Valves replaced in EELV upper stages
Posted: Tue, Aug 21, 2007, 7:32 AM ET (1132 GMT)
A valve implicated in a partial failure of an Atlas 5 rocket in June has been replaced in the engines of the upper stages of both the Atlas 5 and Delta 4. The hydrogen valve in the RL10 engine, used in the upper stages of both rockets, has been modified to prevent a freezeup experienced during an Atlas 5 launch of two NRO reconnaissance satellites in June. The valve allowed liquid hydrogen fuel to leak out, causing the RL10 engine to shutdown several seconds early, placing the satellites into a lower-than-planner orbit. The satellites have been gradually raising their orbits using their own thrusters. The redesigned valve has been incorporated into the engines for upcoming Atlas 5 and Delta 4 launches, with the first being an Atlas 5 launch of a next-generation military communications satellite in mid-September.
A valve implicated in a partial failure of an Atlas 5 rocket in June has been replaced in the engines of the upper stages of both the Atlas 5 and Delta 4. The hydrogen valve in the RL10 engine, used in the upper stages of both rockets, has been modified to prevent a freezeup experienced during an Atlas 5 launch of two NRO reconnaissance satellites in June. The valve allowed liquid hydrogen fuel to leak out, causing the RL10 engine to shutdown several seconds early, placing the satellites into a lower-than-planner orbit. The satellites have been gradually raising their orbits using their own thrusters. The redesigned valve has been incorporated into the engines for upcoming Atlas 5 and Delta 4 launches, with the first being an Atlas 5 launch of a next-generation military communications satellite in mid-September.
Related Links:
| <<previous article | next article>> |
|
news in brief
|
|
New Virgin Galactic spaceplane arrives at Spaceport America
Posted: Sat, Oct 31 10:38 AM ET (1438 GMT) |
|
news links
|
|
Sunday, November 1
Arianespace appoints Filipe de Oliveira as Chief Commercial Officer
Arianespace — 10:50 am ET (1550 GMT) DIA Releases Challenges to Security in Space
Defense Intelligence Agency — 10:46 am ET (1546 GMT) Scientists Are Speeding Up the Development of “Rad-Hard” Materials for Satellites, Nuclear Reactors
PNNL — 10:44 am ET (1544 GMT) Voyager Awarded Interstellar Lab Mission Management Contract
Voyager Space — 10:42 am ET (1542 GMT) Roads on the Moon: Space Mobility Unveils "Mechanical Gravity" and a Patent-Pending Lunar Road System
PR Newswire — 10:41 am ET (1541 GMT) |
