STS -125 (English Space Transportation System) was the mission name for a flight of the U.S. Space Shuttle Atlantis ( OV -104 ) from NASA. It was the 30th flight of the Space Shuttle Atlantis. The launch took place on May 11, 2009 at 18:01:56 UTC.

STS -125 was the fifth servicing flight to the Hubble Space Telescope. He was the first flight of the space shuttle since the Columbia tragedy, which led not to the International Space Station (ISS ) and should also remain the last of its kind.

During the servicing mission SM4 (Service Mission 4 ) all three rate sensor units were replaced with two gyroscopes (means for position control of the telescope ), and the two batteries in the context of five spacewalks. Furthermore, a new sensor for accurate alignment of the telescope was installed on celestial objects. An improved research equipment a new camera and a new spectrometer were installed. Due to the success of this repair flight, the operation of the Hubble Space Telescope is valid until at least 2014 as backed up.

  • 4.1 Damage to the launch site
  • 4.2 Preparation of the orbiter
  • 4.3 plan changes
  • 4.4 The second construction
  • 5.1 Start, rendezvous and capture
  • 5.2 Working on Hubble
  • 5.3 return
  • 5.4 Transfer to Florida
  • 8.1 Notes and references


  • Scott Altman (4th space flight), Commander
  • Gregory C. Johnson ( first space flight), Pilot
  • John Grunsfeld ( fifth space flight), Mission Specialist
  • Michael Massimino ( second space flight), Mission Specialist
  • Andrew Feustel ( first space flight), Mission Specialist
  • Michael Good ( first space flight), Mission Specialist
  • Megan McArthur ( first space flight ), Mission Specialist


Various modules were located in the payload bay of Atlantis to be installed in the Hubble. This was to be:

  • Two accumulator battery modules, in which the electrical power generated by the solar cells is stored which is necessary for the operation of the telescope. They replaced the after 19 years of use worn and outdated original batteries.
  • The Cosmic Origins Spectrograph (COS ), a spectrograph, which divided incident light into its component wavelengths and thus determines quantitative data on the observed object. The device operates in the range of ultraviolet light and thus complements the skills of the Space Telescope Imaging Spectrograph ( STIS ), which should be repaired during this mission. The COS was mounted in place of the Corrective Optics Space Telescope Axial Replacement Unit ( COSTAR ), which corrected the error of the primary mirror of the Hubble axial devices since the first servicing mission. Since all later added modules have since been designed with a built-in correction, COSTAR was no longer required and returned to Earth.
  • A fine guidance sensor ( FGS ), which is used together with the two on-board position sensor to align the telescope and for determining the position of stars.
  • Several New Outer Blanket Layers ( NOBL ), insulating mats, which are intended to stabilize the temperature of the telescope. They were attached to the telescope points at which the outermost insulating layer had been peeled off.
  • Three Rate Sensor Units ( RSUs), each containing two gyroscopes and ensure the precise alignment of the telescope. Since half of the gyroscopes Hubble was no longer functional, all three RSUs were replaced.
  • A Science Instrument Command and Data Handling Unit (SIC & DH), which is responsible for the coding and decoding of data for transfer or for execution. It replaced an identical model, which had a defect since October 2008.
  • A Soft Capture Mechanism ( SCM ), a coupling mechanism, to which later shall put an unmanned spacecraft to bring Hubble to crash and thus to burn-out.
  • The Wide Field Camera 3 ( WFC 3), a camera, which captures images in the near infrared, visible and reinforced in the ultraviolet light spectrum. They should complement the skills to be repaired Advanced Camera for Surveys (ACS ) and replace the Wide Field Planetary Camera 2 ( WFPC -2), which has been active since the first servicing mission. The new model has a higher resolution than its predecessor and covers a wider viewing angle.

In addition, the standard for servicing missions container with spare parts was mounted in the payload bay. Furthermore, in the cargo bay a IMAX 3D camera was mounted, which created images of the servicing mission, and the earth for future documentation under the name " Hubble 3D".


STS -125 is unique because of more specific factors in the history of the shuttle program. It differs regardless of the payload in several respects from both the recent missions to the International Space Station as well as from earlier missions in orbit of the telescope.

