STS-115

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Mission emblem
Mission emblem STS-115
Mission dates
Mission: STS-115
COSPAR-ID : 2006-036A
Crew: 6th
Begin: September 9, 2006, 15:14:55  UTC
Starting place: Kennedy Space Center , LC-39B
Space station: ISS
Coupling: September 11, 2006, 10:48 UTC
Decoupling: September 17, 2006, 12:50 UTC
Duration on the ISS: 6d 2h 2min
Landing: September 21, 2006, 10:21:30 UTC
Landing place: Kennedy Space Center, Lane 33
Flight duration: 11d 19h 6min 35s
Earth orbits: 187
Track height: 340 km
Covered track: 7.9 million km
Payload: Element P3 / P4
Team photo
v. l. No. Front: Brent Jett, Christopher Ferguson; Back: Heidemarie Stefanyshyn-Piper, Joseph Tanner, Daniel Burbank, Steven MacLean
v. l. No. Front: Brent Jett, Christopher Ferguson;
Back: Heidemarie Stefanyshyn-Piper, Joseph Tanner, Daniel Burbank, Steven MacLean
◄ Before / After ►
STS-121 STS-116

STS-115 ( english S pace T ransportation S ystem) is the mission designation for a flight of the US Space Shuttle Atlantis (OV-104) of NASA . The launch took place on September 9, 2006. It was the 116th space shuttle mission and the 27th flight of the space shuttle Atlantis. This 19th flight by a US space shuttle to the International Space Station (ISS) was dedicated to the first operational shuttle flight since the Columbia disaster and the further expansion of the ISS.

team

Mission overview

With this shuttle mission, the International Space Station (ISS) was expanded for the first time since STS-113 in November 2002. The main payload was the P3 / P4 carrier with the solar modules 2A and 4A. This collector is the second of four planned panels that will provide the energy for the ISS. The P3 / P4 segment was installed during three outboard activities. In addition, 360 kilograms of equipment and 470 liters of water were brought to the station and 490 kilograms of parts that were no longer required (completed experiments, equipment, rubbish) were brought back to earth.

Preparations

Originally, when the mission was scheduled for May 2003, NASA wanted to use the Endeavor as an orbiter. After the Columbia accident in spring 2003, the US space agency decided to modernize the Endeavor - the ferry at the Kennedy Space Center (KSC) has been rebuilt since December of that year .

The experience during STS-114 led to the decision in August 2005 to wait another year until the next mission. This enabled the Discovery to be used for both return-to-flight missions. On the other hand it became possible to let the more modern Atlantis carry out the STS-115 mission. This orbiter was actually supposed to be used for the second test flight ( STS-121 ) in autumn 2005 and had even been assembled for take-off.

During the preparations for the STS-115 mission, a new method of installing the filler strips between the heat protection tiles was developed. This is to prevent strips from being shifted during take-off, sticking out of the heat shield and thus leading to aerodynamic changes on the underside of the orbiter, as happened with the STS-114.

The P3 / P4 carrier in May 2005

At the beginning of June 2006, assembly of the solid fuel rocket began in the Vehicle Assembly Building (VAB) and was completed three weeks later. The outer tank for the Atlantis arrived in Florida in the second week of June . In the event of an accident on the STS-121 mission, a rescue flight should be possible as early as mid-August. This would then have carried the mission designation STS-300 .

The outer tank could not be completely completed, as rapid availability was required. For example, the level meters (ECO sensors) had to be replaced. The manufacturer Lockheed Martin sent several dozen employees from Louisiana to KSC to have the final work carried out on site.

Carelessness resulted in the external tank being damaged on June 19th. Workers hit the tank with a portable aerial platform. A piece of insulation foam about an inch thick splintered off. Water dripped from the insulation when the area was repaired. The water probably came from August 2005, when Hurricane Katrina devastated the factory near New Orleans . A small hole was drilled in the insulation to allow the water to drain away. Then it was filled.

After the preparatory work on the orbiter had been completed, the Atlantis was transferred to the VAB on July 24, 2006. There the assembly with the external tank and the two solid fuel rockets took place. The system was rolled to launch pad 39B 6.8 kilometers away on August 2 , after the project had to be postponed twice due to bad weather.

