spacetoday.net: TDRS spacecraft stranded in transfer orbit

Posted: Fri, Mar 22, 2002, 10:53 AM ET (1553 GMT)
TDRS-H illustration (Boeing)

A NASA communications satellite launched two weeks ago is currently stranded in a useless transfer orbit as engineers work on a problem with the spacecraft's propulsion system. NASA Watch first reported late Thursday that the TDRS-I communications satellite, launched March 8 on an Atlas 2A from Cape Canaveral, was still in a transfer orbit after a problem developed with the onboard propulsion system designed to circularize its orbit. Boeing, who built the spacecraft, confirmed the problem in a statement issued late Thursday night, saying that its engineers were working on an issue with the pressure in one of four propellant tanks. NASA has been notified of the problem but had not issued a statement as of early Friday. NASA Watch reported that a shuttle rescue of the satellite was under consideration, but the spacecraft's highly elliptical orbit and high perigee — 8,000 km according to Boeing, 3,500 km according to the latest orbital elements — would make such an effort at a minimum very difficult. TDRS-I, also known as TDRS 9, is the second of three new Tracking and Data Relay Satellites (TDRS), based on the Boeing 601 spacecraft model, used for communications by the shuttle, station, and other spacecraft.