Flight Experience with the ROSAT Mission Planning System.

ROSAT is a scientific spacecraft designed to perform the first all-sky survey with a high resolution X-ray telescope and to investigate the X-ray emission of specific celestial objects. The mission can be broadly divided into three main phases: The test and calibration phase, the survey phase and the pointing phase. These three mission phases present very different requirements on a mission planning system. The generation of the mission timelines is performed by a system written at the German Space Operation Center called the ROSAT Mission Timeline Generator (RMTG). It is the main purpose of this article to present an evaluation of the performance of the RMTG and the experience gained from mission planning in general with the ROSAT satellite over the past 6 years. The advantages and disadvantages of the chosen approach will be presented and the article concludes with a discussion of the impacts of the lessons learned on mission planning of other satellites.