With its unique design, the Boeing 747 is an aesthetically-striking aircraft in its own right. However, two of these iconic double-decker quadjets became perhaps even more conspicuous following the end of their passenger services. Of course, I am referring to the two 747-100s that NASA converted for use as 'Shuttle Carrier Aircraft' in the 1970s and '80s. But what happened to these legendary outsize freighters?

The role of these aircraft

NASA's Shuttle Carrier Aircraft's primary purpose was to ferry its Space Shuttles from place to place. This would often constitute a journey from Edwards Air Force Base, California to the Kennedy Space Center's 4,600-meter 'Shuttle Landing Facility' runway in Florida.

This was because Edwards Air Force Based served as a secondary landing site for the Space Shuttle, in the event of adverse weather in Florida. Once at the Kennedy Space Center, NASA would perform post-flight processing on it. The aircraft were also used to deliver retired orbiters to their respective museums.

N905NA

The first Boeing 747 that NASA purchased was a -100 variant previously registered as N9668. According to Planespotters.net, American Airlines initially took delivery of this aircraft in October 1970. It was one of 16 747-100s that the carrier operated between 1970 and 1985. However, American soon found it was struggling to fill these mammoth airliners.

NASA 747 with Shuttle

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As such, NASA acquired N9668 in 1974, and re-registered it as N905NA. Its initial use was not carrying the Space Shuttle, but instead in a wider study concerning trailing wake vortex research. Before its use as a Shuttle Carrier Aircraft, it also performed test flights in close formation with a Lockheed F-104 fighter jet. These simulated the inflight release of a Space Shuttle from the 747.

Modifications for shuttle-carrying began in 1976. These included vertical stabilizers on the aircraft's tail, which would offer additional stability when carrying the Space Shuttle. Among the other modifications were upgraded engines and avionics, as well as the addition of mounting struts and a crew escape slide. Despite these modifications, it retained aspects of its former American Airlines livery until 1983.

NASA 747 Shuttle Carrier with Endeavour
N905NA departs Edwards Air Force Base, California in 2001, ferrying Space Shuttle Endeavour back to Florida. Photo: Carla Thomas, NASA/DFRC via Wikimedia Commons

NASA eventually withdrew N905NA from use in 2013, a year after the final shuttle-carrying flights. The following year, it was dismantled and then transported to the Johnson Space Center in Houston, Texas for preservation. Since 2016, it has been on display in an area of the center called 'Independence Plaza,' with a replica Space Shuttle attached to it.

N911NA

NASA did not obtain its second Shuttle Carrier Aircraft, N911NA, until 1988, shortly after the Challenger disaster in 1986. Planespotters.net reports that this 747-100SR ('Short Range') came from Japan Airlines, where it had entered service on high-capacity domestic routes in 1973. Its original registration was JA8117.

It flew its first shuttle-carrying mission in 1991. This involved transporting the new Endeavour Space Shuttle to Kennedy Space Center in Florida. The flight originated in Palmdale, California, where the shuttle had been manufactured.

NASA 747 SOFIA

Despite being the newer of NASA's two Shuttle Carrier Aircraft, N911NA was the first to be withdrawn from service. This occurred in February 2012, and, before preservation, NASA used the aircraft as a spare parts source for its 'SOFIA' flying telescope 747SP. N911NA eventually entered preservation two years later and is now on display at the Joe Davies Heritage Air Park in Palmdale, California.

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