhanced
data from GOES-Next satellites before specifying requirements for
future systems. To this end, an assessment group was formed and a
strategy for evaluating GOES-Next data was developed. Although
assessment results for the first year have now been collected from
users, NWS officials estimate that it will take from 2 to 3 more
years to complete the study because of delays in the implementation
of the NWS' new Advanced Weather Interactive Processing System, which
is needed by forecasters to properly display GOES-Next data, and
because many forecasters have not yet been trained in how to make
best use of the enhanced data.\1
NOAA has undertaken several other activities that could help in
defining requirements for a follow-on series. For example, in
developing the GOES I-M Product Assurance Plan, NOAA researchers
suggested possible needs for future spacecraft capabilities. Also, a
2-day conference held in 1994 invited experts from NOAA's research
and operations community to consider future requirements for GOES.
However, because NOAA has neither given formal programmatic
endorsement to establishing future GOES requirements nor set aside
resources to conduct this activity, requirements for the follow-on
series remain undefined.
--------------------
\1 For a further discussion of the Advanced Weather Interactive
Processing System, see Weather Forecasting: NWS Has Not Demonstrated
That New Processing System Will Improve Mission Effectiveness
(GAO/AIMD-96-29), February 29, 1996.
REQUIREMENTS FOR IMAGER AND
SOUNDER DATA APPEAR TO BE
CHANGING
-------------------------------------------------------- Chapter 3:2.2
Although the full range of GOES-Next capabilities is still not
available to all local weather forecasters, many have access to at
least some enhanced GOES-Next products, processed from data collected
by the imager. Several significant new uses of GOES imager data have
already been developed. For example, imager data have been used in
combination with Doppler radar data to enhance winter snowstorm
forecasting in the Great Lakes region, allowing local forecast
offices to closely monitor the development, orientation, and movement
of "lake effect" snow bands, formed when relatively cold air sweeps
across the warmer Great Lakes. Forecasters have also discovered that
combining data from two of the imager's infrared channels allows them
to detect fog at night, a new capability that had not been planned
when the imager was designed. This capability has helped forecasters
in the West give advance warning to airports of the likelihood of
early morning fog that could affect the startup of flight operations.
According to NOAA and NASA officials, many forecasters would also
like to see an increased availability of "rapid scan" images of
severe weather activity, such as thunderstorms and hurricanes. Rapid
scan images are collected at short time intervals--every few
minutes--so that a rapidly evolving storm can be carefully monitored
and its direction and severity predicted. Since accurate prediction
of severe weather is a critical activity for the NWS, there is high
demand for rapid scan data when severe weather develops. However,
GOES imagers cannot simultaneously produce rapidly updated imagery of
storm activity within the continental United States and also collect
a full set of data from the rest of the western hemisphere, which is
important for routine weather forecasting. The conflicting demands
for close-up (or "mesoscale") views of severe storms and broad (or
"synoptic") views of hemispheric weather patterns are difficult to
resolve. As a result, NOAA researchers see a coming need for
significantly more data than the current GOES-Next imager can
produce.
In contrast, usage of GOES-Next sounder data has not progressed as
rapidly and remains largely experimental. Although sounder data from
polar satellites is routinely used in preparing near-term weather
forecasts, geostationary sounder data were never used on a daily
basis in the numerical prediction models that provide the basic
guidance to NWS forecasters until very recently.\2 The sounder on
GOES-4 through GOES-7 was very slow and could not be used at the same
time as the imager. As a result, sounder data were used only for
special experiments. With the advent of GOES-8 in 1994, continuous
geostationary sounder data has been available for the first time.
However, as stated above, these data are available mainly to
researchers. Most weather forecasters have had no direct exposure to
GOES sounder data.
