Spektr-RG

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.{{Cite magazine |url=https://www.science.org/content/article/update-telescope-designed-study-mysterious-dark-energy-keeps-russia-s-space-science |title=Update: Telescope designed to study mysterious dark energy keeps Russia's space science hopes alive |last=Clery |first=Daniel |date=15 July 2019 |journal=Science |publisher=American Association for the Advancement of Science |language=en |doi=10.1126/science.aay3154 |access-date=16 July 2019}}

File:EROSITA overview animation.webm showing the Spektr-RG mission profile]]

The primary instrument of the mission is eROSITA, built by the Max Planck Institute for Extraterrestrial Physics (MPE) in Germany. It is designed to conduct a seven-year X-ray survey,{{cite web |url=http://www.mpe.mpg.de/455799/instrument |title=eROSITA Technical Performance |publisher=Max Planck Institute for Extraterrestrial Physics |access-date=14 June 2019}} the first in the medium X-ray band less than 10 keV energies, and the first to map an estimated 100,000 galaxy clusters.{{cite journal |last=Clery |first=Daniel |date=10 July 2019 |url=https://www.sciencemag.org/news/2019/06/telescope-designed-study-mysterious-dark-energy-keeps-russia-s-space-science-hopes |title=Telescope designed to study mysterious dark energy keeps Russia's space science hopes alive |journal=Science |access-date=15 June 2019}} This survey may detect new clusters of galaxies and active galactic nuclei. The second instrument, ART-XC, is a Russian high-energy X-ray telescope capable of detecting supermassive black holes.

The Spektr-RG mission concept was published in 2005.{{cite web |url=http://hea.iki.rssi.ru/SXG/PROJECT/SXG-eng.htm |date=30 October 2005 |access-date=4 February 2011 |publisher=Russian Space Research Institute |title=Spectrum-RG/eRosita/Lobster mission definition document}} 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 Baikonur Site 81/24. The observatory was integrated into a Navigator satellite bus,{{cite web |last=Zak |first=Anatoly |url=http://russianspaceweb.com/navigator.html |title=The Navigator satellite bus |work=Russian Space Web |date=19 June 2019 |access-date=13 July 2019}} produced by NPO Lavochkin.{{cite web |last=Graham |first=William |date=13 July 2019 |url=https://www.nasaspaceflight.com/2019/07/russian-proton-m-spektr-rg-observatory |title=Russian Proton-M launches Spektr-RG observatory |publisher=NASASpaceFlight.com |access-date=15 June 2019}}

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).{{cite web |url=https://directory.eoportal.org/web/eoportal/satellite-missions/content/-/article/srg |title=SRG (Spectrum Roentgen Gamma) – Satellite Missions – eoPortal Directory |website=directory.eoportal.org |language=en-US |access-date=20 June 2019}}

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.[https://spaceflightnow.com/2019/10/23/german-x-ray-telescope-achieves-first-light/ German X-ray telescope achieves ‘first light’]. Spaceflight Now (23 October 2019). Retrieved on 2020-07-01. The first light image of ART-XC was taken on July 30, 2019.{{Cite web|url=https://www.roscosmos.ru/26624/|title=Новости. Первый свет обсерватории "Спектр-РГ"|website=www.roscosmos.ru|access-date=2019-08-05}}

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.[https://www.mpe.mpg.de/7856215/news20220303 Statement on the status of the eROSITA instrument aboard Spektr-RG (SRG)]

In March 2022, Russia said they turned off one of the two telescopes aboard Spektr-RG (presumably eROSITA) upon request from Germany.[https://www.spacedaily.com/reports/Russia_stops_deliveries_of_rocket_engines_to_US_Roscosmos_Head_Says_999.html Russia stops deliveries of rocket engines to US, Roscosmos Head Says] In June, the head of Roscosmos threatened to unilaterally seize control of the German telescope, citing German officials' "pro-fascist views".{{Cite web |last= |first= |date=2022-06-04 |title=Russia plans to restart German telescope without permission {{!}} DW {{!}} 04.06.2022 |url=https://www.dw.com/en/russia-plans-to-restart-german-telescope-without-permission/a-62033082 |access-date=2022-06-16 |website=Deutsche Welle |language=en-GB}}

{{stack|File:Spektr-RG payloads.png}}

File:Spektr-RG 2020 stamp of Russia.jpg

• BTA-6
• Caucasus Mountain Observatory
• RTT-150
• Sayan Solar Observatory
• International Scientific Optical Network

• Las Campanas Observatory
• Cerro Tololo Inter-American Observatory
• Paranal Observatory
• La Silla Observatory

• IXPE—a high-resolution X-ray telescope measuring polarization of X-rays
• List of X-ray space telescopes
• ROSAT—observed at similar X-ray energies in the 1990s
• TAUVEX—an instrument originally planned for Spektr-RG; it was built but never flown

{{Reflist}}

{{Commons category}}

• [https://www.srg.cosmos.ru/ Official site of the project in Russia]
• [http://www.mpe.mpg.de/eROSITA Official site of the eROSITA telescope]
• [https://www.nature.com/articles/d41586-019-01831-1 Space telescope to chart first map of the Universe in high-energy X-rays]

{{RosKosmos space observatories}}

{{Space observatories}}

{{Russian space program}}

{{Orbital launches in 2019}}

Category:2019 in Russia

Category:Gamma-ray telescopes

Category:Satellites of Russia

Category:Space telescopes

Category:Spacecraft launched in 2019

Category:Spacecraft launched by Proton rockets

Category:X-ray telescopes

Category:Spacecraft using halo orbits

Category:Artificial satellites at Earth-Sun Lagrange points