The launch and ascent of Falcon 9 Flight 20 carrying the ORBCOMM OG2 M2 set of 11 satellites to orbit.

The re-entry burn, the second of three engine firings associated with bringing the first stage of the Falcon 9 launch vehicle back to SpaceX Landing Zone 1. This burn is used to slow and control the rocket as it re-enters Earth's atmosphere and prevent the rocket from being damaged as it makes the transition from hypersonic velocity through the range of supersonic velocities, through the transonic region (sonic boom is generated here), and down to subsonic velocities where the atmosphere itself will maintain the rocket's descent speed at terminal velocity. (High-altitude descent of the first stage of Falcon 9 Flight 20. Note: the boostback burn, the first of the three engine firings necessary to bring the rocket back, occurs above the atmosphere and considerably farther out to sea; it is not captured in this photo.)

The landing burn, the third of three engine firings associated with bringing the first stage of the Falcon 9 launch vehicle back to the coast of Florida for landing. This burn is used to decelerate the rocket from terminal velocity and bring it to a controlled landing at SpaceX Landing Zone 1, CCAFS, Florida.

(Low-altitude descent of the first stage of Falcon 9 Flight 20. Note: the boostback burn, the first of the three engine firings necessary to bring the rocket back, occurs above the atmosphere and considerably farther out to sea; it is not captured in this photo.)