Spektr-RG (Russian: Спектр-РГ, Spectrum + Röntgen + Gamma; also called Spectrum-X-Gamma, SRG, SXG) is a Russian–German high-energy astrophysics space observatory which was launched on 13 July 2019.[4] It follows on from the Spektr-R satellite telescope launched in 2011.[5]
Background
The original idea for this X-ray observatory satellite orbiting above Earth's atmosphere, which filters X-rays, was first proposed in the 1980s by Rashid Sunyaev of the Space Research Institute of the USSR Academy of Sciences. Twenty institutions from twelve countries came together to design a large observatory with five telescopes. However, after the collapse of the Soviet Union, the mission was abandoned due to cost-cutting from the Russian space program Roscosmos. The project was resurrected in 2003 with a scaled-down design.[6]
Overview
eROSITA overview animation from the German Aerospace Center showing the Spektr-RG mission profile
The Spektr-RG mission concept was published in 2005.[9] Construction was finished in 2016, and by mid-2018 it was under integration and testing. It was scheduled to be launched in June 2019 but was delayed to 12 July, before the flight was postponed at the last moment. It launched the next day, 13 July 2019, from BaikonurSite 81/24.[1] The observatory was integrated into a Navigatorsatellite bus,[10] produced by NPO Lavochkin.[11]
Mission profile and orbit
The spacecraft entered an orbit around the Sun, circling the Sun-Earth L2 Lagrangian point in a halo orbit, about 1.5 million kilometres away from Earth. Cruise to that location took three months, during which the two telescopes were checked out and calibrated. The next four years were planned to be spent performing eight all-sky surveys. As a goal, the three years after that are planned for observations of selected galaxy clusters and AGNs
(Active Galactic Nuclei).[12]
On Monday 21 October 2019, Spektr-RG completed a 100-day cruise to L2-point. On 17 October 2019, the main eROSITA instrument achieved first light.[13] The first light image of ART-XC was taken on July 30, 2019.[14]
The operations of eROSITA were suspended on 26 February 2022 after the Russian invasion into Ukraine upon request from Germany. At the time, eROSITA had completed four of its planned eight full-sky surveys.[15]
In March 2022, Russia said they turned off one of the two telescopes aboard Spektr-RG (presumably eROSITA) upon request from Germany.[16] In June, the head of Roscosmos threatened to unilaterally seize control of the German telescope, citing German officials' "pro-fascist views".[17]
Instruments
Spektr-RG instruments. eROSITA is the larger mirrors on the bottom left and ART-XC is the smaller mirrors on the top right.
^ART-XC / SRG overview. M. Pavlinsky; V. Levin; V. Akimov; A. Krivchenko; A. Rotin; M. Kuznetsova; I. Lapshov; A. Tkachenko; R. Krivonos; N. Semena; M. Buntov; A. Glushenko; V. Arefiev; A. Yaskovich; S. Grebenev; S. Sazonov; A. Lutovinov; S. Molkov; D. Serbinov; M. Kudelin; T. Drozdova; S. Voronkov; R. Sunyaev; E. Churazov; M. Gilfanov; B. Ramsey; S. L. O'Dell; J. Kolodziejczak; V. Zavlin; D. Swartz. Proceedings Volume 10699, Space Telescopes and Instrumentation 2018: Ultraviolet to Gamma Ray; 106991Y doi:10.1117/12.2312053 6 July 2018.
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).
