STS-3xx
Encyclopedia
Space Shuttle missions designated STS-3xx (officially called Launch On Need (LON) missions) were rescue missions which would have been mounted to rescue the crew of a Space Shuttle
if their vehicle was damaged and deemed unable to make a successful reentry. Such a mission would have been flown if Mission Control determined that the heat shielding tiles and reinforced carbon-carbon
panels of a currently flying orbiter were damaged beyond the repair capabilities of the available on-orbit repair methods. These missions were also referred to as Launch on Demand (LOD) and Contingency Shuttle Crew Support. No mission of this type was launched during the space shuttle program.
to launch the mission within a period of 40 days of its being called up. During that time the damaged (or disabled) shuttle's crew would have to take refuge on the International Space Station
(ISS). The ISS is able to support both crews for around 80 days, with oxygen supply being the limiting factor. Within NASA, this plan for maintaining the shuttle crew at the ISS is known as Contingency Shuttle Crew Support (CSCS) operations. Up to STS-121
all rescue missions were to be designated STS-300.
After STS-124
the Shuttle missions to the ISS no longer need such a mission since due to the increased capabilities of the ISS, a stranded crew would have sufficient on-board resources to wait for the next Shuttle mission.
In the case of an abort to orbit, where the shuttle is unable to reach the ISS orbit and the thermal protection system inspections suggest the shuttle cannot return to Earth safely, the ISS may be capable of descent down to meet the shuttle. Such a procedure is known as a joint underspeed recovery.
_and_endeavour_(sts-400)_on_launch_pads.jpg)
To save weight, and to allow the combined crews of both shuttles to return to Earth safely, many shortcuts would have to be made, and the risks of launching another orbiter without resolving the failure which caused the previous orbiter to become disabled would have to be faced.
The purpose of the RCO IFM cable was to provide an electrical signal connection between the Ground Command Interface Logic (GCIL) and the flight deck panel switches. With this system, signals could be sent from the Mission Control Center to the unmanned shuttle to control the following systems:
The RCO IFM cable first flew aboard STS-121
and was transferred to the ISS for storage during the mission. The cable remained aboard the ISS until the end of the Shuttle program when it will be brought back to Earth on the final Shuttle flight.
Prior to STS-121 the plan was for the damaged shuttle to be abandoned and allowed to burn up on reentry. The prime landing site for an RCO orbiter would be Vandenberg Air Force Base
in California. Edwards Air Force Base
, a site already used to support shuttle landings, was the prime RCO landing site for the first missions carrying the equipment; however Vandenberg was later selected as the prime site as it is nearer the coast, and the shuttle can be ditched in the Pacific should a problem develop that would make landing dangerous. White Sands Missile Range
in New Mexico
is a likely alternate site. A major consideration in determining the landing site would be the desire to perform a high-risk re-entry far away from populated areas. The flight resource book, and flight rules in force during STS-121 suggest that the damaged shuttle would reenter on a trajectory such that if it should break up, it would do so with debris landing in the South Pacific Ocean.
The Soviet Buran shuttle was also remotely controlled during its entire maiden flight without a crew aboard. Landing was carried out by an on-board, automatic system. Buran was also designed to remotely launch up to 5 nuclear bombs from the payload bay.
As of March 2011 the Boeing X-37
extended duration robotic spaceplane has demonstrated autonomous orbital flight, reentry and landing. The X-37 was originally indented for launch from the Shuttle payload bay, but following the Columbia accident
, it was launched in a shrouded configuration on an Atlas V
.
