Shuttle Carrier Aircraft
| Shuttle Carrier Aircraft | |
|---|---|
| |
| Shuttle Atlantis returning to Kennedy Space Center on the SCA in 1998 | |
| Role | Outsize cargo freight aircraft |
| Manufacturer | Boeing (aircraft & modifications) |
| Introduction | 1977 |
| Primary user | NASA |
| Number built | 2 |
| Developed from | Boeing 747-100 |
The Shuttle Carrier Aircraft (SCA) are two extensively modified Boeing 747 airliners that NASA uses to transport Space Shuttle orbiters. One is a 747-100 model, while the other is a short range 747-100SR.
The SCAs are used to ferry space shuttles from landing sites back to the launch complex at the Kennedy Space Center, or more specifically, the NASA Shuttle Landing Facility, and to and from other locations too distant for the orbiters to be delivered by ground transport. The orbiters are placed on top of the SCAs by Mate-Demate Devices, large gantry-like structures that hoist the orbiters off the ground for post-flight servicing, and then mate them with the SCAs for ferry flights.
In approach and landing test flights conducted in 1977, a test shuttle was released from an SCA during flight and glided to a landing under its own control.[1]
Design and development
The first aircraft, a Boeing 747-100 registered N905NA, was originally manufactured for American Airlines and still carried visible American side stripes while testing Enterprise in the 1970s. It was acquired in 1974 and initially used for trailing wake vortex research as part of a broader study by NASA Dryden, as well as Shuttle tests involving an F-104 flying in close formation and simulating a "release" from the 747.
The aircraft was extensively modified by Boeing in 1976.[2] Its cabin was stripped, mounting struts added, and the fuselage strengthened; vertical stabilizers were added to the tail to aid stability when the Orbiter was being carried. The avionics and engines were also upgraded, and an escape tunnel system similar to that used on Boeing's first 747 test flights was added. The flight crew escape tunnel system was later removed following the completion of the Approach and Landing Tests (ALT) due to concerns over possible engine ingestion of an escaping crew member.
The C-5 Galaxy was considered for the shuttle-carrier role by NASA, but rejected in favor of the 747—in part due to the 747's low-wing design in comparison to the C-5's high-wing design, and also because the U.S. Air Force would have retained ownership of the C-5, while NASA could own the 747s outright.
Flying with the additional drag and weight of the Orbiter imposes significant fuel and altitude penalties. The range is reduced to 1,000 nautical miles (1,850 km), compared to an unladen range of 5500 nautical miles (10,100 km),[3] requiring an SCA to stop several times to refuel on a transcontinental flight. The SCA has an altitude ceiling of 15,000 feet and a maximum cruise speed of Mach 0.6 with the orbiter attached.[3] A crew of 170 takes a week to prepare the shuttle and SCA for flight.[4]
Studies were conducted to equip the SCA with aerial refueling equipment, a modification already made to the U.S. Air Force E-4 (modified 747-200s) and 747 tanker transports for the IIAF. However, during formation flying with a tanker aircraft to test refueling approaches, minor cracks were spotted on the tailfin of N905NA. While these were not likely caused by the test flights, it was felt that there was no sense taking unnecessary risks. Since there was no urgent need to provide an aerial refueling capacity, the tests were suspended.
By 1983, SCA N905NA no longer bore the distinct American Airlines red, white, and blue cheatline. NASA replaced it with its own livery, consisting of a white fuselage and a single blue cheatline.[5]
In 1988, in the wake of the Challenger accident, NASA procured a surplus 747-100SR [1] from Japan Airlines. Registered N911NA it entered service with NASA in 1990 after undergoing modifications similar to N905NA. It was first used in 1991 to ferry the new shuttle Endeavour from the manufacturers in Palmdale, California to Kennedy Space Center.
The two aircraft are functionally identical, although N911NA has five upper-deck windows on each side, while N905NA has only two. The rear mounting points on both aircraft are labeled with similar tongue-in-cheek instructions to "Attach Orbiter Here" or "Place Orbiter Here", clarified by the precautionary note "Black Side Down".[6] Both are currently based at Edwards Air Force Base near the Dryden Flight Research Center in California.
Shuttle Carriers are capable of operating from alternate shuttle landing sites such as those in the United Kingdom, Spain and France. Due to the reduced range of the Shuttle Carrier while mated to an orbiter, additional preparations such as removal of the payload from the orbiter may be necessary to reduce its weight.[7]
After the Shuttle program ends in 2010, the two Shuttle Carriers will be used to transport the orbiters to their final destinations. The carrier aircraft will likely retire sometime afterwards.[citation needed]
Specifications
Data from Boeing 747-100 specifications[8] Jenkins 2000[3]
General characteristics
- Crew: 4: pilot, co-pilot, 2 flight engineers (1 flight engineer when not carrying Shuttle)
Performance
Gallery
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Shuttle Carrier carries Discovery from Edwards AFB to Kennedy Space Center, Florida -
One of the SCAs at its Dryden Flight Research Center home, with a very wet Rogers Dry Lake behind it. -
Aft end of the interior. Note the large stuffed spider mounted on the aft pressure bulkhead. -
The first class section in the nose of N905NA. This is the only area on the main deck that has not been stripped to the bare metal -
Atlantis atop a Shuttle Carrier. -
SCA approaching Endeavour suspended in the Mate-Demate Device (MDD), April, 1994
-
SCA mating with Endeavour in the Mate-Demate Device (MDD), April, 1994
-
SCA ferry flights, 1992
-
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Enterprise separating from N905NA.
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See also
- Captive carry
- NASA Shuttle Landing Facility
- Moonraker, the 1979 James Bond film, which begins with the destruction of an SCA in flight.
Related development
Aircraft of comparable role, configuration, and era
Related lists
References
- ^ NASA - Dryden Flight Research Center (1977). "Shuttle Enterprise Free Flight". NASA. Retrieved November 28, 2007.
- ^ Jenkins 2000, pp. 36-38.
- ^ a b c Jenkins 2000, pp. 38-39.
- ^ Felix Gilette (9 August 2005). "How Does the Space Shuttle Fly Home?". Retrieved 2007-11-23.
- ^ Comparison of photos taken in 1982 and 1983 at Airliners.net
- ^ 2003 Edwards Air Force Base Air Show, see Shuttle Carrier images.
- ^ "Space Shuttle Transoceanic Abort Landing (TAL) Sites". National Aeronautics and Space Administration. December 2006. Retrieved 2009-07-01.
- ^ Boeing 747-200 Technical Specifications, Boeing
Bibliography
- Jenkins, Dennis R. Boeing 747-100/200/300/SP (AirlinerTech Series, Vol. 6). Specialty Press, 2000. ISBN 1580070264.
- Jenkins, Dennis R. Space Shuttle: The History of the National Space Transportation System - The First 100 Missions, 3rd edition. Midland Publishing, 2001. ISBN 0963397451.
External links
