WASHINGTON — NASA awarded Zero Gravity Corp. a $4.7 million, one-year contract to conduct parabolic flights aboard its specially modified Boeing 727 jetliner to provide brief periods of weightlessness for agency experiments and personnel.

Since 2004, Las Vegas-based Zero Gravity Corp., or Zero-G, has been using the its G-Force One aircraft to provide the weightless experience to paying customers including physicist Stephen Hawking and domestic-living maven Martha Stewart.

The NASA contract, announced Jan. 2, could be worth as much as $25.4 million if the agency exercises all four one-year options.

NASA plans to use the flights, departing primarily from the agency?s Johnson Space Center in Houston and Glenn Research Center in Cleveland, to conduct a variety of microgravity experiments and help prepare astronauts for flights on the space shuttle and International Space Station, the agency said in a release.

Zero-G submitted a bid for the flight contract last year after NASA said it was looking for alternatives to operating its own parabolic aircraft, as it has done for decades.

NASA plans to continue to conduct microgravity flights aboard its own C-9 aircraft for the time being, agency spokeswoman Tabatha Thompson said. She said the Zero-G flights would complement NASA?s in-house capability.

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