At the beginning of August the payload, the lattice structure P3 / P4, was loaded into the hold of the Atlantis and a week later the crew carried out the final countdown dress rehearsal. After the two-day flight readiness review, all of the Atlantis systems were declared ready for take-off on August 16. At the same time, August 27, the preliminary start date, was confirmed.

On August 18, NASA ordered a two-day repair because it could not be clearly verified whether the Ku-band antenna was properly attached. The antenna is located on the starboard side of the payload bay directly behind the cockpit and is responsible for the main part of the communication between the space shuttle and the ground station. Although the 150-kilogram antenna had never caused problems since the orbiter's maiden flight, a recent review of the accompanying documents revealed that it was not certain that the four mounting screws were the correct length. NASA technicians suspected that two screws were shorter and that the antenna could break loose during take-off, which could have catastrophic consequences. This very difficult repair was successfully completed on August 20th.

Mission history

First attempt to start

During a thunderstorm at night, lightning struck the lightning rod on Pad 39-B.

The countdown began on August 24, 2006. Before that, the crew arrived at the Kennedy Space Center in Florida. At the beginning of the countdown, NASA said the weather forecast was good, with a 70% chance of good weather. Until a day before the planned start, this chance shrank to 40%. In addition, the launch pad was struck by lightning on August 25, so various systems on the orbiter had to be checked again, which led to delays. For these reasons, the start was initially postponed by one day and later by another day.

Atlantis on August 29th

As recently as August 27, NASA feared that it would have to postpone the start until the end of October, as tropical storm Ernesto was approaching Florida. A day later it was decided to return the shuttle to the secure assembly hall (VAB) on August 29th . Shortly before reaching the VAB, however, the ferry was stopped and transported back to the launch pad. The meteorologists had meanwhile given the all-clear; the tropical storm would not pose a threat to the space shuttle according to the latest weather forecasts, as Ernesto had weakened, it said. A new start date was not initially announced.

Originally, the start window was only open until September 7th, with a daily start option lasting ten minutes. NASA (in theory) had the opportunity to send the shuttle to the ISS by September 13th, but a launch after the 7th would have meant that Roscosmos would have postponed the Soyuz TMA-9 flight originally planned for September 14th have to. The aim was to avoid the shuttle and the Soyuz being docked at the ISS at the same time, since for safety reasons one of the spaceships is not allowed to dock at the station while the other is docked. In addition, a launch after September 18 would have meant that the Soyuz TMA-8 capsule would have had to return to earth at night, which they wanted to prevent.

NASA and Roscosmos finally agreed on August 30th to extend the launch window to September 8th. This was achieved because Roscosmos postponed the Soyuz rocket launch to September 18.

When the Kennedy Space Center reopened on August 31 after the storm passed, NASA technicians found the damage was minimal. Preparations for the start were immediately resumed and a new date set for September 6th.

Second start attempt

On September 3rd, the second countdown of this mission began. At 76 hours, it was six hours longer this time to give the engineers more time to respond to unexpected problems. The day before, the crew of six had arrived at the Kennedy Space Center. After the countdown was resumed, the start date was postponed twice again due to technical problems with the coolant pump in one of the three fuel cells and finally set to September 8th. On September 7th, NASA decided to stick to the scheduled date, although the problem with the fuel cell had not yet been resolved. After a long discussion, the decision was unanimous.

On September 8th, a problem with one of the ECO fuel sensors in the outer tank was also discovered. Less than an hour before the scheduled date, the start was again canceled and postponed by 24 hours. In order not to have to postpone the mission until the end of October, NASA decided to make another launch attempt on September 9th.

Start and pairing

Start of STS-115

The 116th shuttle mission started on September 9, 2006 at 15:14:55 UTC .

The second day of flight and thus the first full day in space began with the traditional wake-up song for the astronauts. "Moon River" was played for the commander Brent Jett . Eighteen hours after take-off, the crew began using the OBSS inspection arm to check the space shuttle for possible damage. The astronauts spent a large part of the working day mainly inspecting the wing leading edges and the orbiter nose. This first examination showed that no defect could be found on the sensitive heat shield, although pieces of the insulating foam had detached from the outer tank at the start.

