For Release: Sept. 11, 1996

Steve Roy
Office of Media Services
(205) 544-0034
steve.roy@msfc.nasa.gov

RELEASE: 96-164

UNDERSTANDING SOIL BEHAVIOR IN EARTHQUAKES, MYSTERIES OF PROTEINS MAY BE UNLOCKED BY MARSHALL STUDIES ON ATLANTIS

Researchers -- seeking to gain a better understanding of soil behavior during earthquakes and to unravel mysteries of proteins found in all living organisms -- are sending their experiments into space aboard the Space Shuttle Atlantis, scheduled to launch Sept. 16.

The low-gravity environment of space will enhance these science investigations, managed by NASA’s Marshall Space Flight Center in Huntsville, Ala.

The flight of Atlantis marks the fourth linkup of the U.S. Shuttle with the Russian space station Mir. And it will bring the return to Earth of U.S. Astronaut Shannon Lucid after a record-setting stay in space for a woman.

Aboard Atlantis will be the Mechanics of Granular Materials experiment, which will look at the behavior of granular materials under very low stresses.

Results of the complete set of experiments aboard Atlantis and subsequent missions could have far-reaching implications, leading to improved selection and preparation of building sites, better management of undeveloped lands, and improved handling of materials in chemical, agricultural and other industries.

This research may be applied to diverse fields such as earthquake engineering, landslides, mining, soil erosion and the irreversible loss of enormous amounts of windblown, fertile soil. Other fields that may benefit from this research include coastal and off-shore engineering, off-road vehicle engineering, and the handling of granular materials such as grains and powders.

For years, scientists conducting studies of granular materials have been frustrated by Earth’s gravity because samples collapse under their own weight in low-stress conditions. In Earth-based studies, it has proven difficult to maintain stability of water-saturated granular materials when pressure in the water increases -- a condition similar to what takes place during earthquakes and leads to the collapse of buildings and bridge foundations.

In space, correct measurements can be made because weight is not a factor, and it is possible to maintain the experiment’s configuration without gravity’s influence.

During the Atlantis mission, test information will be collected. Then the material samples will be returned to Earth and measurements will be taken to examine how the material has changed, to determine the motion of particle groups, and any instabilities.

Dry soil is being studied on this flight, but future Shuttle missions will test water-saturated soil. Some of these tests will be performed under cyclic loading, which is a condition encountered in earthquakes.

Dr. Stein Sture, a professor at the University of Colorado at Boulder, is the principal investigator of the experiment, and Dr. Nicholas C. Costes, a senior research scientist at Marshall Center, is the co-principal investigator. Buddy V. Guynes of Marshall is the project manager.

UNLOCKING SECRETS OF PROTEIN CRYSTALS

In another area of research slated for the flight of Atlantis, the crew will retrieve two closed aluminum cylinders, called dewars, holding hundreds of protein samples grown on the Russian space station Mir over the past nine months. And they will place aboard Mir another dewar filled with new samples to be grown in space during the next several months.

Proteins are important, complex biological molecules, serving a variety of functions in all living organisms. Determining their molecular structures can lead to a greater understanding of their functions and to development of new drug treatments targeting specific human, animal and plant diseases.

But crystals grown on Earth, affected by the forces of gravity, often have internal defects that make scientific analysis of their structures difficult, if not impossible. As proven on Shuttle missions since 1985, certain protein crystals grown in the weightless environment of space are larger, have fewer defects and a greater internal order than those grown on Earth.

The Atlantis mission will continue the longest unbroken flight program of crystal growth research in space. When these protein samples are returned to Earth, they will be studied and compared to those grown on Earth, as well as to others grown in shorter time periods on previous Shuttle flights. Analysis of crystal experiments on previous missions shows successful growth of a number of uniform, high-quality crystals.

The lead investigator for these experiments is Dr. Alexander McPherson, a professor at the University of California at Riverside. Ron King of the Marshall Center is project manager for the study.

Atlantis crew members also will retrieve a second Marshall- developed crystal growth facility, called the Diffusion-Controlled Crystallization Apparatus for Microgravity, installed on the Mir last March. This apparatus uses the liquid-liquid diffusion and dialysis methods for protein crystal growth. Growth is triggered by two solutions which slowly approach supersaturation as they diffuse. Containing 162 experiment units, the diffusion device allows control over the rate of approach to supersaturation, and the crystals grow slowly and methodically over periods of up to six months.

Developed at Marshall Center’s Laboratory for Structural Biology by lead investigator Dr. Dan Carter, the apparatus provides researchers a better opportunity to grow diffraction-sized crystals. Samples grown in space will be compared to those grown by the same method in ground-based studies. Serving as project manager for this experiment is Blair J. Herren of the Marshall Center.

Atlantis is scheduled to dock with Mir on the third day of its mission. Landing is scheduled at the Kennedy Space Center in Florida on Sept. 26, after a nine-day flight.