Onevehicle?s operative life is coming to a close, while the other?s is still inits formative stages. Their legacies will be inexorably linked: Without thespace shuttle, delivery and assembly of the International Space Station?s (ISS)key components would have been difficult at best, and probably could not havehappened.
And whilethe jury is still out as to whether history will deem the space station asuccess, the shuttle almost certainly will be remembered for its dramaticfailures as much as the significant accomplishments its yeoman-like crewsachieved sinceColumbia first flew in April 1981.
In themeantime, 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 flynine more missions to the station.
Five willinvolve installation of new equipment; two are more akin to space-borneteamster jobs, hauling supplies and parts.
Shortlythereafter, the Constellation program, with its Ares launch vehicle and Orionspacecraft, will be ready to take over the mission of carrying people intospace for the next 30 to 40 years and expand the limits of the space frontier beyondlow Earth orbit
The ISS,fully complete by then, will assume the shuttle?s role as an orbitinglaboratory.
At thatpoint, the space shuttle will be relegated to museums, where the first thoughtsthat will come to most visitors? minds will no doubt involve the catastrophiclosses of Challenger in January 1986 and Columbia in February 2003.
Suchreactions may be overly simplistic, but they are understandable in the eyes ofsome who were close to the shuttle program.
?Theshuttle is a remarkable technological achievement, but it is an equallyremarkable policy mistake,? says John Logsdon, the chairman of the Space PolicyInstitute at The George Washington University in Washington and a former memberof the NASA Advisory Council. He also served on the Columbia AccidentInvestigation Board.
The keyerror was the collective belief of the shuttle?s champions that ?it could be asystem that could operate inexpensively, routinely, and with a high level ofsafety,? Logsdon says. ?It met none of those objectives.?
Thoseshortcomings are recognized within NASA — hence the willingness throughout theagency to embrace Administrator Mike Griffin?s pushtoward Constellation as the next logical step toward the return to the Moonand the first trip to Mars.
The shuttleis an ?incredible ship,? says Mike Hawes, program integration manager at NASA?sSpace Operations Mission Directorate. ?It launches like a rocket, flies like asatellite, lands like a plane, and has cargo capacity — particularly a returncargo capacity that?s huge.?
With theshuttle, NASA learned how to mechanize regular access to space, and came toterms with both the good and bad challenges of reusable spacecraft, Hawes says.Until scramjet and ramjet technology gets off the drawing boards and test baysand joins flight lines, the shuttle remains the only fully hypersonic vehicleever to fly regularly and carry crews and payloads as well. The data onhigh-speed aerodynamics collected during shuttle missions will serve thedesigners and engineers of future ultrafast winged aircraft well, he said.
The shuttlealso performed well when called upon to support missions to build the spacestation, Hawes says, providing a platform for extravehicular activity as wellas deployment for space arms and other complicated assemblies.
?But welearned 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 — thetotal production run of orbiters being five — there are unique challenges inmaintaining an industrial base.?
Theshuttle?s unmet aspirations can be traced to the unrealistic conglomeration offunctions it was supposed to perform from the beginning, says Howard E.McCurdy, a professor of public affairs at American University in Washington andauthor of white papers that outline how NASA could operate more efficiently.
?It?simportant to keep in mind the huge controversy, going back to the 1950s,whether a spacecraft should have wings,? says McCurdy. ?Should it have aballistic shape? We go back and forth on that.?
Fixed-wingadvocates prevailed, McCurdy says, convincing decision- makers that ?theX-15 plus reusability equals one-tenth of the cost? of reaching space. Futuregenerations of shuttles were supposed to do the job even better, he says,recalling former NASA Administrator Daniel S. Goldin?s hopes of somedaydeploying shuttles back and forth from space with the reliability of combatfighter aircraft.
Furthercomplicating matters, McCurdy says, ?The project was in a perpetual state ofredesign — not just by the engineers, but by the people who were providing themoney.? Engineers were ?driven crazy,? he says, by the responses they wouldreceive from contractors, field engineers, even political types, who had theaudacity to come back with submissions of drawings with their own ideas of whatthe craft should look like.
?As theysay on Capitol Hill, it [was] the only train in the station. It involved largeamounts of money, infrequent new starts. Everybody gets involved,? McCurdysays.
At thatpoint, projects like the shuttle take on the characteristics of any bigundertaking. Because so many people have so many different objectives, itbecame unwieldy and hard to manage.
?The samething was true with the space station in the beginning,? McCurdy says. While somesupporters wanted the ISS to carry hangars for satellites, others wanted spacetelescopes. The two are mutually exclusive, he says; you cannot have a spacetelescope on one end of a platform and somebody banging on some piece ofhardware in a satellite bay on the other end.
Thatcollective mentality is ?one of the reasons why we spent tens of billions ofdollars on the space station but got nothing but a bunch of Power Pointpresentations,? McCurdy says.
A cityin space
Now, as theISS takes shape, it is emerging as a significant milestone in the history ofcooperative ventures among nations.
The spacestation?s scientific missions, from the U.S. standpoint, chiefly surroundresolving issues related to survival in space. Until we learn how to reducebone mass loss and mitigate the potentially deadly effects of long-termexposure to radiation, there will be no manned missions to Mars.
?But we cantalk about science all we want, but really, international relations are themost important thing,? says Roger D. Launius, the curator of the National Airand Space Museum and former chief historian at NASA. ?That 16 nations [came]together to build the thing peacefully is a very significant development. Itnever happened in past human history, and quite frankly this may be the end ofit, [given] the strife in the world and new strains between us and Russia.?
Thecollaboration may appear touchy-feely to laypersons, but to engineers andscientists it is anything but. Construction and deployment of Canada?s shuttlearm, the European space laboratory and the Japanese science missions meant thatthe task at hand became ?truly multilateral,? says Hawes.
Adding theentry of Russia into the mix in the early 1990s led to appropriate increases inpotential complications to the matrix. U.S. and Russian teams had to learn tocommunicate in each other?s language of program management and engineering.
?We learnedthere is no one formula to doing [international] partnerships,? Hawes says.?What do you mean when you?re talking about ?verification?? How do you test forstructural strength? We found as we integrated the Russians that some [methods]are similar and some are different. Once we got past the language issue, wewere able to build hardware that works once it gets into space, without everseeing its physical counterpart on the ground.?
Thescience, Hawes believes, will sort itself out after the ISS expandsto a six-person crew, up from the present three.
?We?ll havemuch larger capacity to do science both in terms of increased test subjects inwhich the crew is part of our experiment, and also the crew time to apply to abroader range of experiments,? Hawes says.
- New Video - NASA at 50: Part 1, Part 2
- Images - 50 Years of Spaceflight: The Road Ahead
- Video - Back to the Moon with NASA's Constellation