On September 11th at 10:48 UTC the shuttle docked with the International Space Station (ISS). Previously, the Atlantis had made a slow 360 ° turn about the transverse axis at a distance of 180 meters in order to give the ISS crew the opportunity to take high-resolution images of the underside of the orbiter. A good one and a half hours after docking, the hatches between the ISS and the shuttle were opened at 12:30 UTC.

Working on the ISS

View into the open payload bay

Three hours after docking, the lattice structure P3 / P4 to 13:45 UTC with was gripping arm of the orbiter lifted out of its payload bay. At 14:52 UTC the structure was handed over to the ISS robot arm , where it remained until the next day. The arm of the station was controlled by mission specialist Steve MacLean , who described the handover as a "Canadian handshake" because both manipulators come from Canada.

During this mission, a procedure was used for the first time to simplify and shorten the preparation for space exits (EVAs). Until now, the shuttle astronauts breathed in pure oxygen at reduced air pressure (703 hPa ) a few hours before the EVA , before putting on their spacesuits . This time NASA tried what they called "camping". For this purpose, the two astronauts went to sleep in the US airlock Quest on the evening before the EVA . During the night, the nitrogen bound in the tissue was eliminated in order to prevent decompression sickness . This saves valuable oxygen (an entire section does not have to be sealed off) and time, because the necessary preparation happens almost incidentally. The procedure was to be tested for suitability as early as spring 2006 when William S. McArthur and Jeff Williams spent a night in the Quest module. The attempt had to be stopped after the space travelers were awakened by two false alarms.

Tanner outboard

On the fourth day of the flight (September 12) the first of three planned EVAs was on the program. After the two astronauts Stefanyshyn-Piper and Tanner had switched their spacesuits to internal power supply at 9:17 UTC, they left the ISS via the Quest module. The grid structure P3 / P4 supplied had previously been brought to its final position by the Canadarm2. When the last of four large retaining clips clicked into place at 7:48 UTC, the new segment was firmly connected to the P1 girder . Tanner and Stefanyshyn-Piper connected the 17 power and data cables between the booms and the removed protective covers in just under six and a half hours. They also brought the boxes with the two folded solar modules into the position required to extend them. The two mission specialists worked so quickly that they could even carry out some of the EVA tasks that were due for the next day. Only once was Tanner inattentive and let a screw float away. He had just removed a cover plate when the screwdriver slipped and the screw and washer disappeared into space. The exit ended after 6 hours and 26 minutes at 15:43 UTC.

The mission's second EVA began 24 hours after the first. This time Dan Burbank and Steve MacLean were working on the space station's new boom. The two astronauts left the Quest airlock at around 9:05 UTC on September 13. They prepared the two solar panels for their work in seven hours. Burbank and MacLean removed the protective cover and shipping fixings. Most importantly, they adjusted the sun tracking mechanism. This device, called SARJ (Solar Alpha Rotary Joint) for short, ensures that the two solar panels always track the sun. One of the six locking screws on the SARJ was so tight that only the joint muscle strength of both EVA workers could loosen it. Like colleague Tanner when they got out for the first time, the two mission specialists lost a screw when they removed a thermal barrier. The piece floated away and did not get caught in the SARJ mechanism, which could have led to its failure. The EVA ended after 7 hours and 11 minutes at 16:16 UTC.

A solar panel ready to work
Animation showing the construction of the P3 / P4 segment and the unfolding of the solar panels

On the sixth day of the flight (September 14th) the solar panels were unfolded. To ensure that the panels do not tilt when they are opened, the process was carried out step by step. Initially, the engineers in the control center began to unfold the port module 4A halfway around 9:00 UTC. Then the same procedure was followed with the starboard panel 2A. At 11:08 UTC, solar module 4A was fully extended, and 2A was fully deployed at 12:44 UTC. Unrolling began 70 minutes later than planned because one of the two SARJ engines was causing problems. After the tracking unit had been prepared for its task the day before, ground control in Houston had tested its alignment. A software problem had occurred in one of the control motors.

