LIFTOFF!
Pushing ahead to Space Station
November 19, 1997 4:00 p.m.
Flight Day 0
On Wednesday, November 19, at 1:46 p.m. Central Standard Time,
the shuttle Columbia lifted off to begin the 16-day mission to perform fundamental
scientific research in space, investigating Materials Science, Combustion, and Fluid
Physics research experiments. These investigations, some of which have
been in preparation for over a decade, are designed to use the unique environment
of low-gravity to learn about fundamental physical processes that are ordinarily
masked by the presence of gravity.
For the next 16 days, you can follow along and learn about
the science being performed on the mission through activities on this WWW site, as well as the USMP-4
Mission Home Page, and the NASA Shuttle
Web Site. |
|
Applause rippled through the control rooms this
afternoon as the last of a long line of science missions blasted off to
an on-time start.
But while it may seem like the end, the mission scientist, Dr. Peter
Curreri of NASA's Marshall Space Flight Center, sees it as setting the stage
for another beginning.
"No, not at all," Curreri said a few minutes after launch when
he was asked whether he had any sadness over the end of the USMP series.
"We're already looking forward to a number of experiments on the International Space Station"
which is to start assembly next summer. Some of the USMP-4 scientists using
the middeck glovebox aboard this mission hope to continue their work aboard
ISS. Other experiments aboard USMP-4 also will have descendants as new facilities
are added to ISS. |
"USMP has been so successful in the opening of the microgravity
sciences," Curreri said. "More than something ending, it will
serve as a model for science in the future."
USMP-4, aboard Space Shuttle Columbia, will operate in parallel with
a spacewalk and with the deployment and retrieval of the Spartan 201 solar
observatory. USMP-4 activities are directed through the Payload Operations
Control Center at NASA-Marshall.
The largest portion of USMP-4 is on the pair of bridge-like structures
that span the payload bay. There sit four experiment devices to expand our
understanding of materials sciences. Two automated furnaces will grow crystals
of materials valuable in advanced detectors and electronics. Both are employed
to define the sensitivity of these crystals to low-level accelerations.
On the USMP-3 mission, a crystal in the AADSF, for example, grew exceptionally well until the
shuttle's attitude drifted out of position by a mere 15 degrees. Then the
growth became the same as you could get on Earth.
"The sensivity of the science has been quite extraordinary,"
Curreri explained, because when a material takes a long time to solidify,
even low-level accelerations can allow convective flow to start.
The Isothermal Dendritic Growth Experiment (IDGE) will expand its successful studies on the growth
of crystals that form like leaves ("dendrite" is Greek for leaf),
a common effect in many metallic alloys. Curreri said that results from
IDGE's first two flights have been incorporated in a number of math models
of metal formation and soon may be headed for the foundry floor and, eventually,
textbooks.
IDGE will also pioneer telescience where scientists operate experiments
from computers at their home institutions rather than at payload control
here.
Fundamental physics and practical applications also will be addressed
by the Confined Helium Experiment (CHeX) which uses supercooled liquid helium sandwiched
between silicon wafers.
CHeX builds on an earlier experiment, ZENO, on how fluids behave at the
critical point between liquid and solid. Those results, Curreri said, have
found their way into eliminating dangerous solvents from paints and from
the process for decaffeinating coffee.
"CHeX is taking advantage of how matter behaves at the critical
point where the finite size effect comes into play," Curreri. At the
point, small effects are felt across an entire structure rather than on
just a few atoms.
Knowledge gained from this will be applied in the manufacture of advanced
microcircuits which can only be made so much smaller. The smallest components
on chips now are about 0.3 micron (30 millionths of a centimeter wide).
At about 1 percent of that size, the finite size effect will kick in. Designers
will have to compensate for it, or even make it a part of the process, as
they continue to make chips smaller in the quest for greater speed.
"With CHeX," we're beginning to lay out the physics that becomes
the engineering that builds the devices," Curreri said.
And which builds the science missions of the future.
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Author: Dave
Dooling
Curator: Linda Porter
NASA Official: Gregory S.
Wilson
