All the instruments aboard the European Space Agency's X-ray Multi-Mirror telescope are working perfectly observing the inside of a the sealed satellite, the agency announced Friday.
The telescope's controllers began its month-long commissioning procedure on January 4, and an initial check of all instruments and systems confirms that nothing was damaged during the satellite's December 10 launch, said Martin Turner, lead investigator for the XMM's photon imaging camera.
"The spacecraft is behaving perfectly," Turner said, with attitude control, power and telemetry systems all in good condition, along with the observing instruments which are working well at measuring the inside of the still-shuttered satellite.
"We're making sure all the instruments are working properly before we actually expose them to the sky," Turner said.
suffered after it was launched last summer."The thing that took everybody by surprise, including us, was that X-ray mirrors seem to be able to focus damaging particle radiation onto the CCD imagers in these X-ray telescopes, and this had just not been seen or thought of before," Turner said. CCDs, or Charge-Coupled Devices are electronic detectors that are used to produce images in video cameras and modern astronomical cameras.
Although instruments on Chandra and XMM are shielded to protect them from the normal radiation of space, no shielding was placed in front of the CCD detectors. After all, the telescope was designed to view radiation, and it can't function if the entire telescope is sealed.
After several of Chandra's detector arrays were damaged, team scientists developed a procedure to protect the remaining imagers. When the telescope moves through the radiation belts, operators move the CCD arrays out of line with the mirror.
Fortunately for XMM, its camera has a shutter that can be closed to protect it from the intense focused radiation that bounces off the X-ray mirrors.
"In between observations, or whenever the sun gets very active, or certainly when we go though the radiation belts, we will close this shutter," Turner said.
The commissioning process is scheduled to continue into February. After that, scientists will spend weeks testing and calibrating the instruments, and should be ready to begin X-ray astronomy in March.
"We've got a long way to go. This is a hugely complicated satellite with five instruments on board and there's a lot of checking to be done, but at the moment everything's looking fine," Turner said.
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