The radiator is unfolded

On September 15, Stefanyshyn-Piper and Tanner disembarked for the mission's third field assignment. However, they were only able to leave the airlock 45 minutes late. While the two mission specialists were "camping" in Quest, as they had three days earlier, there were problems with the power supply to the module. The pump for regulating the air pressure failed for a short time. At 10:00 UTC, Tanner and Stefanyshyn-Piper were finally able to begin the last EVA of the mission. The program included the final work on the new solar cell surfaces and the recovery of the MISSE container, a basic research experiment that had been on the P6 carrier since the beginning of August 2005 . At 13:05 UTC, they extended the radiator of the P4 solar module and then replaced a defective antenna on the S1 element . They also installed an antenna that is supposed to improve the quality of the television images from the astronaut helmet cameras. The exit ended at 16:42 UTC after 6 hours and 42 minutes.

The eighth mission day (September 16) began for the astronauts with a time off. During the further course of the day, cargo was reloaded and the mandatory joint press conference of both teams was held.

return

ISS photographed after the Atlantis cast off. The new carrier can be seen on the right.

On September 17th at 10:27 UTC the bulkheads between the ISS and Atlantis were closed. There followed a leak test between the two spaceships. The shuttle team also thanked the control center for their good work. After 6 days, 2 hours and 2 minutes, the orbiter undocked from the space station at 12:50 UTC. Before the orbiter finally separated from the station, it flew once around the ISS at a distance of 120 meters. The crew made detailed photo and video recordings and was able to assess the result of their work.

As at the beginning of the flight, the crew checked the heat shield of their spaceship again on the tenth day of the flight (September 18). The 15 meter long OBSS inspection arm, which was connected to the robot arm of the shuttle, was used for this. This was to ensure that Atlantis was not hit by micrometeorites while in orbit. The procedure, which lasted several hours, did not result in any damage.

15 hours after the Atlantis had separated from the station, the new long-term crew started from the Baikonur Cosmodrome for the ISS.

Only seven hours later the crew of the space station had to deal with a defective electron oxygen generator. Some caustic potash had escaped from the device and had given off a strange smell that alarmed the three spacemen. The situation was back to normal after three quarters of an hour.

One of the unknown objects

On September 19, the orbiter's crew prepared for their upcoming return until the astronauts were informed by flight control at around 14:45 UTC that the landing planned for the next day would have to be postponed. Bad weather and a mysterious flying object that had been discovered during the viewing of video recordings in the immediate vicinity of the orbiter forced NASA to postpone the landing scheduled for September 20 by 24 hours. What the object was about, one does not know, explained the ground control.

The object recorded around 6:45 UTC was small, dark, rectangular and flew below the ferry at the same speed and in the same direction. A camera in Atlantis' open payload bay had filmed the object that flew between the orbiter and Earth. Nine hours later, the crew reported another object that mission specialist Dan Burbank had seen with his own eyes and that could be photographed. It was also "quite small" and moved away from the shuttle. Houston decided to postpone the landing for a day because they wanted to find out where these objects came from. The NASA technicians suspect that it was parts that had detached from the spaceship. The question, however, is whether they came from vital areas such as the heat shield.

A new inspection of the orbiter was therefore ordered for the twelfth day of flight (September 20). During the previous sleep period of the astronauts, the NASA engineers had already started with an initial check: The robot arm of the ferry (RMS) had been positioned above the open payload bay. The RMS cameras were used to search the upper area of ​​the space shuttle. Shortly after the morning wake-up call, the crew began a thorough assessment of the condition of the spaceship. Only the RMS and its cameras were used for this. The flight control center was of the opinion that its resolution was high enough to be able to identify changes to the ferry in the order of magnitude of the objects previously sighted. The inspection ended with no results after four and a half hours.

To make sure nothing was overlooked, the procedure was repeated with the inspection arm. All areas had been scanned at around 13:15 UTC. This appraisal did not reveal anything unusual about the space shuttle either. Nevertheless, three more flying parts were observed in the area around Atlantis. All scan data was sent to Houston for further analysis.

