Encyclopedia Astronautica

American earth weather satellite. One launch, 2006.04.28.

CloudSat was selected as a NASA Earth System Science Pathfinder satellite mission in 1999 to provide observations necessary to advance our understanding of cloud abundance, distribution, structure, and radiative properties. CloudSat flew the first satellite-based millimeter-wavelength cloud radar, that was more than 1000 times more sensitive than existing weather radars.

CloudSat was co-manifested with the Calipso (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) satellite for launch aboard a Delta II rocket. CloudSat and Calipso joined three satellites already in orbit ( Aqua, Parasol, and Aura) to form a constellation of satellites known as the A-Train. The satellites flew in a nearly circular orbit with an equatorial altitude of approximately 705 km. The orbit was sun-synchronous, maintaining a roughly fixed angle between the orbital plane and the mean solar meridian. CloudSat maintained a close formation with Aqua and a particularly close formation with Calipso, providing near-simultaneous and collocated observations with the instruments on these two platforms.

Science leader for CloudSat was Graeme Stephens of Colorado State University. NASA's Jet Propulsion Laboratory provided project and mission management and developed CloudSat's instrument, the Cloud Profiling Radar.

CloudSat's primary mission was scheduled to continue for 22 months after launch, in order to allow more than one seasonal cycle to be observed, although radar lifetime data indicates that the radar was expected to operate for three years with a 99 percent probability.

The Cloud Profiling Radar (CPR) was a 94-GHz nadir-looking radar which measured the power backscattered by clouds as a function of distance from the radar. The CPR was developed jointly by NASA/JPL and the Canadian Space Agency (CSA). The overall design of the CPR was simple, well understood, and had strong heritage from many cloud radars already in operation in ground-based and airborne applications. Most of the design parameters and subsystem configurations were nearly identical to the Airborne Cloud Radar, which had been flying on a NASA DC-8 aircraft since 1998.

CPR System Characteristics:

  • Nominal Frequency: 94 GHz
  • Pulse Width: 3.3 microsec
  • PRF: 4300 Hz
  • Minimum Detectable Z*: -26 dBZ
  • Data Window: 0-25 km
  • Antenna Size: 1.95 m
  • Dynamic Range: 70 dB
  • Integration Time: 0.3 sec
  • Vertical Resolution: 500 m
  • Cross-track Resolution: 1.4 km
  • Along-track Resolution: 2.5 km
  • Data Rate: 15 kbps

Gross mass: 848 kg (1,869 lb).
First Launch: 2006.04.28.
Number: 1 .

More... - Chronology...

Associated Countries
See also
  • Delta The Delta launch vehicle was America's longest-lived, most reliable, and lowest-cost space launch vehicle. Development began in 1955 and it continued in service in the 21st Century despite numerous candidate replacements. More...

Associated Launch Vehicles
  • Delta American orbital launch vehicle. The Delta launch vehicle was America's longest-lived, most reliable, and lowest-cost space launch vehicle. Delta began as Thor, a crash December 1955 program to produce an intermediate range ballistic missile using existing components, which flew thirteen months after go-ahead. Fifteen months after that, a space launch version flew, using an existing upper stage. The addition of solid rocket boosters allowed the Thor core and Able/Delta upper stages to be stretched. Costs were kept down by using first and second-stage rocket engines surplus to the Apollo program in the 1970's. Continuous introduction of new 'existing' technology over the years resulted in an incredible evolution - the payload into a geosynchronous transfer orbit increasing from 68 kg in 1962 to 3810 kg by 2002. Delta survived innumerable attempts to kill the program and replace it with 'more rationale' alternatives. By 2008 nearly 1,000 boosters had flown over a fifty-year career, and cancellation was again announced. More...
  • Delta 7420-XC Three stage vehicle consisting of 4 x GEM-40 + 1 x EELT Thor/RS-27A + 1 x Delta K with 3.05 m (10 foot) diameter composite fairing More...

Associated Manufacturers and Agencies
  • NASA American agency overseeing development of rockets and spacecraft. National Aeronautics and Space Administration, USA, USA. More...
  • Ball American manufacturer of spacecraft. Ball Aerospace and Technology, Boulder, Colorado, USA. More...

  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.

Associated Launch Sites
  • Vandenberg Vandenberg Air Force Base is located on the Central Coast of California about 240 km northwest of Los Angeles. It is used for launches of unmanned government and commercial satellites into polar orbit and intercontinental ballistic missile test launches toward the Kwajalein Atoll. More...
  • Vandenberg SLC2W Delta launch complex. Originally a Thor 75 SMS launch pad. Upgraded to a space launch complex in 1966. More...

Cloudsat Chronology

2006 April 28 - . 10:02 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC2W. LV Family: Delta. Launch Vehicle: Delta 7420-XC. LV Configuration: Delta 7420-10C D314.
  • Cloudsat - . Mass: 848 kg (1,869 lb). Nation: USA. Agency: NASA; USAF; CSA. Manufacturer: Ball. Class: Earth. Type: Weather satellite. Spacecraft: Cloudsat. USAF Sat Cat: 29107 . COSPAR: 2006-016A. Apogee: 704 km (437 mi). Perigee: 702 km (436 mi). Inclination: 98.2000 deg. Period: 98.80 min. Summary: Cloudsat carried a 94 GHz cloud profiling radar. Both the Cloudsat and Calipso satellites were in the A-train polar constellation, in the same orbit as the large Aqua and Aura satellites..

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