RatSat
RatSat or DemoSat was an aluminum mass simulator on the fourth flight of the Falcon 1 rocket, launched on 28 September 2008. Ratsat remained bolted to the second stage of the carrier rocket after reaching low Earth orbit. It is an aluminium alloy chamber in hexagonal prism shape with 1.5 m (5 ft) length. The Falcon 1 launch that carried Ratsat to orbit was the first successful orbital launch of any privately funded and developed, liquid-propellant carrier rocket, the SpaceX Falcon 1, something only six nations had successfully accomplished previously. 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. Background Three consecutive flights of the Falcon 1 rocket had ended in failure. In particular, during the third launch of the Falcon 1 in August 2008, the first stage of the rocket after stage separation have residual thrust and slammed into its second stage, resulting in catastrophic damage to the second stage's Kestrel engine. Though the fix for the problem is simple – add a time delay between main engine cut off and stage separation