STS-2

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Mission emblem
Mission emblem STS-2
Mission dates
Mission: STS-2
COSPAR-ID : 1981-111A
Crew: 2
Begin: November 12, 1981, 15:09:59  UTC
Starting place: Kennedy Space Center , LC-39A
Landing: November 14, 1981, 21:23:11 UTC
Landing place: Edwards Air Force Base , Runway 23
Flight duration: 2d 6h 13m 12s
Earth orbits: 36
Track height: 231 km
Orbit inclination : 38.0 °
Covered track: 1.7 million km
Payload: OSTA-1
Team photo
Joe Engle (left) and Richard Truly
Joe Engle (left) and Richard Truly
◄ Before / After ►
STS-1 STS-3

STS-2 ( english S pace T ransportation S ystem ) is a mission designation for the US Space Shuttle Columbia (OV-102) NASA . The launch took place on November 12, 1981. It was the second space shuttle mission, the second flight of Columbia and the first mission in which a reusable spacecraft was launched again into space.

team

STS-2 was the last NASA mission to consist entirely of space novices. This had previously only been the case with the Mercury flights , Gemini 4 , Gemini 7 , Gemini 8 and Skylab 4 . However, Engle and Truly had already flown the prototype Enterprise as part of the Approach and Landing test ; In addition, Engle had reached heights of over 50 miles (approx. 80 km) in three test flights with the X-15 in the 1960s and was therefore already considered a space traveler, at least according to the Air Force definition. For later shuttle flights, the rule was that the commander of a mission had to have previously gained space experience (usually as a pilot of the space shuttle).

Substitute team

Preparations

Work on the space shuttle's second flight began on April 28, 1981 with the return of orbiter Columbia from Edwards Air Force Base to Kennedy Space Center (KSC) in Florida on the back of the shuttle carrier aircraft , a converted Boeing 747. Am The next day the shuttle was towed into the Orbiter Processing Facility (OPF), where complex examinations of the heat shield and preparations for the installation of the payload began immediately.

Meanwhile, in the neighboring Vehicle Assembly Building (VAB), assembly of the two solid fuel rockets (SRBs) began on the launch platform. On April 22nd, the external tank arrived at the space center and was also brought to the VAB to be subjected to a functional test there. It was the last tank on a space shuttle painted white. After the tests were successfully completed, the tank was connected to the SRBs on June 30th.

OSTA-1 pallet is installed in the cargo hold

On April 22, the Canadian-made robotic arm reached KSC to be installed in the orbiter's payload bay later. In addition, the scientific payload OSTA-1 underwent final tests before it was also loaded into the orbiter's hold on July 1. Finally, on August 10, the Columbia was transferred from the OPF to the VAB to be connected to the external tank and the SRBs.

The assembled space shuttle was driven on its launch platform to launch pad 39A on August 31, where the final preparations were made. However , an incident occurred while refueling with hypergolic fuel: while the front reaction control system tanks were being filled with nitrogen tetroxide , around ten liters of the toxic substance leaked and damaged parts of the heat shield. A total of 380 tiles had to be replaced. The launch, which was originally scheduled for October 9th, has been postponed to November 4th.

Mission history

First attempt to start

After all damaged heat protection tiles had been replaced, the countdown began at T-72 hours three days before the start . During the first attempt to start on November 4th, the countdown was stopped when the pressure in the oxygen tank of one of the three fuel cells was too low. The problem was quickly resolved. However, it was discovered a short time later that the oil pressure in two of the three Auxiliary Power Units (APU) that power the orbiter's hydraulic system was too high. As a result, the countdown was stopped 31 seconds before the start to give technicians time to resolve the problem. The weather prevented a later start that day. In the following days, the gearboxes of the APU were flushed through and their filters were replaced.

begin

Columbia was scheduled to take off on November 12th, the 44th birthday of pilot Richard Truly. But first a defective multiplexer / demultiplexer had to be replaced, after which the start time was delayed again by almost three hours because the spare part first had to be flown in from the Boeing plant in Palmdale . Ultimately, Columbia took off at 15:10:00 UTC. The total takeoff weight was 2,027,696 kilograms - 5,986 kilograms more than the first flight. Prior to this mission, several changes were made to the launch platform and the water system at the launch complex in order to prevent damage to the launch site and shuttle heat shield from the SRB pressure wave. The changes were successful. No tiles of the sensitive heat protection were lost and only 12 damaged.

