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Some influential officers within the Air Force, whichhad the responsibility for launching all national security payloads, especially the critical57. U.S. Congress, Office of Technology Assessment, International Cooperation and Competition in CivilianSpace Activities, OTA-ISC-239 (Washington, DC: U.S. Government Printing Office, 1985), p. 10.58. Roger A. Pielke, Jr., “A Reappraisal of the Space Shuttle Programme,” Space Policy, May 1993, pp.133–57.59.

See Logsdon, gen. ed., Exploring the Unknown, 2: 263–69, for a discussion of DOD disenchantment withthe Space Shuttle.60. SLC-6 was originally meant for the launch site of Dyna-Soar; it was then refurbished for the MannedOrbital Laboratory. Both programs, of course, were cancelled, so the site remained unused.****EU4 Chap 2 (161-192)1824/2/0112:45 PMPage 182DEVELOPING THE SPACE SHUTTLEreconnaissance satellites, worried about the frequent delays in Shuttle launches and thelength of time between manifesting a payload on the Shuttle and the actual flight (abouttwenty-four months).61 They reasoned that any major problems encountered in a Shuttlesubsystem could delay the flight of a critical payload.

No matter how successful the Shuttlefleet was, there were likely to be times when it would be grounded for safety purposes, justas entire aircraft fleets may be grounded while investigators examine the causes of majorsubsystem failures and determine appropriate repairs. Privately, some analysts worriedthat the Shuttle might fail catastrophically at some point, leaving the fleet grounded foran extended period. In addition, some argued that even if NASA were able to sustain anaverage Shuttle flight rate of twenty-four per year, that rate would not accommodate theneeds of the Air Force, along with the projected demand from civilian public- and privatesector uses.Hence in 1983, with the strong endorsement of Secretary of the Air Force PeteAldridge, the Air Force began to examine the benefits and costs of developing a new vehicle that it called the Complementary Expendable Launch Vehicle (CELV) to provide“assured access to space.” On January 7, 1984, Secretary of Defense Caspar Weinbergerapproved a defense space launch strategy that included the development of a CELV withsufficient capacity to launch payloads of up to 40,000 pounds.62Air Force officials chose the adjective “complementary” to avoid the appearance ofcompetition with the Shuttle and to emphasize that the CELV would be expected to service DOD launch demand should the Shuttle be unable to meet it for any reason.

Aldridgewas also interested in improving Air Force launch flexibility and maintaining the technology base and production capability that might otherwise be lost.Congressional reaction was mixed. DOD’s authorization and appropriations committees generally supported the move. However, supporters of NASA’s Space Shuttleexpressed concern that CELV development would divert DOD attention away from theShuttle and undercut the funding supporting Shuttle operations.

The Shuttle was developed in part to serve DOD needs, which led to higher operations costs than NASA hadanticipated. Continued DOD use of the Shuttle was needed to help pay for Shuttleupgrades and keep the costs of operations as low as possible.Despite the concerns of some members of Congress, especially those of the HouseCommittee on Science and Technology, DOD’s plans nevertheless carried the day. DODissued a request for proposals (RFP) on August 20, 1984, for the development of a launcher capable of lifting 10,000 pounds to a geostationary transfer orbit from DOD’s EasternTest Range.

The initial RFP called for a total buy of ten launchers. In 1984, the Air Forcehad no official plans to launch the CELV from the Western Test Range at Vandenberg AirForce Base, but intended instead to rely on the Shuttle to lift payloads of up to32,000 pounds into low-Earth polar orbit from Vandenberg.63Martin Marietta won the contract to build an upgraded version of its Titan 34D inFebruary 1985, over competing designs from General Dynamics and from NASA, whichhad proffered a launch vehicle based on Shuttle technology.

This vehicle, which becameknown as the Titan IV, is capable of lifting 40,000 pounds to LEO or 10,000 pounds to geostationary transfer orbit. Martin Marietta achieved the improved payload capacity bystretching the liquid propellant tanks and by upgrading the Titan’s solid rocket motors to61.