NOAA researchers are investigating a number of promising uses for
GOES sounder data. For example, studies performed at the University
of Wisconsin have shown that precipitation forecasts and hurricane
landfall predictions can be improved by using temperature and
moisture data from the sounder in conjunction with the imager data
that is traditionally used for such predictions. Although key NOAA
officials believe sounder data will grow in importance in the future,
the degree of added value that the sounder could contribute to NWS'
prediction models has been difficult to determine. Some researchers
believe the data could significantly improve forecasts, while others
believe the improvement would be only marginal. Meteorologists at
the National Centers for Environmental Prediction, which run the
prediction models that guide NWS forecasters, had been hesitant to
put the sounder data into operational use until they completed their
own evaluations. However, they now plan to begin incorporating GOES
sounder data into their standard prediction models by the middle of
1997.
Given that experience with this data has been limited, it is
difficult to determine how valuable sounder data may be in the
future. In contrast, the well-defined utility of imager data for
critical forecasting activities and the need for additional imager
data suggest that the mix of instruments to be flown on future GOES
satellites should be re-examined. An architecture that would
facilitate a greater collection of imager data and deemphasize
sounder data might better serve user needs. A formal update of user
requirements is needed before the potential advantages of alternative
architectures can be fully assessed.
--------------------
\2 Beginning in February 1997, measurements of precipitable water
from the GOES sounder have been included in the input to the
numerical prediction models.
AN ALTERNATIVE ARCHITECTURE
COULD IMPROVE SYSTEM
FLEXIBILITY AND REDUCE SOME
COSTS
---------------------------------------------------------- Chapter 3:3
According to GOES program officials, current GOES satellites are more
expensive to launch and operate than the earlier generation of
satellites. When NOAA developed the current generation, it moved
from a relatively small and easy to operate spacecraft to one that is
larger and much more complex. The newer satellites require a more
expensive launch vehicle because they are larger and heavier than the
first generation satellites. Furthermore, more extensive ground
support is required to keep the spacecraft operating. These factors
contribute to increased costs.
Aerospace experts in industry and academia have identified a variety
of options for attempting to reduce the costs of weather satellite
systems such as GOES. For example, a number of studies have been
done of alternative architectures based on smaller satellites
carrying fewer instruments, which would have the potential to reduce
launch and production costs. In the case of GOES, an architecture
based on smaller satellites carrying one critical meteorological
instrument instead of two could be considered. According to a recent
study supported by NASA and the Department of Defense, cost reduction
occurs predominantly, although not entirely, in small spacecraft,
which tend to be inherently simpler and cost less than large
spacecraft.\3 Further, a smaller spacecraft would not need as large a
launch vehicle as the current GOES system uses. Currently, GOES
satellites are launched on Atlas IIA vehicles, which cost $80 to $90
million each. Smaller satellites could be designed to use Delta
vehicles, for example, which currently cost $45 to $50 million
apiece, or perhaps an even smaller vehicle. While the actual cost of
launching a smaller GOES satellite 10 or more years from now cannot
be determined, it is likely to continue to be cheaper than the launch
cost for a large satellite.
A recent study by the Applied Physics Laboratory of Johns Hopkins
University shows that a small spacecraft architecture can increase
the flexibility of the system to respond to failures and, in doing
so, potentially reduce costs relative to an architecture based on
larger satellites. For example, in the GOES system, failure of an
instrument or a critical subsystem on one of the current spacecraft
would likely necessitate the launch of a replacement, even though the
original spacecraft might still retain some capabilities. If a
smaller satellite architecture were used, in which each spacecraft
would have only one primary meteorological instrument, the failure of
an instrument would not affect the operations of the instruments
flying on other spacecraft. Similarly, the failure of a critical
subsystem, such as the communications or power subsystems, would only
affect one instrument instead of two. Thus the overall robustness of
the system would be enhanced.
Based on discussions with NOAA, NASA, and academic experts, it
appears that a smaller satellite architecture could also provide
greater flexibility in the deployment of meteorological instruments.
Currently, imagers and sounders are always deployed in pairs (one set
per satellite) so that an operational constellation of a pair of
instruments in both the east and west locations can be maintained.
Flying the instruments on separate spacecraft would allow greater
flexibility to position individual instruments in orbital locations
where they are most needed and to change the locations of specific
instruments in the event of a spacecraft failure or other emergency.
It could also allow deployment of differing numbers of imagers and
sounders to meet changing user needs.
