Tardy NPOESS Instrument Exits Thermal Vac Testing

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An infrared sounding instrument built by ITT Corp. that has been holding up the launch of a U.S. polar orbiting weather satellite successfully completed thermal vacuum testing, Northrop Grumman announced April 28.

The Cross-track Infrared Sounder (CrIS) will be the final instrument delivered for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project spacecraft now scheduled to launch in late 2011. ITT Geospatial Systems of Rochester, N.Y., built the instrument as a subcontractor to NPOESS prime contractor Northrop Grumman Aerospace Systems of Los Angeles.

NPOESS was originally intended to provide operational weather and climate data for both military and civilian users. The NPOESS Preparatory Project was intended to be launched in 2009 to test sensors that would fly several years later on the first NPOESS satellite. The NPOESS satellites were delayed for years with technical difficulties, and the White House in February dismantled the program. The NPOESS Preparatory Project, being built by Ball Aerospace & Technologies Corp. of Boulder, Colo., will continue as planned and be thrust into an operational role.

The CrIS instrument, which is designed to provide detailed information on atmospheric temperature and moisture, was supposed to be delivered in early 2009. That delivery was set back several months when thermal vacuum tests detected problems with some of the sensor’s computer chips. Late in 2009, CrIS was undergoing a final evaluation when contractors discovered that a circuit card assembly was not hardy enough to meet the rigorous standards set for space-based electronics. Instead of just replacing that circuit board, the team, in consultation with NASA officials, decided to conduct another round of thermal vacuum tests on the instrument. The result was an additional six- to nine-month delay in the satellite’s launch.

ITT Geospatial Systems President Christopher Young told Space News in March that the instrument would undergo some final mechanical measurements after coming out of thermal vacuum and would be ready for shipment in June or July.