One
vehicle's operative life is coming to a close, while the other's is still in
its formative stages. Their legacies will be inexorably linked: Without the
space shuttle, delivery and assembly of the International Space Station's (ISS)
key components would have been difficult at best, and probably could not have
happened.
And while
the jury is still out as to whether history will deem the space station a
success, the shuttle almost certainly will be remembered for its dramatic
failures as much as the significant accomplishments its yeoman-like crews
achieved since
Columbia first flew in April 1981.
In the
meantime, there is enough work to go around for both the shuttle and the ISS.
Before the shuttle fleet is retired in 2010, their crews are scheduled to fly
nine more missions to the station.
Five will
involve installation of new equipment; two are more akin to space-borne
teamster jobs, hauling supplies and parts.
Shortly
thereafter, the Constellation program, with its Ares launch vehicle and Orion
spacecraft, will be ready to take over the mission of carrying people into
space for the next 30 to 40 years and expand the limits of the space frontier beyond
low Earth orbit
The ISS,
fully complete by then, will assume the shuttle's role as an orbiting
laboratory.
At that
point, the space shuttle will be relegated to museums, where the first thoughts
that will come to most visitors' minds will no doubt involve the catastrophic
losses of Challenger in January 1986 and Columbia in February 2003.
Such
reactions may be overly simplistic, but they are understandable in the eyes of
some who were close to the shuttle program.
"The
shuttle is a remarkable technological achievement, but it is an equally
remarkable policy mistake," says John Logsdon, the chairman of the Space Policy
Institute at The George Washington University in Washington and a former member
of the NASA Advisory Council. He also served on the Columbia Accident
Investigation Board.
The key
error was the collective belief of the shuttle's champions that "it could be a
system that could operate inexpensively, routinely, and with a high level of
safety," Logsdon says. "It met none of those objectives."
An "incredible
ship"
Those
shortcomings are recognized within NASA — hence the willingness throughout the
agency to embrace Administrator Mike Griffin's push
toward Constellation as the next logical step toward the return to the Moon
and the first trip to Mars.
The shuttle
is an "incredible ship," says Mike Hawes, program integration manager at NASA's
Space Operations Mission Directorate. "It launches like a rocket, flies like a
satellite, lands like a plane, and has cargo capacity — particularly a return
cargo capacity that's huge."
With the
shuttle, NASA learned how to mechanize regular access to space, and came to
terms with both the good and bad challenges of reusable spacecraft, Hawes says.
Until scramjet and ramjet technology gets off the drawing boards and test bays
and joins flight lines, the shuttle remains the only fully hypersonic vehicle
ever to fly regularly and carry crews and payloads as well. The data on
high-speed aerodynamics collected during shuttle missions will serve the
designers and engineers of future ultrafast winged aircraft well, he said.
The shuttle
also performed well when called upon to support missions to build the space
station, Hawes says, providing a platform for extravehicular activity as well
as deployment for space arms and other complicated assemblies.
"But we
learned it was a very expensive machine to operate, care and feed," Hawes says.
"And another thing — because of its long life cycle and small numbers — the
total production run of orbiters being five — there are unique challenges in
maintaining an industrial base."
The
shuttle's unmet aspirations can be traced to the unrealistic conglomeration of
functions it was supposed to perform from the beginning, says Howard E.
McCurdy, a professor of public affairs at American University in Washington and
author of white papers that outline how NASA could operate more efficiently.
"It's
important to keep in mind the huge controversy, going back to the 1950s,
whether a spacecraft should have wings," says McCurdy. "Should it have a
ballistic shape? We go back and forth on that."
Fixed-wing
advocates prevailed, McCurdy says, convincing decision- makers that "the
X-15 plus reusability equals one-tenth of the cost" of reaching space. Future
generations of shuttles were supposed to do the job even better, he says,
recalling former NASA Administrator Daniel S. Goldin's hopes of someday
deploying shuttles back and forth from space with the reliability of combat
fighter aircraft.
Further
complicating matters, McCurdy says, "The project was in a perpetual state of
redesign — not just by the engineers, but by the people who were providing the
money." Engineers were "driven crazy," he says, by the responses they would
receive from contractors, field engineers, even political types, who had the
audacity to come back with submissions of drawings with their own ideas of what
the craft should look like.
"As they
say on Capitol Hill, it [was] the only train in the station. It involved large
amounts of money, infrequent new starts. Everybody gets involved," McCurdy
says.
At that
point, projects like the shuttle take on the characteristics of any big
undertaking. Because so many people have so many different objectives, it
became unwieldy and hard to manage.
"The same
thing was true with the space station in the beginning," McCurdy says. While some
supporters wanted the ISS to carry hangars for satellites, others wanted space
telescopes. The two are mutually exclusive, he says; you cannot have a space
telescope on one end of a platform and somebody banging on some piece of
hardware in a satellite bay on the other end.
That
collective mentality is "one of the reasons why we spent tens of billions of
dollars on the space station but got nothing but a bunch of Power Point
presentations," McCurdy says.
A city
in space
Now, as the
ISS takes shape, it is emerging as a significant milestone in the history of
cooperative ventures among nations.
The space
station's scientific missions, from the U.S. standpoint, chiefly surround
resolving issues related to survival in space. Until we learn how to reduce
bone mass loss and mitigate the potentially deadly effects of long-term
exposure to radiation, there will be no manned missions to Mars.
"But we can
talk about science all we want, but really, international relations are the
most important thing," says Roger D. Launius, the curator of the National Air
and Space Museum and former chief historian at NASA. "That 16 nations [came]
together to build the thing peacefully is a very significant development. It
never happened in past human history, and quite frankly this may be the end of
it, [given] the strife in the world and new strains between us and Russia."
The
collaboration may appear touchy-feely to laypersons, but to engineers and
scientists it is anything but. Construction and deployment of Canada's shuttle
arm, the European space laboratory and the Japanese science missions meant that
the task at hand became "truly multilateral," says Hawes.
Adding the
entry of Russia into the mix in the early 1990s led to appropriate increases in
potential complications to the matrix. U.S. and Russian teams had to learn to
communicate in each other's language of program management and engineering.
"We learned
there is no one formula to doing [international] partnerships," Hawes says.
"What do you mean when you're talking about 'verification?' How do you test for
structural strength? We found as we integrated the Russians that some [methods]
are similar and some are different. Once we got past the language issue, we
were able to build hardware that works once it gets into space, without ever
seeing its physical counterpart on the ground."
The
science, Hawes believes, will sort itself out after the ISS expands
to a six-person crew, up from the present three.
"We'll have
much larger capacity to do science both in terms of increased test subjects in
which the crew is part of our experiment, and also the crew time to apply to a
broader range of experiments," Hawes says.
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