CloudSat

CloudSat is an Earth observation satellite of NASA. He is researching the effects of clouds and aerosols on weather and air quality on earth. The satellite is part of the research program of Earth Observing System (EOS ), which includes a series of environmental satellites.

Mission

CloudSat operates in a 700 km high, sun-synchronous orbit and flies with the CALIPSO satellite and three other environmental satellites (Aura, Aqua and PARASOL ) in formation. These five satellites together form the A-Train. Because CALIPSO and CloudSat were started as the last two satellites, they had to be placed in the formation. Therefore, the launch window on a particular day was just for a second open. Delays were thus not be tolerated.

CloudSat would have after the start had already been postponed several times, to be launched on 21 April 2006 together with CALIPSO aboard a Delta II launch vehicle. Due to technical problems with the communication between CALIPSO and the ground station in France the countdown but was stopped less than a minute before ignition. More Star attempts had to be canceled because of weather or other technical problems.

April 28, 2006 at 12:02 CEST, the satellites were finally launched at the seventh attempt at starting. 97 minutes later CloudSat was separated and suspended in orbit.

The beginning of June were published by NASA first test images. These are, although they are still considered test images, already much better than any previous profile pictures of clouds. First scientific evaluations of the data are expected in early 2007.

CloudSat was designed for a mission duration of at least 22 months and is still in service.

Cloud Profiling Radar

The Cloud Profiling Radar (CPR ) is the only scientific instrument on CloudSat. The radar works with a frequency of 94 GHz, and measures the energy which is reflected from the cloud as a function of their distance. It can draw conclusions about the composition of the clouds, in particular to the presence of water and ice within the cloud, be drawn. The CPR is about 1000 times more sensitive than that of a conventional radar weather satellites, and can thus very thick clouds with heavy rain and snowfall still penetrate and analyze in detail.