Phobos 2 mission: Observations of the solar soft x-ray radiation

This paper discusses the results of the long-term measurements of soft X-ray solar radiation during the Phobos 2 mission to Mars. There are variations in the minimal daily background flux of the X-ray solar radiation over 250 days of the mission, and it is shown that the presence of X-ray precursors is not a necessary and typical characteristic of a solar flare ; estimates are made of the heights of soft X-ray radiation sources, from concurrent observations of solar flares from the spacecraft and the Earth ; specific features of X-ray sounding of the Martian atmosphere are considered.