Delta 4 failure linked to sensor problem
Posted: Sat, Jan 8, 2005, 6:36 PM ET (2336 GMT)
The partial failure of the inaugural launch of the Delta 4 Heavy last month has been traced back to faulty propellant sensors in its three core stages, investigators said Friday. The engines on each of the three common booster core stages shut down 8-9 seconds early when sensors erroneously reported that the stages had run out of propellant. Because of the early shutdown the second stage engine fired longer than planned in an effort to make up for the underperformance, but exhausted its propellant. As a result, its primary payload, a dummy satellite for the US Air Force, ended up in an orbit with a perigee 16,000 km lower than planned. Two small secondary student-built payloads, designed to be deployed while the upper stage was in a low parking orbit, were apparently lost. Despite the problems, Boeing declared that the launch ended up "achieving the major test objectives" of the flight. Two Delta 4 Heavy launches of major military satellites are planned for 2005; the effect of this investigation on those launches remains uncertain.
The partial failure of the inaugural launch of the Delta 4 Heavy last month has been traced back to faulty propellant sensors in its three core stages, investigators said Friday. The engines on each of the three common booster core stages shut down 8-9 seconds early when sensors erroneously reported that the stages had run out of propellant. Because of the early shutdown the second stage engine fired longer than planned in an effort to make up for the underperformance, but exhausted its propellant. As a result, its primary payload, a dummy satellite for the US Air Force, ended up in an orbit with a perigee 16,000 km lower than planned. Two small secondary student-built payloads, designed to be deployed while the upper stage was in a low parking orbit, were apparently lost. Despite the problems, Boeing declared that the launch ended up "achieving the major test objectives" of the flight. Two Delta 4 Heavy launches of major military satellites are planned for 2005; the effect of this investigation on those launches remains uncertain.
Related Links:
| <<previous article | next article>> |
|
news in brief
|
|
Vast signs contract with SpaceX for ISS private astronaut missions
Posted: Sat, Dec 21 11:59 AM ET (1659 GMT) Avio signs ESA contracts for Vega upgrades and Earth science satellite launch
Posted: Sat, Dec 21 11:57 AM ET (1657 GMT) |
|
news links
|
|
Monday, December 23
Isro to launch 24 experiments to space with PSLV Spadex mission
India Today — 7:16 am ET (1216 GMT) Experimental payloads developed by Karnataka-based academia and start-ups to be launched in ISRO upcoming mission
The Hindu — 7:15 am ET (1215 GMT) ISRO to conduct experiments on growing plants in space
The Tribune (India) — 7:15 am ET (1215 GMT) Isro PSLV-C60 Spadex mission: When will it launch and how to watch it
India Today — 7:13 am ET (1213 GMT) NASA probe to fly closer to the Sun than ever before
Axios — 7:12 am ET (1212 GMT) |
