Slide 36 of 125
Notes:
The next two years after Neil Armstrong's and Buzz Aldrin's triumphant moonwalk were a very
difficult time for NASA's manned space program. Administrator Tom Paine and Vice President
Agnew were at first optimistic about the chances of getting their ambitious post-Apollo space
exploration plan approved. But it wasn't to be. Paine's $4.5-billion FY 1971 budget request was
quickly pared down to just $3.333 billion by the White House. Congress later reduced this only
slightly, to $3.269 billion, but only after three difficult roll-call votes. In fact, the House
space subcommittee chairman, Joseph Karth, actually opposed NASA's $10-billion shuttle/space
station plan because he felt it would force the agency to cancel many unmanned programs.
Disgruntled space scientists such as James van Allen and long time opponents of expensive manned
spaceflights such as Democratic Senators William Proxmire and Walter Mondale supported him.
Karth's May 1971 amendment to cancel all funding for NASA's shuttle & station studies was a
53-53 tie, the closest he could come without winning. The White House was equally unsupportive,
and Paine decided to quit his job in September 1970 following numerous disagreements with
President Nixon's budget officials. His final action was to cancel the Apollo 18 and 19 manned lunar
landing missions in order to save money for additional space shuttle studies. NASA now focused all
its future efforts on the shuttle after the space station, space tug and nuclear Mars vehicles all
fell by the wayside during 1970. Then, in May 1971, Nixon's Office of Management and Budget dropped
another bombshell by announcing that NASA should not expect a larger annual budget than about $3.2
billion over the next five years. The fully reusable Phase-B shuttle was all but dead since it would
have required a budget increase to $4.5-5 billion. NASA and its contractors would spend the next six
months frantically searching for cheaper partially reusable alternatives. The most important
Phase-B prime and double-prime results were as follows.
McDonnell-Douglas received a $0.75-million contract extension in March 1971 to investigate the
impact of Grumman's drop tank concept on its Phase B shuttle design. The extension, plus an
earlier structures contract worth $2M, increased the total Phase B contract to $10.9 million.
North American Rockwell's Phase-B shuttle contract was also extended to cover the Grumman
drop-tank concept (left). In June 1971, NASA's new Administrator, James Fletcher, advocated the
H-33 drop tank design with staggered development to reduce the peak funding requirement from
$1.8B to $1.3B per year. The orbiter would be developed first and initially flown atop an
existing expendable rocket stage. In late June, Fletcher extended the Phase-B contracts yet
again, this time by four months and about $2.8 million per team. Each contractor was ordered
to evaluate different expendable boosters plus a shuttle orbiter that carried its liquid
hydrogen *and* liqui d oxygen propellants in an external tank. North American Rockwell
investigated the Saturn S-IC (right) and a stripped-down expendable wingless version of its
Phase-B booster.
Martin Marietta proposed an uprated version of its Titan IIIM rocket. The "Titan IIIL" would have
incorporated four solid rocket boosters and “stretched” propellant tanks to carry a full size
shuttle orbiter plus 29.5t payload. Martin claimed their rocket only would cost $30 million per
launch vs. $75 million for the Saturn S-IC.
Although the LS-200 design was shelved, Lockheed still received about $350,000 a month to continue
working on drop-tank orbiter & solid rocket booster configurations. The Lockheed designs were to
be based on the Manned Spacecraft Center's "MSC-040" concept from May 1971, which turned out to be
essentially the same configuration as the shuttle concept NASA selected six monts later.
Boeing and Grumman were thought to be in an excellent position to land the future shuttle
production contract since their innovative proposals greatly influenced NASA's plans during
1971. The June 1971 contract extension allowed the companies to investigate the Saturn S-IC
interim booster concept (right) as well as various combinations of drop tanks and solid rocket
boosters (left). The concepts in the middle would have utilized combinations of liquid rocket
boosters and expendable propellant tanks.
Boeing unveiled another ingenious shuttle booster design in August 1971. The "RS-1C" configuration
(bottom) would have put wings, landing gear & jet engines etc. on the Saturn V rocket's S-IC
stage, transforming it into a manned flyback booster for the shuttle! It would cost less to
develop than the H-33 configuration's "B-2" booster (top). To further reduce the peak funding
requirement, Boeing also proposed a "Mark I/Mark II shuttle" development program. During the
Mk.I phase, the orbiter would use J-2S engines, ablative thermal protection and other
off-the-shelf systems from project Apollo. Eventually, new hardware such as the Space Shuttle
Main Engine and reusable thermal protection system would be introduced during the "Mark II"
program to reduce the cost per flight and increase payload performance. NASA estimated that the
"Mark I" shuttle would cost $9 million per flight, falling to $5.5 million for the improved
"Mark II".
