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[[Image:Sts-300.recumbent-seats.png|right|thumb|180px|STS-300 lower deck seat layout to accommodate additional crew]]
[[Image:Sts-300.recumbent-seats.png|right|thumb|180px|STS-300 lower deck seat layout to accommodate additional crew]]
Barring [[Space Shuttle Atlantis|''Atlantis's'']] (OV-104) Orbiter Major Modification period, which as of now is cancelled, NASA's remaining two operational vehicles, ''[[Space Shuttle Discovery|Discovery]]'' (OV-103) and ''[[Space Shuttle Endeavour|Endeavour]]'' (OV-105), will still have to back each other up should the need for an STS-3xx mission arise. After ''Atlantis'' completes STS-125, & begins it's "near operational condition" status in fall of 2008, will it too carry its share of Launch-on-Need duty.It will also be used as a parts vehicle for the other two operational shuttles until the end of the shuttle program.
Barring [[Space Shuttle Atlantis|''Atlantis's'']] (OV-104) Orbiter Major Modification period, which as of now is cancelled, NASA's remaining two operational vehicles, ''[[Space Shuttle Discovery|Discovery]]'' (OV-103) and ''[[Space Shuttle Endeavour|Endeavour]]'' (OV-105), will still have to back each other up should the need for an STS-3xx mission arise. After ''Atlantis'' completes STS-125, & begins it's "near operational condition" status in fall of 2008, will it too carry its share of Launch-on-Need duty.


==Pre-ISS era==
==Pre-ISS era==

Revision as of 06:15, 24 July 2007

STS-3xx

Space shuttle missions designated STS-3xx (officially called Launch On Need missions) are rescue missions which would be 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 be flown if Mission Control determined that the heat shielding tiles and reinforced carbon-carbon (RCC) panels of a currently flying orbiter were damaged beyond the normal repair methods. These missions are also referred to as Launch on Demand (LOD).

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 NASA to launch the mission within a period of 40 days of it 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[1]. Within NASA, this plan for maintaining the shuttle crew at the ISS is known as Contingency Shuttle Crew Support (CSCS) operations.[2] Up to STS-121 all rescue missions were to be designated STS-300.

In the case of an abort to orbit, where the shuttle doesn't reach the ISS orbit and the thermal protection system inspections suggest the shuttle could not return to earth safely, the ISS could be brought down to meet the shuttle. Such a procedure is known as joint underspeed recovery [3].

Mission designations for STS-3xx flights
Flight Rescue Flight
STS-114 (Discovery) STS-300 [2] (Atlantis)
STS-121 (Discovery) STS-300 [4] (Atlantis)
STS-115 (Atlantis) STS-301 [4] [2] (Discovery)
STS-116 (Discovery) STS-317 [5] [6] (Atlantis)
STS-117 (Atlantis) STS-318 [6] (Endeavour[citation needed])
STS-118 (Endeavour) STS-322 [6] (Discovery)
STS-120 (Discovery) STS-320 [6] (Atlantis)
STS-122 (Atlantis) STS-323 [6] (Endeavour)
STS-123 (Endeavour) STS-324 [6] (Discovery)
STS-124 (Discovery) STS-326 [6] (Endeavour)
STS-125 (Atlantis) STS-400 [6] (Endeavour)


Prior to STS-121 the plan was for the damaged shuttle to be abandoned and allowed to burn up upon reentry. STS-121 was the first shuttle mission to carry an 8.5-meter cable designed to connect the flight deck manual controls used during landing to an avionics bay in the middeck allowing mission controllers to land the shuttle unmanned if required. Such an unmanned landing may have been considered if the vehicle suffered damage that is too severe to risk a manned reentry, but might have enabled the shuttle to land intact. The landing site for an unmanned landing would have probably been Edwards Air Force Base, in California,[7] where the expanse of dry lake bed gives a large margin for error, unlike KSC where canals border the landing facility. White Sands Missile Range in New Mexico was another possible site. [1] The flight resource book, and flight rules in force during STS-121 suggest that the damaged Orbiter would reenter on a trajectory such that if it should break up, it would do so with debris landing in the South Pacific.[2]

To save weight, and to allow the combined crews of both shuttles to return to Earth safely, many shortcuts would have had to be made, and the risks of launching another orbiter, without resolving the failure which caused the previous orbiter to become disabled would have had to be faced.