The rise of Columbia went without any problems. The SRB were cut off punctually after 2:05 minutes at an altitude of 50.6 kilometers. They hit the Atlantic a little later and, made difficult by bad weather, could be recovered. The three main engines worked satisfactorily. When they were switched off after 8:39 minutes, the shuttle had reached an altitude of 118 kilometers and a speed of 26,669 km / h. A short time later, the external tank was thrown off and burned up in the earth's atmosphere. With two ignitions of the maneuvering system ( OMS ) at T + 10: 40 and T + 41: 58 minutes, they brought the Columbia into the planned, 222-kilometer orbit. Shortly after reaching orbit, the oil temperature of one of the hydraulic power packs (APU) rose unexpectedly. Therefore, the unit had to be shut down a little earlier than planned.

In orbit

A little later, the two astronauts began preparing for the time in orbit. Among other things, the two drained the no longer needed fuel from the main engines and opened the gates of the payload bay.

Shortly before the end of the first day of flight, however, a problem arose that severely impaired the further course of the mission: One of the three fuel cells required for power generation and water treatment failed. After just a few hours, the cell had displayed an increased pH value. When the performance dropped rapidly two hours later, it had to be switched off manually by the two crew members.

The duration of the mission was then reduced from five to three days and, among other things, the tests of the Canadarm robotic arm were canceled. However, the astronauts used the time of their sleeping period, without knowing the ground station, to test the Canadarm anyway.

Re-entry and landing

The re-entry of this mission was the only one in the entire shuttle program that was flown manually rather than by the autopilot. This should be used to check the stability and behavior of the shuttle under heavy loads. The experienced X-15 pilot Engle steered the shuttle from Mach 24 to landing and carried out 29 planned test maneuvers with his control stick. The data obtained from this led to improvements in the systems for later flights.

The Columbia finally touched down on November 14, 1981 at 21:23 UTC at Edwards Air Force Base , runway 23.

After the landing

Despite the shortening from five to two days, 90% of the objectives of the mission were achieved. None of the shuttle's heat protection tiles were lost during the flight , but over a dozen were damaged. On November 25, 1981, Columbia was flown back to the Kennedy Space Center with the Shuttle Carrier Aircraft .

During this flight, serious damage to the O-rings of the solid fuel booster was found for the first time. These rings were then subjected to further tests at three times the pressure of normal flight and then classified as not problematic. The same problem occurred on 14 more flights until the disaster on flight STS-51-L in 1986.

payload

During STS-2, the first major scientific payload was carried on board the shuttle. This was the so-called OSTA-1 payload, a pallet designed by the NASA Office of Space and Terrestrial Applications on which five Earth observation experiments were mounted:

  • The Shuttle Imaging Radar-A (SIR-A) was the most important experiment of OSTA-1. It sent and received microwaves to create map-like images of the ground. Since the radar uses its own energy sources, it is independent of day-night changes, clouds and vegetation. It was hoped with the technology to better localize oil and other mineral deposits. SIR-A was able to obtain images with a resolution of 40 meters for eight hours. The goals were mainly limited to the United States .
  • The Shuttle Multispectral Infrared Radiometer (SMIRR) assisted SIR-A by finding the best spectral bands that could be useful in exploring rock types. An infrared radiometer was used for this.
  • The aim of the Feature Identification and Location Experiment (FILE) was to find techniques that would make earth observation experiments more efficient by only activating the devices when the conditions are sufficient to collect data. Through the different levels of brightness, the experiment tried to distinguish between vegetation, bare ground, water, snow or precipitation.
  • In the experiment called Measurement of Air Pollution From Satellites (MAPS) , the pollution of the middle and upper layers of the atmosphere by carbon monoxide originating from satellites was measured.
  • The Ocean Color Experiment (OCE) was designed to identify schools of fish and marine pollution through the discovery of algae . The experiment was mainly used over the eastern Pacific and Atlantic.

The experiments were placed on a U-shaped pallet in the middle of the payload bay. This aluminum structure was 3 meters long, 4 meters wide and weighed 1,218 kilograms. It was made by the British Aerospace Corp. built.

Trivia

The crew was woken up twice during their mission with passages from the Muppet Show as wake-up calls. Both greetings came from the sketch series "Pigs in Space".

See also

Web links

Commons : STS-2  - album with pictures, videos and audio files

Individual evidence

  1. ↑ Chronological overview of NASA's wake-up calls (pdf, English; 475 kB)