SPACE EXPLORATION BEYOND low Earth orbit has been termed as “exploration class space missions.” Such future missions may involve extended flights to the Moon, asteroids, or Mars and will most likely engage not only governmental space agencies but also the private sector, in what some have termed “the new space race.” During those missions, the risk for a crew member to require advanced medical care, including anesthesia and surgery, is significant. In the first section of this review, human adaptation to the space environment is detailed, with a focus on the cardiovascular system, along with a discussion regarding which medical conditions may arise. The second part of the review focuses on discussing the extensive list of challenges associated with delivering an anesthetic procedure in space or on a foreign planetary surface. The challenge of providing advanced critical care in these settings encompasses many other issues that are beyond the scope of this review, which primarily focuses on anesthetic techniques.