Launch Vehicles
Space Transportation encompasses space launch and orbit transfer vehicles and related propulsion systems for the traditional spacelift missions of delivering payloads to orbit and on-orbit spacecraft propulsion for station-keeping, plus emerging missions such as on-orbit refueling, servicing, maintenance, repositioning, and recovery.
The DoD funded the development of the Atlas, Delta, and Titan families of ELVs (called expendable because they can only be used once) based on ballistic missile technology from the 1950s-60s. In the 1960s, NASA developed the small Scout rocket and the heavy-lift Saturn rockets, both of which are no longer produced.
Today, the Boeing Company manufactures the Delta family of expendable launch vehicles and is part of the Sea Launch joint venture with the Russian/Ukrainian Zenit rocket. Lockheed Martin manufactures the Atlas, Athena, and Titan launch vehicles, and Orbital Sciences Corporation manufactures the smaller Pegasus and Taurus launch vehicles. Both Boeing and Lockheed Martin build portions of NASA’s Space Shuttle, and both companies own equal portions of the United Space Alliance (USA), which manages Shuttle operations and maintenance.
During the 1980s and early 1990s, NASA and DoD worked together on an ultimately unsuccessful effort to develop a new reusable launch vehicle to replace the Shuttle, as well as new expendable launch vehicles. These programs failed because of a combination of technical failures and problems with funding. One unsuccessful effort to create a reusable vehicle was the X-30 or National Aerospace Plane project initiated by President Reagan. The project was doomed by insurmountable technical hurdles with hypersonic technology and was also affected by the end of the Cold War, which made moot some of the impetus for the project.
The DoD employs both military and commercial expendable launch vehicles, occasionally augmented by use of NASA’s Space Shuttle. Military launch systems currently comprise an array of medium- and heavy-lift expendable boosters. The Air Force, NASA and industry are collaboratively funding reusable propulsion technologies with Air Force funding being directed toward supporting militarily unique capabilities. Both independently and in partnership with NASA, industry is developing reusable boosters to add to the launch system inventory and to lower costs to orbit.
The DoD is seeking to ease present bottlenecks in access to space via:
- Increased privatization of the launch infrastructure to broaden the launch base
- A launch-on-demand capability, especially for Space Control and other missions where timeliness to orbit or reconstitution of high-demand space-based systems may be paramount.
This area represents the sine qua non of space power: unless sufficient lift capability becomes readily available at significantly less cost, US capabilities to place its projected systems on orbit in sufficient quantities to achieve mission objectives will increasingly lag behind demand. Major technological advances leading to improved launch capability will be needed to achieve the very first of USSPACECOM’s objectives for the future — Assured Access to Space — without which its other objectives may remain beyond reach.
Improvements to lift capability may be achieved by improving launch and propulsion systems, by reducing the size and weight of spacecraft and payloads, or by some combination of the two. Heavy lift will be needed indefinitely for outsize cargo, so improvements in engines and propellants continue to be a priority. On the other hand, as increasingly fewer spacecraft can do more from a given orbit and/or live longer on orbit, replacements are needed less often, which also reduces relative demand on launch assets.
The advent of reusable launch vehicles (RLVs) will reduce per unit launch costs even further. In parallel, efforts continue to reduce spacecraft size and weight on both a unit and constellation basis. As this miniaturization approach enables entire new classes of small and microsatellites to meet mission utility criteria, the space transportation infrastructure of the future may also include assets that remain on orbit or are recoverable for reuse. Such space support vehicles could provide orbit-changing and maintenance services, thus potentially reducing the life-cycle costs of many space systems.
When these trends and tradeoffs are additionally augmented by on-orbit servicing and replenishment functions, projected launch assets and on-orbit transfer techniques will achieve new levels of capability, efficiency, and flexibility. As a far-term objective, American national space capabilities would be enhanced immeasurably if space launch, on-orbit maneuvers and even recovery could become as responsive, flexible and reliable as they currently are for manned aircraft.
By the early 1990s a growing chorus suggested that America needs to upgrade its existing fleet of expendable launch vehicles. The Titan, Atlas and Delta are all derived from ballistic missiles that were originally developed in the 1950s. Since then, they have been considerably modified to improve their ability to launch satellites. But additional improvements are both possible and needed. In April 1992, the Commerce Department's Commercial Space Transportation Advisory Committee recommended a program for upgrading our existing fleet of launch vehicles. Despite its modest price tag and the great benefits of this program, no action has been taken on these recommendations.
