*Update, 15 July, 9:55 a.m.: At 6:31 p.m. local time on 13 July, Russia’s Spektr-RG x-ray observatory was launched from the Baikonur Cosmodrome in Kazakhstan.
Spektr-RG, an x-ray satellite to be launched on 21 June from Kazakhstan, aims to map all of the estimated 100,000 galaxy clusters that can be seen across the universe.
First proposed more than 30 years ago as part of a Soviet plan for a series of ambitious “great observatories” along the lines of NASA’s Hubble Space Telescope, Spektr-RG fell victim to cost cutting in cash-strapped, post-Soviet Russia.
But roughly €500 million satellite, which will carry German and Russian x-ray telescopes, was reborn early last decade with a new mission: not just to scan the sky for interesting x-ray sources, such as supermassive black holes gorging on infalling material, but to map enough galaxy clusters to find out what makes the universe tick.
Resurrection began in 2003 with plans for a smaller mission with a U.K.-built all-sky x-ray monitor and MPE’s x-ray survey telescope, called ROSITA—which had been destined for the ISS but was grounded by the Challenger space shuttle disaster.
Galaxy clusters are among the best indicators, says x-ray astronomer Andrew Fabian of the Institute of Astronomy (IoA) in Cambridge, U.K. “Clusters are the most massive objects in the universe, the pinnacle of galaxy formation, and are very sensitive to cosmological models.”
By mapping the clusters, says Esra Bulbul of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, who recently joined the MPE team, Spektr-RG “will study the evolution of the structure of the universe.”