Weldon’s logic centered around the phase-out of the Air Force Titan IVB heavy lift booster and the gradual introduction of the heavy lift versions of the Boeing Delta IV and Lockheed Martin Atlas V EELV configurations. By Congressional compromise with the Air Force in 1997 production of the Titan IV rockets was ended with a 40th booster, 39 designated for launches of military payloads and a 40th booster as a flight spare. All 40 units have been built and the Titan assembly line under conversion to the EELV program.

The Air Force launch contract with Lockheed ends in 2003, with a contract option for preparation and launch of the back-up unit in 2004 if needed. After that, there will be no other alternative for large military and classified satellite launch by U.S. carriers other than elements of the EELV fleet.

Although Weldon expressed concern, there has not been any major delays in either company’s EELV development program. The first launch of a medium-lift EELV, a Delta IV rocket, is expected next year. Boeing and the Air Force have contracted for a payload-less test flight of the heavy Delta IV vehicle prototype to flight prove the design before committing military payloads on board. And as a result of a decision between Lockheed Martin and the Air Force last year, there will not be a heavy-lift Atlas V pad at Vandenberg Air Base in California, meaning that only the Delta IV heavy lifter will offer larger payload launching capability for sun-synchronous missions once the Titan IVB has been retired.

But Weldon’s concerns may be moot. All U.S. military payloads have begun the transition to launch aboard the EELV designs. Only the Defense Support Program (DSP) satellite was built with the capability for launchings aboard the Space Shuttles as well as expendable rockets, but the last Shuttle-capable DSP was orbited in 1991. The Air Force and Defense Department, citing Shuttle delays and launch uncertainty that began well before the 1986 Challenger accident, developed the Complementary Expendable Launch Vehicle (CELV) in 1985 and two versi.

The CELV became the Titan IVA and B and the MLV I and II became the Delta II and Atlas expendable rocket families. All are to be replaced by the EELV system, although the extension of the Delta II well into the decade is possible. Reviews conducted in 1996 and 1997 found it more cost effective to avoid military use of Shuttles and fly out the remaining Titan rockets under the existing contract.

Weldon identified Columbia as a potential military satellite launcher because that orbiter, delivered to NASA in March 1979 and flown into space for the first time on April 12, 1981, was heavier than its other sister vehicles, making it unsuitable for space station assembly and thus theoretically available for other, non-NASA missions.

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