Making a decision about this or any other alternative architecture is
not a simple task. Clearly, there are drawbacks to the small
satellite architecture as well as advantages. Using such an
architecture could require significantly more spacecraft launches,
for example, even though the launch vehicles used would be smaller.
The increased launch workload would have to be manageable by
available launch facilities and ground crews. Ground operations,
though possibly simplified for each spacecraft, would have to handle
a larger total number of spacecraft. Also, the secondary instruments
currently flown on GOES satellites would have to be accounted for,
either within the new architecture or on other satellite systems. In
reaching a decision on an architecture for a follow-on system, NOAA
will need to carefully weigh these factors against the potential
benefits of moving to small satellites.
--------------------
\3 James R. Wertz and Wiley J. Larson, eds., Reducing Space Mission
Cost (Microcosm Press, Torrance, CA: 1996), p. 10.
ADVANCED TECHNOLOGY COULD
IMPROVE PERFORMANCE
---------------------------------------------------------- Chapter 3:4
Technological advances have been made in recent years that strongly
suggest that more efficient and effective instruments and spacecraft
could be designed today to replace the current GOES series, which was
designed in the early 1980s and uses 1970s technology in its
meteorological instruments.
While the planned continuation series satellites will incorporate
some improvements to the design of the spacecraft bus to improve
pointing and power management, further improvements could be made
with a new spacecraft design. In a recent evaluation of the state of
spacecraft technology, the National Research Council identified a
number of new technologies that could contribute to smaller
spacecraft that are cheaper to build and operate. For example,
greater operational autonomy could be built into the spacecraft's
control systems, allowing them to carry out orbit determination and
station-keeping with less intensive involvement of ground
controllers. High-density computers and memory devices combined with
advanced software techniques could enable extensive on-board data
processing and screening, reducing the amount of data to be
transmitted to earth. Such data processing advances could be of
critical importance in compensating for the increased data volumes
that would likely be produced by more advanced meteorological
instruments.\4
According to NASA and aerospace industry experts, significant
advances have been made in sensor technology, which, if incorporated,
could result in faster meteorological instruments that could produce
significantly higher resolution data. Specifically, technological
advances now allow for placing a much larger array of more sensitive
optoelectronic detectors inside the instruments, thus producing
higher resolution data more quickly. In 1996, NASA's Goddard Space
Flight Center proposed developing and flying an experimental
satellite to be called the Geostationary Advanced Technology
Environmental System (GATES) that would demonstrate this technology,
known as focal plane arrays. Other proposals for advanced
geostationary weather imagers have also been made in recent years,
based on focal plane array technology. For example, the MITRE
Corporation prepared a report in 1993 that assessed the development
of an advanced focal plane array imager that could fly as a secondary
payload on a commercial communications satellite. MITRE concluded in
its study that such an imager would be feasible and would offer
improved resolution and radiometric performance.\5 MIT's Lincoln
Laboratory also completed a conceptual design study of an advanced
imager. The study found that it would be feasible to exploit
advanced technologies, such as focal plane arrays, to resolve the
conflict in forecasters' need for simultaneous close-up and broad
views.
A focused effort would be needed to develop focal plane array
technology for possible use in the GOES system. According to an
analysis by the Aerospace Corporation, although focal plane arrays
are now considered the state of the art in infrared sensor
technology, they are generally designed for highly specialized
purposes and can be expensive to produce.\6 A necessary enabling
technology for focal plane array sensors is active cooling, which has
advanced to the point that it is being considered for use in
operational systems, according to aerospace experts. However,
further development and testing is still needed to demonstrate that
active coolers can remain reliable over long lifetimes.
As another example, work underway by the University Corporation for
Atmospheric Research shows that small, low earth orbiting satellites
equipped with special receivers can use Global Positioning System
(GPS) signals to measure temperature and humidity in the atmosphere.
Preliminary results indicate that this system, called GPS/MET
(Meteorology), may provide superior vertical resolution in the lower
atmosphere compared to the GOES sounder. Further development and
expansion of this system could reduce the need for potentially
expensive improvements to the GOES sounder to improve its accuracy.
