STS-133

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Mission emblem
Mission emblem
Mission dates
Mission: STS-133
COSPAR-ID : 2011-008A
Crew: 6th
Begin: February 24, 2011, 21:53:24 UTC
Starting place: Kennedy Space Center , LC-39A
Space station: ISS
Coupling: February 26, 2011, 19:14 UTC
Decoupling: March 7, 2011, 12:00 UTC
Duration on the ISS: 8 d, 16 h, 46 min
Number of EVA : 2
Landing: March 9, 2011, 16:57:17 UTC
Landing place: Kennedy Space Center
Flight duration: 12 d, 19 h, 4 min, 50 s
Track height: 360 km
Payload: EXPRESS Logistics Carrier 4, PMM Leonardo
Team photo
v. l. To the right: Benjamin Drew, Nicole Stott, Eric Boe, Steven Lindsey, Michael Barratt and Steve Bowen
v. l. To the right: Benjamin Drew, Nicole Stott, Eric Boe, Steven Lindsey, Michael Barratt and Steve Bowen
◄ Before / After ►
STS-132 STS-134

STS-133 ( english S pace T ransportation S ystem ) is a mission for the US Space Shuttle Discovery (OV-103) of NASA . This was the 133rd and third to last shuttle flight and the 39th and final flight of the Discovery.

During the STS-133 (ISS-ULF5) mission, the fourth EXPRESS Logistics Carrier (ELC4) and supplies were brought to the International Space Station with the PMM Leonardo . The PMM Leonardo remained permanently on the ISS. Two space exits were made. A special payload inside Leonardo was a humanoid robot called Robonaut 2 , developed jointly by NASA and General Motors , which was to be tested by the ISS crews after the shuttle returned to Earth.

team

The crew was originally supposed to consist of five people in order to save weight. On September 18, 2009, NASA announced six crew members:

At the time of the announcement, Stott and Barratt were still in space as members of ISS Expedition 20 .

Originally Tim Kopra was part of the crew, but was replaced by Bowen on January 19th, as Kopra was injured in a bicycle accident on January 15th. This makes Bowen the only NASA astronaut to have participated in two consecutive flights. The record for the shortest time span between two missions is still held by the crew of STS-83 and STS-94 .

Preparations

The Discovery upon arrival at the launch complex

After its previous mission, STS-131 , the Discovery was pulled into Orbiter Processing Facility 3 for the usual maintenance and repair work . Among other things, the Ku-band antenna that had failed at the beginning of the previous mission was repaired there. The right-hand OMS engine segment was also dismantled in order to be able to replace a defective helium valve. The ET-137 outer tank reached the Kennedy Space Center on May 8, 2010 and was transferred to the Vehicle Assembly Building two days later . It was lowered between the two solid fuel rockets on June 15 . The completion of the work was delayed by a few days because one of the separation bolts was damaged and had to be replaced. On September 9th, the Discovery was transferred to the VAB for the last time to prepare for launch . For this reason, the so-called rollover was significantly extended so that the employees on site had various photo opportunities. The rollover was delayed by one day due to the break in a 24- inch main water pipe, which required the one-day reduction to only absolutely necessary personnel. After the assembly on the external tank, the Discovery left the VAB on September 20 for its last scheduled rollout in the direction of launch system 39-A .

In mid-October, the crew flew to the Terminal Countdown Demonstration Test at the launch site, where they were able to familiarize themselves with the space shuttle and the safety devices and run a countdown simulation. Around the same time, technicians reported a hydrazine leak in the rear of the Discovery, which was attributed to a connector between the two tanks of the space shuttle. It was changed on the launch system under difficult conditions. On October 25th, after acceptance of the flight readiness review, November 1st was set as the first start date.

GUCP problems and outside tank damage

The first start date on November 1st was postponed by three days after a reserve control unit for main engine 3 experienced a voltage spike and displayed incorrect values. The problem could be solved by simply interrupting, but they wanted to give the engineers enough time to understand the problem. The second attempt on November 4, before the start of refueling the external tank, was discarded due to bad weather and a further postponement of 24 hours was ordered.

The crack in the intermediate tank area

With a delay of around 20 minutes, the cooling down of the fuel lines at 11:00 UTC signaled the start of refueling the external tank. This process ended prematurely, however, because a hydrogen concentration of more than 6% was found at a ground umbilical carrier plate (GUCP, pronounced Gup) between the hydrogen tank and the discharge line for evaporating hydrogen. This violated both the start criteria and the safety rules, whereupon the attempt was stopped and the tank was emptied. It was then decided to abandon the remaining start window in favor of a detailed analysis of the problem and, depending on the results of the investigation, to try a start on November 30th at the earliest. After this decision had been made, it became known that a crack had formed in the foam outer layer of the tank, which would have prevented a start and also had to be repaired. During the preparations for the repair of the foam crack, two cracks were discovered underneath the foam on a reinforcing rib (stringer) in the aluminum shell of the intermediate tank area, which should be repaired by placing a reinforcing piece.

