STS-61

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Mission emblem
Mission emblem STS-61
Mission dates
Mission: STS-61
COSPAR-ID : 1993-075A
Crew: 7th
Begin: December 2, 1993, 09:27:00  UTC
Starting place: Kennedy Space Center , LC-39B
Number of EVA : 5
Landing: December 13, 1993, 05:25:33 UTC
Landing place: Kennedy Space Center, Lane 33
Flight duration: 10d 19h 58m 33s
Earth orbits: 163
Rotation time : 96.5 min
Orbit inclination : 28.4 °
Apogee : 594 km
Perigee : 588 km
Covered track: 7.1 million km
Team photo
v. l. No. Back: Richard Covey, Jeffrey Hoffman, Thomas Akers Front: Kenneth Bowersox, Kathryn Thornton, Story Musgrave, Claude Nicollier
v. l. No. Back: Richard Covey, Jeffrey Hoffman, Thomas Akers
Front: Kenneth Bowersox, Kathryn Thornton, Story Musgrave, Claude Nicollier
◄ Before / After ►
STS-58 STS-60

STS-61 ( english S pace T ransportation S ystem) is a mission designation for the US Space Shuttle Endeavor (OV-105) of NASA . The launch took place on December 2, 1993. It was the 59th space shuttle mission and the fifth flight of the space shuttle Endeavor.

STS-61 was the first maintenance mission for the Hubble Space Telescope . The main objective was to correct the faulty optics of the telescope with the COSTAR instrument (Corrective Optics Space Telescope Axial Replacement). Furthermore, the Wide Field / Planetary Camera 2 (WFPC-2) was built into the telescope. In addition, two sets of gyroscopes were exchanged and the solar collectors replaced. For the first time, five exits were made during a shuttle flight , including the second longest to date.

team

Main team

replacement

Preparations

After its last mission, STS-57 , the Endeavor was brought back to the Orbiter Processing Facility , where, in addition to routine re-inspections and repairs, the Spacelab module and the EURECA satellite were removed from the payload bay. The Endeavor was transferred to the Vehicle Assembly Building on October 21, where it was attached to the external tank connected to the solid fuel rocket . The shuttle was then driven to launch facility 39 A on October 28th .

On October 30th, a severe storm passed over Cape Canaveral , which caused damage to the Payload Changeout Room, a clean room area of ​​the launch system through which access to the space shuttle's payload bay is possible. In order to be able to start repairs as quickly as possible, it was decided to start the Endeavor from starter system 39 B. The second rollaround in the history of the shuttle took place on November 15th.

On November 18, an error occurred in the chassis hydraulic system. A so-called “delta-p transducer” failed. Since only this one out of four failed and only three delta-p transducers are required for the start, the shuttle to the Orbiter Processing Facility was not rolled back.

The crew arrived at the Kennedy Space Center on November 27 , and the countdown began a little later .

Mission overview

begin

The first attempt to take off on December 1st was canceled due to bad weather for an emergency landing on the Shuttle Landing Facility . There was also a ship in the Solid Rocket Booster landing zone. It was decided to try again a day later. There were no problems with the second take-off attempt and so the Endeavor was able to leave for Hubble on December 2 at 09:27 UTC. The solid fuel rockets were dropped two minutes after take-off, after eight minutes the main engines were switched off and the external tank was dropped 10 seconds later.

Rendezvous and capture

On the second day of the flight, several engine starts were carried out in order to increase the approach speed to Hubble. The spacesuits and the robot arm of the shuttle were also checked for functionality. In addition, the air pressure in the cabin has been lowered by 45% to prevent space sickness when exiting.

At the beginning of the third day of flight, Jeffrey Hoffman was able to see Hubble through binoculars. He also noticed that one of Hubble's solar collectors had bent 90 degrees. Another series of engine starts brought the Endeavor just a few kilometers behind Hubble. From there, Richard Covey took over manual control and initially brought the Endeavor into a position below Hubble. From there he maneuvered her up to about ten meters from Hubble. At 8:48 UTC, Claude Nicollier caught it with the robotic arm and after 38 minutes inserted it into a holder in the payload bay.

Working on Hubble

The first field mission began just six hours later with astronauts Story Musgrave and Jeffrey Hoffman. Two gyroscope units, which are used to align and stabilize the telescope, were replaced. Then the electronic units that control the gyroscopes were swapped. Eight fuses were also replaced. This exit took 7 hours and 50 minutes. With problems opening the access doors, the EVA took longer than planned and was the second longest exit in NASA history.

View of the telescope from the space shuttle during the mission. In the background the north west coast of Australia

The next day (fifth day of the flight) the solar cells built by ESA were replaced by Thomas Akers and Kathryn C. Thornton. The first panel could not be rolled up because of a kink. It was therefore dismantled during the night phase of orbit and thrown overboard when daylight entered and slowly "sailed" away. Then the new solar panel was installed. The second panel was rolled up, dismantled and stowed in order to bring it back to earth for later analysis by ESA. Then the second new panel was installed and the outdoor use ended after six and a half hours.

The sixth day of flight saw the expansion of the WFPC (Wide Field Planetary Camera) camera by Story Musgrave, who was supported by Jeffrey Hoffman. The WPFC was replaced by a more powerful camera and its own correction optics (WFPC2). Magnetic field sensors, the “compass” of the telescope, were also replaced. They were likely damaged by UV radiation.

On the seventh day of the flight, Thornton and Akers installed the COSTAR correction optics (Corrective Optics Space Telescope Axial Replacement) for the error in the main mirror during the fourth EVA , which corrects the beam path for all devices in the telescope (except for the WFPC2, which had its own correction) again enabled sharp images. In addition, the on-board computer has been upgraded with additional memory and a coprocessor. It was only six weeks after the "Hubble glasses" had been installed that it was possible to verify that the correction really worked. The telescope could now be used seriously for scientific purposes for the first time in over three years in space.

On the eighth day of the flight, the drive electronics of the solar panels were replaced, again with Musgrave and Hoffman. Then the electronics were activated and after a number of difficulties and a few nudges by the astronauts, the solar power plants finally unfolded and aligned themselves with the sun.

Expose

On the ninth day of the flight, the space telescope was switched to internal power supply. In the event of unforeseen problems, there were plans for two more field missions. There were no complaints, however, and clearance for the satellite to be deployed was given by the Houston ground station. Claude Nicollier lifted it out of the loading bay with the robotic arm and left it to its own devices until the next STS-82 visit .

landing

The landing took place on December 13, 1993 at 05:25:37 UTC on the Shuttle Landing Facility , runway 33. The shuttle took 53 seconds to roll onto the runway and covered a distance of 2,415 m. The landing weight was 96 tons.

Others

Except for Kathryn Thornton , all crew members had a cameo appearance on an episode of the US sitcom Listen Who's That Hammering . Richard Covey explains that Kathryn Thornton has to take care of the important things at NASA .

STS-61 was still Flight Director Gene Kranz's last mission before he retired.

See also

Web links

Commons : STS-61  - album with pictures, videos and audio files