. However, NASA spent some effort researching rescue options even before the disaster. Before the ISS was launched, or in the event of the shuttle being unable to reach the station, shuttle crews would have had to transfer directly between shuttles. The orbiters would have been unable to dock, so while they used their RMS arms to grapple each other, the crew would have made an EVA
between the shuttles. This would have been carried out using the two EVA-designated mission specialists wearing the Shuttle/ISS Extravehicular Mobility Unit
(EMU) spacesuits, while the remaining crew would have been sealed up in pressurized Personal Rescue Enclosure
and carried over either by hand, or using a pulley system (akin to that of a clothesline pulley) like that employed in the Apollo
program for lifting samples from the Moon's surface into the Lunar Module
.
was a Hubble Space Telescope
servicing mission. Since the Hubble telescope orbits at a higher altitude and a lower orbital inclination compared to the International Space Station, there was no option for a shuttle crew to use the ISS as a safe haven; In response, NASA developed a plan to conduct a shuttle-to-shuttle rescue mission, similar to proposed rescue missions for pre-ISS flights. This rescue mission, designated STS-400, could have been launched as early as seven days after the launch of STS-125, as the maximum time the STS-125 crew could have remained on the damaged shuttle (Atlantis
) was 23 days. For this mission, the rescue shuttle (Endeavour
) was rolled out to its launch pad after the STS-125 shuttle, creating a rare scenario of two shuttles being on the launch pads at the same time. When this occurred, it was 19th and final time in Shuttle Program history that two shuttle vehicles occupied both KSC launch pads at the same time. The mission had its own, unique flight plan that differed from previous rescue flight plans.
was the last scheduled flight of the Shuttle program. Because no more were planned after this, a special mission was developed as STS-335 to act as the LON mission for this flight. This would have paired Atlantis
with ET-122
, which has been refurbished following damage by Hurricane Katrina
. Since there would be no next mission, STS-335 would also carry a Multi-Purpose Logistics Module
filled with supplies to replenish the station.
The Senate authorized STS-135
as a regular flight on 5 August 2010
, followed by the House authorization on 29 September 2010, and later by President Obama on 11 October 2010. However funding for the mission remained dependent on a subsequent appropriation bill.
Nonetheless NASA converted STS-335, the final Launch On Need mission, into an operational mission (STS-135) on 20 January 2011. On 13 February 2011, program managers told their workforce that STS-135 would fly “regardless” of the funding situation via a continuing resolution. Finally the U.S. government budget approved in mid-April 2011 called for $5.5 billion for NASA's space operations division, including the space shuttle and space station programs. According to NASA, the budget running through 30 September 2011 ended all concerns about funding the STS-135 mission.
With the successful completion of STS-134, STS-335 was rendered unnecessary and launch preparations for STS-135 continued as Atlantis neared LC-39A during her rollout as STS-134 landed at the nearby Shuttle Landing Facility.
For the STS-135, no shuttle was available for a rescue mission, but there was a different rescue plan, which was not used.
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
if their vehicle was damaged and deemed unable to make a successful reentry. Such a mission would have been flown if Mission Control determined that the heat shielding tiles and reinforced carbon-carbon
Reinforced carbon-carbon
Carbon fibre-reinforced carbon is a composite material consisting of carbon fibre reinforcement in a matrix of graphite. It was developed for the nose cones of intercontinental ballistic missiles, and is most widely known as the material for the nose cone and wing leading edges of the Space Shuttle...
panels of a currently flying orbiter were damaged beyond the repair capabilities of the available on-orbit repair methods. These missions were also referred to as Launch on Demand (LOD) and Contingency Shuttle Crew Support. No mission of this type was launched during the space shuttle program.
Procedure
The orbiter and four of the crew which were due to fly the next planned mission would be retasked to the rescue mission. The planning and training processes for a rescue flight would allow NASANASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
to launch the mission within a period of 40 days of its being called up. During that time the damaged (or disabled) shuttle's crew would have to take refuge on the International Space Station
International Space Station
The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
(ISS). The ISS is able to support both crews for around 80 days, with oxygen supply being the limiting factor. Within NASA, this plan for maintaining the shuttle crew at the ISS is known as Contingency Shuttle Crew Support (CSCS) operations. Up to STS-121
STS-121
STS-121 was a space shuttle mission to the International Space Station flown by Space Shuttle Discovery. The main purposes of the mission were to test new safety and repair techniques introduced following the Columbia disaster of February 2003 as well as to deliver supplies, equipment and...
all rescue missions were to be designated STS-300.
