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The Cape, Chapter 3, Section 2

Medium and Light Military Space Operations

Evolution of the NAVSTAR Global Positioning System and Development of the DELTA II

Communications satellites continued to play an important role in military space operations, but the NAVSTAR GPS program opened up a whole new field for space support operations at the Cape in the 1980s: the launching of satellites to provide highly accurate three-dimensional ground, sea and air navigation. The U.S. Navy and Air Force began the effort in the early 1960s with a series of studies and experiments dealing with the feasibility of using satellite-generated radio signals to improve the effectiveness of military navigation. After ten years of extensive research, the services concluded that Defense Department requirements would be best served by a single, highly precise, satellite-based Global Positioning System (GPS). In December 1973, the Defense Navigation Satellite System (later know as NAVSTAR GPS) entered its concept validation phase. The technology necessary to field the GPS was confirmed during that phase, and four advanced development model Block I NAVSTAR satellites were launched on ATLAS F boosters from Vandenberg's Space Launch Complex 3 (East) between 22 February and 11 December 1978. Two more Block I satellites (NAVSTAR 5 and NAVSTAR 6) were launched on ATLAS F boosters from Complex 3 (East) on 9 February and 26 April 1980. By the end of 1980, the NAVSTAR GPS constellation was arranged in two orbital planes of three satellites each, orbiting Earth at an altitude of approximately 10,900 nautical miles. Following the GPS development phase in the early 1980s, the Air Force planned to procure and deploy a constellation of 24 Block II GPS satellites via Space Shuttle by the end of 1987. Funding cuts in 1980 and 1981 reduced the planned constellation to 18 Block II satellites and added a year to their deployment, but the program continued to move ahead.16

As preparations for the Block II GPS satellite program continued, a Block I replenishment satellite was launched on an ATLAS E booster from Complex 3 (East) on 18 December 1981. Unfortunately, a hot gas generator on one of the ATLAS booster's main engines failed shortly after lift-off, and the vehicle crashed about 150 yards from the pad. The next replenishment satellite launch was postponed while ATLAS engines were refurbished and test-fired in 1982, but the mission was finally launched successfully from Complex 3 (West) on 14 July 1983. The satellite (NAVSTAR 8) replaced NAVSTAR I in the 240-degree orbital plane of the GPS constellation. The last three Block I satellite missions (NAVSTARs 9, 10 and 11) were launched on ATLAS E boosters from Complex 3 (West) on 13 June 1984, 8 September 1984 and 8 October 1985. All three launches were successful, and the satellites performed as planned.17

On 20 May 1983, the Air Force signed a $1.2 billion five-year fixed price contract with Rockwell International's Satellite Systems Division for the procurement of 28 Block II NAVSTAR GPS satellites. The contract was the Defense Department's first multi-year procurement of production model satellites, and, as a "block buy," it reduced the average cost of a Block II satellite by about 24 percent (e.g., $40,600,000 versus $52,000,000). The ambitious production schedule called for the first spacecraft in Fiscal Year (FY) 1984. Six more Block II satellites were expected to be built in FY 1985. Nine more satellites were anticipated in FY 1986, followed by eight more GPS spacecraft in FY 1987. The last four Block II satellites were scheduled for assembly in FY 1988. In the meantime, the Air Force and McDonnell Douglas reached agreement in the summer of 1983 on a separate $169,400,000 contract to provide payload assist modules (e.g., the PAM-DII) to boost 28 Block II satellites from the Shuttle's orbit into their own elliptical transfer orbits. NAVSTAR Support facilities were the next order of business: as Block II satellites and PAM-DII modules arrived at the Cape, they were to be mated to each other in a NAVSTAR Processing Facility (NPF) modified expressly for that purpose. One of the Cape's old MINUTEMAN missile assembly buildings-MAB-2-was chosen as the site for the facility, and the NPF design was completed in April 1984. In June 1984, a $3,800,000 construction contract was awarded to W & J Construction Corporation of Cocoa, Florida to build the facility. Modifications to a Propellant Servicing Facility (PSF) and a Motor Inert Storage (MIS) building raised the overall cost of the project to approximately $4,500,000. The ground breaking ceremony for the NAVSTAR Processing Facility was held on 5 July 1984, and construction was completed in July 1985.18

Testing of the first Block II satellite was well underway in 1985, but the NAVSTAR II satellite program was already markedly behind schedule. Serious workmanship problems began to surface in the electronic flight boxes supplied by Rockwell's Strategic Defense and Electro-Optical Systems Division in Anaheim, California, and this situation threatened more delay. A "tiger team" was organized to reopen, inspect and repair all the flight boxes earmarked for the program, but, despite the company's best efforts, the first production Block II would not be ready for launch by the date indicated in the contract (e.g., 22 August 1986). By the fall of 1985, the first Block II mission had to be rescheduled from October 1986 to January 1987. On a brighter note, the first PAM-DII payload assist module and the Block II NAVSTAR qualification satellite (GPS-12) arrived at the Cape on 22 January and 21 March 1986 respectively. Under the NAVSTAR II Pathfinder program, the PAD-DII and the qualification satellite were processed to verify the readiness of facilities and ground equipment to support NAVSTAR II operations. The PAM-DII was built up and checked out by April 1st, and a Combined Systems Test (CST) was completed on the satellite at the NAVSTAR Processing Facility on 10 April 1986. The satellite and PAM-DII were mated and checked out successfully on 16 May 1986.19

