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...
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...
designation is composed of a prefix and suffix separated by a dash. The prefix for operational shuttles is OV, for Orbiter Vehicle
The suffix is composed of two parts: the series and the vehicle number.
- 0 - Non-flight ready shuttles
- 1 - Flight ready shuttles
The vehicle number is sequentially assigned within the series, beginning with 1. Therefore, there can never be an OV-100 as it would read "Orbiter Vehicle Series 1 Vehicle 0".
Many proposals to build a second generation of orbiters, externally compatible with the current system but internally new, refer to them as "OV-200" or "OV-2xx" in order to differentiate them from the "current generation", the OV-100s. This terminology is informal, and it is unlikely that any Shuttle-derived vehicle built will be given such designation.
- OV-098 (unofficial and honorary) - Space Shuttle Pathfinder
, a structural mockup
- OV-099 - Space Shuttle Challenger
Space Shuttle Challenger was NASA's second Space Shuttle orbiter to be put into service, Columbia having been the first. The shuttle was built by Rockwell International's Space Transportation Systems Division in Downey, California...
, originally STA-099
- OV-101 - Space Shuttle Enterprise
The Space Shuttle Enterprise was the first Space Shuttle orbiter. It was built for NASA as part of the Space Shuttle program to perform test flights in the atmosphere. It was constructed without engines or a functional heat shield, and was therefore not capable of spaceflight...
- OV-102 - Space Shuttle Columbia
Space Shuttle Columbia was the first spaceworthy Space Shuttle in NASA's orbital fleet. First launched on the STS-1 mission, the first of the Space Shuttle program, it completed 27 missions before being destroyed during re-entry on February 1, 2003 near the end of its 28th, STS-107. All seven crew...
- OV-103 - 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...
- OV-104 - 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...
- OV-105 - 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 originally intended to be used as a Structural Test Article, rather than a flight-capable orbiter; as such, the numbering was changed when she was rebuilt. Enterprise
, on the other hand, was intended to be rebuilt into a flight-capable orbiter; it was found to be cheaper to rebuild STA-099 than OV-101, so she remained unflown. The designations were not altered, despite these changes in plans.
Note that while Pathfinder
is referred to as OV-098, she should not be confused with MPTA-098
The Main Propulsion Test Article was built by Rockwell International as a testbed for the definitive propulsion and fuel delivery systems for the U.S...
- the Main Propulsion Test Article, a steel frame (looking nothing like an Orbiter) used to test the Space Shuttle Main Engine
The RS-25, otherwise known as the Space Shuttle Main Engine , is a reusable liquid-fuel rocket engine built by Pratt & Whitney Rocketdyne for the Space Shuttle, running on liquid hydrogen and oxygen. Each Space Shuttle was propelled by three SSMEs mated to one powerhead...
was originally a "fit check" unit, a simple mockup resembling the production Orbiters in size, shape and weight, intended to be used to ensure that ground handling facilities would be sized to handle Orbiters. She was later rebuilt to resemble them cosmetically, and is currently on display with the 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...
used during the propulsion tests (designated MPTA-ET
The Main Propulsion Test Article External Tank was built by NASA to be used in conjunction with MPTA-098 for structural tests of the Space Shuttle Main Engines prior to construction of flyable craft...
). To further add to the confusion, it appears that Pathfinder was never formally numbered, and the OV-098 designation is both unofficial and
retroactive. MPTA-098 was later rebuilt into the Shuttle-C
The Shuttle-C was a NASA proposal to turn the Space Shuttle launch stack into a dedicated unmanned cargo launcher. This would use the Space Shuttle external tank and Space Shuttle Solid Rocket Boosters , combined with a cargo module that would attach to Shuttle hardpoints and include the Space...
mockup during the 1990s; it is currently in storage at the Stennis Space Center.
In keeping with this theme, other pieces of ground hardware used by the Space Shuttle program have been given OV-xxx designations; these include:
- OV-095 - a mockup in the Shuttle Avionics Integration Laboratory
The Shuttle Avionics Integration Laboratory was a facility at Lyndon B. Johnson Space Center in Houston, Texas.It was the only facility in the Space Shuttle Program where actual orbiter hardware and flight software can be integrated and tested in a simulated flight environment...
(SAIL) at Johnson Space Center.
- MPTA-098 - the Main Propulsion Test Article, as above
- OV-106 - an administrative name given to the set of structural components manufactured to replace those used in the construction of Endeavour; however, the contract for these was cancelled shortly afterwards, and they were never completed.