Pressure-fed Reusable Winged S-IC Flyback
Development Peak Development Peak
Grumman $4.08 $1.02 $4.5 $1.11
North American Rockwell $5.12 $0.94 $5.79 $1.21
McDonnell-Douglas $5.16 $0.81 $7.51 $1.30
Lockheed -- -- $4.41 $0.99
After NASA reluctantly dropped its Saturn V-derived manned flyback booster, the only options
left were large unmanned rockets that would be recovered and reused after falling back into
the sea. NASA's Marshall Spaceflight Center had proposed a large, simple liquid propellant
rocket motor that would not require costly turbopumps since the propellant injection would be
pressure-fed. The tanks would have to be strong and heavy to withstand the pressure, making it
relatively easy to recover them at sea. NASA wanted its contractors to investigate the pressure-fed
unmanned booster option during Phase B double prime in October 1971-March 1972. The main
alternatives were now:
- Parallel expendable solid rocket motors. Proposed concepts:
[1] McDonnell-Douglas/Martin Marietta, [5] North American Rockwell/General Dynamics,
[8] Grumman/Boeing.
- Parallel recoverable pressure-fed liquid rocket boosters.
[2] McDonnell-Douglas/Martin Marietta, [4] North American Rockwell/General Dynamics,
[7] Grumman/Boeing.
- A single recoverable pressure-fed liquid rocket booster.
[3] McDonnell-Douglas/Martin Marietta, [6] North American Rockwell/General Dynamics.
- A single recoverable liquid rocket booster derived from the Saturn S-IC stage.
[9] Grumman/Boeing.
The contractors reported their findings and recommendations in February 1972. Boeing recommended
its own S-IC stage with retrorocket/parachute recovery at sea and also urged that solid rocket
motors should be eliminated from further consideration. Lockheed and McDonnell-Douglas (who initially
was quite optimistic about the pressure-fed booster) again advocated solids, noting that expendable
Thor, Delta, Titan & Scout solid rocket motors had a very good safety record. North American
Rockwell again refused to pick a favored concept and only noted that a case could be made for either
solid or liquid boosters depending on what cost goals were most important.
Space Shuttle solid rocket booster separation. NASA finally decided what type of booster it
was going to use in March 1972: recoverable solid rocket boosters (SRBs)! The SRBs would
be slightly more expensive per flight but the development cost and risk was lower than for the
pressure-fed "big dumb booster" option. Both options had their share of problems, though. The pressure-fed
booster was anything but simple since it would have to be very big, require thick-walled propellant
tanks and welds several centimeters thick. No large recoverable booster had ever been built before
and NASA was not sure if the required technological capabilities existed. Another concern was: what
happens if a tank ruptures during ascent? All engines would shut down, with disastrous consequences.
The solid rocket booster had a totally different problem since it could not be shut down until all
the propellants had burned out! But at least the aerospace industry had some previous experience
with large solid rocket motors although NASA's test firings of 4m and 6.6-meter diameter engines
had ended in 1967. NASA claimed a handful of tests with the Titan III solid rocket boosters had
"proved" the spent casings could be recovered from sea and refurbished for 10-20 reuses. But the
decision would come back to haunt the agency 14 years later.
So the Space Shuttle configuration finally evolved. Its far from sleek appearance was the result
of an almost continuous juggling of compromises. The project's many critics often regarded the
ungainly craft as a "camel" (an animal obviously designed by a committee), but it did come close
to meeting the staggering array of payload requirements, cost trade-offs, crossrange specifications,
schedule and budget constraints and operational conditions that shaped it. But as NASA Deputy
Administrator George Low warned in a speech before the National Space Club on February 17, 1972,
the real challenge was to develop a "productive Space Shuttle" -- "one that performs as required,
can be developed at a reasonable cost and is economical to operate. If we meet the first two of
these objectives, but not the third, we will have developed a white elephant." The next
chapter will examine the economic case for the Space Shuttle.
“Key Space Shuttle Decisions Near” -- AW&ST 1971/March 29/p.45
“Orbiter Selection Due by Mid-1972” -- AW&ST 1971/June 28/p.16
“Winged Saturn Studied for Shuttle” -- AW&ST 1971/September 20/p.16
“NASA Plans Concurrent Booster, Orbiter” -- AW&ST 1971/October 25/p.12
“Three Shuttle Booster Concepts Studied” -- AW&ST 1972/January 10/p.46
“Alternate Booster Evaluation Set” -- AW&ST 1972/January 24/p.36
“Pressure-Fed Booster Explored” -- AW&ST 1972/January 24/p.40
“Two Reports on the Space Shuttle” -- Space World 1972/November/p.16