STS -400

After the Columbia disaster plans for the rescue of a crew have been developed, their shuttle was no longer capable of re-entry. It was as a Contingency Shuttle Crew Support ( CSCS) designated profile with the general mission designation STS -3xx developed in which the crew is evacuated to the International Space Station and there waiting for a rescue shuttle. This profile, however, requires that the orbit of the International Space Station, which has an orbital inclination of 51.6 °, the destination of the mission is to be rescued. This requirement is not met for a Hubble servicing mission with an inclination of 28.5 ° and is not subsequently achieved by orbital maneuvers. Accordingly, NASA had initially fall further Hubble flights. However, after scientists exerted pressure on NASA, Hubble to drive again, you started by an ISS - independent alternative look. We developed an on several spacewalks in a rapidly launched rescue shuttle -based, plan, which as STS -400 was attached to the mission rules for STS -125. STS -125 is thus the only mission for a special rescue plan was drawn up. The role of the rescue shuttle would have taken over the Endeavour.

TAL abort options

STS -125 was the first shuttle mission ever, which had to make do in the case of a TAL abort start with just a single emergency landing on the east side of the Atlantic. With this it was the location in Spain Morone Air Base, which in earlier Hubble missions came into use and is still used today for flights. According to the rules start taking Morone an important role as a shuttle may generally only start when at least one TAL landing site has good weather for a landing.

During previous Hubble missions were used as further VALLEY emergency landing of the Banjul International Airport in The Gambia and the Ben Guérir Air Base in Morocco, which are disabled as such. However, the cut-off time for Banjul was given during the launch.


Damage to the launch site

During the launch of the STS -124 mission is the launch pad had suffered severe damage. As pointed out in a number of other starts, concrete slabs which cover the starting system is pushed out. It was unusual, however, that several firebricks were destroyed in a fire pit the launch site at the start and as debris rains destroyed a separation fence. During the preparation phase on STS -125 tests were conducted, which should help to figure out what exactly had caused the incident. In addition, the necessary repairs have been made. To this end, the remains of the fire bricks were removed from the wall and replaced by new ones. Applying a heat protection product was completed on 1 August 2008, the launcher was released five days later.

Preparations of the orbiter

After the end of its final mission, STS- 122, Atlantis was rolled to the Orbiter Processing Facility (OPF ), where the follow-up took place. Simultaneously, the coupling adapter has been removed because it was not needed on this mission.

On July 15, the external tank was delivered, which was installed after an investigation on August 3 between the Solid Rocket Booster. A few days after delivery, three of the four cargo containers were delivered. In them camped the new components to be installed during the mission. The last container reached the Kennedy Space Center in early August.

Due to Tropical Storm Fay, the transfer of Atlantis to the Vehicle Assembly Building ( VAB) was delayed for several days and finally took place on August 23 (UTC). There she was attached to the external tank and rolled on 4 September to the launch pad 39 -A after delays caused by a small defect at a connection point of the tank as well as the level-1 Hurricane Hanna. Due to various problems with the payload in which, among other things, a Contamination was found by bacteria, which had to be adjusted, the payload container was driven with the cargo until September 21 to the launch and pulled into the Rotating Service Structure. Its content has been mounted in the payload bay on September 26.

On September 21, the team arrived at the Kennedy Space Center to the Terminal Countdown Demonstration Test ( TCDT ) in order to deal there with the on-site training of rescue equipment and to inspect the hardware for flight. After starting the simulation, the crew flew for more workouts on September 22 back to the Johnson Space Center.

Plan changes

On 29 September 2008, NASA announced that on board the Hubble Space Telescope, the primary science instrument Command and Data Handler (SIC & DH) had failed, a hardware component that is responsible for caching and transmission of scientific data to Earth. Since the error of this unit could not be repaired, NASA scientists tried successfully, the reserve system ( "backup system" ) to boot, which had not been used since the test phases in the late 1980s, why was uncertain whether this component at all correct would work. As a result of this failure to install a replacement module was included in the flight plan. However, since such a module was not available before April 2009, and the crew needed preparation time, STS -125 has been postponed and the launch of STS- 126 brought forward. Thus, the Atlantis was discharged from the 13th October and rolled back on October 20th of the starting system 39A to the VAB to make room for the Endeavour that of the starting system 39B, where she stood by as a rescue shuttle for Atlantis, on 25 October there was rolled. The task of the rescue shuttles should henceforth take over the Discovery.

