CAMBRIDGE, Mass.--As they go about their daily activities, the crew
members currently aboard the Russian space station Mir are also
participating in an experiment designed by MIT engineers.
The results will give researchers a better understanding of how
crew members physically affect their environment. The data could save
millions in the design of future space structures like the scheduled
international space station. Currently there is very little data on the
forces astronauts exert on spaceships, so engineers must over-design the
racks housing sensitive experiments that could be disturbed by
astronauts' movements.
In a second part of the experiment, the researchers will videotape
crew members playing darts to study how they adapt to zero gravity.
The experiment, led by Assistant Professor Dava J. Newman of the
Department of Aeronautics and Astronautics, was launched to Mir in late
April and was activated May 10. It will continue through December,
possibly longer if funding permits. During this time up to nine
astronauts and cosmonauts will participate.
Professor Newman conducts training sessions for the experiment with
all of the crew members involved. Recently she returned from Russia,
where she trained the two cosmonauts and one astronaut who will relieve
those currently aboard Mir in August.
MEASURING FORCES
Key to the experiment are specially instrumented footloops, a
handhold, and a push-off pad. Data will be collected on the forces
applied as the crew uses these sensors to get around or anchor
themselves. The researchers are also interested in how frequently those
forces are applied.
This is the second flight for the experiment. The first, in 1994,
was aboard the Space Shuttle Columbia. That flight yielded the first
data on the forces associated with astronauts' everyday activities, and
showed that previous estimates of those forces were off by an order of
magnitude.
"We found that each astronaut had an average force value of 28
Newtons," Professor Newman said. In contrast, "for the space-station
models they're still using 800 Newtons for crew input. So we're showing
them an order of magnitude reduction with our data."
The larger estimates were based on studies in the 70s with
astronauts aboard Spacelab. Those studies, however, represented the
extreme. "For example, the astronauts were pushing off one wall and
soaring to another wall as fast as they could," Professor Newman said.
"We are measuring the forces associated with everyday, common
activities."
Results from the current experiment, dubbed Enhanced Dynamic Load
Sensors (EDLS), will add to the pool of data on how astronauts affect
their environment. For the first time, the researchers will also
correlate crew forces with spacecraft acceleration. This "will allow us
to start piecing together the overall picture of what is happening up
there," Professor Newman said.
DARTS IN SPACE
In addition, the researchers plan to study crew members' motion in
zero gravity and how they adapt to weightlessness. "We're interested in
looking at changes in human motor control in different gravity
environments," Professor Newman said.
To do so they will videotape crew members as they play darts. With
the help of four cameras, "I can basically trace out the entire arm
motion so we can get three-dimensional data," Professor Newman said.
"We'd like to have them do this part of the experiment as soon as
possible after they've arrived on Mir, then at the middle and end of
their time there. That way we should get great data on how they adapt to
their new environment."
Other engineers involved in EDLS are Professor Edward F. Crawley of
the Department of Aeronautics and Astronautics; Dr. Marthinus C. van
Schoor, a lecturer in the department, and Michail Tryfonidis, a graduate
student in the department. Mr. Sherwin Beck of NASA's Langley Research
Center is a co-investigator and technical monitor of EDLS. Payload
Systems, Inc., of Cambridge built the hardware for the experiment. The
work is funded by NASA.
