The crew of Space Shuttle Columbia was unaware of the damage to their spacecraft during their re-entry into Earth's atmosphere on February 1, 2003.
The damage, caused by a piece of foam insulation detaching from the external tank during launch, went undetected by the crew and ground control. The foam strike breached the shuttle's thermal protection system, exposing the wing to extreme heat during re-entry.
While the crew had access to some data on the shuttle's systems, they had no indication of the critical damage to the wing. The crew reported a normal flight and even joked about the mission's success during re-entry.
The crew tragically perished when the shuttle disintegrated over Texas due to the heat damage. The accident prompted a thorough investigation and significant changes to NASA's safety protocols.
