The three identical satellites were launched together on one rocket in 2013. Two satellites orbit almost side-by-side at the same altitude – initially at about 460 km, descending to around 300 km over the lifetime of the mission. The third satellite is in a higher orbit, at 530 km, and at a slightly different inclination. Credit: ESA–P. Carril, 2013

The three identical Swarm satellites were launched together on one rocket in 2013. Two satellites orbit almost side-by-side at the same altitude – initially at about 460 km, descending to around 300 km over the lifetime of the mission. The third satellite is in a higher orbit, at 530 km, and at a slightly different inclination. Credit: ESA–P. Carril, 2013

For the past few days, experts from ESA’s Space Debris Office at ESOC in Darmstadt, Germany, have been assessing a conjunction (read: collision) forecast issued by the US armed forces’ Joint Space Operations Center (JSpOC) located at Vandenberg Air Force base in California.

Read the full post on the rocket science blog