Jun. 1, 2009 (United Press International) -- Three U.S. companies have been chosen to supply NASA with liquid nitrogen and liquid oxygen.

Linde LLC of Murray Hill, N.J., will supply approximately 256,500 tons of liquid nitrogen and approximately 173,000 tons of liquid oxygen to the National Aeronautics and Space Administration's Goddard Space Flight Center in Greenbelt, Md., the Stennis Space Center in Mississippi and the Michoud Assembly Facility in New Orleans. The five-year contract, with two one-year options, is valued at $28.8 million.

Air Products and Chemicals Inc. of Allentown, Pa., was given a five-year contract to supply approximately 197,250 tons of liquid nitrogen and approximately 26,000 tons of liquid oxygen to NASA's Glenn Research Center in Cleveland and Marshall Space Flight Center in Huntsville, Ala. The contract, with two one-year options, is valued at approximately $14.2 million.

Air Liquide Industrial of Houston was given a three-year contract with two one-year options to supply liquid nitrogen and oxygen to the Johnson Space Center in Houston. That contract is valued at about $6.1 million.

NASA said the liquid nitrogen will be used for pneumatic actuation, purging, cooling and pressurization of equipment. The liquid oxygen will be used as an oxidizer in cryogenic rocket engines and as a breathing agent for astronauts.