By Associated Press

Astronauts and cosmonauts killed in the history of space exploration:

Jan. 27, 1967
Astronauts Gus Grissom, Edward H. White and Roger B. Chaffee die when a fire sweeps their command module during a ground test at Kennedy Space Center.

April 24, 1967
Soviet cosmonaut Vladimir Komarov is killed when his Soyuz I spacecraft crashes on return to Earth.

June 29, 1971
Cosmonauts Georgy Dobrovolsky, Vladislav Volkov and Viktor Patsayev die during re-entry of their Soyuz 11 spacecraft. A government commission disclosed that the three died 30 minutes before landing because a faulty valve depressurized the spacecraft.

Jan. 28, 1986
The space shuttle Challenger explodes 73 seconds after launch, killing all seven astronauts aboard, including Christa McAuliffe, intended to be the first teacher in space. Other astronauts killed were Francis "Dick" Scobee, Michael J. Smith, Ellison S. Onizuka, Judith A. Resnik, Ronald E. McNair and Gregory B. Jarvis.

Feb. 1, 2003
Space shuttle Columbia breaks apart in flames about 203,000 feet over Texas, 16 minutes before it was supposed to touch down in Florida. All seven aboard were killed: William McCool, Rick Husband, Michael Anderson, Kalpana Chawla, David Brown, Laurel Clark and Ilan Ramon, who was Israel's first astronaut.