Last resort

An astronaut returning from Mars discovers there is a pinhole leak in his ship. Too small to find, but enough to exhaust his air before he gets back to Earth. He can discover no solution, so he takes the Last Resort--a drug that is a mix of hallucinogens and brain-boosters that may expand his thought processes. If it doesn't kill him. Some nice description and good science in what is basically a one character story.  Also included, the novellette, "The Standadardized Man"