On 20 September at 18:22 CEST, the joint ESA/CNES team at ESOC confirmed that handover of Galileo satellites 9 & 10 to the Galileo Control Centre in DLR near Munich for continuation of their mission was complete.
After a flawless orbit injection by Soyuz on 11 September, the critical launch & early orbit phase (LEOP) went extremely well, and both satellites are in excellent health and now enroute to their final operational orbits.
The pair of satellites stepped through an intense series of check-outs, confirmations, mode changes, configurations and health verifications by the joint ESA/CNES mission team working around the clock at ESOC, Darmstadt, Germany.
A series of thruster burns were designed to start the drift of the two satellites toward their target orbital positions. “The overall mission status is fully nominal, and we conducted the first burn, on 14 September at 16:58 UTC [18:58 CEST],” says Jérémie Benoist, co-Flight Director from CNES.
Each satellite performed a series of three drift-start thruster burns, running anywhere from a few tens of seconds to a few tens of minutes. “Following the burns performed during the LEOP phase, the satellites will continue naturally drifting, ending up in their final desired operational orbits at about 23 222 km after another set of thruster burns, planned to achieve fine positioning in orbit, around the end of October,” says Liviu Stefanov, co-Flight Director from ESA.
The formal hand-over time corresponds to the time that the second of the two was handed over; the first was handed over on 19 September. The spacecraft were fully nominal at the time of handover.
While LEOP at ESOC for the mission operations team is now completed, ESA’s Flight Dynamics team will continue supporting the manoeuvre phase until the two spacecrafts are in their final orbital slot, in a few weeks.
This means that flight dynamics experts at ESOC will continue to calculate and provide the manoeuvre “products”, the highly detailed plan for how long and when a burn must be executed, to support the drift stop and fine positioning of the recently launched Galileo satellites.
“By then, most of the CNES operations engineers will have returned to Toulouse, and we will begin a new the training period for the next set of Galileo satellites,” says Jérémie. “Our team-mates at ESOC will do the same, and, for the next launch, we’ll come together again to conduct the final simulation training at the CNES control facilities in Toulouse.”
As part of the overall service provided to Europe’s Galileo project, ESA and CNES teams are conducting the LEOPs alternately from Darmstadt and Toulouse.
“Once again, everything is going very well with the joint team at ESOC,” says Liviu.
“Both Jérémie and I are very impressed with their expertise and dedication, which, together with a near-perfect injection, have helped make this one of the smoothest Galileo LEOPs yet.”
The next pair of Galileo satellites are expected to be launched in mid-December 2015.