Technician at GUCP

While the repairs were being made, engineers began to grapple with the problems. The problem of the GUCP leak could soon be traced back to an incorrectly adjusted setting that was not considered, as the pick-up arm changes its position slightly due to the hydrogen flowing through. In the present case, however, the GUCP was adjusted so unfavorably that the movement of the arm drastically increased the amount of escaping hydrogen at the point. Since one was now aware of this circumstance, one believed to have safely solved the problem. With regard to the cracks on the tank, however, there was no certainty that the foam would not flake off during take-off and hit the space shuttle. Despite various analyzes and an inspection of the affected section with X-rays , it was decided that only a test could bring the necessary security. The Discovery was fully refueled on December 17th as a test, while various sensors and markings documented the behavior of the tank with the fuels on board. The details of the test in this regard were still pending analysis, but it was found that the repairs to the GUCP were successful and the hydrogen concentration remained within the normal range.

In order to be able to examine the inaccessible areas of the intermediate tank at the launch pad, the entire launch structure was rolled back into the Vehicle Assembly Building on December 22, 2010. Between Christmas and New Year the entire intermediate tank was examined with X-rays and four more cracks were found on the back of the tank, which should be repaired by January 7, 2011. It was also decided to attach reinforcement elements at the connection points to the solid rocket rockets . This work should take about a week. However, since decisions on further modifications were still pending, it was decided not to target the start window at the beginning of February any longer. On January 14th, February 24th was announced as the start date. In the days that followed, the work was completed and Discovery was transferred back to the launch pad on February 1st, where launch preparations were resumed. Another Flight Readiness Review was held on February 18, with February 24 being the first date. The crew reached the Kennedy Space Center two days later.

Mission history

Start, rendezvous and pairing

Start of the discovery

On February 21, the countdown to the start began, which was set for February 24 at 21:50 UTC. The weather did not cause any problems, although Edwards Air Force Base and White Sands were not available as emergency landing sites in an abort-once-around scenario. The countdown went flawlessly until the T-9 minute break. Shortly before the final GO / NO-GO survey, a computer problem was discovered at a headquarters of the 45th Space Wing responsible for ground safety. In the start control center it was therefore decided to let the countdown continue to the T − 5 minute mark after the scheduled interruption and then stop again in order to have more time to solve the problem. The start was finally released and the countdown continued with only two seconds remaining in the start window. The Discovery took off for the last time at 21:53:24 UTC with a delay of around three minutes, so that after 2 minutes the boosters burned out and were thrown off and after a flight of 8.5 minutes the engines were switched off and the external tank was thrown off. The further ascent profile that ultimately led to the rendezvous with the ISS remained within the parameters, so that no additional engine ignition was necessary. After launch, the orbiter was configured for work over the next few days. The cargo hold doors were opened and the robotic arm activated and tested before the crew went to bed.

Flight day two (February 25) was used for the usual inspection of the heat shield on the leading edge of the wing and the "nose" of the Discovery using the Orbiter Boom Sensor System . On that day, the spacesuits, which should be worn during the spacecraft operations, were unpacked and some preparations were made for the docking maneuver on the following day.

The rendezvous with the ISS took place on the third day of the flight (February 26th). Before coupling, the Discovery did the rendezvous pitch maneuver so that the station crew could capture the state of the heat shield in photos. The first contact (soft capture) took place at 19:14 UTC, but due to the relative movements between the station and the shuttle, one had to wait about 40 minutes before the shuttle's docking ring could be retracted in order to close the remaining gap (hard dock). Preparations for opening the hatches were then started so that the crews could greet each other at 21:16 UTC. With the Discovery, there were for the first time seven individual space vehicles (in addition to it, two Soyuz and Progress spaceships as well as an Automated Transfer Vehicle and an H-2 Transfer Vehicle ) with a total mass of around 530 tons at the space station. This is just about the take-off weight of an Airbus A380 . After the usual safety briefing, the ELC-4 was transferred from the loading bay to its final position on the same day, despite exceeding normal working hours .

Working on the ISS

The fourth day of the flight (February 27) was mainly used for cargo transfers between the middle deck of the shuttle and the station. Initial interviews were also conducted with US broadcasters. Towards the end of the day, Drew and Bowen prepared for their first exit and spent the night in the airlock in a procedure known as a campout to reduce the inert gases in their bodies (mainly nitrogen ) and thus prevent decompression sickness .