NOAA officials involved in GOES acquisition and development agree
that new approaches and technologies need to be considered, given
that the follow-on GOES program will be subject to cost constraints.
In public presentations, NOAA officials have stressed the importance
of looking at new ways of doing the GOES mission, including flying
smaller GOES satellites or constellations of small satellites
carrying different instruments. However, NOAA has not yet conducted
any in-depth analysis of alternative approaches.
--------------------
\4 National Research Council, Aeronautics and Space Engineering
Board, Technology For Small Spacecraft (National Academy Press,
Washington, DC: 1994).
\5 A.S Cherdak, et al., Imaging From Nondedicated Satellites (The
MITRE Corporation, McLean, VA: 1993), p. 6-1.
\6 The Aerospace Corporation, Infrared Systems and Technology:
Executive Summary (undated).
CHOOSING A FOLLOW-ON DESIGN
APPROACH WILL REQUIRE THOROUGH
ENGINEERING ANALYSIS
---------------------------------------------------------- Chapter 3:5
If revised user requirements suggest that a new GOES architecture may
be needed, thorough engineering analysis of a range of design options
will then be necessary. Past experience in developing NASA
spacecraft, such as the Hubble Space Telescope and the Gamma Ray
Observatory, shows a clear correlation between the amount of
resources focused on the early phases of a project, which include
concept definition and engineering trade studies, and the ability of
that project to meet its cost and schedule commitments.
NASA has a standard project model that it generally uses for planning
spacecraft development. The NASA model calls for a six-phase life
cycle, the first three phases of which are all dedicated to ensuring
that the proposed project is well defined, feasible, and will likely
meet requirements. The first phase, called the Pre-Phase A or
Advanced Studies phase, is intended to produce a broad spectrum of
ideas and alternatives from which new projects can be selected.
Possible system architectures are defined in this phase, and initial
cost, schedule, and risk estimates are developed. The second phase,
Phase A or Preliminary Analysis, determines the feasibility and
desirability of a suggested new system by demonstrating that a
credible, feasible design exists after considering alternative design
concepts by conducting feasibility and risk studies. The third
phase, Phase B or Definition, aims to define the project in enough
detail to establish an initial baseline capable of meeting mission
needs. During this phase, system functional and performance
requirements along with architectures and designs become firm as
engineers conduct trade studies of design options for the various
systems and subsystems that make up the spacecraft. These trade
studies are conducted iteratively in an effort to seek out
cost-effective designs.
According to NASA, it is generally accepted that cost overruns in the
later development phases of a spacecraft project are caused by
inadequate attention to the early phases of mission design. This
principle was borne out in the GOES-Next development experience,
which suffered an over 200 percent cost increase\7 and serious
schedule slippages. Because development risks were thought to be
well understood and manageable, NOAA did not authorize and NASA did
not require that engineering analysis be done prior to GOES-Next
development work. However, as discussed in chapter 1, a number of
technical problems arose that were expensive and time-consuming to
fix. In addition, some of NOAA's performance requirements for the
spacecraft, such as the pointing requirement mentioned in chapter 2,
had to be relaxed because the planned spacecraft could not meet them.
If a more thorough engineering analysis of the proposed design had
been conducted early on, these problems likely could have been
identified and resolved more cheaply and expeditiously.
--------------------
\7 This figure is based on the change in NOAA's official cost
estimate for the overall development of GOES-Next, which increased
from $640 million in 1986 to $2.0 billion in 1996.
COLLABORATING WITH NASA COULD
HELP NOAA DEVELOP NEW SATELLITE
CAPABILITIES
---------------------------------------------------------- Chapter 3:6
NOAA faces several significant obstacles in developing a new
architecture for its geostationary satellite system. Most
significantly, as numerous industry and government aerospace experts
told us, it is difficult and expensive to develop new satellite
capabilities within the constraints of an operational program such as
NOAA's. Research and development are more effectively conducted
separately, with proven results incorporated into the operational
program afterwards. Originally, all of NOAA's satellites and
meteorological instruments were developed experimentally by NASA and
subsequently adopted for operational use by NOAA. However, NASA
canceled its formal weather satellite research program in 1981 and is
now reluctant to fund technology demonstration projects that will
primarily benefit NOAA.
