We received a nice note yesterday from ESA's Jean-Michel Bois, Mission Director at ATV-CC, explaining details on the work involved with planning and scheduling communications with ATV-2.
Since ATV separated from its Ariane launcher on 16 February, all communications between ATV Control Centre (ATV-CC) in Toulouse and the vessel - receipt of telemetry and sending of telecommands - have been achieved via data relay satellites. Two relay satellite systems are in use: NASA's Tracking and Data Relay Satellite System (TDRSS) and ESA's own Artemis satellite.
Jean-Michel writes:
During the current 'phasing' period (i.e. manoeuvring so as to match the ATV orbit with that of the ISS), ATV is communicating primarily via NASA's TDRSS. ATV-CC is using Artemis as a back-up and as a complement when TDRSS communication slots are not available.
The TDRSS satellites can ensure communication during ATV's complete orbit (about once every 90 minutes) thanks to the fact that the system comprises multiple satellites. These are set in a ring in permanent geosynchronous orbit with at least one looking down on all regions the Earth (and on ATV as well!).
ESA's single Artemis satellite is also in geo-orbit, located at 21.4ºE, and offers around 40 minutes of continuous contact during each of ATV's orbits. ESA's Redu station, in Belgium, houses the Artemis mission control room (more details here).
At ATV-CC, it's the task of mission planners and the 'Ops Manager' on console to prepare and manage the communication coverage; this team works in very close coordination with their NASA and Redu counterparts.













