April 4, 2008
New Moon Rocket Needs Shock Absorbers
NASA officials said Thursday that they are developing special shock absorbers for a new moonship to stop potentially fatal vibrations.
The design of the space shocks, theoretically similar to the equipment used to lessen the shake, rattle and roll on an off-road pickup, should be ready by fall for the Ares 1 rocket. The rocket, which also is in the design stage, will carry the Orion moon capsule into orbit by March 2015.
Space agency officials outlined their strategy to dull the vibrations Thursday following congressional hearings in Washington and the release of a critical report by the Government Accountability Office. Lawmakers at a House subcommittee's hearing joined GAO auditors in expressing new concerns about the rocket's design and development. Some questioned whether the agency can realize its goal to return astronauts to the moon by 2020.
In the Senate, some Republicans joined Democrats in calling for a $1 billion increase in the space agency's budget. They said the funds were needed to help NASA overcome technical obstacles and ensure the agency maintains a focus on climate studies, robotic science missions and aeronautics.
Deadly sound waves
When the vibration threat was discovered in October, it was characterized as the top threat to the design of the new moon rocket, Rick Gilbrech, NASA's exploration chief, said.
A computer model uncovered the vibration. It was caused by sound waves generated by the thrust inside the rocket as well as the natural vibrations of the rocket's structure as it flies. When the waves from the two sources meet, the forces could damage the spacecraft and shake the astronauts to death.
After consultations with experts inside and outside the agency, NASA's exploration managers will develop the shock absorbers. The devices could be placed at the top of the Ares' first stage and at the bottom of the rocket.
The seats used by the astronauts could also be fitted with shock absorbers to dampen the remaining vibrations.
"We have a set of solutions," said NASA's Steve Cook. "This is not a show-stopper."
However, in a report and in testimony before a House space subcommittee, GAO officials raised new concerns about technical issues. The report said there was no current industry capability to produce the heat shield for Orion and no facilities to test Ares' engine.
"While this is a phase for discovery and risk reduction, there are considerable unknowns as to whether NASA's plans for the Ares 1 and Orion vehicles can be executed within schedule goals, as well as what these efforts will ultimately cost," GAO official Cristina Chaplain told the subcommittee.
She said the GAO did not know whether NASA's architecture and design solutions will work.
NASA's Gilbrech said the agency intends to deal with most of the issues by the time it finishes major design reviews for the Ares and Orion in August and September.
Rep. Mark Udall, D-Colo., a member of the subcommittee, expressed concerns that NASA's exploration ambitions threaten advances in other areas, including climate studies.
Rep. Nick Lampson, D-Stafford, who sits on the subcommittee and whose district includes the Johnson Space Center, urged more support for exploration and expressed concern the U.S. could lose its lead to other spacefaring nations.
"It is indeed time for humans to go beyond low-earth orbit," he said. "I just hope those humans are from the United States of America."
In another NASA hearing across Capitol Hill, Sen. Barbara Mikulski, D-Md., chairman of an appropriations subcommittee, sounded a call she has made for two years running.
Mikulski called for the agency's $17.6 billion budget request for 2009 to grow by $1 billion, restoring unanticipated NASA expenditures to recover from the 2003 Columbia breakup and crash.
The measure, also supported by Sen. Kay Bailey Hutchison, R-Texas, and Sen. Richard Shelby, R-Ala., failed to win passage in the 2007 and 2008 budgets.
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