In order to maintain the plans for both the Shuttle program as well as for the Constellation program that Atlantis was dismantled on 11 November 2008 by its external tank and returned to the Orbiter Processing Facility to be submitted to a General Maintenance ( Orbiter Major Down Period). The external tank and its booster were used by the Discovery during the STS -119 mission.

The second structure

In early January 2009 the company began assembling the SRB for the second building. A month later, the external tank was installed. The Atlantis left on March 23, their direction again OPF and VAB was mounted on the following day on the external tank. In this operation, a piece of hardware fell down and damaged the heat shield. The damage was then assessed, and it was decided to repair the damage in the VAB. The Atlantis returned on March 31 back to the launch base 39A.

The now befundene as operational spare parts for the SIC & DH was transferred on March 29 to KSC. The crew flew on 1 April to the Kennedy Space Center, to make himself familiar with the equipment again. On April 18, the payload was transported to the launch and assembled in the following days in the payload bay. During this work, one of the radiators has been damaged in the payload bay, but the damage could be repaired on site. As there were no further problems May 11th, 18:01 UTC was named as first available date during the April 30, conducted Flight Readiness Reviews.

Mission History

Start, rendezvous and capture

The following days were the last to start preparation activities which do not fall within the scope of the countdown. This included, among other things, charging the new battery modules Hubble and other recent work in the payload bay. Finally, the launch team at 19:30 UTC gathered in the control center, so the countdown could begin half an hour later. At 21:00 UTC the team met at the Shuttle Landing Facility one and went to the crew quarters of the Operations and Checkout Building. On the same day the gates of the payload bay were closed. Over the next two days, the space shuttle was further loaded and refueled. After one, apart from a smaller ice formation on the external tank, easy countdown, the Atlantis took off at 18:01:56 UTC. The Solid Rocket Boosters were burning after two minutes of flight as scheduled and were separated. The main engines were disabled after eight and a half minutes and use the external tank dropped shortly thereafter.

During the ascent, a sensor on one of the engines will display incorrect values ​​. The control center in Houston ordered the crew to ignore this because it does not affect the engine efficiency. In the event of a communication loss during the start-up phase, the crew could use these values ​​as an indication of a crash. At the Flammableitkanal the launch site a good 2 -square-meter surface and some gas pipelines was damaged for nitrogen or compressed air. The schedule for Endeavour was not compromised by the necessary repair work.

40 minutes after the start of the first thruster firing, the OMS -2 burn was conducted, which increased the orbit of the space shuttle and stabilized. An hour later, the payload bay doors were opened. Some time later, the robot arm of the shuttle as well as some components were activated in the payload bay of Atlantis. After a short movement test the condition of the payload bay, the crew cabin and the forward wing edge was first observed by the cameras on the robot arm. The pictures gained replace the images of the ISS flights usually carried out Rendezvous Pitch Maneuvers.

On the second flight day (May 12 ) was, as usual, since STS -114, the heat shield tested using the Orbiter Boom Sensor System ( OBSS ). This study was extended for this flight is and focused not only on the front wing edges and the nose of the Space Shuttle, but also to the lower heat shield and the engine section. This happened also to compensate for the absence of the Rendezvous Pitch Maneuver. In the investigation slight surface damage was found in a 50 -cm-long area at the wing roots, which are believed to have originated through a 106 seconds after launch from the Start Video recognizable falling part.

Inside the Space Shuttle preparations were made for the spacewalks meanwhile. Thus, the space suits were unpacked and prepared for their first jobs, are recharged by replacing the batteries and the oxygen tanks of the life support system were filled. Furthermore, the air pressure inside the shuttle from normal pressure (1013 hPa) was reduced to 703 hPa, so that the amount of dissolved in the body tissues of the spaceman inert gases ( mainly nitrogen ) decreased accordingly. This bent of decompression sickness before during spacewalks and allowed to waive a long Voratmen of oxygen. Furthermore, we flipped the platform, which should be mounted on Hubble, from the start to the working position.

