A-train (satellite constellation)

:"For the subway, see A (New York City Subway service); for other uses, see A Train. The "A-train" is a constellation of six Franco-American Earth observation satellites in sun-synchronous orbit at an altitude of 690 kilometers above the Earth. [«A-train Symposium October 2007: Constellation keeps its promises», "CNESMAG", January 2008.] They are spaced a few minutes apart from each other so their collective observations may be used to build high-definition three-dimensional images of the Earth's atmosphere and surface.

The train consists of the satellites:
* Aqua, launched on May 4, 2002;
* Aura, launched on July 15, 2004;
* PARASOL ["Polarization and Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar"] , launched on December 18, 2004;
* CALIPSO, launched on April 28, 2006;
* CloudSat, launched with CALIPSO on April 28, 2006;
* OCO, [ [http://oco.jpl.nasa.gov/ OCO homepage] ] due for launch around December 2008.
* Glory, [ [http://glory.gsfc.nasa.gov/ Glory homepage] ] due for launch in 2009.

Notes

External links

* [http://www.boston.com/news/science/articles/2006/06/09/nasa_shelves_climate_satellites/ NASA satellite program impacted]
* [http://oco.jpl.nasa.gov/ NASA Program Page]
* [http://www.orbital.com/SatellitesSpace/LEO/OCO/ Orbital Sciences Program Page]