Mars Observer
Mars Observer was a NASA spacecraft launched on September 25, 1992, to study the planet Mars. It was designed to gather detailed information about the Martian surface, atmosphere, and geology, using advanced scientific instruments.
The mission aimed to enhance our understanding of Mars and its potential for past or present life. Unfortunately, communication with Mars Observer was lost just before it was set to enter orbit around Mars in August 1993, leading to the mission's premature end. Despite this, the mission contributed valuable insights into future Mars exploration efforts.