Crystals, no larger than a millimeter (a fraction of an inch or about the size of a tooth on the edge of a postage stamp), were photographed under a microscope. Students grew crystals from biological solutions in their classrooms and prepared solutions that will form crystals on board the Space Station. Photo: University of California at Irvine

Students from middle and high schools across America are helping with the first long-duration experiment that astronauts will place aboard the International Space Station this week when the Space Shuttle Atlantis heads back to the unique, orbiting laboratory.

The students have prepared about 150 of the 500 biological samples that the crew will transfer from the Shuttle to the Space Station during the STS-106 mission set for launch Sept. 8.

As part of a NASA pilot education program, students have grown crystals in their classrooms and learned about biological substances that carry out many important functions for humans, animals and plants.

"Involving students in the first Space Station experiment is a great way to teach them biochemistry and show them how our first permanent outpost in space can be used for research," said Dr. Alex McPherson, head investigator for the experiment and a biochemistry professor at the University of California in Irvine.

The students -- working in university laboratories with McPherson and other scientists from NASA's Microgravity Research Program at the Marshall SpaceFlight Center in Huntsville, Ala. -- mixed biological solutions and sealed the chemicals in small tubes or pipettes. The samples were frozen to -320 degrees Fahrenheit (-196 degrees Celsius or 77.3 degrees Kelvin).

Just before the Shuttle launch, scientists will place the samples in the Enhanced Gaseous Nitrogen Dewar -- a vacuum-jacketed container, similar to a large thermos bottle, with an absorbent inner liner saturated with liquid nitrogen. Once in orbit, the liquid nitrogen will boil off inside the unpowered, unattended thermal enclosure, and the samples will thaw.

Teacher Andrea Reeder, left, and three of her students from Germantown, Tenn., High School prepare biological samples for flight aboard the International Space Station. Photo: NASA-MSFC

Before thawing is complete, the crew will move the dewar to the Space Station where crystals will slowly form for several weeks. When the Shuttle returns to the Station in October, the dewar will be brought back to Earth where scientists will retrieve and analyze the crystals to determine the structure of biological molecules.

"There are many ways to grow crystals," said McPherson. "The dewar allows us to fly hundreds of samples at once, so we can look at a variety of conditions and determine which ones produce the best crystals." McPherson has been a leader of NASA-sponsored crystallization projects since 1984 and received NASA's Exceptional Scientific Achievement Medal in 1999. He has published numerous journal articles describing crystals grown on the Space Shuttle and the Russian space station Mir.

This experiment sets the stage for more complex structural biology experiments to be flown in the U.S. Laboratory Destiny when it is attached to the Space Station early next year.

"The Space Station is a unique space laboratory where we will be able to perform experiments for longer periods, in sophisticated facilities and under conditions that are more controlled," said Ron Porter, manager of the Biotechnology Program at the Marshall Center. "We are pleased students, who will be the scientists and engineers of the future, were able to have a hands-on role in this first experiment."

The students and teachers who helped prepare flight samples are from Alabama, California, Florida and Tennessee. Students and teachers from 20 other states attended classes as part of the pilot education program sponsored by the Marshall Center -- NASA's Lead Center for Microgravity Research, the University of California in Irvine, the University of Alabama in Huntsville, Alabama A&M University, the Alabama Space Grant Consortium, the Florida Space Grant Consortium, the BellSouth Pioneers, and Alabama Science in Motion -- a special science program of the Alabama State Department of Education.

Students and teachers from Alabama, Florida and Tennessee will attend the September launch of the Space Shuttle at the Kennedy Space Center in Florida.