NASA SUPPORTED WEATHER
SATELLITE TECHNOLOGY
DEVELOPMENT IN THE PAST
-------------------------------------------------------- Chapter 3:6.1
NASA originally developed prototypes of both the GOES system and
NOAA's polar-orbiting weather satellite system, using its own
funding. The first experimental satellite dedicated to
meteorological observations, called the Television and Infrared
Observational Satellite 1 (TIROS 1), was launched by NASA in 1960.
Nine more experimental TIROS satellites were launched between 1960
and 1965. These experimental satellites gave NASA the opportunity to
test a number of significant technological features that since have
become standard on meteorological satellites, such as including a
transmitter that would allow weather stations around the world to
receive data from the satellite when it is overhead. These early
satellites also gave the U.S. weather forecasting community the
opportunity to experiment with the data transmitted back from the
satellites to determine its best uses. The first geostationary
meteorological observations were made by NASA's Applications
Technology Satellites (ATS 1 through 3), launched in 1966 and 1967.
As with the early TIROS polar satellites, the ATS satellites gave
NASA and NOAA the opportunity to gain experience in operating
meteorological satellites in geostationary orbits and analyzing their
observations on an experimental basis.
In 1973, NASA and NOAA formalized their successful ongoing
relationship by establishing the Operational Satellite Improvement
Program (OSIP) at NASA. Through the OSIP program, NASA continued to
fund the development of the Nimbus series of experimental
polar-orbiting weather satellites. Derivatives of many of the
meteorological instruments developed for the Nimbus program are now
being operated on NOAA's polar-orbiting satellites. For example, the
High Resolution Infrared Radiometer which flew on Nimbus 1 in 1964
was a progenitor of the Advanced Very High Resolution Radiometer
(AVHRR) that currently flies on NOAA polar-orbiting satellites. The
AVHRR, in turn, was the basis for the design of the current GOES
imager. Despite the success of OSIP, NASA canceled the program in
1981 because of budgetary pressures.
NASA's elimination of OSIP left NOAA without the engineering support
required to design, develop, and test new spacecraft and instrument
technologies before incorporating them into the agency's operational
satellite systems. According to NASA and NOAA officials, many of the
technical problems that plagued GOES-Next development could have been
addressed and resolved more efficiently and less expensively within
the context of a smaller, experimental precursor program, such as
OSIP.
NASA DEVELOPMENT ACTIVITIES
COULD ONCE AGAIN SUPPORT
NOAA NEEDS
-------------------------------------------------------- Chapter 3:6.2
Although OSIP no longer exists as an ongoing program to improve
weather satellites, NASA has several avenues within its existing
programmatic structure for undertaking research and demonstration
projects related to advanced weather satellites. However, no such
projects are currently being funded.
As mentioned above, NASA's Goddard Space Flight Center proposed
developing and flying its experimental GATES satellite in 1996.
Although it would lack a sounder and other secondary GOES
instruments, GATES would feature a much faster and more efficient
imager that would take advantage of advanced focal plane array
technology to include more channels and offer higher resolution than
the current GOES imager. If successful, GATES could demonstrate the
feasibility of addressing user needs for more imager data from a
small satellite platform. However, only preliminary design work for
the GATES system has been completed to date.
Further opportunities for collaboration may exist within NASA's New
Millennium or Earth System Science Pathfinder programs. The New
Millennium Program is a NASA effort to develop and validate
revolutionary technologies that will enable the construction of
highly capable and agile spacecraft in the 21st century. The program
has already committed to the development of an advanced land imager,
which will be its first earth science mission. A geostationary
weather monitoring mission is also under consideration, along with a
number of other possibilities, but no commitment has yet been made.
While the New Millennium program is focused on space technology, the
Earth System Science Pathfinder program is a similar effort aimed at
furthering earth science. An advanced geostationary weather
monitoring mission could also fit within its mission.
