Astro 1 - Mission

The "Astro Observatory" was developed as a system of telescopes that could fly multiple times on the space shuttle. Astro-1 consisted of three ultraviolet telescopes and an X-ray telescope. The primary objectives of this observatory were to obtain (1) imagery in the spectral range 1200-3100 A (Ultraviolet Imaging Telescope, UIT); (2) spectrophotometry in the spectral region 425 to 1850 A (Hopkins Ultraviolet Telescope, HUT); (3)spectrapolarimetry from 1250 to 3200 A (Wisconsin Ultraviolet Photopolarimetry Experiment, WUPPE); and (4) X-ray data in the bandpass between 0.3 and 12 keV (Broad Band X-ray Telescope, BBXRT). Since many science objectives and selected astronomical targets of the three instrument teams were inter-related, simultaneous observations by all four instruments were planned.

The telescopes were mounted on a Spacelab pallet in the payload bay of the shuttle (flight STS-35). The Spacelab Instrument Pointing System (IPS), pallets, and avionics were utilized for attachment to the Shuttle and for control and data handling. Astro-1 required both mission specialists and payload specialists to control its operations from the Shuttle aft flight deck. Instrument monitoring and quick-look data analysis were performed for real-time ground operations. During the flight both on-board Digital Display Units malfunctioned, and the star guidance system calibration was not possible. The observing sequences were rescheduled during the flight, and instrument pointing was done by hand by the astronauts, and from the ground.

As a result of the numerous technical glitches, the returned data volume was less than half of that originally planned, and the scientific return was about 67% of the stated goals of the mission. Astro-1 was returned to earth 17:54 U.T., December 11, 1990. However, the mission was very successful in that 231 observations of 130 unique astronomical targetrs were made.

The follow-up flight, Astro-2, was dedicated to studies of many astronomical objects, and included increasing participation of guest investigators.