When NASA required a solution to transport its approximately 100-ton space shuttles, the agency turned to the aviation industry for a capable aircraft. After careful consideration, NASA selected the Boeing 747 over the Lockheed C-5 Galaxy, primarily due to its structural design and power capabilities. The decision was pivotal for the shuttle program, enabling seamless transport operations.
The design of the 747, with its wings positioned below the main fuselage, provided a more stable platform for carrying the shuttle. In contrast, the C-5’s high-wing configuration would have made it challenging to mount the shuttle securely. Additionally, the Boeing 747 was powered by four robust engines, specifically the Pratt & Whitney PW4000 series, generating 48,600 pounds of thrust each. This impressive power made the 747 an ideal candidate, capable of handling a maximum gross taxi weight of 713,000 pounds.
NASA modified two Boeing 747s for the shuttle transport role. The first, designated NASA 905, was a 747-123 model acquired from American Airlines in 1974 for $15,601,192. The second aircraft, NASA 911, a 747-100SR-46, was procured in 1989 from Japan Air Lines. Both aircraft underwent extensive modifications, including the addition of three large struts to support the shuttle’s weight.
The modifications did not stop there. Engineers reinforced the fuselage to accommodate the shuttle, which altered the aircraft’s aerodynamics. To enhance stability, two additional vertical stabilizers were added to the tail. These changes were essential, as the orbiter’s thermal protection tiles required careful handling to avoid damage.
During the initial testing phase in 1977, NASA 905 featured an innovative crew escape system that utilized pyrotechnics. The process of placing the shuttle onto the 747 was elaborate, involving structures known as Mate-Demate Devices. These devices lifted the orbiter high enough for the 747 to be positioned underneath for attachment.
For over a decade, NASA 905 was the sole aircraft transporting shuttles, but the introduction of NASA 911 in late 1990 allowed both jets to share the responsibilities. Following the retirement of the shuttle fleet, NASA 905 completed three final ferry missions, including a notable delivery of the Discovery to the Smithsonian National Air and Space Museum, where it made a celebratory flyover of Washington D.C. at an altitude of approximately 1,500 feet.
NASA 911 was retired in February 2012 and is now on display at the Joe Davies Heritage Airpark. Later that year, NASA 905 retired and became part of a significant exhibit at Space Center Houston. The legacy of these aircraft not only highlights NASA’s innovative spirit but also showcases the profound impact of aviation technology on space exploration.
