Where to Launch and Land the Space Shuttle? (1971-1972)
NASA’s ambition in 1971 was to build a fully reusable Space Shuttle which it could operate much as an airline operates its airplanes. The typical fully reusable Shuttle design in play in 1971 included a large Booster and a smaller Orbiter (image at top of post), each of which would carry a crew.
The Booster’s rocket motors would ignite on the launch pad, drawing liquid hydrogen/liquid oxygen propellants from integral internal tanks. At the edge of space, its propellants depleted, the Booster would release the Orbiter. It then would turn around, reenter the dense part of Earth’s atmosphere, deploy air-breathing jet engines, and fly under power to a runway at its launch site. Because it would return to its launch site, NASA dubbed it the “Flyback Booster.” It would then taxi or be towed to a hanger for minimal refurbishment and preparation for its next launch.
The Space Shuttle Orbiter, meanwhile, would arc up and away from the Booster. After achieving a safe separation distance, it would ignite its rocket motors to place itself into Earth orbit. After accomplishing its mission, it would fire its motors to slow down and reenter Earth’s atmosphere, where it would deploy jet engines and fly under power to a runway landing. As in the case of the Booster, the Orbiter would need minimal refurbishment before it was launched again.
Unlike an expendable launcher – for example, the Saturn V moon rocket - a fully reusable Space Shuttle would not discard spent parts downrange of its launch site as it climbed to Earth orbit. This meant that, in theory, any place that could host an airport might become a Space Shuttle launch and landing site.
NASA managers felt no need for a new launch and landing site; they already had two at their disposal. They planned to launch and land the Space Shuttle at Kennedy Space Center (KSC) on Florida’s east coast and Vandenberg Air Force Base (VAFB), California. Nevertheless, for a time in 1971-1972, a NASA board reviewed some 150 candidate Shuttle launch and landing sites in 40 of the 50 U.S. states. A few were NASA-selected candidates, but most were put forward by members of Congress, state and local politicians, and even private individuals.
The Space Shuttle Launch and Recovery Site Review Board, as it was known, was chaired by Floyd Thompson, a former director of NASA’s Langley Research Center in Hampton, Virginia. The Board got its start on 26 April 1971, when Dale Myers, NASA Associate Administrator for Manned Space Flight, charged it with determining whether any of the candidate sites could host a single new Shuttle launch and landing site as versatile as KSC and VAFB were together. The consolidation scheme aimed to trim Shuttle cost by eliminating redundancy.
The proposed Space Shuttle launch and landing sites were a motley mix. Many were Defense Department air bases of various types (for example, Patuxent Naval Air Station, Maryland), while a few were city airports (for example, the Lincoln, Nebraska Municipal Airport). Texas proposed two sites at the Big Bend of the Rio Grande River and Wyoming offered 11 of its 23 counties. KSC and VAFB were on the list, as were NASA’s Marshall Space Flight Center in Huntsville, Alabama, and Ellington Air Force Base in Houston, Texas, which had as its chief function to serve NASA’s Manned Spacecraft Center.
Texas had the most candidate sites (22) of any state, while Nebraska and Wyoming tied for second place with 12 sites each. Furthest north and east were Presque Isle Air Force Base, Dow Air Force Base, and Loring Air Force Base in Maine. Furthest south were sites around Brownsville, Texas. VAFB was the westernmost site considered.
The 10 states that contained no candidate Space Shuttle launch and landing sites lacked obvious disqualifying features (or, at least, appeared no more or less qualified than most of the states that included candidate sites). Alaska and Hawaii were disqualified because they were located too far from established U.S. space industry. The Midwestern states of Iowa, Illinois, Indiana, and Minnesota contained no sites, though candidates existed in neighboring states Missouri, Kansas, Nebraska, North Dakota, South Dakota, Wisconsin, Ohio, and Michigan. West Virginia alone among states east of the Mississippi River and south of the Ohio River lacked a candidate site. The east coast states of Rhode Island, Connecticut, and New Jersey rounded out the list of no-shows.
In its efforts to cull unsuitable sites, the Thompson Board focused most of its attention on the effects of sonic booms, the sudden waves of air pressure produced when an aircraft or spacecraft exceeds the speed of sound (that is, “breaks the sound barrier”). Sonic booms, which the Board wrote had “the startling audibility and dynamic characteristics of an explosion,” were a bone of contention in the U.S. in the early 1970s; concern at the time over possible injury to people on the ground and damage to structures helped to kill U.S. plans to develop a supersonic passenger aircraft akin to the Anglo-French Concorde.
The Thompson Board determined that the Space Shuttle would generate its most powerful sonic boom during ascent, while the Booster and Orbiter formed a single large vehicle. The Booster’s rocket plume would, for purposes of calculating sonic boom effects, make the ascending, accelerating spacecraft appear even bigger. The Shuttle’s flight path characteristics – for example, the pitch-over maneuver that it would perform as it steered toward orbit – would create a roughly 10-square-mile “focal zone” for sonic boom effects about 33 nautical miles downrange of the launch site.
“Overpressure” in the focal zone would almost certainly exceed six pounds per square foot (psf) and might reach 30 psf, which would be powerful enough to damage structures (plaster and windows could suffer damage at an overpressure as low as three psf, the Board noted). Winds could unpredictably shift the focal area by several miles. The Board urged that “the severe overpressures associated with the focal zone. . .be prevented from occurring in any inhabited area.”
