Boeing 747 and Space Shuttle
Radio-Controlled 1/40-scale Test Models
Donated by John Kiker
Astronaut Robert “Hoot” Gibson, who serves as AMA Ambassador, was a friend of John. Hear him discuss about the models’ history in this video.
In the mid-1970s, during the development of the Space Shuttle program, National Aeronautics and Space Administration (NASA) decided to transport the shuttle piggyback on a Boeing 747, but it was unclear if the shuttle could be successfully launched in-flight from atop the 747.
To prove that it was possible, John Kiker, an engineer at the NASA Johnson Space Center Spacecraft Design Division, and a model aviation enthusiast, decided to investigate the possibility of releasing a shuttle in-flight using model aircraft. He did this because, he “believe[s] Radio Control scale models are a good means of providing an initial indication of Orbiter control characteristics and separation dynamics before you start flying the real thing with live pilots.” He enlisted the help of fellow NASA engineer and modeler, Owen Morris.
A 1/40-scale Orbiter model, originally designed for floatation tests by NASA, was modified so it could be flown by Radio Control and was ballasted to simulate the weight and center of gravity of the full-scale Orbiter. The completed model weighed nearly 4 pounds, and with 242 square inches of wing area, it yielded a wing loading of 38.09 ounces per square foot.
After several successful in-flight releases from a Sterling Gazariator, NASA asked if the Gazariator could be replaced with a scale model of a Boeing 747. A Scale 747 would provide more accurate aerodynamic information and be more attractive for press releases. Kiker and Morris agreed, and work began on creating the model. NASA workshops created another model Orbiter (based again on the floatation model), while Kiker and Morris built the 747 from drawings provided by Boeing.
The 747 fuselage consisted of a balsa box to which foam was added, carved to shape, and then covered with fiberglass. The wings were made with two pieces of foam, sheeted with balsa and covered with MonoKote (a plastic film covering that shrinks when heated). To make the model easier to fly, the wing chord was increased an inch and the airfoil was changed to one that would provide better low-speed lift. Retractable landing gear by Carl Goldberg and two K&B 0.40s with fuel pumps completed the model.
John and Owen described the first flight of the model in a November 1976 Model Aviation News article.
“On the afternoon of April 30  quite a crowd of spectators and photographers gathered to watch the first flight of the 747, with John as the pilot. The takeoff roll was about 250 feet as predicted and was uneventful except for a wheel shimmy on one of the main gears. The model rotated easily and climbed out rapidly. The model could not be trimmed enough in pitch so a good amount of down stick was held for the entire flight. Control responses was very good about all axes, and the model flew even faster than expected. The retracts worked fine and all was well until it came time to land. Because of the high speed of the approach and the unfamiliarity of the flying site the model touched down in the grass off of the paved runway and cartwheeled. Although the damage was relatively light it was decided to retire for the day to repair both model and nerves before attempting another flight.”
Watch film footage of the first flight, and the crash landing.
The successful test launches of the models in 1976 helped prove that the full-scale Orbiter could be air-launched from a 747.
The models were used for other testing, as well. In a 1989 letter Thomas McPherson described his use of the Space Shuttle test model.
“I have worked at NASA Johnson Space Center for many years and played a part in the NASA R/C Boeing 747 – Space Shuttle combination on display at the Museum. The early efforts to fly the Shuttle model after its release from the 747 were a disaster. The model was just too sensitive in pitch and cutting down the control throws didn’t help. There was a real concern that the model, flying at the same c.g. [center of gravity] as the prototype [Shuttle Enterprise], and made from factory drawings, was exhibiting and aerodynamic flaw which might carry over to the real Space Shuttle. With my background in full scale stability and control testing I was put in charge of a low, low budget test program to find the problem. I designed and had built a simple support rig for the Shuttle model which mounted to a pickup truck (a poor man’s wind tunnel). I calibrated the transmitter stick travel to elevon deflection, and with a movie camera filming the Shuttle and a wind vane, roared up and down the runways at Ellington AFB collecting elevon deflection vs. angle of attack data. That data defined the stable trim deflection to be preset in flyable, but always a handful. Later on we looked at the addition of canards to the Shuttle as a means of allowing a more forward c.g. location. I believe I truck tested that configuration and recall flying the launch airplane several times for R/C flight tests. Technically the canards worked, but practically there was, and is, no way to make a modification like that to the present Shuttle design.”