However, other proponents suggested that America also needs realistic and achievable plans for the next generation of launch vehicles. It is suggested that existing rockets must be improved and we must establish fair trade agreements. But these measure will not be enough. Eventually new and more capable launch vehicles will be needed.
By the end of the Cold War there were four different programs to develop future launch vehicles. The National Launch System was intended to develop a new family of conventional rockets. The National Aerospace Plane program, sometimes referred to as the Orient Express, was intended to develop a winged, air-breathing launch vehicle that can reach orbit without needing additional booster rockets. The Delta Clipper program hoped to combine the best features of both of these programs. And efforts continued on improving the Space Shuttle.
Combined, these projects cost a billion dollars a year, at a time when money was difficult to find. The price-tag on completing development of any one of them was at least ten billion dollars, money that will be very difficult to find. The US may be able to finance the development of one new launch system. But it will certainly not be able to afford them all. Indeed, by the mid-1990s all four had been abandoned.
While the American space shuttle program had recovered from the Challenger accident of January 1986, major uncertainties remained concerning the Shuttle's maximum flight rate(1) and safety. These successes did not alter the American military decision to cease reliance on the Shuttle system.(2) Indeed, although previous plans had called for two Defense Department missions on the Shuttle each year throughout the 1990's,(3) by early 1989 the Air Force decided to completely withdraw from the Shuttle after 1993, flying only those Shuttle missions that had been paid for prior to the Challenger accident.(4)
The military's expendable launch vehicle program got off to a slow start, with inaugural launches planned for 1988 slipping into 1989.(5) But despite this slow beginning, total spending on expendable launch vehicles from 1989 through 1994 approached $10 billion.(6)
The centerpiece of the military's launch vehicle program was the Titan 4.(7) Engineering problems delayed the initial launch from October 1988 to June 1989,(8) and the Titan 4 development program experienced a $208 million cost overrun.(9) Additional difficulties were encountered with the Solid Rocket Motor Upgrade program which is intended to increase the payload of the booster.(10) Despite these problems, a new contract for 18 of these boosters brought the total order to 41, at a cost of about $7 billion.(11) Of these boosters, 13 were used by the Air Force(12) for launching Milstar communications satellites and DSP early warning satellites, while the remaining 28 will be used to launch photo reconnaissance and imaging radar satellites.
The first flight of the Delta 2, carrying a Navstar navigation satellite, was delayed from late 1988 to 14 February 1989, due to a variety of minor problems, and subsequent launches also experienced delays.(13) The initial order for 20 Delta 2's was marred by a $140 million cost overrun,(14) which was somewhat surprising given the relatively minor changes the Delta 2 represented compared with prior versions of the Delta.(15) Despite these problems, subsequent orders are anticipated at a rate of four per year in the mid-to-late 1990's to maintain the Navstar navigation satellite constellation.(16)
A total of 14 Titan 2's were ordered, for launching Naval Space-Based Wide Area Surveillance System satellites, DMSP military weather satellites, NOAA civilian weather satellites, and the LANDSAT 6 resource monitoring satellite.(17) The second Titan 2 flight came on 6 September 1989, with the successful launch of an Air Force Space Based Wide Area Surveillance System radar satellite.
Other booster developments in 1989 included the final Titan 34D was launched on 4 September 1989,(18) and continued work on the Atlas 2, which will be used primarily for DSCS III communications satellites.(19)
In addition to these traditional booster programs, four new launch systems are also under development. The Pegasus and Taurus rockets were intended to support small military satellite programs in the near-term. The Advanced Launch System (ALS) and the National Aero-Space Plane (NASP) program, initiated by the Reagan Administration in the mid-1980's, were directed at very ambitious long-term objectives. During 1989 ALS and NASP were greatly reduced in scope. Indeed, in this regard, the first year of the Bush Administration witnessed the dismantlement of some of the central elements of the Reagan Administration's launch vehicle program.
