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Russia Launches Spektr-RG, a New X-Ray Observatory, into Space

A Russian and European all-sky-survey satellite is safely in space following a successful launch on a Proton rocket in Saturday (July 13).

The Spektrum-Röntgen-Gamma mission, also known as Spektr-RG, is a joint project between the Russian space agency, Roscosmos, and the German space agency, DLR. Spektr-RG launched to space from the Baikonur Cosmodrome in Kazakhstan at 8:31 a.m. EDT (1231 GMT, or 5:31 p.m. local time).

Saturday's launch followed weeks of delays. An attempt to launch the Spektr-RG mission on June 21 was delayed by a battery drain on the Proton rocket's Block DM upper stage, according to Spaceflight Now. Roscosmos then postponed a second launch attempt Friday (July 12) due to an potential issue with the booster.

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Spektr-RG will next navigate to a stable orbit in space called a Lagrange point (specifically, L2), where the gravitational forces of two large objects — in this case, the sun and the Earth — balance each other out. This location will allow Spektr-RG to perform its observations while using a minimal amount of fuel.

The spacecraft is expected to detect 100,000 galaxy clusters, 3 million supermassive black holes, tens of thousands of star-forming galaxies, the presence of plasma (superheated gas) and many more types of objects, according to Roscosmos.

The observatory includes two X-ray mirror telescopes, called ART-XC and eROSITA. ART-XC (a Russian payload) will examine the higher energies of X-rays, up to 30 keV, while eROSITA (Extended Roentgen Survey with an Imaging Telescope Array) is optimized for an energy range of 0.5 to 10 keV.

KeV is a measure referring to electrical potential difference. A single electron volt (eV) is a unit of energy equal to the amount of energy an electron (negatively charged particle) gains when it is accelerated from rest through a potential difference of 1 volt. A kiloelectron volt (keV) is equal to 1,000 electron volts. 

ART-XC will have a narrower field of view and is designed to look at objects with a lower range of energies than eROSITA, according to Russian Space Web's Anatoly Zak. "The overlap in the sensitivity of eROSITA and ART-XC was reported to be useful for the calibration of the two instruments and increasing the reliability of their scientific results," he wrote.

Spektr-RG is expected to be calibrated in about three months; it will then perform its survey. 

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Elizabeth Howell
Staff Writer, Spaceflight

Elizabeth Howell, Ph.D., is a staff writer in the spaceflight channel since 2022. She was contributing writer for (opens in new tab) for 10 years before that, since 2012. As a proud Trekkie and Canadian, she also tackles topics like diversity, science fiction, astronomy and gaming to help others explore the universe. Elizabeth's on-site reporting includes two human spaceflight launches from Kazakhstan, three space shuttle missions in Florida, and embedded reporting from a simulated Mars mission in Utah. She holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, and a Bachelor of Journalism from Canada's Carleton University. Elizabeth is also a post-secondary instructor in communications and science since 2015. Her latest book, Leadership Moments from NASA, is co-written with astronaut Dave Williams. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday.