This is a major section of a massive piece of kit called the “extended ROentgen Survey with an Imaging Telescope Array’ (eROSITA) X-ray telescope”, currently being attached to a spacecraft called the Spektrum-Röntgen-Gamma (SRG), set to be launched from the Kazakh steppe any day now.
The mission is a project of the German space agency DLR.
SRG is expected to travel about 1.5 million kilometres from Earth, until it reaches a stable position of equilibrium between the planet and the sun, known as a Lagrange Point.
Once there, it will deploy eROSITA and other onboard instruments to observe the entire sky and search for and map galaxy clusters, active black holes, supernova remnants, X-ray binaries and neutron stars.