Boeing 747History, variants & specifications

The Shuttle Carrier Aircraft

NASA's two Shuttle Carrier Aircraft were modified Boeing 747s that ferried Space Shuttle orbiters across the United States. Both were retired in 2012.

NASA Shuttle Carrier Aircraft seen from above in flight with a Space Shuttle orbiter mounted on its back
An orbiter rides on struts above the fuselage. Note the fins added to the tailplane.NASA

NASA used two heavily modified Boeing 747s as Shuttle Carrier Aircraft: NASA 905, a 747-100 bought from American Airlines, and NASA 911, a 747-100SR formerly flown by Japan Air Lines.

Why they were needed

A Space Shuttle orbiter returned from orbit as an unpowered glider. It landed where conditions allowed — often at Edwards Air Force Base in California, when Florida weather ruled out Kennedy Space Center — and then had no way of getting home.

It could not be driven any distance, could not be shipped economically, and could not fly itself. The only practical answer was to carry it, and the only aircraft with the strength, the wing and the runway performance to do that was the 747.

What was modified

The changes were extensive:

  • Mounting struts on top of the fuselage, attached to reinforced structure, to carry the orbiter’s weight.
  • Vertical fins on the tailplane tips. An orbiter sitting on the back badly disturbs airflow over the tail, and those fins restore the directional stability lost as a result — the most visible modification, and the quickest way to identify an SCA in a photograph.
  • A stripped interior. Airline furnishing was removed to save weight, leaving instrumentation and a small number of seats.
  • Structural strengthening through the fuselage to carry loads it was never designed for.

Loading required a purpose-built gantry, the mate-demate device, which lifted the orbiter and lowered it onto the aircraft.

What it cost to fly

Carrying an orbiter is aerodynamically brutal. Drag rises enormously, so range falls sharply — ferry flights across the United States required several refuelling stops that an unladen 747 would not need. Altitude and speed were both restricted.

Retirement

The aircraft outlived their purpose. With the Space Shuttle programme ending in 2011, the SCAs flew their final missions in 2012, delivering the surviving orbiters to museums — including Discovery, whose last flight ended with a low pass over Washington DC.

NASA 905 is displayed at Space Center Houston, mated to the shuttle mock-up Independence, and visitors can walk through both. NASA 911 is preserved at Joe Davies Heritage Airpark in Palmdale, California.

Key specifications
ManufacturerBoeing
VariantBoeing 747 Shuttle Carrier Aircraft
StatusRetired 2012; both preserved
Number built2
  • Space Shuttle orbiter being lowered onto a NASA Shuttle Carrier Aircraft using the mate-demate device
    Mating an orbiter needed a purpose-built gantry — the mate-demate device.NASA
  • Space Shuttle Discovery atop the NASA Shuttle Carrier Aircraft on its final ferry flight
    Discovery's last flight, to museum display in 2012.NASA
  • Two NASA Shuttle Carrier Aircraft parked on a wet ramp at sunset
    NASA 905 and NASA 911, the only two aircraft ever configured for the job.NASA

Video

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NASA on the Shuttle Carrier AircraftNASA Johnson

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A detailed tour through a Shuttle Carrier AircraftPaul Stewart

Frequently asked questions

Why did NASA need to carry the Space Shuttle on a 747?
The orbiter was a glider on return and could not fly itself between sites. When it landed at Edwards Air Force Base in California rather than Florida, it had to be flown back to Kennedy Space Center — and the only practical way was on the back of an aircraft.
Which 747s were the Shuttle Carrier Aircraft?
NASA 905, a 747-100 formerly of American Airlines, and NASA 911, a 747-100SR formerly of Japan Air Lines. NASA 905 is displayed at Space Center Houston and NASA 911 at Joe Davies Heritage Airpark in Palmdale.

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