The samples have been in space since 2001.
CLEVELAND (AP) -- NASA researchers and their high school collaborators in Ohio are looking forward to the shuttle's return to space for the first time since 2003 and a return trip loaded with experiments from the space station.
"What's most unique about getting these samples back is that they've been exposed to the space environment a long time," Kim de Groh, a senior research engineer, said Monday at the NASA Glenn Research Center where she works.
"In the past, the opportunities have only been on the shuttle, where they might be exposed for only a week or two weeks at a time."
The shuttle Discovery, scheduled to lift off Wednesday from Cape Canaveral, Fla., will retrieve two packs of experiments from the space station and replace them with a new experiment pack.
The experiments, placed on the outside of the space station Aug. 16, 2001, have focused on the effect of long-term space exposure to materials used on the outer shell of spacecraft.
"We're looking at materials that would survive on the outside of spacecraft," de Groh said in an interview after NASA officials briefed reporters on the NASA Glenn efforts to improve shuttle safety and develop onboard experiments.
The return to space for the shuttle, long-awaited by NASA, also has been much-anticipated by students from the Hathaway Brown School in nearby Shaker Heights who have collaborated on the experiments.
Catherine McCarthy, 16, a junior from suburban Beachwood, was in eighth grade when the Columbia disaster occurred. She has volunteered with the NASA-Hathaway Brown collaboration for more than two years.
"We've been very involved in this," according to McCarthy, who said NASA researchers "trust us and they take our data as real data, which it is."
She said the Hathaway Brown team findings concluded that extended solar and space exposure can make spacecraft exteriors brittle.
According to de Groh, the returning experiment packs include seven types of experiments and 86 material samples in addition to the Hathaway Brown experiment. The outbound experiment pack contains three experiments designed at Glenn with 85 material samples.