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INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) is a currently operational space telescope for observing gamma rays. It was launched by the European Space Agency into Earth orbit in 2002, and is designed to detect some of the most energetic radiation that comes from space. It was the most sensitive gamma ray observatory launched until eclipsed by ''Fermi''. INTEGRAL is an ESA mission in cooperation with the Russian Space Agency and NASA. It has had some notable successes, for example in detecting a mysterious 'iron quasar'. It has also had success in investigating gamma-ray bursters and evidence for black holes. ==Mission== Because gamma rays and X-rays cannot penetrate Earth's atmosphere, direct observations must be made from space. INTEGRAL was launched from Baikonur spaceport, in Kazakhstan. The 2002 launch aboard a Proton-DM2 rocket achieved a 700 km perigee. The onboard thrusters then raised the perigee out of the residual atmosphere, and the worst regions of the radiation belts. The apogee was trimmed with the thrusters to synchronize with Earth's rotation, and thus, the satellite's ground stations. INTEGRAL's operational orbit has a period of 72 hours, and has a high eccentricity, with perigee close to the Earth at 10,000 km, within the magnetospheric radiation belt. However, most of each orbit is spent outside this region, where scientific observations may take place. It reaches a furthest distance from Earth (apogee) of 153,000 km. The apogee was placed in the northern hemisphere, to reduce time spent in eclipses, and maximize contact time over the ground stations in the northern hemisphere. It is controlled from ESOC in Darmstadt, Germany, ESA's control centre, through ground stations in Belgium (Redu) and California (Goldstone). Fuel usage is within predictions. INTEGRAL has already exceeded its 2.2-year planned lifetime; barring mechanical failures, it should continue to function for six years or more. its mission has been extended to Dec 2016.〔(Integral operations )〕 Its orbit was adjusted in Jan/Feb 2015 to cause a safe (southern) reentry in Feb 2029. There should be sufficient fuel left for science operations past 2020, 〔(INTEGRAL manoeuvres for the future )〕 if ESA judges that the scientific return of the missions continues justifying its operating costs. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「INTEGRAL」の詳細全文を読む スポンサード リンク
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