Ironically, the vehicle that resulted from the Air Force need to launch national security payloads, theTitan IV, has proved nearly as difficult to make operational and almost as costly as the Shuttle.62. See Documents II-40 through II-44 in Logsdon, gen. ed., Exploring the Unknown, 2: 390–410.63. Discussion between Congressman George Brown and Secretary of the Air Force Pete Aldridge, “SpaceShuttle Requirements, Operations, and Future Plans,” hearings before the Subcommittee on Space Science andApplications of the Committee on Science and Technology, U.S.

House of Representatives, 98th Cong., 2d. sess.,July 31–August 2, 1984, p. 86.****EU4 Chap 2 (161-192)4/2/0112:45 PMPage 183EXPLORING THE UNKNOWN183seven segments rather than the five and a half segments used by the Titan 34D.64 Fairingsof up to 86 feet long would accommodate Shuttle-size payloads. The Titan IV was designedwith the capability to carry no upper stage, a Centaur upper stage, or an inertial upperstage (IUS).65 The first Titan IV was launched on June 14, 1986, with an IUS upper stage.In October 1987, Martin Marietta contracted with Hercules to develop and manufactureSRBs with graphite-epoxy casings, capable of adding 8,000 pounds capacity to LEO. Afterthe failure of the Shuttle Challenger, the Air Force’s plans to develop the CELV seemedalmost prescient.Losing ChallengerAlthough every knowledgeable observer recognized that there was some potential fora major Shuttle failure, the press and the broader public in the early 1980s paid littleattention to the risks of human spaceflight.

Even those close to the Shuttle system let downtheir guard. As one successful launch followed another, some engineers and flight directors began to submerge their concerns about troublesome items that lay on the criticalpath to a safe launch. Hence, the nation was dealt an extremely rude shock when, onJanuary 28, 1986, the orbiter Challenger, carrying seven crew members, seemed to disappear behind a huge fireball just over a minute after liftoff and disintegrated before theeyes of thousands of observers at the launch site and millions more watching the launchon live television coverage.

It was a numbing sight, played over and over again on television, as people all over the world attempted to come to grips with what had happened.66Launch vehicle reliability has always been a concern; most launch vehicles havedemonstrated launch success rates of between 90 and 98 percent. Launch officials worryespecially about the safety of vehicles that carry human crews. As long ago as 1977, formerNASA Administrator James Fletcher had expressed his concerns to then NASA DeputyAdministrator Alan M.

Lovelace about the overall Space Shuttle system and whetherNASA had the right people working the problem of launch reliability and safety. [II-37]Engineers and other observers familiar with the Shuttle’s many systems and points ofpotential weakness had their theories about the cause of the catastrophic failure, yetbecause of the complexity of the Shuttle system, it took careful analysis by a large team ofexperts to determine the exact cause. NASA began to work on the problem immediatelyby pulling together all of the available film footage, launch operations documents, andother materials that might be relevant to the investigation. NASA even employed a deepsea diving company to locate and retrieve parts of the failed launcher from the oceanfloor.

Although senior NASA officials would have preferred to carry out their own analysis outside the glare of publicity, as had been the case following the Apollo 1 fire, the highly public and dramatic loss of life that had occurred on January 28 made an independentexternal review almost inevitable. On February 3, President Reagan signed ExecutiveOrder 12546, which directed the establishment of a high-level commission, chaired by former Secretary of State William P. Rogers, to examine the evidence and determine not onlywhat had happened, but also why it had.

[II-38] The Presidential Commission on theSpace Shuttle Challenger Accident, supported by NASA and other federal agencies, gathered evidence, investigated the chain of events, and held public hearings.64. The first stage was stretched by almost eight feet to increase propellant volume by 10 percent, and thesecond stage was stretched almost two feet, resulting in increased propellant volume of 5 percent.

The solidrocket motors are manufactured by the Chemical Systems Division of United Technologies.65. With the IUS and a fifty-six-foot fairing, the Titan IV stands 174 feet tall.66. The incident was especially numbing because NASA had worked particularly hard to generate publicinterest in the flight, which carried teacher Christa McAuliffe, who would have been the first teacher in space.****EU4 Chap 2 (161-192)1844/2/0112:45 PMPage 184DEVELOPING THE SPACE SHUTTLEAs the investigation revealed, the joint between the first and second motor segmentwas breached about fifty-nine seconds into the flight. Flames from the open joint struckthe external tank and caused its liquid hydrogen and liquid oxygen tanks to rupture.