Twenty-five years ago today, NASA's space shuttle Challenger exploded and broke apart just after liftoff, killing seven astronauts – including civilian teacher Christa McAuliffe – in one of the worst space disasters in U.S. history.
The 1986 space shuttle Challenger disaster was NASA's first public spaceflight failure and second fatal spaceflight failure. Every year at this time, NASA remembers the Challenger crew, as well as the seven astronauts killed on the shuttle Columbia during re-entry on Feb. 1, 2003, and three Apollo 1 astronauts who died in a pad fire aboard their capsule on Jan. 27, 1967.
Challenger's ill-fated flight, STS-51L, gained wide attention because of the presence of New Hampshire high school teacher Christa McAuliffe on the shuttle's crew as NASA's first Teacher in Space. She was joined by Challenger mission commander Richard "Dick" Scobee, pilot Michael J. Smith, mission specialists Ronald McNair, Ellison Onizuka, Judith Resnik and payload specialist Gregory Jarvis.
Here's a look at the Challenger space shuttle disaster, why it happened and its impact now 25 years later:
Friday, Jan. 28
Photo Gallery: Remembering Challenger – NASA's First Shuttle Disaster
See photos of the Challenger astronauts who lost their lives on Jan. 29, 1986.
Challenger Shuttle Disaster at 25: NASA Recalls Darkest Moments
NASA is observing its three darkest moments in spaceflight, including today's 25th anniversary of the space shuttle Challenger disaster that killed seven astronauts on Jan. 28, 1986.
Image of the Day: Remembering the Fallen
NASA Administrator Charles Bolden places a wreath at Arlington National Cemetery as part of NASA's Day of Remembrance, Thursday, Jan. 27, 2011. The memorial recognizes the Apollo 1, Challenger and Columbia crews, along with other NASA personnel lost in the course of space exploration.
Challenger Widow: Shuttle Disaster Should Drive Exploration Forward
The memory of the crew of the ill-fated space shuttle Challenger must lead the United States toward a brighter future in space exploration, the widow of Challenger's commander said today.
Thursday, Jan. 27
Obama Honors Astronauts Lost in Space Exploration
President Barack Obama today called on the country to push forward toward new space frontiers as he honored those Americans who have lost their lives in the pursuit of space exploration.
Photo Gallery: The Apollo 1 Fire
NASA's first experience with spaceflight tragedy occurred on Jan. 27, 1967, when a fire killed Apollo 1 astronauts Gus Grissom, Ed White and Roger Chaffee during a launch pad test. See photos of the crew's training and fire aftermath.
Will Human Spaceflight Ever Truly Be Safe?
Launching people into space can be risky, as the Challenger tragedy shows. As space tourism gets set to take off, now is a good time to ask: How safe is human spaceflight?
Learn about the inherent risks for astronauts embarking on space exploration missions to orbit and deep space.
Wednesday, Jan. 26
25 Years After Challenger: How Grief Inspired Teachers and Students
Millions of students were watching when the space shuttle Challenger broke apart just after liftoff on Jan. 28, 1986, killing all seven members of its crew, including America's first teacher astronaut, Christa McAuliffe.
Challenger Remembered: Q&A with Teacher Astronaut Barbara Morgan
NASA educator astronaut Barbara Morgan reflects on the space shuttle Challenger accident 25 years ago that killed America's first teacher astronaut, Christa McAuliffe.
Tuesday, Jan. 25
Space Shuttle Challenger Disaster FAQ: What Went Wrong
This week marks the somber 25th anniversary of the accident that killed seven astronauts aboard NASA's space shuttle Challenger. Here are some of the most frequently asked questions about the disaster, as well as their answers.
Monday, Jan. 24
Remembering Challenger: NASA to Mark Space Tragedy Anniversaries
NASA will commemorate three space tragedies this week, which also marks 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.