NOAA officials also recognize that development of a new generation of
instruments and spacecraft would benefit from greater collaboration
with NASA. NOAA recently agreed to modest participation, at a rate
of $1 million per year, in NASA's GATES project, which in February
1997 became part of a new Advanced Geostationary Studies program.
However, NOAA has generally been reluctant to provide funding to NASA
to support new research efforts, believing that they should be NASA's
responsibility. NOAA did not previously provide funding for NASA's
OSIP program.
CONCLUSIONS
---------------------------------------------------------- Chapter 3:7
NOAA faces a difficult decision in determining how and when to
proceed with development of a next generation GOES system. Because
of budget constraints, NOAA has decided not to begin planning for a
follow-on system until after fiscal year 2002. While delaying the
start of a follow-on GOES program saves funds in the near term, it
also incurs a significant measure of risk, in that NOAA, as a result,
may have to procure more of the continuation series type of satellite
farther into the future, delaying the opportunity to adopt an
improved design. Indeed, the continuation series is now necessary
because the start of a follow-on program has been delayed repeatedly
since 1989.
Deferring development of a follow-on GOES satellite system is risky
because it forgoes consideration of two kinds of potential benefits.
First, a follow-on system could provide the opportunity to design a
system architecture that is more flexible, less costly, and better
able to meet users' needs. Second, a follow-on system could
incorporate advanced technologies that could lead to improvements in
weather forecasts in the future. We believe that these potential
benefits are significant and that a decision on when and how to
develop the follow-on generation is one that should be carefully
considered.
MATTERS FOR CONGRESSIONAL
CONSIDERATION
---------------------------------------------------------- Chapter 3:8
Given that options may exist for NOAA to develop a significantly
improved follow-on GOES system, the Congress may wish to closely
examine the costs and benefits of different approaches for the
timing, funding, and scope of the follow-on program. Further, the
Congress may also wish to examine NASA's potential role in working
with NOAA to support the needs of geostationary weather satellites
within NASA's advanced spacecraft technology programs.
RECOMMENDATIONS
---------------------------------------------------------- Chapter 3:9
We recommend that the Administrator of the National Oceanic and
Atmospheric Administration prepare a formal analysis of the costs and
benefits of several alternatives for the timing, funding, and scope
of the follow-on program, including the possibility of starting the
program as early as fiscal year 1998 and the potential need to fund
some types of technology development apart from the operational
satellite program. This analysis should be provided to the Congress
for its use in considering options for the future of the GOES
program.
AGENCY COMMENTS AND OUR
EVALUATION
--------------------------------------------------------- Chapter 3:10
The Secretary of Commerce did not concur with our recommendations to
reconsider NOAA's decision to defer the follow-on program and to
prepare a formal analysis of options for such a program. The draft
that we provided to Commerce for comment was based on the fiscal year
1997 budget, which showed that a follow-on program would begin in
2000. However, the fiscal year 1998 budget request, released since
then, shows no follow-on program beginning through 2002. In
discussions with us, NOAA officials confirmed that a follow-on
program is not being planned until 2003 at the earliest.
Commerce did provide information on four small research efforts that
it has recently funded or that are currently underway to examine
advanced technology and alternative architectures for potential
adoption in the future. Two of these were initiated in February
1997, as we were completing our review. They include the Advanced
Geostationary Studies program being supported by both NOAA and NASA
and the contract with the Jet Propulsion Laboratory to develop design
concepts for an advanced imager. The other two items mentioned by
Commerce in its comments are an Aerospace Corporation study of
possible future architectures, begun in late 1996, and support from
MIT's Lincoln Laboratory for several items, including the Aerospace
architecture study, the advanced imager work, and a geostationary
microwave sounder study.
We believe that these are valuable activities and have included
references to them where appropriate in the report. However, they do
not obviate our overall concerns about planning for the future of the
GOES program. Activities such as these are useful but do not
represent a commitment to exploring all options and developing a new
generation of satellites. The fiscal year 1998 NOAA budget request
does not allow for either a follow-on program to formally begin until
2003 at the earliest or for enhanced instruments to be flown on the
continuation series. Therefore, NOAA's ability to take action based
on the results of these studies is questionable. Other studies
funded by NOAA, such as the work on advanced sounders and imagers
that is mentioned in our report, have not led to any operational
implementation.
