Discussion The A-Train

[MikeB]

The magazine "Physics Today" had an article in July about a constellation of earth-observation satellites, informally dubbed the A-Train. Many orbinauts will find it interesting (it's not too technical). The satellites are all at 705 km altitude, inclination 98.2 degrees, and within just a few minutes of each other.

What I found interesting was this: "Launched in 2006, CloudSat and CALIPSO were placed in a tight formation, with a separation of 12.5 s or 93.8 km. The satellites are so close that CloudSat must make regular orbit maneuvers to compensate for the different atmospheric drag it experiences"

Sounds like a very high-precision operation to keep them all coordinated.

 

[Urwumpe]

What I found interesting was this: "Launched in 2006, CloudSat and CALIPSO were placed in a tight formation, with a separation of 12.5 s or 93.8 km. The satellites are so close that CloudSat must make regular orbit maneuvers to compensate for the different atmospheric drag it experiences"

Sounds like a very high-precision operation to keep them all coordinated.

If you think this is close, take a look at two other Earth-Observation buddies. 300m separation, the closest formation flying for prolonged times.

http://www.dlr.de/eo/en/desktopdefault.aspx/tabid-5727/10086_read-21046/

 

[Wishbone]

Formation flying is the state of the art today, interferometry being the only sensible way to overcome limitations of a single sensor.

 

[MikeB]

Sorta makes you feel good about physics, doesn't it?

 

[tblaxland]

If you think this is close, take a look at two other Earth-Observation buddies. 300m separation, the closest formation flying for prolonged times.

IIRC TerraSAR-X/TanDEM-X are basically twins which should make their drag much more similar than with CloudSat/CALIPSO. Not that it detracts from its accomplishments.

 

[orb]

And how about Swedish Prisma -Tango & Mango satellites (there's even a thread for them) flying in formation in distance between them down to 7 meters? Though, they are rather for testing/demonstrating formation flying, and not to do other tasks.

 

[Wishbone]

The only thing that remains is launch 20 microsats (say, with electrostatic stationkeeping) in a vee formation and start transmitting the Flight of the Valkyries once the formation comes into the sunlight...