If implemented, it is highly likely such a mission would be the last flight of a Space Shuttle and mark the end of the Shuttle program.[8]

Crew

STS-114 Rescue (STS-300)

Subset of STS-121 Crew

STS-121 Rescue (STS-300)[4]

Subset of STS-115 Crew

STS-115 Rescue (STS-301)

Subset of STS-116 Crew

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 [9]

Remote Control Orbiter

The Remote Control Orbiter (RCO) is a term used by NASA to describe a Shuttle that could perform entry and landing without a human crew onboard. To this end, NASA developed the RCO in-flight maintenance (IFM) cable. The cable is approximately 28 feet long, weighs over 5 lbs, and has 16 connectors.[10]

The purpose of the RCO IFM cable is 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 stowage during the mission. The cable will remain aboard the ISS until the end of the Shuttle program at which time it will be brought back to Earth on the final Shuttle flight.

Shuttle backup plan

File:Sts-300.recumbent-seats.png
STS-300 lower deck seat layout to accommodate additional crew

Barring Atlantis's (OV-104) Orbiter Major Modification period, which as of now is cancelled, NASA's remaining two operational vehicles, Discovery (OV-103) and Endeavour (OV-105), will still have to back each other up should the need for an STS-3xx mission arise. After Atlantis completes STS-125, & begins it's "near operational condition" status in fall of 2008, will it too carry its share of Launch-on-Need duty.

Pre-ISS era

Before the ISS was launched, shuttle crews would have had to transfer directly between shuttles, should a rescue have been needed. 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.

Timeline

  • 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
  • FD-21 Deorbit Burn - Burn occurs four hours after separation. 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 after 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.[2]
  • FD-45->47 The rescue flight catches up with the ISS, conducting heat shield inspections en-route.
  • FD-47 The rescue flight will dock 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 Progress resupply spacecraft is launched at later date to resupply ISS crew. ISS precautionary de-crew preparations begin.
  • FD-58 De-crew ISS due to CELSS O2 exhaustion in event Progress unable to perform resupply function.

The above timeline is presented with respect to the flight day (FD) of the mission to be rescued.

STS-125 rescue

STS-125 is a Hubble Space Telescope servicing mission. As the Hubble is in a very different orbit from the International Space Station, there is no option for a shuttle crew to use the ISS as a safe haven, and planning for a rescue mission would have to be very different. A rescue flight would have to be ready to launch only ten days after call up as the maximum time the crew could remain on the shuttle is 23 days. For this mission, the rescue shuttle will be rolled to its launch pad about two weeks before the STS-125 shuttle, creating a rare scenario of two shuttles being on the launch pads at the same time. The mission would probably follow a similar procedure to the pre-ISS era plan, as outlined above. The rescue mission designation for STS-125 is STS-400. It could require a shuttle to shuttle docking, where the rescue shuttle is above the damaged shuttle but upside down and facing the other direction so a docking is possible.

References

  1. ^ Flight Readyness Review Briefing, Transcript of press briefing carried on NASA TV, 17 June 2006
  2. ^ a b c d e Contingency Shuttle Crew Support (CSCS)/Rescue Flight Resource Book. 12 July, 2005 Cite error: The named reference "CSCSResourceBook" was defined multiple times with different content (see the help page).
  3. ^ Engineering for Complex Systems Knowledge Engineering for Safety and Success Project
  4. ^ a b c "STS-121 Nasa Press Kit"NASA Press Kit - STS-121, May 2006.
  5. ^ Nasa Assurance Technology Center News Article
  6. ^ a b c d e f g h NASA Launch Schedule (Via Hipstersunite.com) Cite error: The named reference "launchschedule" was defined multiple times with different content (see the help page).
  7. ^ http://www.nasaspaceflight.com/content/?id=4582
  8. ^ Watson, Traci (2005-03-22). "The mission NASA hopes won't happen". USA Today. Retrieved 2006-09-13. {{cite news}}: Check date values in: |date= (help)
  9. ^ STS-114 Flight Readyness Review Presentation
  10. ^ Kestenbaum, David (2006-06-29). "Emergency Rescue Plans in Place for Astronauts". NPR. Retrieved 2006-09-19. {{cite news}}: Check date values in: |date= (help)
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