After STS-124
STS-124
STS-124 was a Space Shuttle mission, flown by Space Shuttle Discovery to the International Space Station. Discovery launched on 31 May 2008 at 17:02 EDT, moved from an earlier scheduled launch date of 25 May 2008, and landed safely at the Kennedy Space Center's Shuttle Landing Facility, at 11:15...
the Shuttle missions to the ISS no longer need such a mission since due to the increased capabilities of the ISS, a stranded crew would have sufficient on-board resources to wait for the next Shuttle mission.
In the case of an abort to orbit, where the shuttle is unable to reach the ISS orbit and the thermal protection system inspections suggest the shuttle cannot return to Earth safely, the ISS may be capable of descent down to meet the shuttle. Such a procedure is known as a joint underspeed recovery.
| Flight | Rescue Flight |
|---|---|
| STS-114 STS-114 -Original crew:This mission was to carry the Expedition 7 crew to the ISS and bring home the Expedition 6 crew. The original crew was to be:-Mission highlights:... (Discovery Space Shuttle Discovery Space Shuttle Discovery is one of the retired orbiters of the Space Shuttle program of NASA, the space agency of the United States, and was operational from its maiden flight, STS-41-D on August 30, 1984, until its final landing during STS-133 on March 9, 2011... ) |
STS-300 (Atlantis Space Shuttle Atlantis The Space Shuttle Atlantis is a retired Space Shuttle orbiter in the Space Shuttle fleet belonging to the National Aeronautics and Space Administration , the spaceflight and space exploration agency of the United States... ) |
| STS-121 STS-121 STS-121 was a space shuttle mission to the International Space Station flown by Space Shuttle Discovery. The main purposes of the mission were to test new safety and repair techniques introduced following the Columbia disaster of February 2003 as well as to deliver supplies, equipment and... (Discovery) |
STS-300 (Atlantis) |
| STS-115 STS-115 Note:The P3/P4 Truss segment and batteries were so heavy that the crew count was reduced from seven to six.-Crew notes:... (Atlantis) |
STS-301 (Discovery) |
| STS-116 STS-116 -Crew notes:Originally this mission was to carry the Expedition 8 crew to the ISS. The original crew was to be:-Mission highlights:* The STS-116 mission delivered and attached the International Space Station's third port truss segment, the P5 truss.... (Discovery) |
STS-317 (Atlantis) |
| STS-117 STS-117 - Crew Notes :The initial crew manifest before the Columbia accident was:Astronaut Mark Polansky was originally slated to pilot this mission, but was moved to STS-116, which he commanded... (Atlantis) |
STS-318 (Endeavour Space Shuttle Endeavour Space Shuttle Endeavour is one of the retired orbiters of the Space Shuttle program of NASA, the space agency of the United States. Endeavour was the fifth and final spaceworthy NASA space shuttle to be built, constructed as a replacement for Challenger... ) |
| STS-118 STS-118 - Crew notes :Astronaut Clayton Anderson originally was slated to be launched to the ISS on this mission, but was moved to STS-117. His replacement was Alvin Drew.... (Endeavour) |
STS-322 (Discovery) |
| STS-120 STS-120 -Crew notes:As commander of STS-120, Pamela Melroy became the second woman to command a space shuttle mission. Additionally, the Expedition 16 crew that received STS-120 was commanded by Peggy Whitson, the first female ISS commander... (Discovery) |
STS-320 (Atlantis) |
| STS-122 STS-122 STS-122 was a NASA Space Shuttle mission to the International Space Station , flown by the Space Shuttle Atlantis. STS-122 marked the 24th shuttle mission to the ISS, and the 121st space shuttle flight since STS-1.... (Atlantis) |
STS-323 (Discovery*) |
| STS-123 STS-123 -Mission parameters:* Mass:* Orbiter liftoff: * Orbiter landing: * Perigee: 336 kilometers * Apogee: 346 kilometers * Inclination: 51.6 degrees* Period: 91.6min-Mission payloads:... (Endeavour) |
STS-324 (Discovery) |
