Launch Dress Rehearsal
06 December 1999 13:45
Kourou, 5:00 on Monday 6 December. It was an early morning rise for the XMM campaign team for the launch dress rehearsal. Their colleagues from the launcher teams got up even earlier! The rehearsal took place in the Jupiter Mission Control, the Launch Control Centre (CDL3) and in the S1 building, and across the Atlantic at the XMM Mission Control centre in Germany.
The Jupiter Mission Control room
The rehearsal went through all the sequences that will be followed on launch day, from the spacecraft configuration, the weather reports, switching XMM to onboard power, the start of the Ariane-5 synchronised automatic sequence seven minutes before Vulcain ignition, the different Ariane-5 flight sequences, separation of the satellite and its first acquisition.
Concerning the launcher, there was no rehearsal of the main stage (EPC) filling or Vulcain engine cooling as this had been done two weeks ago at the launch zone.
The rehearsal went without problem. After the exercise, both Robert Laini and Philippe Kletzkine, respectively XMM ESA Project Manager and AIV Manager expressed their satisfaction. "Everything went fine. We are now ready to do just as well for the actual launch on December 10".
The day's events were also closely followed by Roger Bonnet, ESA Director of Science and John Credland , ESA Head of Scientific Projects Department. They had just flown in from Europe to support the XMM AIV team for the final stretch of the launch preparation.
and in Darmstadt
All hands were on deck at the European Space Operations Centre in Darmstadt Germany. Staff involved in the XMM launch and the spacecraft's first orbits were behind their consoles some six hours before the liftoff time. In phase with Kourou they rehearsed the launch procedures right through until the moment XMM will be acquired by the Perth tracking station.
The master of ceremonies in ESOC's Main Control Room was Alan Smith, the Flight Operations Director. Using 20 different voice circuits, he liased with half a dozen local teams (network, spacecraft operations, flight dynamics, software co-ordination...) and with XMM Project Manager Robert Laini in Jupiter Mission Control in Jupiter.
Flight Operations Director Alan Smith, behind him Hubert Barri of the XMM Project team.
As the different steps of the launch countdown and flight operations were displayed on a wall display, large digital clocks ticked away to the key moments: the liftoff from Kourou, the release of the spacecraft and the first acquisition of XMM's telemetry, by the Villafranca tracking station near Madrid.
The rehearsal included one simulated hold in the launch countdown, which had been programmed - and also a surprise one! Their purpose was to test everyone's ability to reconfigure their systems and be rapidly ready for a new liftoff time. All the more important considering the launch window is only 30 minutes long. Each time the ESOC teams resynchronised their clocks and were back in step with Kourou when the launch range manager in Kourou resumed the count.
'Flying XMM by the book': the multi-volume Flight Operations Plan, a mammoth documentation whose latest version was distributed to staff just prior to the rehearsal.
A curious sensation followed whilst the main events of the flight were announced. Everyone had to imagine Ariane-5 climbing into space. Booster separation, fairing jettison, end of main stage burn... The perfect ride XMM has been waiting for. Thirty-one minutes after liftoff, XMM was released and 30 seconds later Villafranca came on the line to say the satellite signal was being received loud and clear.
Meanwhile, fuelling of Ariane 504's upper storable propellant stage has been completed on schedule, finishing shortly before the dress rehearsal.
Ground support Equipment (GSE) used during the XMM campaign has been repacked for transportation back to Europe. The spacecraft mass may be 3.8 tons, but the GSE represents some 250 tons of equipment.
The STM model of XMM is assembled and is now ready to be moved to the Guiana Spaceport Museum on 8 December.
Top right - Ground support equipment packed to go home.
Bottom right - XMM STM ready to be put on show in the Kourou Museum.
Last Update: 03 January 2006