Cape Canaveral, Fla. ? The international space station is about to get its first real research scientist.

But with only three people on board and loads of maintenance work, astronaut-biochemist Peggy Whitson will not have all that much time to devote to experiments. She will squeeze in as much science as she can during her 4 1/2-month stay.

Liftoff aboard the space shuttle Endeavour is scheduled for 6:44 p.m. CDT today, though stormy weather could keep the spacecraft grounded until next week.

The shuttle will drop off Whitson and her two Russian crewmates and return home with the three men who have been living up there since December.

Whitson, 42, will be the first person with a Ph.D. and the first American without a military background to live on the space station. She will be only the second woman to move in.

A fresh batch of experiments and scientific equipment is going up on Endeavour, bringing the space station close to its research capacity.

The research will involve plants, crystals, fluids, liver cells, radiation and vibration monitoring, and a slew of medical experiments involving lung function and kidney stones, Whitson’s specialty.

“This is probably where we’ll really start getting serious about some of the science aspects on space station,” said Paul Geery, a Boeing manager.