by U.S.A.F.’ Space and Missile Center’s History Office Los Angeles Air Force Base

The Space and Missile Systems Center is the birthplace and cradle of military space and the central hub of military space acquisition excellence. SMC’s mission is to deliver unrivaled space and missile systems to the joint warfighter and our nation, producing innovative, affordable, and operationally effective space systems of separate subsystems that could carry out different missions.

We continue our review of military satellite systems and we examine…

Infrared Early Warning Systems
The MIDAS program, the third offshoot of WS 117L, focused on developing a satellite with an infrared sensor to detect hostile ICBM launches. It began its life as a separate program when AFBMD placed the infrared portion of WS 117L under a separate contract with Lockheed effective 1 July 1959.

The payload consisted of an infrared sensor array and telescope inside a rotating turret mounted in the nose of an Agena spacecraft. Plans which were never carried out called for an operational constellation of eight satellites in polar orbits to constantly monitor launches from the Soviet Union. Unfortunately, the program’s first four test satellites launched in 1960 and 1961 ended in a launch failure and early on-orbit failures.

DOD kept the program in a research and development phase rather than approve an operational system in 1962. The MIDAS program was lengthened and renamed Program 461. The next two launches in 1962 also ended in an early on-orbit failure and a launch failure. Finally, a satellite launched on 9 May 1963 operated long enough to detect 9 missile launches.

After another launch failure in 1963, the last Program 461 satellite, launched on 18 July 1963, operated long enough to detect a missile and some Soviet ground tests. Data collection and analysis continued until 1968 under Lockheed’s contract for Program 461 to support the next early warning program. Additional launches in 1966, using improved spacecraft and sensors, demonstrated the system’s increasing reliability and longevity.

Although a launch on 9 June 1966 failed, launches on 19 August and 5 October 1966 placed their spacecraft into highly useful orbits, where their infrared sensors gathered data for a year, reporting on 139 American and Soviet launches. The MIDAS program and its successors were declassified in November 1998.

DOD initiated a new program late in 1963 to develop an improved infrared early warning system, which ultimately became the Defense Support Program. After an early phase known as Program 266, a contract for development of Program 949, the Defense Support Program (DSP), was awarded to TRW for the spacecraft on March 6, 1967 and to Aerojet for the infrared sensor on March 1967.

The new concept involved placing the satellites into orbits at geosynchronous altitude, where only three or four would be necessary for global surveillance. Like MIDAS, the satellites would employ telescopes and IR detectors, but the necessary scanning motion would be accomplished by rotating the entire satellite around its axis several times per minute. An evolving network of two, and later three, large ground stations in Australia, Europe, and the continental U.S. controlled the spacecraft and data. The first DSP satellite was launched on 6 November 1970, using a Titan IIIC launch vehicle.

A long series of increasingly larger, more sophisticated, and more reliable satellites followed,22 all of them except one launched on Titan III or Titan IV vehicles.²³ By early 2003, twenty DSP satellites had been successfully launched.²⁴ They provided a level of early warning that was, by then, indispensable for both military and civil defense. They also carried sensors that performed nuclear surveillance, a mission inherited from the Vela system. Although designed for strategic uses, DSP proved to be more versatile. During the Persian Gulf War, it provided early warning against tactical missiles as well.

By 1997, SMC and Air Force Space Command had exploited that capability by adding central processing facilities and tactical ground stations to provide DSP tactical data to battlefield commanders more rapidly and efficiently. During the early 1990s, SMC pursued concepts and technologies for follow-on systems to replace the DSP. By 1994, the concept for a system to succeed DSP was known as the Space-Based Infrared System (SBIRS). SBIRS would be an integrated system that would support several missions: missile warning, missile defense, battlespace characterization, and technical intelligence.

The SBIRS concept actually included two planned satellite systems, referred to as SBIRS High²⁵ and SBIRS Low.²⁶ Both were heirs of infrared technology developed for the Ballistic Missile Defense Program (earlier known as the Strategic Defense Initiative) during 1983-1995.

SBIRS High was focused on the detection and tracking of missiles during the earlier phase of their flight, while their motors were generating heat and infrared signatures in short wave lengths. SBIRS Low would add the capability of tracking and reporting other data about missiles during the middle portions of their flight, when their infrared signatures were at longer wave lengths.

SMC awarded a 10-year development contract for SBIRS High to Lockheed Martin on 8 November 1996. The SBIRS High program had to be restructured during 2001 to deal with potential cost and schedule overruns, but its technical progress continued. In December 2001, a consolidated SBIRS Mission Control Station (MCS) at Buckley AFB, Colorado, was declared operational. The MCS provided a central capability for command and control of all operational DSP satellites.

The completion of this first segment of the ground system upgrade allowed older DSP ground stations to be closed. Plans called for the ground system to continue to evolve to support satellites of the SBIRS High system. By early 2003, a payload for elliptical orbits in SBIRS High was undergoing ground testing. To prepare for the development of SBIRS Low, SMC awarded contracts for on-orbit demonstrations to TRW on 2 May 1995 and to Boeing on 2 September 1996. However, the SBIRS Low program began a gradual transfer of oversight back to the Missile Defense Agency during the same period.

References
²² DSP satellites launched during 1970-1973 weighed 2,000 pounds, had a design life of 1.25 years, and incorporated 2,000 lead sulfide detectors operating in the short wave infrared range; they could see targets only below the line of the earth’s horizon. Satellites launched beginning in 1989 weighed 5,250 pounds, had a design life of 3 years, and incorporated 6,000 lead sulfide detectors with an additional set of mercury cadmium telluride detectors operating in the short wave and medium wave infrared range; they could see targets both below and above the line of the earth’s horizon. See Major James Rosolanka, “The Defense Support Program (DSP): A Pictorial Chronology, 1970-1998,” SBIRS Program Office. ²³ DSP-16 was launched on a Space Shuttle (STS-44) on 24 November 1991.

²⁴ Two more DSP satellites remained in storage: Flights 22 and 23. No more were under contract because plans had called for DSP’s successor, the Space-Based Infrared System, to reach operational status in time to take over operations from DSP’s orbital constellation.

²⁵ The technological basis for the high-altitude follow-on system to detect missile launches was an earlier program under OSD’s Strategic Defense Initiative (SDI) known as the Boost Surveillance and Tracking System (BSTS). It had been transferred to the Air Force in FY 1992 and had gone through several conceptual changes known as the Advanced Warning System (AWS), the Follow-on Early Warning System (FEWS), and the Alert Locate and Report Missiles (ALARM) program. 26 The technological basis for the low-altitude follow-on system to track missiles in the middle portion of their trajectories had also been an SDI program. It had been known as the Space Surveillance and Tracking System (SSTS) during the mid and late 1980s and as Brilliant Eyes during the early 1990s.

To Be Continued…
Please join us in the next issue of MilsatMagazine as we continue with the history of military satellites, courtesy of the U.S.A.F.’ Space and Missile Center’s History Office, Los Angeles Air Force Base, El Segundo, California