Why Space Shuttle Columbia broke apart on reentry in 2003

Space Shuttle Columbia broke apart over Texas on February 1, 2003, because foam insulation from its external tank had struck its left wing about 82 seconds after launch, damaging the leading edge so that the searing heat of reentry destroyed the wing. All seven STS-107 astronauts were killed about 16 minutes before their planned landing in Florida: Rick Husband, William McCool, Michael Anderson, David Brown, Kalpana Chawla, Laurel Clark and Ilan Ramon, Israel’s first astronaut.

NASA knew about the strike while Columbia was still in orbit. Engineers spotted it in routine review of launch film, and on January 23, the mission’s eighth day, flight director Steve Stich emailed Husband and McCool a video clip of the impact, assuring them it was no concern for reentry because foam had hit shuttles before. Engineers asked for high-resolution imaging of the wing; managers turned the request down. Nothing in the telemetry, video or crew reports showed damage.

After the breakup, searchers in Texas and Louisiana spent more than three months gathering debris and recovered about 38% of Columbia by weight. At the Southwest Research Institute in San Antonio, investigators then fired foam at reinforced carbon-carbon panels like those on the wing’s leading edge. The Columbia Accident Investigation Board traced the strike to left-wing panels 5 to 9.

Its August 2003 report faulted more than foam. The board found NASA had grown complacent about foam shedding because it had never caused serious trouble beyond post-flight repairs, echoing the cultural failures behind Challenger in 1986.

The shuttles stayed grounded for more than 29 months, until Discovery flew STS-114 in July 2005, and the fleet retired in 2011. One experiment came home alive: tiny C. elegans roundworms survived reentry and the crash inside the wreckage.