Matra Marconi Space (MMS) of Bristol has delivered the $47 million Attitude and Orbit Control System (AOCS) for Europe's largest spacecraft, the X-ray Multi Mirror (XMM) telescope, to prime contractor Daimler-Benz Aerospace Space Systems.
The AOCS is the "heart of the mission" of the European Space Agency's (ESA) XMM, according to Mike Backler, project manager at MMS Bristol. It will enable the telescope to maintain a stability of 0.2arc/s over 10s during an observation period of 40h, providing the most sensitive images yet of the hottest objects in the universe.
The telescope will peer halfway back into the history of the universe, with the ability to detect millions of X-ray sources. It will be five times more X-ray sensitive than NASA's Advanced X-Ray Astrophysics Facility telescope being launched by Space Shuttle Columbia in January 1999.
The XMM, which will be launched by an Ariane 5 in August 1999, is equipped with three X-ray imaging cameras, two high-resolution X-ray spectrometers and a 300mm-diameter optical monitoring telescope. It is over 10m (30ft) long, weighs 3,900kg and will be placed into a 114,000 x 7,000km orbit, taking 48h to make one revolution of the Earth, enabling it to avoid interference from the Earth's radiation for as long as possible.
The system has a nominal mission life of two and a half years, but ESA hopes it will operate for up to 10 years. To save costs, ESA plans to use the XMM service module design for other spacecraft, including the Integral gamma ray observatory, to be launched in 2001.
ESA is already looking to the next X-ray telescope, to be called Xeus, which will be sensitive enough to reach 80% back into the history of the universe - before the birth of galaxies.
Source: Flight International
