EROSITA

eROSITA is an X-ray telescope built by the Max Planck Institute for Extraterrestrial Physics (MPE) in Germany for launch by Roscosmos of Russia on board the Spektr-RG, which also carries the Russian telescope "ART-XC". eROSITA will effectively replace the 1990s ROSAT telescope when it reaches its orbit after a planned launch in Spring 2018 .

The telescope consists of seven identical mirror modules with 54 nested, gold-coated mirrors each, arranged to collect the high-energy X-ray photons and guide them to the X-ray sensitive cameras. The cameras were also custom-built at MPE, with X-ray CCDs manufactured from high-purity silicon. For optimum performance, the cameras are cooled to -90°C using a heat pipe system. eROSITA is expected to be 25 times more sensitive than ROSAT.

Spektr-RG will be at the second Lagrange point (L2).

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