Get Away Special (GAS) and Hitchhiker Small Payloads

Getaway Special was a NASA program that offered interested individuals, or groups, opportunities to fly small experiments aboard the Space Shuttle. The program, which was officially known as the Small, Self-Contained Payloads program, was canceled following the Space Shuttle Columbia disaster on February 1, 2003.
The Hitchhiker Program (HH) was a NASA program established in 1984 and administered by the Goddard Space Flight Center (GSFC) and the Marshall Space Flight Center (MSFC). The program was designed to allow low-cost and quick reactive experiments to be placed on board the Space Shuttle. The program was discontinued after the failure of STS-107.