In a ceremony today at the National Aeronautics and Space Administration's Goddard Space Flight Center, officials will be presented with seven scientific experiments designed by Prince George's County high school students for flight aboard a U.S. space shuttle next year.

Some of the experiments will test the effect of the absence of gravity in space, while others test the effects of radiation.

The largest group of student-made projects ever approved for space flight at a single time, the seven experiments were selected in 1982 from 61 entries. They are part of NASA's Get-Away Special program, which allows companies or other groups to purchase room in space shuttles to conduct experiments in space.

Orbital Systems Ltd., an aerospace engineering firm in Lanham, purchased a five-cubic-foot canister for use on the shuttle and donated it to the Montgomery County and Prince George's school systems. Montgomery students will also contribute seven experiments for the shuttle, but four have not yet been completed.

The canister containing the experiments will be strapped to the wall of the shuttle's cargo bay. NASA officials have not determined when the experiments will travel, but a spokesman said it will probably be in 1986.

The students were asked to measure some scientific reaction under controlled conditions at school. Similar experiments will be performed during the flight to see what effect space has on the phenomena.

Students at Suitland High School, for instance, are studying the effects of radiation on a type of bacteria that attacks a virus in the intestinal tract.

Lisa Simpson, a senior who has acted as a spokeswoman for the project at presentations before the county school board and parent-teacher groups, said "a potential benefit of the project is that it may give scientists a better understanding of bacteria that can lead to the production of new vaccines against viruses which may harm man."

Simpson said she thinks the project is "doing a lot to help Suitland. The school has never done something this big. It's definitely something to be proud of."

In addition, said Suitland biology teacher William Wultich, who is a faculty adviser for the project, "Students have gained a lot of practical experience, not only in biology, but in electronics, drafting designs and writing reports. They get a feel for what research is all about, and a feel for what is new and what has not been looked at."

At Bowie High School, students are testing the effects of zero-gravity on the growth of radishes. Radish seeds will be placed in a clear gelatin inside a cylindrical apparatus, and a camera will take pictures of them once every four hours.

Other Prince George's participants are students from Eleanor Roosevelt, Oxon Hill and Friendly high schools.