We believe that continued deferral of the follow-on program is risky
because it forgoes the opportunity to identify and develop a
potentially more effective and economical architecture. Furthermore,
the longer that NOAA continues without actively considering other
options for a future system, the more it risks having to procure
additional continuation series satellites, because the availability
date for a fully developed new satellite system will slip farther
into the future.
(See figure in printed edition.)Appendix I
COMMENTS FROM THE DEPARTMENT OF
COMMERCE
============================================================ Chapter 3
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
GAO COMMENTS
--------------------------------------------------------- Chapter 3:11
1. NOAA does not have an official name for this series of
satellites. During our audit, NOAA officials originally referred to
the series as "clones." Later, after revising their procurement
strategy, they referred to them as "gap fillers," the term we used in
our draft report. We have adopted the phrase "continuation series"
for our final report.
2. Discussed in "Agency Comments and Our Evaluation" section of
chapter 3.
3. In the report, we point out that NOAA's launch backup policy is
arbitrary. (See chapter 2.) All spacecraft programs have to address
the risk of launch failure. However, NOAA's approach of designating
certain launches as "planned failures" and providing backup
spacecraft for only those launches is arbitrary, because NOAA does
not know in advance which launches will actually fail. In other
words, the risk of a launch failure is no greater for the "planned
failure" than for any of the other launches, which do not have
specifically designated backups. Although NOAA's approach is
effective in putting an extra spacecraft into the production stream
to compensate for a launch failure, it is ineffective in providing
backup for each launch. An alternative approach would be to schedule
each launch to be backed up by the next spacecraft in the production
stream. Such an approach would not require procurement of any
additional spacecraft or launch vehicles and would enhance NOAA's
ability to compensate for launch failures by planning to have
spacecraft always available for backup launches.
4. When we began our review in March 1996, we received documentation
from NOAA indicating that the GOES-9 spacecraft was expected to last
a full 5 years. After technical problems developed on GOES-8 and
GOES-9, NOAA officials reduced their estimate of the expected
lifetime of GOES-9 to 3 years.
5. In the final report, we have combined the intent of the two
recommendations that appeared at the end of chapter 3 in the draft
report. The draft that we provided to Commerce was based on its
fiscal year 1997 budget, which showed that a GOES follow-on program
would begin in 2000. However, the fiscal year 1998 budget request,
released since then, shows no follow-on program beginning through
2002. In discussions with us, NOAA officials confirmed that a
follow-on program is currently not planned until 2003 at the
earliest. Therefore, our final report focuses on the need for NOAA
to prepare a formal analysis of the costs and benefits of
alternatives for the timing, funding, and scope of the follow-on
program.
MAJOR CONTRIBUTORS TO THIS REPORT
========================================================== Appendix II
ACCOUNTING AND INFORMATION
MANAGEMENT DIVISION,
WASHINGTON, D.C.
-------------------------------------------------------- Appendix II:1
John A. de Ferrari, Assistant Director
Elizabeth L. Johnston, Evaluator-In-Charge
DENVER FIELD OFFICE
-------------------------------------------------------- Appendix II:2
Jamelyn A. Smith, Senior Information Systems Analyst
RELATED GAO PRODUCTS
NOAA Satellites (GAO/AIMD-96-141R, September 13, 1996).
Weather Forecasting: NWS Has Not Demonstrated That New Processing
System Will Improve Mission Effectiveness (GAO/AIMD-96-29, February
29, 1996).
Weather Satellites: Action Needed to Resolve Status of the U.S.
Geostationary Satellite Program (GAO/NSIAD-91-252, July 24, 1991).
Weather Satellites: Cost Growth and Development Delays Jeopardize
U.S. Forecasting Ability (GAO/NSIAD-89-169, June 30, 1989).
*** End of document. ***
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