Experiments built or designed by members of the Space Dynamics Lab at Utah State University are ready to go into space with the shuttle Discovery April 23 following seven weeks of delays, the lab director said Monday.

Discovery and USU's payload were to have been launched on March 9, but the flight was delayed after NASA officials discovered a crack in a shuttle door hinge.The spacecraft was removed from the launch pad for repair and its payload was left on the pad until the shuttle could be returned, said Allan Steed, director of Systems Delivery for USU's Space Dynamics Lab.

The principal payload aboard the shuttle will be CIRRIS 1A, an infrared sensor designed and manufactured at the northern Utah campus perhaps better known for its agricultural programs.

CIRRIS - Cryogenic Infrared Radiance Instrument for Shuttle - was designed and manufactured by the Air Force Geophysics Laboratory at Hanscom Air Force Base, Mass.

CIRRIS 1A is a cryogenically cooled optical instrument which will examine the upper reaches of the Earth's atmosphere and the aurora to determine their makeup and dynamic behavior.