On each mission, when not subjecting themselves to medical and psychological testing, space station crews perform hundreds of scientific experiments. All experiments are selected by a panel of NASA scientists from thousands of suggestions. Each is then carefully planned and all needed hardware is assembled. Prior to liftoff, each crew rehearses the steps required for each experiment to minimize failures. Much is at stake: Multimilliondollar projects can be rendered useless if an experiment is botched.

Scientists representing nearly all major branches of knowledge have jockeyed to gain permission to conduct experiments on Salyut, Skylab, Mir, and the ISS. Everyone has recognized that their unique environments, far beyond Earth's atmosphere and floating in weightlessness, hold extraordinary potential for new discoveries in many fields. Those fields given the highest priority have been astronomy, earth environmental study, material development, botany, combustion and fluid physics, and military reconnaissance...