Improved production of future medicines and better recovery of crude oil could result from an instrument that studied the behavior of liquid drops in microgravity on a recent 16-day flight of the Space Shuttle Columbia, according to NASA scientists.

The Drop Physics Module-2 (DPM-2), one of 16 experiments aboard the U.S. Microgravity Laboratory-2 that flew on the shuttle last month, uses sound waves to manipulate liquid drops for close study. It enables scientists to test basic theories of fluid physics that cannot be proved on Earth because of gravity.

"It gave us very good data, two weeks of data," said DPM-2 Project Scientist Arvid Croonquist of NASA's Jet Propulsion Laboratory. "Now we need to study that data to see what it implies and how it can be applied."

One of the efforts, he said, may contribute in time to the treatment of some hormonal ailments such as diabetes. One part of the experiment studied a pair of chemicals that could be used to make a protective membrane for living cells to be transplanted into a patient's body as part of hormone therapy. To simulate making the membrane, the scientists employed a substance made of polymers or long molecules, the same material used for soft contact lenses. The experiment's intent was to see the effects of reduced gravity on the bonding of polymers.

The second part of the study was to see if there is a force that can be used to place the mass of cells within the membrane. Using a water drop inside an oil drop, the astronaut operators showed that this force is very small. In microgravity fluid processes evolve much more slowly than they would on the ground, and the scientists can study videos of the experiment instead of the high-speed imaging required for ground-based studies, Croonquist said.

Another part of the experiment looked at how the surface of water drops interact with different chemicals, called surfactants. They are similar to chemicals used in detergents to help water remove grease or oils from surfaces. Using these experiments to confirm a model developed by DPM-2 scientists, he said, could lead to better ways to mix chemicals with steam to recover additional crude oil from previously pumped fields.

Other objectives of the experiment were the study of rotating drops splitting into smaller drops and to relate flows in the interior of a drop to the motion of its surface.

An acoustic chamber is at the center of the Drop Physics Module-2. Liquids are injected into the chamber and then manipulated with sound waves. An astronaut-scientist controls the experiment via a special computer while video and film cameras record the behavior of the liquid droplets.

Former payload specialist Dr. Eugene Trinh, who flew with the DPM-1 in 1992, monitored the data transmission using ground based instruments at the operations center at NASA's Marshall Space Flight Center in Huntsville, AL. Principal investigators of the experiment were Dr. Taylor Wang of Vanderbilt University and Dr. Robert Apfel of Yale University.

DPM-2 was built by Loral Electro-Optical Systems, Inc. The experimental work aboard the shuttle was done under contract to NASA's Office of Life and Microgravity Science and Applications.

"Much of the mission success should be attributed to the hard work of the JPL/Loral team in preparing for the mission," said DPM-2 Manager David Gallagher.

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