Shuttle Carrier Aircraft
|Shuttle Carrier Aircraft|
|NASA's Shuttle Carrier Aircraft 905 (front) and 911 (rear)|
|Role||Outsize cargo freight aircraft|
|Manufacturer||Boeing (aircraft & modifications)|
|Developed from||Boeing 747-100|
The Shuttle Carrier Aircraft (SCA) are two extensively modified Boeing 747 airliners that NASA used to transport Space Shuttle orbiters. One is a 747-100 model, while the other is a short range 747-100SR.
The SCAs were used to ferry Space Shuttles from landing sites back to the Shuttle Landing Facility at the Kennedy Space Center, and to and from other locations too distant for the orbiters to be delivered by ground transport. The orbiters were placed on top of the SCAs by Mate-Demate Devices, large gantry-like structures that hoisted the orbiters off the ground for post-flight servicing then mated them with the SCAs for ferry flights.
Design and development 
The Lockheed 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.
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 appears in the background of a scene from The Six Million Dollar Man's second season episode "The Deadly Replay", which was filmed in 1974 at Edwards AFB.
The aircraft was extensively modified by Boeing in 1976. While first-class seats were kept for NASA passengers, its main cabin and insulation were 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.
Flying with the additional drag and weight of the Orbiter imposed significant fuel and altitude penalties. The range was reduced to 1,000 nautical miles (1,850 km), compared to an unladen range of 5500 nautical miles (10,100 km), requiring an SCA to stop several times to refuel on a transcontinental flight. Without the Orbiter, the SCA needed to carry ballast to balance out its center of gravity. The SCA had an altitude ceiling of 15,000 feet and a maximum cruise speed of Mach 0.6 with the orbiter attached. A crew of 170 took a week to prepare the shuttle and SCA for flight.
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 to have been 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. That year, this aircraft was also used to fly Enterprise on a tour in Europe, with refuelling stops in Goose Bay, Canada; Keflavik, Iceland; England; and West Germany. It then went to the Paris Air Show.
In 1988, in the wake of the Challenger accident, NASA procured a surplus 747-100SR 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.
Based at the Dryden Flight Research Center within Edwards Air Force Base in California the two aircraft were functionally identical, although N911NA has five upper-deck windows on each side, while N905NA has only two. The rear mounting points on both aircraft were labeled with humorous instructions to "Attach Orbiter Here" or "Place Orbiter Here", clarified by the precautionary note "Black Side Down".
Shuttle Carriers were capable of operating from alternative 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 have been necessary to reduce its weight.
Shuttle Carrier N911NA retired on February 8, 2012 after its final mission to the Dryden Aircraft Operations Facility in Palmdale, California, and will be used as a source of parts for NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA).
Shuttle Carrier N905NA was used to ferry the retired Shuttles to their respective museums. It returned to the Dryden Flight Research Facility at Edwards Air Force Base in California after a short flight from Los Angeles International Airport on September 24, 2012. It will soon join N911NA as a source of spare parts for NASA's SOFIA aircraft. NASA engineers surveyed N905NA and determined that it had few parts usable for SOFIA, and 905 is now intended to be preserved and displayed in Houston. Three former NASA aircraft are on static display in the Houston area - two T-38s at the front entrance of Space Center Houston, and the former NASA KC-135 930 Vomit Comet. On May 3, 2013, the Space Center announced plans to display SCA 905 with the mockup shuttle Explorer mounted on its back.
- Crew: 4: pilot, co-pilot, 2 flight engineers (1 flight engineer when not carrying Shuttle)
- Length: 231 ft 4 in (70.5 m)
- Wingspan: 195 ft 8 in (59.7 m)
- Height: 63 ft 5 in (19.3 m)
- Wing area: 5,500 ft² (510 m²)
- Empty weight: 318,000 lb (144,200 kg)
- Max. takeoff weight: 710,000 lb (322,000 kg)
- Powerplant: 4 × P&W JT9D-7J turbofans, 50,000 lbf (222 kN) each
- Cruise speed: Mach 0.6 (397 knots, 457 mph, 735 km/h)
- Range: 1,150 mi (1,000 nmi, 1,850 km) while carrying Shuttle
- Service ceiling: 15,000 ft (4,500 m) (with Shuttle)
Ferry flights 
Ferry flights generally originated at Edwards Air Force Base in California or on one occasion White Sands Missile Range in New Mexico following mission STS-3 which landed there, especially in the early days of the Space Shuttle program or when weather at the Shuttle Landing Facility (SLF) at the Kennedy Space Center prevented ending missions there. Flights generally ended at the SLF. A number of flights began at the Dryden Flight Research Center following delivery of the orbiter from Rockwell International to NASA from the nearby facilities in Palmdale, California.
