Which mission was completed first, Cos-B or Uhuru?
Cos-B:  The mission was completed on April 25, 1982, after the satellite had been operational for more than 6.5 years, four years longer than planned and had increased the amount of data on gamma rays by a factor of 25. Uhuru (satellite): Uhuru was the first satellite launched specifically for the purpose of X-ray astronomy. Uhuru (satellite):  Uhuru was a scanning mission, with a spin period of ~12 minutes.
i don't know