A total of three times the OMS engines were activated for NC ignitions. This thruster firings changed the orbit of Atlantis and brought them to an intercept course with Hubble. Hubble himself shut the damper of the primary mirror in preparation for the arrival of Atlantis. Over the night from the second to third day of flying and the transmission antennas of the telescope were collapsed.

On the third flight day (May 13 ) the rendezvous took place. Early in the flight day two thruster firings took place, another NC ignition and compared to strong NH- ignition, which brought the Atlantis in 15.24 km distance from Hubble. There, the last major engine ignition, the TI- Burn took place which initiated the first phase of the rendezvous. After two minor course corrections, the Space Shuttle reached a position a few hundred meters below Hubble. Scott Altman took over from the time when the manual control of the Atlantis and flew them up close to the telescope. He then flew a pitch maneuvers, so Megan McArthur could take the telescope with the robot arm. She moved her arm then so that Hubble could be mounted on the platform and connected to the power supply of the shuttles. Rest of the day spent with the crew of photographic documentation of Hubble's exterior and preparations for the first exit, where the WFPC -2 and the SIC & DH should be replaced.

Working on Hubble

Flight day four ( 14 May) began with the final preparations for the exit. John Grunsfeld and Andrew Feustel put on their space suits and went into the airlock. There she breathed for the further reduction of the inert gases is a about 45 minutes oxygen before decompression of the air lock has been initiated. They began to phase with the switching of the suits on internal power supply at 12:52 UTC. First they carried out some preliminary tasks. This included, among other things, to install a small foot holder at the end of the robot arm, so Feustel was able to climb this. Megan McArthur was able to use the robotic arm to allow Feustel access to the jobs. While Feustel was moved to the position of the WFPC -2, Grunsfeld worked in the payload bay and opened the shutters of the camera container. He also mounted a bracket in the removed devices could be stored temporarily.

Andrew Feustel began working on WFPC - 2 by a handle mounted on it. During removal, however, several problems occurred with a screw, which prevented the immediate removing the device. After this problem was solved, Feustel pulled the camera from the telescope and brought it to the temporary holder. Then, the robot arm maneuvered him so that he could remove the WFC -3 from its container and insert it into Hubble. While WFPC -2 was pushed into the container of her successor, was WFC -3 an initial test, is only checked at the whether the device was active. The function test, in which the base data transmitted by the camera are evaluated, it was several hours later.

The next task was to replace the SIC & DH unit. Feustel was it brought to the door on which the faulty unit was mounted. While he undid the latch bolt and removed the unit, Grunsfeld replaced the SIC & DH new from their starting position and brought her to Feustel. With him, they exchanged the units and installed the equipment obtained in each case to the same positions in which they had previously taken the other. The new SIC & DH completed their initial test and subsequent functional test successfully.

Since Grunsfeld was quickly finished with this task, he assembled the Soft Capture Mechanism on Hubble. As there was some time available, he took some " Lock -over -center kits " (Lock), which were mounted in preparation for the third exit at one of Hubble's doors. They allowed a faster opening of the door. During the assembly, which Feustel performed again, there were difficulties with a bolt, why were installed by the Locks three planned only two. The installation of the third Locks was indeed begun, but later canceled and for another, the lock mechanism similar installed. Following this work, the duo went back into the airlock and closed the exit at 16:12 UTC after seven hours and 20 minutes. The rest of the day was the preparation for the next exit, whose goal was the replacement of the RSUs and the first battery.

