Posted: Sun, Apr 23, 2006, 1:42 PM ET (1742 GMT)
The launch of two Earth sciences satellites was postponed again early Sunday because of a lack of airborne tracking assets. The Delta 2 carrying the CALIPSO and CloudSat spacecraft was scheduled to lift off from Vandenberg Air Force Base in California early Sunday morning, but the launch was postponed because a refueling aircraft, needed to support a separate aircraft that would track the launch, would not be available in time for the launch. The next launch date has not been announced, but will likely be either Monday or Tuesday depending on range availability and other issues. 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:

•  AP article
•  AFP article
•  NasaSpaceFlight.com article
•  Spaceflight Now launch status center