The American military's interest in smaller satellites was matched by an effort sponsored by the Defense Advanced Research Projects Agency (DARPA) to develop the new small boosters that would be needed to launch such satellites. Most prominent of these ws the Pegasus, a two-stage solid fuel winged booster that would be air-launched, initially from the same B-52 that was used to launch the X-15 experimental aircraft in the 1960's.(20) The initial flights of Pegasus carried a variety of experimental scientific and engineering test satellites,(21) with each flight costing about $10 million,(22) comparable to the launch cost of other small launchers such as the Scout. As a result of problems encountered during initial captive carry tests, the first flight, initially planned for July 1989,(23) was delayed to March 1990.(24)
Based on their successful development of Pegasus, Orbital Sciences Corporation and Hercules were awarded a contract to develop a more powerful, ground-launched Standard Small Launch Vehicle (SSLV), with an initial flight anticipated in the second quarter of 1991.(25) This new Taurus booster, which consisted of a first stage from the MX Peacekeeper ICBM, and a second and third stage based on the two stages of the Pegasus, was able to place about 450 kilograms into polar orbit at a cost of $16 million.(26) Later growth versions are projected to have double this capacity, as well as the ability to place over 150 kilograms in geosynchronous orbit.(27) The anticipated Taurus launch rate is planned to grow from 2 flights in 1991, to as many as six or seven per year by 1995,(28) though these ambitions were in fact not realized.
The Advanced Launch System (ALS) emerged in the mid-1980's as the rocket that would be used to deploy the space-based elements of the Strategic Defense Initiative program. Because the SDI was initially projected to require many thousands of tons of payload to low Earth orbit, ALS was intended to reduce the cost of space transportation by an order of magnitude, from about $10,000 per kilogram to less than $1,000 per kilogram.(29) Thus the Bush Administration inherited a plan for development of the Advanced Launch System that called for the Defense Acquisition Board to approve advanced development of the system in early 1990, leading to a first flight in 1998 and a full operational capability in 2000.(30) This effort would lead to the development of a modular family of launch vehicles, with a payload capacity to low Earth orbit ranging from 5,000 kilograms to 200,000 kilograms, that would replace existing expendable launch vehicles in the 2000-2005 time frame.(31)
However, by late 1989 it had become increasingly apparent that the requirements for the ALS program had largely disappeared.(32) The initial phase of SDI would be deployed using existing Titan 4 and Atlas 2 rockets, and the launch requirements for subsequent phases of SDI deployment were too vague to require immediate development of ALS.(33) With total development cost of ALS pegged at $15 billion through its first flight in 1998,(34) the need for ALS seemed increasing doubtful.(35) By year's end the ALS program, once the centerpiece of space planning, had been reduced to a $150 million per year propulsion development effort.(36)
The most ambitious of the new American launch vehicle programs was the National Aero-space Plane (NASP) project, officially known as the X-30, and unofficially as the Orient Express. Begun in 1985, NASP aimed to develop a new type of super-sonic combustion ramjet (scramjet) engine that could propel an aircraft to near-orbital speeds.(37) Potential military missions included air defense or reconnaissance. As a space launch vehicle, NASP was thought to promise aircraft-style safety and convenience with operating costs that would be a fraction of those of conventional rockets or the Space Shuttle.
But by early 1989, there were increasing doubts that NASP would find military missions other than space launch,(38) as well as growing concerns about the technical feasibility of the concept.(39) Based on these concerns, the Air Force decided in early 1989 to withdraw its support from the project.(40) Initial planning for the X-30 program had anticipated total funding of $570 million in 1990, and $620 million in 1991, with most of this money coming from the Air Force.(41) In an effort to save the project, the National Space Council gained Congressional support for a revised plan, with $254 million for 1990 and $277 million for 1991, about evenly divided between NASA and the Air Force.(42) This reduction in funding delayed the decision on proceeding with the prototype program from September 1990 to March 1993,(43) the first flight from 1994 to 1996, and the first orbital flight from 1996 to after 1998.(44)
In 1994, the Clinton Administration issued a National Space Transportation Policy to delineate the roles DoD and NASA would each play in developing new space launch vehicles. Under the 1994 policy, NASA was to concentrate on developing and demonstrating reusable vehicle technology, while the DoD would focus exclusively on expendable launch vehicles.
The 1994 policy directed NASA to conduct research designed to demonstrate by the year 2000 a rocket engine that could fly to orbit using only a single stage (rather than the multiple-stage rockets that are used today). In response, NASA began two experimental flight test programs in 1995, the X-33 (with Lockheed Martin) and X-34 (with Orbital Sciences).
NASA's RLV technology development programs included experimental flight projects intended to demonstrate operational capabilities (X-33, X-34, X-40A, and X-37). The X-33 was intended to demonstrate technologies and operational concepts with the goal of reducing space transportation costs to one tenth of their current level. The Boeing Co. and the Air Force entered into a cooperative arrangement to develop a Space Maneuver Vehicle, or X-40A, as part of a military space plane program.[1] This program involved development of a reusable spacecraft that could be launched on a variety of launch vehicles, remain in orbit while performing military or civilian missions, and then return to Earth. Finally, the Pathfinder X-37 Program includes the development of the X-37 in-space flight demonstrator, which is the first experimental vehicle to be flown in both orbital and reentry environments.
