MIT team finds that the ratio of component atoms is vital to performance.
NASA successfully launched space shuttle Discovery on June 2 with the Alpha Magnetic Spectrometer (AMS), developed by a science team led by principle investigator Samuel C.C. Ting, the Thomas Dudley Cabot Professor of Physics and Noble laureate in physics. The AMS particle physics experiment was designed to search for antimatter and dark matter.
Shortly after launch, a problem developed with Discovery's primary KU-band antenna system, which downloads telemetry continuously through NASA's Tracking and Data Relay Satellite System (TDRSS). This problem limited the amount of real-time data which could be analyzed during the mission by scientists on the ground. An inflight maintenance procedure by the flight crew failed to resolve the antenna problem.
Fortunately, all data from the AMS experiment were also stored on magnetic disc drives aboard the shuttle, so researchers can do detailed analysis after the shuttle returns from space.
As of June 8, project scientists had received more than 400 minutes of AMS telemetry by using the shuttle's S-band antenna system in FM mode to transmit to local NASA and Air Force ground stations.
The data received on the ground indicates that "the detector is working perfectly," Professor Ting said. "Using a laser spectrum comparison technique, we were able to measure the dimensional accuracy of the instrument to within one micron, so we are very happy with this."
Although the loss of the primary high-speed datalink was "a little anticlimactic," said Michael H. Capell, senior research scientist at the Laboratory for Nuclear Science, "we are excited about the data we are getting."
The shuttle crew includes mission specialists Franklin R. Chang-Diaz (PhD in physics, 1977), making his sixth space flight, and Wendy B. Lawrence (SM in ocean engineering, 1988), making her third flight. Dr. Chang-Diaz has the primary responsibility for the AMS experiment and its operation in space.
The AMS experiment has received strong support within NASA and the Department of Energy. "I've said that the Space Station will be an orbiting laboratory capable of conducting world-class science, and the addition of an experiment whose science team is led by a Nobel laureate is one more step in realizing the full potential of the Space Station," said NASA Administrator Daniel S. Goldin.
In January 2002, space shuttle Atlantis is scheduled to deliver the AMS experiment to the International Space Station for a three-year mission.
John Tylko, SB '79 in aeronautics and astronautics, is a special correspondent for MIT Tech Talk.
A version of this article appeared in MIT Tech Talk on June 10, 1998.