Posted: Thu, Apr 27, 2006, 1:08 PM ET (1708 GMT)
The launch of two Earth-observing satellites was called off once again Thursday, this time because of a problem with a sensor on the Delta 2 launch vehicle. The launch, which had been scheduled for Thursday morning at Vandenberg Air Force Base in California, was postponed Wednesday night after engineers found a problem with a nitrogen temperature sensor on the vehicle's second stage. The launch has been tentatively rescheduled for Friday at 6:02 am EDT (1002 GMT). Launch attempts since last Friday have been scrubbed for a variety of reasons, including communications problems, lack of available tracking planes to monitor the launch, and poor weather. The two spacecraft are designed to study the role of clouds in shaping the planet's climate. CALIPSO, a joint project of NASA and the French space agency CNES, carries a lidar and camera to study clouds and aerosols in the atmosphere; CloudSat has a radar designed to provide a three-dimensional map of cloud cover.

Related Links:

•  Lompoc (Calif.) Record article
•  AFP article
•  Spaceflight Now launch status center