Neither the X-33 nor the X-34 was able to successfully demonstrate a vehicle, and NASA terminated both programs in March 2001. NASA had spent approximately $1.2 billion on the X-33 and $205 million on the X-34 by the time the programs were cancelled. Lockheed Martin said that it had spent $356 million of its own money on the X-33.
At the same time, the 1994 policy directed the DoD to work with industry to modernize or “evolve” the expendable launch vehicle fleet under the Evolved Expendable Launch Vehicle (EELV) program “to reduce costs while improving reliability, operability, responsiveness, and safety.” The policy also directed the U.S. Government to meet its future launch needs by purchasing commercial launch services.
In 1995, DoD began funding the development of the latest generation of Delta and Atlas launch vehicles through the EELV program. Under that program, DoD has awarded contracts to Boeing valued at $1.88 billion ($500 million for development plus $1.38 billion for 19 launches) for the Delta IV, and contracts to Lockheed Martin valued at $1.15 billion ($500 million for development plus $650 million for 9 launches) for the Atlas V. EELV contracts were awarded to both companies to ensure that DoD would not be forced to rely on a single supplier. Each company has spent about $1 billion of its own money on EELV development. DoD also has a variety of other programs to develop new launch vehicles and vehicle components.
Six closely spaced failures hit American launch programs from August 1998 to May 1999. They included three Air Force Titan IVs and destroyed three important payloads: a satellite from the National Reconnaissance Office, an early warning satellite from SMC’s Defense Support Program, and a military communications satellite from SMC’s Milstar program. At the direction of both Congress and the president, DOD set up an independent review known as the Launch Broad Area Review (BAR) to study the causes of the failures and recommend remedial measures.
The BAR confirmed that the immediate causes were unrelated, but it issued a set of recommendations on 1 November 1999 that broadened SMC’s responsibility for each DOD launch from acquisition of the hardware through delivery of the spacecraft on orbit. As a result, SMC’s responsibility for hardware and engineering throughout every launch became clear, explicit, and formal. By May 2003, Air Force launches were experiencing one of the longest unbroken strings of successful launches in history.
Some low-level cooperation between NASA and DoD on rocket technologies continued even under the 1994 policy, but cooperation began again in earnest around 2000. In the wake of failures in the X-33 and X-34 programs, NASA proposed the Space Launch Initiative, under which it would cooperate with DoD on both reusable and expendable launch technologies.
DoD hoped the EELV would be less expensive to purchase than previous launch vehicles. However, that assumed a thriving commercial launch business that would add to the demand for the new rockets. Instead, the demand for commercial launches has plummeted. In 1999, 76 commercial payloads were launched, producing $2.3 billion in launch revenues, while in 2003 only 18 commercial payloads representing $1.2 billion were launched. Furthermore, competition has become more intense even as the number of launches has declined.
By 2005 the domestic launch industry had suffered economically from the recent decline in demand for commercial launches, making the costs of these rockets more expensive. In addition to serving the government’s launch needs, aerospace companies also serve the commercial launch market. For example, satellite telecommunication companies purchase launches from commercial launch vehicle providers to carry their communications satellites into orbit.
While the government’s demand for launch vehicles from aerospace companies has remained steady, the private sector’s demand has dropped precipitously in recent years (due in large part to the use of fiber optics and cellular technologies). This sharp downturn in the commercial launch vehicle market increased the prices that commercial providers charge NASA and the DoD. For the previous decade or so, US aerospace companies had also faced increasing competition from foreign launch companies, particularly Arianespace, which is partially owned by European governments.
The President’s space exploration initiative announced on 14 January 2004 would have a significant impact on the launch industry. While NASA does use expendable launch vehicles for some of its current needs, such as earth science satellites, NASA uses the Space Shuttle (and Russian Soyuz vehicles) to launch humans into space and uses the Space Shuttle and Russian vehicles for related cargo needs. Under the President’s proposal, the Shuttle would be retired around 2010. The proposal does not say what NASA will use to take cargo to and from the International Space Station after that time or what will be used to launch payloads to the Moon or other locations. The President proposed developing a new vehicle, called the Crew Exploration Vehicle (CEV), to launch humans after the Shuttle is retired, but NASA has not yet decided what kind of rocket would lift the CEV.