Figure 105: NAVSTAR II Payload and PAM-D Upper Stage

Following the Challenger disaster in January 1986, the GPS Program Office replanned the first eight Block II satellites for flights on the new Medium Launch Vehicle (the DELTA II) in lieu of the Space Shuttle. The Shuttle was still being considered for the next eight GPS missions (e.g., two spacecraft per Shuttle flight), but its prospects for NAVSTAR missions dimmed as pressure increased to replenish the GPS constellation quickly and meet user needs. In August 1987, the Secretary of the Air Force decided to transfer all but four of the 28 NAVSTAR II satellites from the Shuttle to the DELTA II. Only two NAVSTAR II satellites remained on the Shuttle's manifest by the end of FY 1988, and those last two spacecraft were reassigned to the DELTA II in the spring of 1989. In any event, the first NAVSTAR II launch slipped two years to January 1989 (though some optimists thought it might occur as early as October 1988). Hopefully, 21 GPS satellites would be in orbit by January 1991. In the meantime, arrangements were made to store Block II satellites and suspend work on batteries, apogee kick motors and other components with short shelf lives. Those necessary actions added $153 million to the Block II contract.20

The changes in launch vehicles and schedules for the NAVSTAR II launch program affected the Air Force's contract with McDonnell Douglas for 28 PAM-DII upper stages. The PAM-DII was designed to boost a NAVSTAR II satellite into transfer orbit after it had been released from the Shuttle at an altitude of approximately 160 nautical miles. The DELTA II would use a different upper stage-a newly configured PAM-D-to boost the NAVSTAR II payload into transfer orbit. Following the decision to go with the DELTA II, the Air Force cancelled the PAM-DII contract. The U.S. Government only accepted 16 PAM-DIIs it had already purchased.21

As noted in Chapter I, Space Division awarded the Medium Launch Vehicle (MLV) contract to McDonnell Douglas Astronautics Company on 21 January 1987. Together with its options, that DELTA II contract was valued at $669,000,000. McDonnell Douglas also had at least four firm orders from non-military customers to launch DELTA II vehicles on commercial missions. However, unlike earlier commercial arrangements, the company would no longer be under contract to NASA. Under the new Commercial Expendable Launch Vehicle program encouraged by President Reagan since 1983, McDonnell Douglas would be responsible for producing, marketing and launching its commercial DELTA IIs. The Air Force would be responsible for ensuring safety and environmental standards for commercial as well as military launches, but McDonnell Douglas would have greater responsibility in meeting those standards (including quality control). Both launch pads (17A and 17B) would be equipped to handle commercial and Defense Department missions. McDonnell Douglas and its subcontractors were soon hard at work preparing the pads for the new DELTA II vehicles.22

Figure 106: Mobile Service Towers at Complex 17 (looking north)
October 1988

The DELTA IIs would be taller than earlier DELTA vehicles (e.g., 130 feet versus 112 feet), and one of the contractor's first tasks was to raise Complex 17's Mobile Service Tower (MST) 20 feet to accommodate the DELTA II's longer stages. Other modifications revolved around Pad 17A initially because Pad 17B was committed to the DELTA 181 mission which was scheduled to be launched in February 1988. While DELTA 181's first stage was being erected in October 1987, the steelwork subcontractor (Butler Construction Company) began falling behind on Pad 17A. Seven weeks later, Butler was seven weeks behind schedule. Though bureaucratic delays and changes in McDonnell Douglas' job orders were cited for the holdup, the problem seemed to gravitate toward steel fabrication delays at MET-CON's offsite shop. Whatever the real cause of the delay, MET-CON was willing to make up the lost time "if paid to do so." A recovery schedule was created to get Pad 17A's modifications back on track and completed by mid-February 1988. In the meantime, offsite steelwork was accelerated to avoid further delays once work on Pad 17B began. The contractor expanded his workweek to ten hours per day, seven days a week in January 1988. Pad 17's modifications were essentially complete by mid-April 1988, and Pad 17B's work was on schedule. The contractor's remarkable recovery was due in large part to having most of the offsite prefabrication work completed before modifications on Pad 17B began.23

Unfortunately, trouble loomed from a different quarter in July 1988: McDonnell Douglas ran into trouble getting some fiber optic equipment it ordered for Pad 17A, and the first DELTA II launch was rescheduled from 13 October 1988 to 8 December 1988. There was still plenty of work to be done, and the contractor's people extended their workdays from 6:00 a.m. to 9:00 p.m. to complete the tasks that remained. (In some instances, people returned as early as 4:00 a.m. the next morning to meet their schedules from the previous day.) Test discrepancies in McDonnell Douglas' plant also delayed the first launch somewhat longer, but the first DELTA II's first stage was erected on Pad 17A by 2 November 1988. The vehicle's interstage was installed at the pad on November 5th, and the solid rocket motors were mated to the vehicle a few days later. The range contractor and ESMC's engineers completed launch data connections between the blockhouse and Pad 17 around the middle of November 1988. On 24 January 1989, command and telemetry verification tests confirmed reliable links between Sunnyvale and Colorado Springs for the upcoming NAVSTAR II GPS mission. Following final prelaunch tests, the countdown was picked up on 12 February 1989, but it was scrubbed at 1827Z due to excessive high altitude winds. The countdown was picked up again on February 14th, and lift-off was recorded at 1829:59.988Z on 14 February 1989. The first DELTA II placed the first NAVSTAR II GPS payload into the proper transfer orbit. The mission was a success.24

The Cape: Miltary Space Operations 1971-1992
by Mark C. Cleary, Chief Historian
45 Space Wing Office of History
1201 Minuteman Ave, Patrick AFB, FL 32925

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