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The Future of NASA's Human Spaceflight: Shuttle-Derived Technology Takes the Lead

The Future of NASA's Human Spaceflight: Shuttle-Derived Technology Takes the Lead
New Idea: Concept illustration of Crew Exploration Vehicle attached to a shuttle solid rocket booster. Image
(Image: © Alliant Techsystems Inc.)

NASA has decided that its next launch vehicle for getting humans into space will be based on the space shuttle system, including its main engines, solid rocket boosters and external tank. There will be one big difference, though, instead of riding along the side of the new rocket, astronauts in the future will be riding on top on top of their next launcher -- above any debris that might fall off.

Speaking to reporters via telephone July 29, NASA Administrator Mike Griffin said the agency's plans are the result of an intensive Exploration Systems Architecture Study he ordered in late April to plot NASA's return to the moon by 2020. That study will be publicly unveiled in "a few weeks," Griffin said.

Sourceswith detailed knowledge of the study results said NASA will need to spend $5billion to develop the crew launcher, a price tag that includes the solidrocket booster-based vehicle itself, a new upper stage and all necessary launchinfrastructure.

TheCrew Exploration Vehicle, which NASA hopes to field around 2011, is expected tocost another $5 billion to develop and would be designed both to service thespace station and to carry astronauts to lunar orbit. A heavy-lift launchercapable of delivering 125 metric tons of cargo to low Earth orbit would befinished after the smaller crew launch vehicle, according to NASA's plan, andwould also cost in the neighborhood of $5 billion to develop.

TheCrew Exploration Vehicle, according to NASA's plan, will be a capsule capableof accommodating three people and a limited amount of cargo for space stationmissions, a crew of four for a lunar mission and up to six people to dock withan awaiting Mars-bound vehicle.

Unlikethe shuttle orbiter, which is mounted to the side of the external tank and inthe path of foam and other debris coming off the tank, the Crew ExplorationVehicle would launch at the top of the stack--out of the way of any debris thebooster and upper stage might shed. NASA would adopt the same type of in-linedesign for the heavy-lift launcher as well, putting the cargo canister up top.

"Aslong as we put the crew and valuable cargo up above the tank we don't care whatthey shed," Griffinsaid, explaining to reporters why he remains confident in the shuttle-derivedapproach even after Discovery's close call.

Discovery'sreturn to flight July 26 was marred by a close call with a falling chunk ofinsulating foam that broke free from its external tank about two minutes afterliftoff. NASA officials previously had said they made great strides in reducingtank debris in the two and a half years since a chunk of foam brought down the Columbia, agencyofficials said. After the July 26 launch incident, they admitted they werewrong and said they clearly have more work to do and will not fly the shuttleagain until the foam problem is solved.

Analysisof the spacecraft on orbit also revealed that two gap-fillers, ceramic fibercloth used to keep the orbiter's heat-resistant tiles from clattering againstone another during launch, had come loose and were jutting out of thespacecraft's underbelly. Discovery astronaut Stephen Robinson will attempt onWednesday a spacewalk in an effort pluck out the filler material.

Priorto Discovery's return to flight, NASA also was closing in on its options forcompleting the International Space Station. Sources familiar with the planningeffort said agency officials have been looking at two main scenarios.

Onescenario involves conducting 17 shuttle flights before retiring the shuttle inSeptember 2010, and includes launching Europe's and Japan's space stationmodules, but not outfitting them with additional science equipment. The otherscenario involves conducting 11 shuttle flights and postponing launching theinternational partners' modules until NASA completes its proposed heavy-liftlauncher. Knowledgeable sources said the 17-flight scenario will become moretentative with each month the shuttle is down and more or less untenable if theshuttle is not flying again come spring.

WhileGriffin saidNASA has not given up on flying in September, experts outside the agency saidit is unlikely the shuttle will be cleared for flight in time for that launchwindow.

"Septemberseems awfully close," said James Hallock, amember of the Columbia Accident Investigation Board. "I think they've gota lot of things to do."

NASAwould have one last shot for the year in November, but that window is only acouple days long. NASA first attempted to launch Discovery July 13, but thatlaunch campaign was stood down nearly two weeks to give the agency time totroubleshoot a not yet fully resolved fuel sensor glitch.

Oneformer spaceflight official said NASA could be facing a longer delay than it isready to admit.

Griffin said he isnot ready to concede defeat and has appointed a "tiger team" totackle the foam problem and find a fix.

NASAwas widely praised for swiftly deciding to stand down the shuttle fleet untilit understands and fixes the foam problem. White House spokesman ScottMcClellan said President George W. Bush is confident in Griffin and his team at NASA and appreciatesthe agency's commitment to safety. House Science Committee Chairman SherwoodBoehlert (R-N.Y.) and space and aeronautics subcommittee chairman Rep. KenCalvert (R-Calif.) issued a joint statement saying"NASA is handling this situation exactly as it should." Former NASAAdministrator Sean O'Keefe told Space News that NASA's recent actions are proofpositive that a safety-oriented mindset has taken hold since the Columbia accident."If there was still any doubt that the culture has changed, this shouldend it," O'Keefe said.

Anumber of space policy observers looking beyond the immediate engineeringchallenge ahead to the bigger picture, saw the turn of events as a significantsetback for NASA.

"Wehave a series of commitments that require flying the shuttle, that's why thisis such a nasty problem with no clear escape route," said John Logsdon, aColumbia Accident Investigation Board member who directs the Space PolicyInstitute at George Washington Universityhere. "I don't envy the people who have to figure their way out of thiscorner."

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