NASA at Half Mast: Remembering Fallen Astronauts

NASA will commemorate three space tragedies this week. This is the 25th anniversary of the shuttle Challenger accident that killed seven astronauts. The space agency will also pause to remember the 2003 loss of the shuttle Columbia and its crew and the earlier Apollo 1 fire that killed three astronauts. For more, click here.

From left, Apollo 1 astronauts Virgil I. "Gus" Grissom, Edward White and Roger Chaffee in front of their Saturn 1 launch vehicle at the Kennedy Space Center. All three astronauts later perished during a fire on the pad January 27, 1967.

Apollo 1 crew members walk across a catwalk to the Launch Pad 34 White Room on January 27, 1967. This was to have been the last major test of the spacecraft , simulating the liftoff during an actual launch. For a first-hand recollection of the launch pad disaster, click here for a Q&A with Stephen B. Clemmons, who had been on duty at the launch complex that tragic day.

Less than a minute into its launch on Jan. 28, 1986, the space shuttle Challenger broke apart. No crew members survived the accident. The problem later was traced to a faulty O-ring seal in the craft's right solid rocket booster.

Official portrait shows the STS-51L crew members: Back row (L to R): Ellison S. Onizuka, Sharon Christa McAuliffe, Greg Jarvis and Judy Resnik. Front row (L to R): Mike Smith, Dick Scobee and Ron McNair

A solid fuel rocket booster disappears behind the contrail of the explosion of the space shuttle Challenger 28 January 1986 over Kennedy Space Center as debris from the orbiter begins to fall to earth. The US space shuttle exploded seconds after lift-off, killing it crew of seven. Challenger was 72 seconds into its flight, travelling at nearly 2,000 mph at a height of ten miles, when it was suddenly envelope in a red, orange and white fireball as thousands of tons of liquid hydrogen and oxygen fuel exploded.

Crew of the STS-107 shuttle Columbia while in orbit. This photo was recovered from an undeveloped film cannister found with the wreckage of the capsule, which was destroyed upon reentry Feb. 1, 2003. The problem was due to heat shield damage that was sustained during launch.

From left (bottom row): Kalpana Chawla, Rick Husband, Laurel Clark, and Ilan Ramon (who represented the Israeli Space Agency.) From left (top row) are David Brown; William McCool, and Michael Anderson.

Israelis visit the military grave of Israeli Air Force Colonel Ilan Ramon in the Nahalal cemetery May 5, 2003 in northern Israel. Ramon was a mission specialist on the ill-fated Columbia Space Shuttle flight STS-107.

This NASA handout image shows the Space Shuttle Columbia during reentry as it passes over the Starfire Optical Range at Kirkland Air Force Base, New Mexico on February 1, 2003. Shuttle crash investigators have scrutinized this image which some believe shows damage to the left wing of the shuttle. NASA Mission Control lost contact with the Space Shuttle Columbia during the reentry phase of mission STS-107 on February 1, 2003 and later learned that the shuttle had broken up over Texas. Debris from the wreckage drifted hundreds of miles from central Texas to Louisiana. All seven astronauts on board the Shuttle died in the crash.

David M. Brown, STS-107 mission specialist, peers through a portal window on the overhead bulkhead in the Research Double Module aboard the Space Shuttle Columbia.