The Spektr-RG or Spectrum-XG (SXG) is a Russian-German observatory-class mission. The observatory is intended to study the interplanetary magnetic field, galaxies and black holes. It will carry a complement of five telescopes spanning the energy range from the far ultraviolet to the hard X-ray, plus an all-sky monitor.
The mission is a revived, redesigned version of the earlier Spektr-RG (SXG) mission cancelled in 2002. The development of this new mission was started in 2005.
The payload consists of:
- eROSITA (Extended Röntgen Survey with an Imaging Telescope Array) Wolter telescopes provided by the Max Planck Institute for Extraterrestrial Physics (Germany)
- ART-XC Coded-mask telescopes provided by IKI/VNIIEF (Russia)
SXG will be in a halo orbit around the Lagrange point L-2. The mission will spend 3 months flight to L2 including verification and calibration phases, then 4 years performing an all sky survey (8 × ½ year) and finally 3.5 years pointed observations.
The satellite will be based on Lavochkin's Navigator bus and was to be launched on a Zenit-3F combination. The launch was originally to take place in 2013, but was delayed to late 2016 or early 2017 and later it was moved to 2018. Due to the delays, a switch to a Proton-M Blok-DM-03 booster was done. In late 2017, it was reoported that the launch slipped to spring 2019 due to problems with the radio equipment needed to send scientific data back to Earth. The problems are said to be related to the need to replace Western-built electronic components by Russian ones as a result of the sanctions.
On 1 March 2022, after Germany?s research ministry ordered a suspension of collaboration with Russia due to the Russian invation in Ukraine, the Max Planck Institute for Extraterrestrial Physics put the main instrument on Russia?s Spektr-RG research satellite in safe-mode: the German-run eRosita x-ray survey telescope, meant to probe the universe?s large-scale structure. The eRosita can be reactivated.