| STS-124 STS-124 STS-124 was a Space Shuttle mission, flown by Space Shuttle Discovery to the International Space Station. Discovery launched on 31 May 2008 at 17:02 EDT, moved from an earlier scheduled launch date of 25 May 2008, and landed safely at the Kennedy Space Center's Shuttle Landing Facility, at 11:15... (Discovery) |
STS-326 (Endeavour) |
| STS-125 STS-125 STS-125, or HST-SM4 , was the fifth and final space shuttle servicing mission to the Hubble Space Telescope .Launch occurred on 11 May 2009 at 2:01 pm EDT... (Atlantis) |
STS-400 STS-400 - Early mission plans :Three different concept mission plans were evaluated: The first would be to use a shuttle-to-shuttle docking, where the rescue shuttle docks with the damaged shuttle, by flying upside down and backwards, relative to the damaged shuttle... (Endeavour) |
| STS-134 STS-134 STS-134 was the penultimate mission of NASA's Space Shuttle program. The mission marked the 25th and final flight of . This flight delivered the Alpha Magnetic Spectrometer and an ExPRESS Logistics Carrier to the International Space Station. Mark Kelly served as the mission commander... (Endeavour) |
STS-335 (Atlantis) |
* – originally scheduled to be Endeavour, changed to Discovery due to contamination issues.
To save weight, and to allow the combined crews of both shuttles to return to Earth safely, many shortcuts would have to be made, and the risks of launching another orbiter without resolving the failure which caused the previous orbiter to become disabled would have to be faced.
Flight hardware
A number of pieces of Launch on Need flight hardware have been built in preparation for a rescue mission including:- An extra three recumbent seats to be located in the aft middeck (ditch area)
- Two handholds located on the starboard wall of the ditch area
- Individual Cooling Units mounting provisions
- Seat 5 modification to properly secure in a recumbent position
- Mounting provisions for four additional sky genies
- Escape Pole mounting provisions for three additional lanyards
Remote Control Orbiter
The Remote Control Orbiter (RCO), also known as the Autonomous Orbiter Rapid Prototype (AORP), was a term used by NASA to describe a shuttle that could perform entry and landing without a human crew on board via remote control. NASA developed the RCO in-flight maintenance (IFM) cable to extend existing auto-land capabilities of the shuttle to allow remaining tasks to be completed from the ground. The cable is approximately 28 feet (8.5 m) long, weighs over 5 lb (2.3 kg), and has 16 connectors.The purpose of the RCO IFM cable was to provide an electrical signal connection between the Ground Command Interface Logic (GCIL) and the flight deck panel switches. With this system, signals could be sent from the Mission Control Center to the unmanned shuttle to control the following systems:
- Auxiliary Power UnitAuxiliary power unitAn auxiliary power unit is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft, as well as some large land vehicles.-Function:...
(APU) start and run - Air Data Probe (ADP) deployment
- Main Landing GearLanding GearLanding Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...
(MLG) arming and deployment - Drag chute arming and deployment
- Fuel cellFuel cellA fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. Hydrogen is the most common fuel, but hydrocarbons such as natural gas and alcohols like methanol are sometimes used...
reactant valve closure
The RCO IFM cable first flew aboard STS-121
STS-121
STS-121 was a space shuttle mission to the International Space Station flown by Space Shuttle Discovery. The main purposes of the mission were to test new safety and repair techniques introduced following the Columbia disaster of February 2003 as well as to deliver supplies, equipment and...
and was transferred to the ISS for storage during the mission. The cable remained aboard the ISS until the end of the Shuttle program when it will be brought back to Earth on the final Shuttle flight.
