Professor Edward Crawley of the Department of Aeronautics and Astronautics recently appeared on national TV with other scientists in a forum aimed at educating viewers about the research that will be carried out on the planned international space station.
The forum, which was produced by NASA and presented by the Public Broadcasting Service, took the form of a live videoconference broadcast via satellite to about 20,000 viewers at more than 700 sites in the United States. Participating scientists showed explanatory videos and discussed various areas of research; after each segment, they answered questions faxed or phoned in by viewers around the country.
Professor Crawley, director of MIT's Space Engineering Research Center, spoke about engineering research, technology and the commercial development of space. The videoconference also featured overviews of life sciences research (which included comments by Professor Laurence Young of aero/astro) and microgravity research.
The shuttle Columbia, scheduled for launch this week, will carry an experiment of Professor Crawley's that is designed to yield infotrmation on the vibration of large structures in space and how astronauts physically affect their environment as they go about their activities. For example, the stresses on the large solar arrays caused by the shuttle's decelerating thrusters during docking will be measured, he said.
The space station is expected to be completed by the year 2001. The United States, which has budgeted $2.1 billion per year for construction for the next four to five years, will provide primary support structures, major subsystems including power, data, communications and thermal control, and habitation and laboratory modules. Russia will provide systems to support navigation and power generation, an emergency crew rescue vehicle, and laboratory modules. Europe, Japan and Canada are also contributing components.
The vacuum and zero-gravity conditions at the space station will allow research and testing that can't be done on Earth, videoconference scientists said. "The space station provides a shirt-sleeve environment for engineering research on gravity-dependent phenomena," Professor Crawley noted.
Among the topics to be studied are electrodynamics, fluid dynamics (how liquids behave under zero-gravity conditions), energy storage and conversion, and the space station itself, which "will represent a marvelous opportunity to study the behavior and operations of large spacecraft," he said. Assembly of antennae and other large structures "will be an area of active investigation," he added in response to a viewer question. Information obtained about ground-developed and space-tested systems such as solar sails and low-power thrusters will allow more economical space exploration, he said.
Other scientists outlined areas of life sciences research planned for the space station. Studies of how zero-gravity living affects the human body's metabolism and tissues (for example, fluid retention in the upper body and bone-mass loss) could lead to better understanding of diseases such as osteoporosis, explained Dr. Clarence Sams, manager of cell and developmental biology research and of the Technical Operations Program at NASA's Johnson Space Center.
Professor Young, who was a backup payload specialist for the Spacelab Life Science 2 mission of the shuttle Columbia last October, discussed his experiments on the vestibular system, which regulates the body's balance and orientation. Scientists also hope to learn about sensory and regulatory systems from the behavior in space of plants and animals such as tadpoles. Another space station goal is to develop and test advanced human life support systems whereby oxygen is regenerated, wastes and carbon dioxide are removed, and water is recycled.
Microgravity research will focus on combustion, materials science, fluid physics and biotechnology, explained Dr. Robert Rhome, director of NASA's Microgravity and Applications Division. Space conditions will allow the production of alloys and the growth of gelatinous protein crystals. Crystalline substances such as elastase (used in the treatment of emphysema) and malic acid can be grown on Earth, but the crystals are much larger and better when produced in space. "The difference in the quality of the crystals was dramatic," said Dr. Lawrence DeLucas, a professor at the University of Alabama and a payload specialist for materials processing experiments.
"We must really develop a new zero-gravity technology, a technology born in space to work in space, to enable the exploration we envision for the next millennium and beyond," Professor Crawley said.
A version of this article appeared in the March 2, 1994 issue of MIT Tech Talk (Volume 38, Number 24).
