In the 1980s and 1990s NASA began to concentrate on building Space Shuttles. Four Shuttles were built in 1985. The first to launch was the Space Shuttle Columbia in April 12, 1981. At this time the public began to lose interest in the space program and NASA faced budget cuts. They had planned for the Space Shuttles to cost less as they could be used more than once. But eventually it turned out the Space Shuttles were more expensive as building them in the first place cost more money than normal. There were further problems for NASA after the Space Shuttle Challenger disintegrated in flight in 1986, killing all seven of its astronauts. The incident is known as the Challenger Disaster.