Prior to STS-121 the plan was for the damaged shuttle to be abandoned and allowed to burn up on reentry. The prime landing site for an RCO orbiter would be Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
in California. Edwards Air Force Base
Edwards Air Force Base
Edwards Air Force Base is a United States Air Force base located on the border of Kern County, Los Angeles County, and San Bernardino County, California, in the Antelope Valley. It is southwest of the central business district of North Edwards, California and due east of Rosamond.It is named in...
, a site already used to support shuttle landings, was the prime RCO landing site for the first missions carrying the equipment; however Vandenberg was later selected as the prime site as it is nearer the coast, and the shuttle can be ditched in the Pacific should a problem develop that would make landing dangerous. White Sands Missile Range
White Sands Missile Range
White Sands Missile Range is a rocket range of almost in parts of five counties in southern New Mexico. The largest military installation in the United States, WSMR includes the and the WSMR Otera Mesa bombing range...
in New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
is a likely alternate site. A major consideration in determining the landing site would be the desire to perform a high-risk re-entry far away from populated areas. The flight resource book, and flight rules in force during STS-121 suggest that the damaged shuttle would reenter on a trajectory such that if it should break up, it would do so with debris landing in the South Pacific Ocean.
The Soviet Buran shuttle was also remotely controlled during its entire maiden flight without a crew aboard. Landing was carried out by an on-board, automatic system. Buran was also designed to remotely launch up to 5 nuclear bombs from the payload bay.
As of March 2011 the Boeing X-37
Boeing X-37
The Boeing X-37 is an American unmanned vertical-takeoff, horizontal-landing spaceplane. The X-37 is operated by the United States Air Force for orbital spaceflight missions intended to demonstrate reusable space technologies...
extended duration robotic spaceplane has demonstrated autonomous orbital flight, reentry and landing. The X-37 was originally indented for launch from the Shuttle payload bay, but following the Columbia accident
Space Shuttle Columbia disaster
The Space Shuttle Columbia disaster occurred on February 1, 2003, when shortly before it was scheduled to conclude its 28th mission, STS-107, the Space Shuttle Columbia disintegrated over Texas and Louisiana during re-entry into the Earth's atmosphere, resulting in the death of all seven crew members...
, it was launched in a shrouded configuration on an Atlas V
Atlas V
Atlas V is an active expendable launch system in the Atlas rocket family. Atlas V was formerly operated by Lockheed Martin, and is now operated by the Lockheed Martin-Boeing joint venture United Launch Alliance...
.
Pre-ISS era
The STS-3xx missions were developed in the aftermath of the loss of ColumbiaSpace Shuttle Columbia disaster
The Space Shuttle Columbia disaster occurred on February 1, 2003, when shortly before it was scheduled to conclude its 28th mission, STS-107, the Space Shuttle Columbia disintegrated over Texas and Louisiana during re-entry into the Earth's atmosphere, resulting in the death of all seven crew members...
. However, NASA spent some effort researching rescue options even before the disaster. Before the ISS was launched, or in the event of the shuttle being unable to reach the station, shuttle crews would have had to transfer directly between shuttles. The orbiters would have been unable to dock, so while they used their RMS arms to grapple each other, the crew would have made an EVA
Extra-vehicular activity
Extra-vehicular activity is work done by an astronaut away from the Earth, and outside of a spacecraft. The term most commonly applies to an EVA made outside a craft orbiting Earth , but also applies to an EVA made on the surface of the Moon...
between the shuttles. This would have been carried out using the two EVA-designated mission specialists wearing the Shuttle/ISS Extravehicular Mobility Unit
Extravehicular Mobility Unit
The Space Shuttle/International Space Station Extravehicular Mobility Unit is an independent anthropomorphic system that provides environmental protection, mobility, life support, and communications for a Space Shuttle or International Space Station crew member to perform extra-vehicular activity...
