The ROSAT launch on June 1, 1990 happened to be after the IAU Colloquium No. 123 before the deadline for submitting manuscripts. I therefore take the liberty to deviate grossly from the manuscript of my talk and give a short up to date mission summary. A more complete description of the mission can be found in References 1 and 2.
The launch of the Delta II rocket was perfect and the orbital parameters reached are very close to nominal: height 580 km, inclination 53°. The predicted satellite’s lifetime in this orbital is at least 10 years. The switch-on of the spacecraft and instrument subsystems could be completed without any losses. All systems are in good health.