Cracked fuel door hinges on the space shuttle Discovery may delay for about one month three Utah State University experiments planned for outer space, a USU Space Engineering Center official says.

Center Director Frank Redd said this week that shuttle Discovery flight carrying the USU experiments could be pushed from March 9 well into April."We know there's going to be a slip" in the launch date from Kennedy Space Center, Fla., Redd said. "It could be delayed up to three weeks to a month, but we probably won't find out until at least Thursday."

National Aeronautics and Space Administration officials have been trying to determine whether the hinges could be repaired or must be replaced. They hold two small doors closed once the external fuel tank drops away after liftoff. The doors must remain closed during Discovery's re-entry.

The primary USU research vehicle on Discovery is CIRRIS, for Cryogenic Infrared Radiance Instrument for Shuttle. It will remain in the shuttle cargo bay during the eight-day flight while its 9-foot-long telescope is aimed at the Earth's upper atmosphere.

The other two experiments are the Infrared Background Signature Survey and the Shuttle Kinetic Infrared Test. The German-built IBSS was calibrated by USU researchers, while SKIRT was made by Space Systems Engineering, a USU spinoff company in the school's Research and Technology Park.

All three satellite applications for the Strategic Defense Initiative determine the makeup of the upper atmosphere and observe shuttle thruster exhaust plumes. The information could help in developing sensors for detecting missiles.

IBSS will be released from the shuttle and float alongside, also taking upper atmosphere measurements and monitoring the thrusters. SKIRT will remain in the cargo bay, studying a phenomenon called shuttle glow to determine if each shuttle has a distinctive aura.