Top grades and special honors for her schoolwork have become the rule for 16-year-old Rachel Safman. But the Gaithersburg High School student's work also is being recognized by the National Aeronautics and Space Administration, which will include one of her science class experiments on a space shuttle mission later this year.

Next week Safman will accompany her experiment -- a process to reduce the weight and density of manufacturing materials, but not their strength -- to the Johnson Space Center in Houston for safety reviews and consultations with the shuttle astronauts.

She will go to the Kennedy Space Center in Cape Canaveral later this year for the launch of the mission that will conduct her experiment and others, as well as deploying and collecting satellites. She is responsible for a final report on the experiment after the shuttle returns.

Safman's experiment was was of 10 selected by NASA from 200 submitted in the 1983 Student Shuttle Involvement Program competition. In the five years that the program has existed, 12 student experiments have been sent to space.

Safman is one of three area students who have been finalists, but her experiment will be the first of the three to be sent aloft.

Other local finalists, chosen in 1984, were Jane McCabe of Eleanor Roosevelt High School in Greenbelt and Karen Jarrard of Montgomery Village Junior High in Gaithersburg. Their projects are to go up on future missions.

McCabe's experiment studies the effects of antibiotics on bacteria in the zero gravity of space and Jarrard's the effects of a weightless environment on electrical stimulation of atrophied body muscles.

"We take [the student experiments] very seriously," said program director Michael Bowie. The experiments, funded by corporate sponsors, have potential applications in private industry and research, he noted.

The student competition also helps "humanize the shuttle program," Bowie said, explaining, "It's good for the nation to prepare youngsters who could be potential recruitees to work for NASA."

"Significant breakthroughs" resulted from a recent student shuttle experiment on the healing effects of zero gravity on six arthritic rats, Bowie said. Another experiment revolved around 3,000 honeybees that were tested to determine what effect zero gravity had on their honeycomb-manufacturing skills.

Under another NASA-sponsored program, the Getaway Special, private or industrial experiments are sent with the mission for fees ranging from $3,000 to $10,000. The Getaway experiments, some of which also have been designed by students, are set in canisters in a cargo area of the spacecraft, while the experiments from the special student program are conducted by shuttle astronauts, Bowie said.

After Safman's project was selected, NASA helped her find a corporate sponsor, Fairchild Space Co. of Germantown. Fairchild has spent two years and $90,000 refining Safman's experimental process.

James Newell, the Fairchild engineer who worked with her on the project, said his company considers such a venture "in-house research and development," as well as good publicity for the Fairchild Industries Inc. division.

Newell said he enjoyed working with Safman because of her interest and dedication to the project and because, "whenever she's around, I don't need my calculator. She can multiply and divide in her head."

Safman said the idea for her experiment evolved from a lecture that she heard at the National Air and Space Museum during a summer class for gifted and talented students. The lecturer spoke of the zero gravity pull in space and how a substance or object once placed there will not move.

Safman said she had this concept in mind in ninth grade at Montgomery Village Junior High, when she was assigned to do a science experiment for the NASA competition.

In her experiment, the shuttle's astronauts will inject air into molten metal. The zero gravity of space will keep the six separate injected air bubbles, or cavities, in place in the metal. After cooling, the process will have created a light-weight, low-density metal that still has significantly high strength.

Previous space experiments tried to create the air bubbles by including chemicals that create air in a material, but they failed, Newell said. Safman's method is new.

Creating porous materials in space could prove useful in constructing space stations and in space mining, Newell said.

If the experiment is successful, Safman said, she also sees her porous metal process as an alternative to the widely used honeycomb-shape fabrication of metals and other materials. Like a bee's honeycomb, materials with such a fabrication have side-by-side hollow air cavities and are light in weight.

Material so fabricated is sturdy and can resist compression forces, but not torque forces that twist or strike the material at an angle, she said. Her system of using isolated air-bubble cavities would resist torque because none of the air-bubble hollows run completely through the material as the honeycomb cavities do, Safman said. Applications for her method of fabricating include aeronautics or automobile manufacturing, she said.

Before entering her senior year at Gaithersburg this fall, Safman will continue working as a science aide at the National Bureau of Standards and will study for six weeks in Israel at the Weizmann Institute of Science. She also helps prepare young men and women for bar mitzvahs and bat mitzvahs at the Gaithersburg Hebrew Congregation.

Safman said she would like one day to attend Harvard University and earn medical and doctorate degrees in biomedical engineering.