Ratsat
Ratsat, or DemoSat, was a 165-kilogram (363-pound) non-functional boilerplate spacecraft used as a mass simulator on the fourth flight of the Falcon 1 rocket.
Ratsat was carried to orbit on the first successful orbital launch of any privately funded and developed, liquid-propelled carrier rocket, the SpaceX Falcon 1.
The launch, identified as Falcon 1 Flight 4, was conducted by SpaceX, and also marked the first time the Falcon 1 rocket successfully achieved orbit, after three consecutive failures on the three previous launch attempts.
Ratsat remained bolted to the second stage of the carrier rocket after reaching low Earth orbit. It has a hexagonal prism shape, 1.5 m (5 ft) long.
SpaceX co-founder Elon Musk estimates that Ratsat will remain in orbit for between five and ten years before burning up in the atmosphere.
Preparations
When the fourth flight was first announced in August 2008, shortly after the third flight failed, it was planned for launch in September. The rocket that was used to conduct the test flight was originally built to launch the RazakSAT satellite. The test flight was introduced into the launch schedule because Astronautic Technology Sdn Bhd (ATSB) required a successful flight to be conducted before RazakSAT could be launched.