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Boeing / Lockheed Phase B straight-wing shuttle concept.
NASA issued the Phase-B request for proposals in Feburary 1970 after setting up a joint shuttle
evaluation panel with the US Air Force. The next round of studies would be far more extensive.
NASA's Manned Spacecraft Center (which was overseeing the orbiter contracts) and Marshall
Spaceflight Center (responsible for the booster) could not agree on how much crossrange the shuttle
really would need, so the contractors were asked to design both 370km-crossrange straight-wing and
2700km-crossrange delta-wing versions of the orbiter. Three consortiumsinitially submitted bids:
Lockheed/Boeing, McDonnell-Douglas/Martin Marietta, and North American Rockwell / General Dynamics.
Grumman later submitted a fourth bid. NASA expected to award two three 11-month contracts worth
$8 million each, before launching a full-scale “phase C/D” effort to develop the shuttle by 1977.
But unexpected budget cuts soon forced the agency to delay the schedule.
Boeing/Lockheed Phase B delta-wing shuttle concept.
The booster would be 64m long and powered by 11 rocket engines while the 352.9-tonne delta-wing
orbiter would be 50.3m long with a crossrange capability of 2,400km. The Air Force regarded Maxime
straight-wing orbiter as outright dangerous since its flight plan called for a stall maneuver at
12.2km altitude followed by a controlled dive to 7.6km to pick up speed again. This was necessary
because the shuttle would be reentering nose-high and it would be travelling too slowly for the
wings to provide any lift when the nose finally gets pushed down. The Air Force (and leading
NASA/MSFC officials such as Dale Myers) preferred a delta wing which would permit a normal
gliding reentry. The delta provides better trim and drag across the entire flight path, from
hypersonic reentry to subsonic flight, although the landing speed will be higher than for a
straight-wing. Faget objected that the delta would be heavier, although it did offer more room
for the landing gear. What settled the argument in the end was the USAF crossrange requirement
since the shuttle would have to capable of overflying the Soviet Union and return to base after
a single orbit, only 90 minutes later. Due to the Earth's rotation, the base would have moved
by 2000km in 90 minutes so this defined the shuttle's crossrange requirement. But NASA paid a
heavy price for this, since the resulting additional weight and complexity added well over 20%
to both development and operations costs of the shuttle. To the Air Force, the only shuttle
capability that seemed really valuable was the ability to inspect and retrieve satellites in
space as well as deploy 18,144kg military spy satellites. NASA had no choice, though, since it
badly needed the considerable US Air Force space traffic to boost the shuttle “market” -- the
basic justification for the extremely high initial investment of the system. As the space
station project was postponed indefinitely in mid-1970, it became increasingly clear that
one-third of the shuttle payloads would be military satellites. NASA also needed USAF political
support in Congress, where influential Senators and Representatives were adamantly opposed to
Paine's grandiose and expensive post-Apollo space exploration plan. The Department of Defense
was, at best, a lukewarm shuttle supporter and there was little military interest in a low-cost
space transportation system since the existing Titan and Atlas rockets were quite sufficient for
USAF needs. It was not even interested in sharing the cost with NASA.
"Spaceflight and Rocketry -- a Chronology”, David Baker:, Facts on File Inc, 1996, ISBN 0-8160-1853-7
”The Space Shuttle Decision” -- T.A. Heppenheimer, NASA History Office, NASA SP-4221, 1999