Europe's X-ray telescope is riding high

时间:2019-03-07 10:11:02166网络整理admin

By Duncan Graham-Rowe THE world’s most powerful X-ray telescope was successfully launched last week on board the Ariane 5 rocket. Officials at the European Space Agency breathed a collective sigh of relief as their biggest gamble yet paid off. Carrying the X-ray Multi-Mirror telescope (XMM) as its first commercial launch was a risk because of Ariane 5’s chequered history. The first test flight, in 1996, ended in a ball of flames seconds after take-off, destroying the Cluster solar science mission; the second in 1997 veered off course after a problem with its coolant system made the rocket spin faster than expected, upsetting its control system. But in 1998 it was third time lucky as everything went to plan. A repeat of these problems last week would not only have clouded Ariane 5’s future but also have lost ESA’s most expensive and most complex satellite. But in less than an hour after leaving its launch pad at Kourou in French Guiana, the $690 million satellite was in orbit and under the control of the operations centre at Darmstadt, Germany. The XMM has already beamed back to base conventional photographs of itself—just to prove that nothing is amiss. XMM will fly in an elliptical 48-hour orbit, ranging between 7000 and 114 000 kilometres of the Earth. It will be used to try to unlock some of the secrets of black holes, gamma-ray bursts and cannibalistic stars. Thanks to the tennis court-sized collecting area of its mirrors, XMM is more than five times as sensitive as the Chandra telescope that was launched by NASA earlier this year. Its resolution is less sharp, however, which means that the two orbiting X-ray observatories should complement each other. With any luck,