Based on this and other criteria, the Thompson Board trimmed the list of candidate single Space Shuttle launch and landing sites to just seven. These were: KSC; VAFB; Edwards Air Force Base, California; Las Vegas, Nevada; Matagorda Island, Texas; Michael Army Air Field/Dugway Proving Ground, Utah; and Mountain Home Air Force Base, Idaho.
As the Thompson Board continued its deliberations, the Space Shuttle design was undergoing rapid and profound changes. At its 22 June 1971 meeting, the Board discussed NASA Administrator James Fletcher’s 16 June announcement that the space agency would spread out Shuttle costs by adopting “series development” of the Booster and Orbiter. The Orbiter would be developed first. Until the Booster could be developed, the Orbiter would be coupled with an “interim expendable booster” – possibly a modified Saturn V S-IC stage - that would separate after depleting its propellants and fall back to Earth downrange of the launch site.
In addition, Fletcher had told reporters, Shuttle contractors would abandon work on the Orbiter’s reusable internal liquid propellant tanks in favor of expendable external tanks that would supply liquid oxygen/liquid hydrogen propellants to the Orbiter’s main engines. The expendable external tanks would be less technologically challenging than their reusable internal counterparts and thus would have a lower development cost. The tanks would break up high in the atmosphere after separating from the Orbiter.
The Thompson Board received a whirlwind series of briefings on the Shuttle design changes at KSC, the Manned Spacecraft Center, and Marshall Space Flight Center in late September 1971, after which Floyd Thompson called a two-month recess to give the Shuttle design time to firm up. Then, on 5 January 1972, Fletcher announced that President Richard Nixon would seek new-start funding for the Space Shuttle Program in the Fiscal Year (FY) 1973 NASA budget.
On 15 March 1972, as NASA and Nixon’s Office of Management and Budget jousted over the Shuttle’s development cost, Fletcher announced that the reusable Booster would be abandoned entirely in favor of a stack comprising a single expendable External Tank (ET) and a pair of reusable Solid Rocket Boosters (SRBs). After expending their propellant, the SRBs would separate from the Orbiter/ET combination and descend on parachutes. NASA’s Office of Manned Space Flight subsequently determined that the SRBs could not safely touch down in “a controlled manner” on land; they would instead need to splash down and be recovered at sea.
The Thompson Board met just twice more. At its 27 March 1972 meeting, it discussed the implications of the 15 March booster decision, and officially eliminated all non-coastal candidate Shuttle launch and landing sites from consideration. At its final meeting on 6 April 1972, the Board compared the cost of building and operating a single new Space Shuttle launch and landing facility at Matagorda Island, 65 miles south of Houston, Texas, with the cost of modifying and operating both KSC and VAFB.
The Board’s members assumed that NASA would build five Orbiters, begin Space Shuttle flights in FY 1978, and ramp up to 60 Shuttle missions per year beginning in FY 1985. To launch that many missions – more than one per week - from Matagorda Island, the Shuttle fleet would need one Orbiter Thermal Protection System (TPS) maintenance and checkout bay, three vehicle assembly highbays for mating Orbiters with their ET/twin SRB booster stacks, three Mobile Launcher Platforms for transporting the Shuttle/ET/twin SRB combinations to their launch pads, three launch pads, three firing rooms, and one Orbiter landing strip.
If NASA opted for the dual-site approach, three Orbiters based at KSC would conduct 40 missions per year using one Orbiter TPS bay, two vehicle assembly highbays, two Mobile Launcher Platforms, two pads, two firing rooms, and one landing strip. The two Orbiters based at VAFB would conduct 20 missions per year using one Orbiter TPS bay, one vehicle assembly highbay, two Mobile Launcher Platforms, one pad, one firing room, and one landing strip. The KSC/VAFB plan would thus need one more TPS bay, Mobile Launcher, and landing strip than the Matagorda Island plan.
The single-site plan would, however, incur greater construction costs than the dual-site plan, for the simple reason that Matagorda Island had no spaceflight infrastructure already in place. The Board estimated that Matagorda Island construction and operations would cost $5.365 billion through FY 1990, while KSC and VAFB would together cost $5.137 billion. The single-site plan would, as predicted, lead to reduced Shuttle operations costs, but these savings would amount to only $87.6 million. Constructing the Matagorda Island site would, on the other hand, cost $315 million more than would modifying KSC and VAFB to support Shuttle launches. This meant that the single-site option would cost $228 million more than the dual-site option.
In addition to its greater monetary cost, the single-site option would introduce substantial programmatic risk and societal costs. The Texas coastal site was partly privately owned, so construction could not begin there until NASA had negotiated purchase of the private land. Infrastructure such as roads, railways, an electric grid, a harbor, an airport, waste treatment plants, and a water system would need to be built new or expanded. Thousands of workers would need to relocate to the area in less than five years, placing enormous strain on local housing, schools, and what few amenities existed in the immediate area. At the same time, the communities around KSC, already under pressure as the Apollo Program drew to an end, would suffer catastrophic job losses.
The Thompson Board briefed James Fletcher on its results on 10 April 1972. Just four days later, Fletcher told a press conference at NASA Headquarters that Space Shuttles would launch from KSC starting in 1978 and that launches from VAFB would be phased in early in the 1980s.
Space Shuttle Launch and Recovery Site Review Board, NASA, 10 April 1972.
Space Shuttle: The History of the National Space transportation System – The First 100 Missions, Dennis R. Jenkins, 3rd edition, January 2001.
Chronology: MSFC Space Shuttle Program – Development, Assembly, and Testing Major Events (1969-April 1981), MHR-15, NASA George C. Marshall Space Flight Center, December 1988.