Landing of Atlantis

At around 15:45 UTC, Wayne Hale , director of the shuttle program, gave the go-ahead to land the next day. The inspections carried out by the crew were evaluated and it was found that the Atlantis (especially the heat shield) was in excellent condition. Hale explained that while the cause of the mysterious objects had still not been determined, they were not from an area of ​​the ferry that was important for reentry.

After twelve days in orbit, the orbiter's crew initiated a return to Earth on September 21. As planned, the brake engines fired over the Indian Ocean at 9:14 UTC for two and a half minutes ( Deorbit Burn ). 52 minutes before sunrise, the Atlantis touched down punctually at 10:21:30 UTC on runway 33 of the Kennedy Space Center and came to a halt a minute later. The six astronauts left the space shuttle three quarters of an hour later. That same afternoon, the Atlantis was rolled into its assembly hall ( Orbiter Processing Facility ), where it was prepared for its next space flight .

Micrometeorite hit the radiator

On October 6, NASA announced that it was found damaged by a micrometeorite during the routine follow-up inspection of the orbiter at the Kennedy Space Center . The impact was in the radiator of the right cargo hold door and had a diameter of 2.7 millimeters. The foreign body penetrated the 13 millimeter thick aluminum sheet while the payload bay was open. It emerged on the other side, damaging the material in an area two and a half centimeters wide, leaving a 7 millimeter crack and a tiny hole 0.8 millimeters. According to NASA, there was no danger to the crew or the space shuttle.

See also

Web links

Commons : STS-115  - album with pictures, videos and audio files

swell

  1. ↑ NASA: Shuttle Status Report , June 2, 2006 (English)
  2. ↑ NASA: Shuttle Status Report , June 21, 2006 (English)
  3. ↑ NASA: NASA's Space Shuttle Atlantis Moves to Launch Pad , August 2, 2006 (English)
  4. ↑ NASA: NASA Gives' Go 'for Space Shuttle Atlantis' Launch , August 16, 2006 (English)
  5. ↑ NASA: Tricky Replacement Brings Peace of Mind , August 21, 2006 (English)
  6. ^ William Harwood: Lightning delays Atlantis launch a day. Spaceflight Now, September 26, 2006, accessed September 20, 2014 .
  7. ^ William Harwood: Rollback options assessed. Spaceflight Now, September 27, 2006, accessed September 20, 2014 .
  8. ↑ NASA: Shuttle Atlantis Rolls Back to Launch Pad to Ride Out Ernesto , August 29, 2006 (English)
  9. ↑ NASA: NASA Announces Space Shuttle Atlantis Launch Date , August 31, 2006 (English)
  10. ↑ Atlantis is cleared for liftoff. Florida Today, September 8, 2006
  11. ↑ NASA: NASA Postpones Shuttle Atlantis Launch, Aims for Saturday , September 8, 2006 (English)
  12. ↑ NASA: NASA's Shuttle Atlantis Begins Mission to the Space Station , September 9, 2006 (English)
  13. ↑ NASA: STS-115 Status Report # 5 , September 11, 2006 (English)
  14. ↑ Astronauts to activate pivot. Florida Today, September 13, 2006
  15. ↑ NASA: STS-115 Status Report # 9 , September 13, 2006 (English)
  16. ↑ NASA: STS-115 Status Report # 11 , September 14, 2006 (English)
  17. ↑ NASA: STS-115 Status Report # 13 , September 15, 2006 (English)
  18. ↑ NASA: STS-115 Status Report # 17 , September 17, 2006 (English)
  19. ↑ NASA: STS-115 Status Report # 19 , September 18, 2006 (English)
  20. ^ Atlantis in need of one last look. Florida Today, September 20, 2006
  21. ↑ NASA: STS-115 Status Report # 23 , September 20, 2006 (English)
  22. ↑ NASA: NASA Welcomes Space Shuttle Crew Back to Earth , September 21, 2006 (English)
  23. ↑ Houston Chronicle: Space debris put small hole in shuttle , October 6, 2006 (English)
This article was added to the list of excellent articles on October 29, 2006 in this version .