A-train in 2013. As of 2020, the A-Train consists of four satellites. CloudSat and CALIPSO are no longer officially part of the constellation.
A-train in 2013. As of 2020, the A-Train consists of four satellites. CloudSat and CALIPSO are no longer officially part of the constellation.

The A-train (from Afternoon Train) is a satellite constellation of four Earth observation satellites of varied nationality in sun-synchronous orbit at an altitude of slightly variable for each satellite.[1]

The orbit, at an inclination of 98.14°, crosses the equator each day at around 1:30 pm solar time, giving the constellation its name (the "A" stands for "afternoon"[2]) and crosses the equator again on the night side of the Earth, at around 1:30 am.

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 Earth's atmosphere and surface.

Satellites

Active

A-train and C-train in 2019
A-train and C-train in 2019

The train, as of January 2022,[3][4][5] consists of three active satellites:

Past

Failed

References

  1. ^ «A-train Symposium October 2007: Constellation keeps its promises», CNESMAG, January 2008
  2. ^ NASA, Introducing the A-Train, 10.26.10 (accessed April 30 2012)
  3. ^ Smith, Joseph M. "Aqua Turns 20".
  4. ^ "Individual A-Train Missions". June 5, 2012. Retrieved 2013-11-15.
  5. ^ a b Greicius, Tony (2018-02-23). "CloudSat Exits the "A-Train"". NASA. Retrieved 2018-04-01.
  6. ^ CNES News on Calipso
  7. ^ Sister Satellites, Briefly Separated, Working Together Again
  8. ^ "OCO homepage". Archived from the original on 2018-09-09. Retrieved 2008-02-10.
  9. ^ Media Briefing Scheduled To Discuss Orbiting Carbon Observatory Mission
  10. ^ Glory homepage Archived 2008-09-16 at the Wayback Machine