The primary payload of mission STS-35 was ASTRO-1, the fifth flight of the Spacelab system and the second with the Igloo and pallet train configuration.
The primary objectives were round-the-clock observations of the celestial sphere in ultraviolet and X-ray spectral wavelengths with the ASTRO-1 observatory, consisting of four telescopes: Hopkins Ultraviolet Telescope (HUT); Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE); Ultraviolet Imaging Telescope (UIT), mounted on the Instrument Pointing System (IPS).
The Instrument Pointing System consisted of a three-axis gimbal system mounted on a gimbal support structure connected to a Spacelab pallet at one end and the aft end of the payload at the other, a payload clamping system for support of the mounted experiment during launch and landing, and a control system based on the inertial reference of a three-axis gyro package and operated by a gimbal-mounted microcomputer.
The Broad-Band X-Ray Telescope (BBXRT) and its Two-Axis Pointing System (TAPS) rounded out the instrument complement in the aft payload bay.

The crew split into shifts after reaching orbit, with Gardner, Parker, and Parise comprising the Red Team; the Blue team consisted of Hoffman, Durrance, and Lounge.
Commander Vance Brand was unassigned to either team and helped coordinate mission activities.
The telescopes were powered up and raised from their stowed position by the Red Team 11 hours into the flight.
Observations began under the Blue Team 16 hours into the mission after the instruments were checked out.
In a typical ASTRO-1 ultraviolet observation, the flight crew member on duty maneuvered the Shuttle to point the cargo bay in the general direction of the astronomical object to be observed.
The mission specialist commanded the pointing system to aim the telescopes toward the target.
They also locked on to guide stars to help the pointing system
remain stable despite orbiter thruster firings.
The payload specialist set up each instrument for the upcoming
observation, identified the celestial target on the guide television, and provided the necessary pointing corrections
for placing the object precisely in the telescope's field of view.
He then started the instrument observation sequences
and monitored the data being recorded.
Because the many observations created a heavy workload, the payload
and mission specialists worked together to perform these complicated operations and evaluate the quality of
observations.
Each observation took between 10 minutes to a little over an hour.

Issues with the pointing precision of the IPS and the sequential overheating failures of both data display units (used for pointing telescopes and operating experiments) during the mission impacted crew-aiming procedures and forced ground teams at Marshall Space Flight Center (MSFC) to aim  the telescopes with fine-tuning by the flight crew.
BBXRT was directed from the outset by ground-based operators at Goddard Space Flight Center and was not affected.
The X-ray telescope required little attention from the crew.
A crew member would turn on the BBXRT and the TAPS at the beginning of operations and then turn them off when the operations concluded.
After the telescope was activated, researchers at Goddard could "talk" to the telescope via computer.

Before science operations began, stored commands were loaded into the BBXRT computer system.
Then, when the astronauts positioned the Shuttle in the general direction of the source, the TAPS automatically pointed the BBXRT at the object.
Since the Shuttle could be oriented in only one direction at a time, X-ray observations had to be coordinated carefully with ultraviolet observations.
Despite the pointing problems, the full suite of telescopes obtained 231 observations of 130 celestial objects over a combined span of 143 hours.
Science teams at MSFC and Goddard estimated that 70% of the mission objectives were completed.
ASTRO-1 was the first shuttle mission controlled in part from the Spacelab Mission Operations Control facility at MSFC in Huntsville, Alabama.

During the fligh
The primary payload of mission STS-35 was ASTRO-1, the fifth flight of the Spacelab system and the second with the Igloo and pallet train configuration. The primary objectives were round-the-clock observations of the celestial sphere in ultraviolet and X-ray spectral wavelengths with the ASTRO-1 observatory, consisting of four telescopes: Hopkins Ultraviolet Telescope (HUT); Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE); Ultraviolet Imaging Telescope (UIT), mounted on the Instrument Pointing System (IPS). The Instrument Pointing System consisted of a three-axis gimbal system mounted on a gimbal support structure connected to a Spacelab pallet at one end and the aft end of the payload at the other, a payload clamping system for support of the mounted experiment during launch and landing, and a control system based on the inertial reference of a three-axis gyro package and operated by a gimbal-mounted microcomputer. The Broad-Band X-Ray Telescope (BBXRT) and its Two-Axis Pointing System (TAPS) rounded out the instrument complement in the aft payload bay.
The crew split into shifts after reaching orbit, with Gardner, Parker, and Parise comprising the Red Team; the Blue team consisted of Hoffman, Durrance, and Lounge. Commander Vance Brand was unassigned to either team and helped coordinate mission activities. The telescopes were powered up and raised from their stowed position by the Red Team 11 hours into the flight. Observations began under the Blue Team 16 hours into the mission after the instruments were checked out. In a typical ASTRO-1 ultraviolet observation, the flight crew member on duty maneuvered the Shuttle to point the cargo bay in the general direction of the astronomical object to be observed. The mission specialist commanded the pointing system to aim the telescopes toward the target. They also locked on to guide stars to help the pointing system
remain stable despite orbiter thruster firings. The payload specialist set up each instrument for the upcoming
observation, identified the celestial target on the guide television, and provided the necessary pointing corrections
for placing the object precisely in the telescope's field of view. He then started the instrument observation sequences
and monitored the data being recorded. Because the many observations created a heavy workload, the payload
and mission specialists worked together to perform these complicated operations and evaluate the quality of
observations. Each observation took between 10 minutes to a little over an hour.
Issues with the pointing precision of the IPS and the sequential overheating failures of both data display units (used for pointing telescopes and operating experiments) during the mission impacted crew-aiming procedures and forced ground teams at Marshall Space Flight Center (MSFC) to aim  the telescopes with fine-tuning by the flight crew. BBXRT was directed from the outset by ground-based operators at Goddard Space Flight Center and was not affected. The X-ray telescope required little attention from the crew. A crew member would turn on the BBXRT and the TAPS at the beginning of operations and then turn them off when the operations concluded. After the telescope was activated, researchers at Goddard could "talk" to the telescope via computer.
Before science operations began, stored commands were loaded into the BBXRT computer system. Then, when the astronauts positioned the Shuttle in the general direction of the source, the TAPS automatically pointed the BBXRT at the object. Since the Shuttle could be oriented in only one direction at a time, X-ray observations had to be coordinated carefully with ultraviolet observations. Despite the pointing problems, the full suite of telescopes obtained 231 observations of 130 celestial objects over a combined span of 143 hours. Science teams at MSFC and Goddard estimated that 70% of the mission objectives were completed. ASTRO-1 was the first shuttle mission controlled in part from the Spacelab Mission Operations Control facility at MSFC in Huntsville, Alabama.
During the fligh
STS-35