When the space shuttle Endeavour lifts off tomorrow, it’ll be carrying an Iowa soybean experiment to the International Space Station. Radio Iowa’s Soybeans may someday be a big part of an astronaut’s diet on the space station and on long trips to other planets. Daria Schmidt is research director at Pioneer Hi-bred International, based in Johnston. Schmidt says these experimental soybeans will grow aboard the space station for 70 days before they’re brought back to earth for study.Schmidt says the beans will be grown in a self-contained chamber aboard the station. When they’re returned home, they’ll be tested for their oil, carbohydrate composition, meal and other analysis.One of the astronauts who’ll tend the plants in orbit grew up on an Iowa farm. Mount Ayr native Peggy Whitson is to be the first Iowa woman in space. The launch time is still being kept secret but Endeavour is expected to lift off sometime between 3 and 7 P-M central time tomorrow (Thursday).