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The Cape, Chapter 3, Section 5

Medium and Light Military Space Operations

Strategic Defense Initiative Missions and the NATO IVA Mission

In addition to the NAVSTAR II missions, there were four Strategic Defense Initiative (SDI) missions launched from Complex 17 in the mid-to-late 1980s and 1990. The first of those experimental missions was DELTA 180. It involved the placement of a DELTA second stage and a Payload Adapter System (PAS) in two 120-nautical-mile-high time-synchronous orbits with slightly different inclinations. The overall objectives of the mission were to: 1) gather optical spectral data from rocket propulsion sources and 2) confirm guidance and navigation algorithms. A DELTA Model 3920 vehicle was used for the booster, and the countdown proceeded smoothly to DELTA 180's lift-off from Pad 17B at 1508:01Z on 5 September 1986. According to the post-launch debriefing report submitted by the Eastern Test Range organization after the mission, DELTA 180 was "a tremendous success both from a launch and orbital support standpoint." The mission marked the first use of an expendable launch vehicle in support of an SDI mission at the Cape.34

Figure 113: DELTA 180 launch
5 September 1986

Figure 114: DELTA 181 launch
8 February 1988

The next DELTA/SDI mission from the Cape was DELTA 181. Like the DELTA 180 mission, DELTA 181 involved the placement of a DELTA second stage in low-Earth orbit, but it included the deployment of two payloads as the object of a series of experiments in orbit. One of the payloads was a plume generator package, and the other was a science package containing eight test objects and four reference objects. A sensor module, consisting of a command and data handling system and seven scientific experiments, remained with the DELTA's second stage to scan elements of both packages once they were deployed. The sensor module was equipped with ultraviolet, infrared, radar and laser sensors to gather a tremendous amount of data on the "signatures" generated by the deployed payloads. That data was transmitted via two wideband telemetry downlinks to stations on the ground. Data from approximately 100 ground-based sources funneled into the Cape via communications satellites. The mission required more than 200 radar tracking maneuvers over a period of two days, and recorded data continued to come in for about ten days after the experimental portion of the mission was completed. Put simply, DELTA 181 presented the Eastern Range with one of the most complex support missions in history.35

Concerning the launch itself, the countdown for the DELTA 181 mission was picked up at 1557Z on 8 February 1988. It proceeded smoothly to lift-off at 2207:00Z. As the DELTA Model 3910 booster climbed away from Pad 17B, the launch vehicle rolled out of its 115-degree launch azimuth into a flight azimuth of 94 degrees. The DELTA's second stage was injected into a 90 x 120-nautical-mile orbit inclined 28.7 degrees to the equator. Data was collected during the first seven orbits, then the second stage boosted itself into a 171-nautical-mile circular orbit during its eighth revolution. During the ninth and tenth orbits, the sensor module's telemetry and tape recorder systems were verified. Over the next ten days, the sensor module transmitted its recorded data to designated ground stations in the DELTA 181 support network. The mission was highly successful.36

Figure 115: DELTA 183 on Pad 17B
15 March 1989

The next SDI mission was DELTA 183. It involved the DELTA STAR spacecraft, which contained a suite of sensors, a command and data handling system, seven scientific instruments and a Laser Illumination Detection System (LIDS). Like the DELTA 181 mission's data, DELTA 183 data was transmitted via telemetry downlink to stations on the ground. The primary objectives of the mission were to: 1) observe the DELTA's second stage rocket "burns" in various background environments and 2) record and transmit data about those background environments in general. The DELTA 183 launch was attempted for the first time on 15 March 1989, but the countdown was scrubbed due to launch vehicle and spacecraft problems. The second countdown was attempted on 24 March 1989, and it went well. The DELTA Model 3920 booster lifted off Pad 17B at 2150:49Z on the 24th, and the vehicle rolled into a flight azimuth of 60 degrees. During the first phase of the mission, the DELTA's second stage placed the DELTA STAR into a low-Earth orbit inclined 47.7 degrees to the equator. After coasting for approximately one-half revolution, the second stage fired again to circularize its orbit at an altitude of 269 nautical miles. The DELTA STAR spacecraft then separated from the second stage, and the second stage performed an evasive maneuver. The DELTA STAR observed the second stage's de-orbit burn and reentry into the atmosphere. During the second phase of the mission, the DELTA STAR made observations and transmitted data to ground stations over the next several months.37

A DELTA II Model 6925 launch vehicle was used to boost two more SDI payloads into orbit from Pad 17B on 14 February 1990. The first payload, LOSAT L, was designed to measure the absolute intensity of low energy ultraviolet, visible and infrared laser beams transmitted from a ground site to a target satellite. The second payload, LOSAT R, validated ground-based laser relay technology in the areas of beam stabilization, pointing and beacon tracking. Following lift-off at 1615:00Z on February 14th, the DELTA II rolled into a flight azimuth of 75 degrees and accomplished the "dogleg" maneuvers required to inject the payloads into their proper orbits. The LOSAT L was injected into a 546-kilometer circular orbit, and it was turned over to the U.S. Naval Research Laboratory to support various SDI studies. After the LOSAT L payload was released, the DELTA II's second stage completed a retrograde burn before releasing the LOSAT R payload into a 470-kilometer circular orbit. The U.S. Air Force Weapons Laboratory in Albuquerque, New Mexico was responsible for the LOSAT R, but a ground station on Maui, Hawaii controlled the spacecraft. The mission was successful.38

We can complete our review of the Cape's DELTA military space operations with a brief look at the NATO IVA mission. As we noted earlier, the NATO IIID communications satellite was launched in November 1984 as a gap filler in the NATO constellation until enhanced NATO IV spacecraft were introduced. The NATO IVA was the first of those enhanced satellites. It was launched from Pad 17B on a Commercial DELTA II Model 7925 vehicle on 8 January 1991. The countdown on January 7th went smoothly for the most part, but a built-in hold had to be extended 68 minutes due to weather constraints. The vehicle lifted off the pad at 0053:01Z on January 8th. The $110,000,000 NATO IVA spacecraft entered its 400 x 19,242-nautical-mile transfer orbit approximately 28 minutes and 48 seconds into the mission. Like its predecessors, the NATO IVA was designed to provide communications between NATO member nations in Europe, the North Atlantic and the eastern seaboard of the United States. The satellite had an operational life expectancy of seven years.39

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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