Course XVI Experiment Flies With Columbia ShuttleBy Hyun Soo Kim
Space Shuttle Columbia will lift off from Cape Canaveral, Fla., this morning, weather permitting, carrying an experiment designed by MIT professors in the Department of Aeronautics and Astronautics.
The Middeck O-gravity Dynamics Experiment (MODE) will test how large structures vibrate in space. Another part of the experiment will measure the forces that astronauts exert while doing routine activities in the shuttle.
MODE will help in understanding the structural dynamic behavior of jointed truss structures -- which resemble construction crane booms -- in low gravity. The findings will be applied to the structural designs of the planned international space station and earth observation platforms, as well as other large structures.
The study of routine human forces will be the first one ever done in space. "There have been a lot of experiments on maximal force loads, but none on daily force loads," said Dr. Kimberly Scholle, MODE integration engineer at Payload Systems Inc., which is acting as a liaison between NASA and the Institute.
"This experiment will help understand how crew interferences affect the structure of the design and enable building more efficient structures," Scholle said.
The key MIT researchers for MODE are: Professor Edward F. Crawley PhD '76, Visiting Scientist Marthinus C. van Schoor PhD '89, and Assistant Professor Dava J. Newman PhD '89. To oversee the experiment, van Schoor and Newman left this week for the Lyndon B. Johnson Space Center in Houston, and the John F. Kennedy Space Center in Cape Canaveral, Fla., respectively.
MODE measures truss vibrations
MODE is a truss structure and a rotary joint connected to an actuator -- a mechanism for moving an object -- which produces vibrations. Sensors along the structure will collect its responses to vibrations, and MODE's experiment support module will store the data. When full deployed, it is 72 inches long with an 8-inch square cross section.
The rotary joint of the structure was designed to approximate the dynamics of the Alpha joint that is proposed for the space station.
The other half of MODE measures human forces through three types of instrumented sensors -- pushpads, footloops, and handholds -- that will be mounted in the shuttle passageways to the flight deck. These sensors have the same dimensions as the ordinary pushpads, handholds, and footloops so that "ideally the crew members will become used to them, and in a sense forget about them," Newman said.
Each sensor is also attached to the MODE's experiment support module. The MODE's experiment support module will measure the truss structure's vibrations for approximately a 40-hour period, and the human forces for about 70 hours.
The experiment will be set up by the astronauts in the middeck of the space shuttle. The middeck is the main living quarters of the astronaut, located under the flight deck. It is approximately 6 feet wide, 14 feet long, and 7 feet high, according to Scholle.
Students worked on experiment
At least 15 undergraduates and eight graduate students have worked on the MODE project.
Sergei V. Bobronikov G has worked on MODE for the past year and a half. He performed ground-based experiments, processed data, and created computer models of the structure. "Now I am trying to predict space behavior of the structure using computer models and ground tests," Bobronikov said.
Bobronikov said that MODE "will study the influence of gravity without the ground experiments or computer models." He added, "It will better predict space behavior of structures. We can then design lighter structures which will be more flexible and withstand vibrations better."
"It is exciting to work with real space hardware and a real mission," Bobronikov said. "I don't think that students have that many chances to work with real space hardware," he said.
Bobronikov also hopes that MODE will run successfully in space. "My thesis will be based on it, so I hope everything will be okay."