The first action on the fifth flight day (May 15 ) concerned the inspection of a relatively small area of the lower heat shield. This site was not detected during the flight day - two - inspection and only for completeness rescheduled, only the cameras were used on the robot arm. During this 45 -minute action, Michael Massimino and Michael Good were preparing for their exit. They switched their spacesuits at 12:49 UTC on internally and left the airlock. While Good fastened to the robot arm, Massimino opened the container, which included the RSUs. He also mounted a tool for getting out. Massimino then went to the work site to Hubble, opened it, and prepared them for the work. Meanwhile, Good took the first unit from the container and was transported to the telescope. There he broke the old unit and built the new one without any problems. He flew back, tucked the old unit and took another. However, this unit should prove defective and thus was in Hubble useless, which is why it was stowed away and replaced with a spare unit. The last unit could be easily re-install. All three new RSUs passed the initial and later the function test.

Despite the lateness of the hour it was decided to carry out the exchange of the first battery module. So Good was maneuvered to the new working position, where he opened the door and the battery module triggered by the door inside. After the electronic connections are disconnected, he flew to Massimino and swapped the old module to the new one. He then mounted the battery and joined them. They also insisted both tests. After a minor additional task in preparation for the next exit betook themselves " the Mike " back into the airlock, which was placed around 20:45 UTC under pressure again. With seven hours and 56 minutes they reached the eighth place on the list of longest spacewalks. Preparations for the next exit, mounted at the COS and ACS should be repaired ended the day the astronauts.

Against all expectations, was the third exit, the second of the duo Grunsfeld / Feustel, better than originally thought. After they had begun its withdrawal on the sixth day of flying (May 16 ) at 13:35 UTC, both worked to COSTAR to exchange against the Cosmic Origins Spectograph. This work was carried out similar to the replacement of the WFPC -2 against WFC -3 and could be carried out without problems. COS was the initial and the function test.

Then the astronauts started to work at the Advanced Camera for Surveys, which should be the first instrument ever repaired during a spacewalk. John Grunsfeld, who carried out all the work to ACS, it had to remove part of the outer casing of the device, which is only by excision was possible. He brought a device to the housing which cut a hole in the fairing and thereby resulting residual materials einbehielt, so they posed no more threat to astronauts. Then Grunsfeld installed a tool on the top plate of the actual work location. This tool enabled him to remove 32 screws, which would not otherwise be captured. Grunsfeld then took advantage of a special hand tool and removed the four cards of the electronic system of the camera. These cards had suffered a short circuit in January 2007 and had since then functioning. When removing the card, there were no difficulties, so Grunsfeld at the end of this task was an hour before schedule. So the duo was granted permission to begin with the second part of the ACS works. These works were not intended for this exit and were also in the entire mission planning according to the SIC & DH- failure only optional in the flight plan. So Grunsfeld set up a box in the slot, which contains the same components that were also on the cards. It also put the power supply which is necessary for the use of the box. They then completed the ACS work and began to leave the workplace. The Advanced Camera for Surveys was previously the initial test. The schedule extended by the additional work from 6.5 to 7.66 hours exit ended already after 6 hours and 36 minutes around 20:11 UTC.

Although ACS passed the initial test, was the functional tests that the high-resolution channel of the device did not respond. They had already expected that this channel would not be reactivated by the repair, though hopes had insisted.

The exit four of the mission began on the seventh day of flying (May 17 ) at 13:45 UTC. During her second exit, the duo Massimino / Good the Space Telescope Imaging Spectograph ( STIS ) should reactivate a repair. They needed to remove some terminals on the housing and a holder of the cover plate. However, removal of a bolt of the support rod was not possible, so this Massimino had to finally break out. He then installed a tool on the top plate, which captured the total of 111 screws that had to be removed for access to the inside. Thereafter, the circuit board has been removed and replaced with a new one even when STIS. Due to the highly advanced time, the planned installation of a NOBL insulation mat was no longer carried out and completed the exit at 21:47 UTC. With eight hours and two minutes of this exit is ranked in sixth place in the list of the longest spacewalks.

STIS passed the initial test, however, turned during the function test in a security mode, since the temperature of the device was too much. A new function test should be performed as soon as the temperature would have stabilized.

After the end of the exit Hubble was rotated 180 °, making the back of the previously unseen telescope was visible. It was found that the insulation on the body which originally had in the fourth exit to be renewed, was heavily damaged. It was decided to perform this task during the fifth exit.

