Laurence D. Savadove

The commander of a spaceship orbiting 250 miles above Earth disappears through the airlock and is ejected into space. Although at first it appears to have been an accident, some of the crew come to suspect that it may have actually been a murder.

A murder plot by a terminally ill English teacher, to capitalize on the double indemnity clause in his life insurance, hires one of his students to do the deed.