Space Shuttle thermal protection system
On February 1, 2003, the Space Shuttle "Columbia" was destroyed on reentry due to a failure of the TPS. The investigation team found and reported that the probable cause of the accident was that during launch, a piece of foam debris punctured an RCC panel on the left wing's leading edge and allowed hot gases from the reentry to enter the wing and disintegrate the wing from within, leading to eventual loss of control and breakup of the shuttle.
District of Columbia retrocession
The District of Columbia retrocession was the process of returning to the U.S. commonwealth of Virginia a part of the land that had been ceded to the federal government of the United States for the purpose of creating its federal district and capital city. The land was taken in 1790. It was returned, after many stages of federal and state approval, in March of 1847.