STS-400

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STS-400 mission emblem.

STS-400 ( English S pace T ransportation S ystem) is the mission name for a rescue mission that was prepared for the event of irreparable damage to the Atlantis on the Space Shuttle mission STS-125 . It was planned to use the US space shuttle Endeavor to rescue the seven crew members of the Hubble maintenance mission in an emergency . Since STS-125 was carried out without damaging the space shuttle, the mission was never carried out.

Planned team

The STS-400 crew

The rescue mission crew consisted of four of the astronauts who carried out the STS-126 mission in November 2008 : a commander, a pilot and two mission specialists with experience in space exits :

Originally, four members of the STS-123 team from March 2008 were planned for this purpose:

In the meantime, however, Mike Foreman has been assigned to the STS-129 mission and Bob Behnken to the STS-130 mission . Both flights were only operated in late 2009 and early 2010, respectively. For this reason, STS-400 was assigned a different crew.

Main differences from a normal rescue mission

While the International Space Station (ISS) serves as a safe haven for the main mission on a normal rescue mission, it cannot be reached from Hubble's orbit. Therefore, a new rescue plan had to be developed for the rescue of a Hubble maintenance mission. This includes a switch based on three space exits.

Preparations

Atlantis (front) and Endeavor on the launch systems.

After its final mission, the Endeavor was taken to the Orbiter Processing Facility (OPF), where routine follow-up inspections were carried out. It then stood ready as a rescue shuttle for the STS-326 mission in the event that the crew of the STS-124 mission were forced to stay on the ISS due to a defective heat shield. After a successful end to the STS-124 mission, preparations for the flight began on July 11, 2008 in the Vehicle Assembly Building (VAB) by starting to assemble the Solid Rocket Booster . The external tank arrived on August 11th and was installed between the boosters on August 29th. The Endeavor was installed on the external tank on September 12th, one day after the rollout from the OPF to the VAB, so that the rollout to the 39B launch system could take place on September 19th.

Change of plan

Rescue plan

The STS-125 mission was postponed to January 2009 at the earliest due to Hubble's scientific formatting calculator, which failed at the end of September and was replaced while the STS-125. The Atlantis was unloaded on October 13th and returned to the VAB on October 20th. The Endeavor was transferred to launch facility 39A on October 23 and started from there on the STS-126 mission.

Since the Endeavor was already prepared as a rescue shuttle at that time, but its main mission STS-126 has now been brought forward and it has been replaced by the Discovery as a rescue shuttle, this is the only shuttle mission for which two shuttles have been actively prepared. Due to this change, a change in the mission designation in STS-401 could not be ruled out.

On October 30, it was announced that the spare part would not be available until April 2009, which is why the role of the rescue shuttle was returned to the Endeavor.

At the beginning of 2009 it was announced that an option that had previously been discarded would be considered again in order to ensure a July launch of Ares IX . This option, called "single pad", would bring the Endeavor to launch facility 39A in front of the Atlantis and prepare it as far as possible so that it can be rolled back into the VAB. The Atlantis would then drive to the launch facility and take off normally. The launch facility would then be prepared for another launch so that the Endeavor could start 15 days after the Atlantis at the latest. If this option had been chosen, the Constellation program could have taken over launch system 39B immediately and modified it as much as for the launch of Ares IX. However, the "Dual Pad" variant remained, as the preparations for Ares IX were behind schedule and the major work on the launch system had already been completed.

The Endeavor was transferred to the VAB on April 10, where it was mounted on the external tank over the Easter weekend. She was driven to launch facility 39B on April 17th. In order to ensure a quick start in an emergency, the crew went into quarantine on May 11, 2009. A few days later, the Endeavor reached the state it must have before the start of the countdown, three days before the start. It stayed in this configuration until the countdown started on May 20th to reduce the response time. Only one day later, the Atlantis was given permission to return and the Endeavor released from its rescue task. The Atlantis landed at Edwards Air Force Base on May 24th. A week later, the Endeavor was transferred to launch facility 39A, from which it took off on July 15 for the STS-127 mission .

Mission plan

Shuttle-Shuttle constellation during the rescue mission
Astronauts shimmy along a rope

During the first day of flight, the cargo hold flaps would have been opened and the orbiter boom sensor system (OBSS) would have been prepared for checking the heat shield on the second day of flight by the remote manipulator system (RMS) taking it . In the course of the first day of flight, several engine starts would have provided the necessary orbit height of 600 km. During flight day two, the OBSS would have been stowed away and preparations would have been made for the astronauts to be rescued. In addition, the space suit ( Extravehicular Mobility Unit EMU) on the rescue shuttle would have been prepared for the transfer to Atlantis. After all, the rendezvous with the Atlantis would have been carried out and this would have been taken with the Endeavor robotic arm.

An external mission was planned for the third day . Megan McArthur and Andrew Feustel would have switched during the exit . In addition, the EMU would have been transferred in the opposite direction and a rope would have been stretched between the airlocks. John Grunsfeld would also have switched, but would have taken part in the second disembarkation the following day, during which he would have helped transport two spacesuits to and four Advanced Crew Escape Suits (ACE-Suits) from the Atlantis. In addition, Gregory H. Johnson would have switched. Grunsfeld would also have climbed into the Endeavor and been replaced by Michael Massimino , who would have participated in the second and third exit. During the last exit, he, Scott Altman and Michael Good and the last three take-off and landing suits would have changed to the Endeavor rescue shuttle, but the Hubble maintenance mission shuttle would have had to be released from the rescue shuttle. In addition, the rope would have been removed and kept ready to manually loosen the Endeavor's robotic arm if necessary.

The late-night inspection of the heat shield would have taken place on flight day five, on flight day six an attempt would have been made to land at the Kennedy Space Center .

The Atlantis would have been burned up by a destructive re-entry and the debris would have fallen north of Hawaii .

swell

  1. ↑ Chris Bergin: NASA draws up their Hubble rescue plans. nasaspaceflight.com, November 10, 2007, accessed April 23, 2009 .
  2. ↑ Chris Gebhardt: Pre-empting Hubble: MOD reviews STS-125/400 requirements. nasaspaceflight.com, April 2, 2009, accessed April 23, 2009 .

Web links

Commons : STS-400  - collection of pictures, videos and audio files