Posted: Thu, Nov 18, 2004, 8:31 AM ET (1331 GMT)
An engine burn on Wednesday failed to raise the orbit of the International Space Station as much as expected, potentially forcing a delay in the launch of a Progress cargo spacecraft next month. The Progress M-50 spacecraft docked to ISS fired its engine for 548 seconds on Wednesday with the intent of producing a delta-v of 2.6 meters per second, raising the orbit of the station by 4.4 km to correct for gradual orbital decay caused by atmospheric drag. However, the engine burn resulted in a delta-v of only 1.6 m/s, resulting in an orbit increase of 2.9 km. The cause of the underperformance is under investigation. While the shortfall does not pose and risk to the station, Russian officials said Thursday it could force them to delay the launch of a new Progress spacecraft, currently scheduled for December 23, one or two days to choose a "more rational ballistic phase".

Related Links:

•  RIA Novosti article about maneuver
•  RIA Novosti article about Progress delay
•  Florida Today article
•  NASA Space Station On-Orbit Status report for November 17