Disconnect, re-entry and landing

Landing at the Kennedy Space Center (video, 2 min, 30 s)

On March 7, the Discovery successfully undocked from the ISS and made a scenic flight around it. On March 9, the brake engines were ignited at 15:52 UTC for 2 minutes and 31 seconds, which decelerated the space shuttle at 96.7 m / s (approx. 348 km / h) and thus initiated reentry . The Discovery landed at 16:57:17 UTC (17:57:17 hrs CET ) at the Kennedy Space Center. The landing was originally supposed to take place on March 7th, but it was decided to extend the mission by two days in order to have enough time to assemble the logistics module on the ISS.

Trivia

On the STS-133 and STS-134 missions , NASA offered the opportunity to upload a photo on its own website under the motto Fly Your Face in Space , which was then shot into space. In addition, another website made it possible to choose the so-called wakeup songs for the STS-133 mission under the motto NASA's Space Rock . In addition, users could submit their own compositions, which were then used as a wakeup song for the STS-134 mission.

This was originally planned as the last flight in the shuttle program, which is why the landing at Edwards Air Force Base in California was initially planned. Then the shuttle was supposed to undertake a farewell tour across the United States to the Kennedy Space Center .

See also

Web links

Commons : STS-133  - Album with pictures, videos and audio files

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  1. ↑ a b c STS 133 Mission Updates. NASA February 26, 2011; archived from the original on March 3, 2011 ; accessed on February 26, 2011 (English).
  2. ↑ Thomas Pallmann: Discovery leaves the International Space Station. raumfahrer.net, March 6, 2011, accessed on March 6, 2011 : "At 1:00 p.m. CET the docking clamps loosened and a spring mechanism slowly pushed Discovery away from the space station"
  3. ^ Logistics module to be modified for new mission. Spaceflight Now, December 6, 2009, accessed December 25, 2009 .
  4. ↑ ISS to get permanent logistics module lab. September 4, 2009, accessed on November 13, 2009 (English).
  5. ↑ Robonaut 2: First humanoid robot in space. netzwelt.de, April 15, 2010, archived from the original on December 28, 2015 ; Retrieved May 2, 2010 .
  6. ↑ Chris Gebhardt: STS-133 refined to a five crew, one EVA mission - will leave MPLM on ISS. NASASpaceflight.com, August 4, 2009, accessed August 12, 2009 .
  7. ↑ NASA names crew for final space shuttle mission. Spaceflight Now, September 18, 2009, accessed September 19, 2009 .
  8. ↑ Astronaut Steve Bowen Named To STS-133 Space Shuttle Crew; Media Teleconference scheduled for 3:30 pm CST. nasa.jov, January 19, 2011, accessed January 19, 2011 .
  9. ↑ Chris Bergin: STS-133: Discovery's SSMEs removed - ET-137 arrives in Florida. NASASpaceflight.com, May 8, 2010, accessed December 18, 2010 .
  10. ↑ Chris Bergin: STS-133 stack takes shape as Discovery prepares for summer in her OPF. NASASpaceflight.com, June 16, 2010, accessed December 18, 2010 .
  11. ↑ Chris Bergin: STS-133: STS-133: Discovery rolls over to VAB following eventful OPF flow. NASASpaceflight.com, September 9, 2010, accessed December 18, 2010 .
  12. ↑ Chris Bergin: STS-133: Discovery arrives at Pad 39A - ET-122 to ship on Tuesday. NASASpaceflight.com, September 20, 2010, accessed December 18, 2010 .
  13. ↑ Chris Bergin: STS-133: TCDT completed - Engineers troubleshooting leaky flight cap. NASASpaceflight.com, October 15, 2010, accessed December 19, 2010 .
  14. ↑ Chris Bergin: STS-133: Discovery to undergo unique leak repair to avoid rollback. NASASpaceflight.com, October 18, 2010, accessed December 19, 2010 .
  15. ↑ Chris Bergin: STS-133: Launch delayed at least 24 hours due to Main Engine Controller issue. NASASpaceflight.com, November 2, 2010, accessed December 19, 2010 .
  16. ↑ Chris Bergin: STS-133: Discovery delayed ahead of tanking for 24 hours. NASASpaceflight.com, November 4, 2010, accessed December 19, 2010 .
  17. ↑ Chris Bergin: STS-133 SCRUB: Discovery's tanking suffers GUCP leak. NASASpaceflight.com, November 5, 2010, accessed December 19, 2010 .
  18. ↑ Chris Bergin: STS-133: Structural defect / cracks found under foam damage on ET-137. NASASpaceflight.com, November 10, 2010, accessed December 19, 2010 .
  19. ↑ Chris Gebhardt: Discovery / ET-137 Tanking Test complete - Flight Rationale data drive. NASASpaceflight.com, May 8, 2010, accessed December 19, 2010 .
  20. ↑ Chris Bergin: NASA evaluate STS-335 flight - STS-133 targets cross country farewell tour. NASASpaceflight.com, October 13, 2009, accessed October 13, 2009 .