(EMU) spacesuits, while the remaining crew would have been sealed up in pressurized Personal Rescue Enclosure
Personal Rescue Enclosure
The personal rescue enclosure or "rescue ball" was developed as a solution for transporting astronauts from one Space Shuttle to another in case of an emergency. The device was produced as a prototype but never flew on any missions....
and carried over either by hand, or using a pulley system (akin to that of a clothesline pulley) like that employed in the Apollo
Project Apollo
The Apollo program was the spaceflight effort carried out by the United States' National Aeronautics and Space Administration , that landed the first humans on Earth's Moon. Conceived during the Presidency of Dwight D. Eisenhower, Apollo began in earnest after President John F...
program for lifting samples from the Moon's surface into the Lunar Module
Apollo Lunar Module
The Apollo Lunar Module was the lander portion of the Apollo spacecraft built for the US Apollo program by Grumman to carry a crew of two from lunar orbit to the surface and back...
.
Sample timeline
Had a LON mission been required, a timeline would have been developed similar to the following:- FD-10 A decision on the requirement for Contingency Shuttle Crew Support (CSCS) is expected by flight day 10 of a nominal mission.
- FD-10 Shortly after the need for CSCS operations a group C powerdown of the shuttle will take place.
- FD-11->21 During flight days 11 ~ 21 of the mission the shuttle will remain docked to the international space station (ISS) with the hatch open. Various items will be transferred between the shuttle and ISS.
- FD-21 Hatch closure will be conducted from the ISS side. The shuttle crew remains on the ISS, leaving the shuttle unmanned
- FD-21 Deorbit Burn – Burn occurs four hours after separation. Orbiter lands at Vandenberg Air Force Base under remote control from Houston. (Prior to STS-121, the payload bay doors would have been left open to promote vehicle breakup.)
- FD-45 Launch of rescue flight. 35 days from call-up to Launch for the rescue flight is a best-estimate of the minimum time it will take before a rescue flight is launched.
- FD-45->47 The rescue flight catches up with the ISS, conducting heat shield inspections en-route.
- FD-47 The rescue flight docks with the station, on day three of its mission.
- FD-48 Shuttle crew enters the rescue orbiter. Vehicle with a crew complement of 11 undocks from ISS.
- FD-49 Rescue orbiter re-enters atmosphere over Indian or Pacific Ocean for landing at either Kennedy Space Center or Edwards Air Force Base. A Russian ProgressProgress spacecraftThe Progress is a Russian expendable freighter spacecraft. The spacecraft is an unmanned resupply spacecraft during its flight but upon docking with a space station, it allows astronauts inside, hence it is classified manned by the manufacturer. It was derived from the Soyuz spacecraft, and is...
resupply spacecraft is launched at later date to resupply ISS crew. ISS precautionary de-crew preparations begin. - FD-58 De-crew ISS due to ECLSSISS ECLSSThe International Space Station Environmental Control and Life Support System is a life support system that provides or controls atmospheric pressure, fire detection and suppression, oxygen levels, waste management and water supply...
O2OxygenOxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
exhaustion in event Progress unable to perform resupply function.
STS-125 rescue
STS-125STS-125
STS-125, or HST-SM4 , was the fifth and final space shuttle servicing mission to the Hubble Space Telescope .Launch occurred on 11 May 2009 at 2:01 pm EDT...
was a Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
servicing mission. Since the Hubble telescope orbits at a higher altitude and a lower orbital inclination compared to the International Space Station, there was no option for a shuttle crew to use the ISS as a safe haven; In response, NASA developed a plan to conduct a shuttle-to-shuttle rescue mission, similar to proposed rescue missions for pre-ISS flights. This rescue mission, designated STS-400, could have been launched as early as seven days after the launch of STS-125, as the maximum time the STS-125 crew could have remained on the damaged shuttle (Atlantis
Space Shuttle Atlantis
The Space Shuttle Atlantis is a retired Space Shuttle orbiter in the Space Shuttle fleet belonging to the National Aeronautics and Space Administration , the spaceflight and space exploration agency of the United States...