The final withdrawal of the mission took place (May 18 ) on the eighth day of flying. Grunsfeld and Feustel left at 12:20 UTC for the third time the crew cabin and worked on the replacement of the second battery module. The work required for this coincided with those of its counterpart and could be carried out without problems. The battery consisted of the initial test. Astronauts started then to remove one of the three fine guidance sensors from its holder, so that a new could be mounted in position. The works were comparable with the exchange of WFPC -2 and were completed without any problems.

Because these tasks were completed in less than three hours, permission was granted to install the three NOBLs. Before installing the new insulation but first had each the old mats are removed. For the rear brackets and fastenings of the mats had to be solved and severed part. While this is easily worked with the first of the three mats, made the second more trouble. After the mat was replaced could be continued with the third mat. Then configured Grunsfeld and Feustel the robot arm and the payload bay for the trip home. It was a little accident with the telescope: John Grunsfeld prepared the platform just to the folding of the next day prior when he accidentally collided with the transmitting antenna of the telescope for low frequencies and this damaged. It worked then still work, but it was decided at short notice to repair the damage immediately. Grunsfeld and Feustel completed the last exit of the mission after seven hours and two minutes at 19:22 UTC. With a total of 36 hours and 56 minutes spacewalks during this mission, the longest time during a single mission, the Hubble Service program ended after 23 exits with a total duration of 166 hours and six minutes. John Grunsfeld, who participated in a total of nine of these exits, reached the third place in the list of spaceman with the largest outboard experience at 58 hours and 30 minutes. It was also the last time that a withdrawal was completed on schedule on the airlock of the shuttle.

Shortly after the end of the exit, the transmit antennas are expanded for high transmission rates again. Furthermore, it turned Hubble back to the starting position.


On flight day nine (19 May ) Hubble was separated from the Shuttle. Megan McArthur took to Hubble with the robotic arm, removed it from the service platform and lifted it out of the payload bay. After the protective bulkhead of the mirror had been opened, the telescope at 12:57 UTC was released. Subsequently, the Atlantis was slowly moved away from the telescope until she was far enough away to enable her engine and continued to remove. The crew then began with the late inspection of the heat shield and the collapse of the maintenance stage in preparation for landing. The perigee of the sheet was lowered to 300 km in order to reduce the risk by micrometeorites and space debris by a thruster firing.

The tenth day of flying (May 20 ) was released to the crew members. They gave the traditional press conference and had the opportunity to speak with the crew of the International Space Station. Furthermore, initial preparations were for landing. On the eleventh day of flying (May 21 ), these activities were continued and checked the flight control systems for landing.

The landing of Atlantis was scheduled for the twelfth day of flying ( May 22 ) at the Kennedy Space Center, but the two landing opportunities were discarded due to bad weather. For flight day 13 (May 23 ) and the Edwards Air Force Base was activated. Overall, there were six landing facilities on three orbits ( three at KSC and three on the EAFB ), which, however, were all rejected.

Flight day 14 (May 24 ) was the penultimate planned mission day, so had to be a landing without the presence of technical obstacles. It was first worked on the first landing opportunity at Kennedy Space Center, but was rejected because of the uncertain weather. In the next orbit, it was decided 20 minutes before the deorbit burn due to the still volatile weather at KSC for the second landing opportunity at Edwards AFB and lit to 14:24 UTC the engines. 75 minutes later the ferry on track 22. The astronauts left about an hour later the Space Shuttle and peer-reviewed before they were sent to their quarters.

Transfer to Florida

After landing the Atlantis was drawn to the mater- demate device, where she was raised in preparation for mounting on the Shuttle Carrier Aircraft. Further there an engine cover has been installed, in order to improve the aerodynamic conditions. On 1 June at 15:03 UTC, the aircraft took off for the first section to Biggs Army Airfield in El Paso, where the composite remained overnight. The next day we went at 12:41 UTC on. There were more refueling stops at Lackland AFB in San Antonio and on the Columbus AFB inserted in Columbus before they landed at 22:53 UTC on the NASA Shuttle Landing Facility. The Atlantis was dissolved in the next few days from the aircraft and transferred in preparation for their next mission STS -129 in the Orbiter Processing Facility.