this Dec 2013 flight when they started development on the second stage recovery. Prior to that the F9 second stage only made the five minutes burn and was then left in orbit. They spent the subsequent four years working on the second stage recovery until the plan was abandoned.The second stage made two burns during launch. The first burn lasted for five minutes and 20 seconds and was followed by an 18-minute coast phase.
Once the coast ends, the engine successfully restarted – a key first for SpaceX – to make a one-minute burn. Spacecraft separation followed, five minutes after the end of the second burn.
Related link: Falcon 9 v1.1 successfully lofts SES-8 in milestone launch