The last ferry flight with Endeavour started on September 19, 2012 with flight from Kennedy Space Center to Ellington Field. The second leg on September 20, 2012 Ellington Field to Edwards Air Force Base. The third and final leg was flown on September 21, 2012 when it departed Edwards Air Force Base and headed north along the California central valley, conducted a circuit over Sacramento, and then proceeded to the San Francisco Bay Area. In the Bay Area, the flight proceeded along the east side of the bay, passing over Oakland, Berkeley, El Cerrito, and Richmond before crossing the bay and conducting two loops over San Francisco, passing over the Golden Gate Bridge each time. The flight then proceeded south along the west side of the bay, conducting a low fly-over at NASA Ames Research Center/Moffett Air Field before turning south, along the way making a pass over Vandenberg Air Force Base, which was once slated to be a launch site for the Space Shuttle program. As it approached the Los Angeles area, the SCA/Endeavour conducted flyovers of various landmarks in the greater LA region, including the Hollywood Sign and the Griffith Observatory in Los Angeles as well as the Rose Bowl and the NASA Jet Propulsion Lab (JPL) in Pasadena. As it approached from the south along the Pacific coast, it also passed over several communities, provided sighting opportunities for thousands of spectators.
Discovery was delivered to the Udvar-Hazy Center of the Smithsonian Institution's National Air and Space Museum in Chantilly, Virginia, near Washington, D.C. on April 19, 2012. On April 17, 2012, Discovery was flown atop a Shuttle Carrier Aircraft escorted by a NASA T-38 Talon chase aircraft in a final farewell flight. The 747 and Discovery flew over Washington, D.C. and the metropolitan area around 10 am and arrived at Dulles around 11 am. The flyover and landing were widely covered on national news media.
See also 
- Airborne aircraft carrier
- NASA Shuttle Landing Facility
- Moonraker (film), 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
- NASA - Dryden Flight Research Center (1977). "Shuttle Enterprise Free Flight". NASA. Retrieved November 28, 2007.
- Jenkins 2000, pp. 36-38.
- Brack, Jon (2012-09-17). "Inside the Space Shuttle Carrier Aircraft". National Geographic. Retrieved September 17, 2012.
- 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.
- Shuttle Carrier Aircraft N911NA album on Photobucket
- "Space Shuttle Transoceanic Abort Landing (TAL) Sites". National Aeronautics and Space Administration. December 2006. Retrieved 2009-07-01.
- Boeing Phantom Ray to catch shuttle ride at Lambert
- NASA's Shuttle Carrier Aircraft 911's Final Flight
-  A graphic history of 35 years of space shuttle ferry flights now adorns the upper forward fuselage of NASA Shuttle Carrier Aircraft 905. (NASA / Tony Landis)
- Boeing 747-100 Technical Specifications, Boeing
- "STS Chronology". NASA.
- Jenkins, Dennis R. Boeing 747-100/200/300/SP (AirlinerTech Series, Vol. 6). Specialty Press, 2000. ISBN 1-58007-026-4.
- Jenkins, Dennis R. Space Shuttle: The History of the National Space Transportation System - The First 100 Missions, 3rd edition. Midland Publishing, 2001. ISBN 0-9633974-5-1.
|Wikimedia Commons has media related to: Shuttle Carrier Aircraft|
- NASA fact sheet
- NASA SCA images
- Interview with SCA Pilot and Former Astronaut Gordon Fullerton
- Interview with SCA Crew Chief Pete Seidl
- Hoot Gibson talks about John Kiker's 747 ferry model