It's a little too late to celebrate, but April 12th was the 25th anniversary of the 1st US Space Shuttle launch. When the Space Shuttle Columbia, STS-1, was launched on April 12, 1981, it was a live test flight according to commander John Young and his pilot Robert Crippen.
Don't miss the video of Crippen & Young discussing the first flight. In the 25 years since the launch, the STS (Space Transportation System) program has had many setbacks and tragedies, but it is interesting to hear of the Shuttle program spoken of with optimism as well as trepidation.