) was 23 days. For this mission, the rescue shuttle (Endeavour
Space Shuttle Endeavour
Space Shuttle Endeavour is one of the retired orbiters of the Space Shuttle program of NASA, the space agency of the United States. Endeavour was the fifth and final spaceworthy NASA space shuttle to be built, constructed as a replacement for Challenger...
) was rolled out to its launch pad after the STS-125 shuttle, creating a rare scenario of two shuttles being on the launch pads at the same time. When this occurred, it was 19th and final time in Shuttle Program history that two shuttle vehicles occupied both KSC launch pads at the same time. The mission had its own, unique flight plan that differed from previous rescue flight plans.
STS-335
STS-134STS-134
STS-134 was the penultimate mission of NASA's Space Shuttle program. The mission marked the 25th and final flight of . This flight delivered the Alpha Magnetic Spectrometer and an ExPRESS Logistics Carrier to the International Space Station. Mark Kelly served as the mission commander...
was the last scheduled flight of the Shuttle program. Because no more were planned after this, a special mission was developed as STS-335 to act as the LON mission for this flight. This would have paired Atlantis
Space Shuttle Atlantis
The Space Shuttle Atlantis is a retired Space Shuttle orbiter in the Space Shuttle fleet belonging to the National Aeronautics and Space Administration , the spaceflight and space exploration agency of the United States...
with ET-122
Space Shuttle external tank
A Space Shuttle External Tank is the component of the Space Shuttle launch vehicle that contains the liquid hydrogen fuel and liquid oxygen oxidizer. During lift-off and ascent it supplies the fuel and oxidizer under pressure to the three Space Shuttle Main Engines in the orbiter...
, which has been refurbished following damage by Hurricane Katrina
Hurricane Katrina
Hurricane Katrina of the 2005 Atlantic hurricane season was a powerful Atlantic hurricane. It is the costliest natural disaster, as well as one of the five deadliest hurricanes, in the history of the United States. Among recorded Atlantic hurricanes, it was the sixth strongest overall...
. Since there would be no next mission, STS-335 would also carry a Multi-Purpose Logistics Module
Multi-Purpose Logistics Module
A Multi-Purpose Logistics Module is a large pressurized container used on Space Shuttle missions to transfer cargo to and from the International Space Station . An MPLM was carried in the cargo bay of a Shuttle and berthed to the Unity or Harmony modules on the ISS. From there, supplies were...
filled with supplies to replenish the station.
The Senate authorized STS-135
STS-135
STS-135 was the final mission of the American Space Shuttle program. It used the orbiter Atlantis and hardware originally processed for the STS-335 contingency mission, which was not flown. STS-135 launched on 8 July and was originally scheduled to land on 20 July 2011, but the mission was...
as a regular flight on 5 August 2010
, followed by the House authorization on 29 September 2010, and later by President Obama on 11 October 2010. However funding for the mission remained dependent on a subsequent appropriation bill.
Nonetheless NASA converted STS-335, the final Launch On Need mission, into an operational mission (STS-135) on 20 January 2011. On 13 February 2011, program managers told their workforce that STS-135 would fly “regardless” of the funding situation via a continuing resolution. Finally the U.S. government budget approved in mid-April 2011 called for $5.5 billion for NASA's space operations division, including the space shuttle and space station programs. According to NASA, the budget running through 30 September 2011 ended all concerns about funding the STS-135 mission.
With the successful completion of STS-134, STS-335 was rendered unnecessary and launch preparations for STS-135 continued as Atlantis neared LC-39A during her rollout as STS-134 landed at the nearby Shuttle Landing Facility.
For the STS-135, no shuttle was available for a rescue mission, but there was a different rescue plan, which was not used.