Cardiovascular research in space: considerations for the design of the human research facility of the United States Space Station.

NASA has recently celebrated its 25th anniversary, and it has been over 15 years since a man first set foot upon the lunar surface. The space agency is now making plans for "permanent" human presence in space to consist of an orbiting station staffed by both career astronauts and visiting investigators. What have we learned from the experience of two and a half decades of manned space flight? How well will the human organism tolerate longer duration or repeated space flights? What physical or psychological traits will be beneficial or detrimental to future space travellers? What additional considerations or investigations should be planned on the United States Space Station? This brief review summarizes our knowledge of space physiology as it relates to the cardiovascular system. Only actual flight information is utilized; no attempt is made to include the wealth of ground based simulation data, nor are areas remote to the cardiac system discussed. Gaps in current understanding are highlighted in a manner of suggested plans for future space flight investigations.