Astronauts’ sleep may get lost in space

During a 5-month stint on the space station Mir in 1997, U.S. astronaut Jerry M. Linenger and his two Russian counterparts confronted a severe fire, failures of the oxygen generator and communications systems, and a near-collision with a resupply ship. As if that weren’t enough, Linenger also found himself wrestling with his own biology: After 3 months in space, his body’s clock apparently lost its daily rhythm.