While the second stage powered JCSAT-14 towards orbit, SpaceX attempted to land the first stage atop a barge in the Atlantic Ocean. Following separation from the second stage, the first stage reoriented itself and performed a boostback burn to put itself on course for the landing platform.

Two further burns were made; to slow the rocket as it entered the atmosphere and as it approached the landing platform.

An Autonomous Spaceport Drone Ship (ASDS) was deployed to serve as the downrange landing point for Friday’s mission as the rocket did not have sufficient fuel reserves to return to Cape Canaveral and SpaceX’s dry land landing site, Landing Zone 1 (LZ-1).

The ASDS, named Of Course I Still Love You after a ship in the Culture series of stories by novelist Iain M. Banks, was last used in the successful recovery of the first stage of the Falcon 9 that launched the CRS-8 Dragon mission in April. This marked the first time a first stage was successfully recovered at sea, however one land-based recovery attempt had previously succeeded.

CRS-8 was a low Earth orbit mission; due to the higher velocity required for Friday’s geostationary launch SpaceX were less optimistic about the chances of succeeding. A similar attempt during the SES-9 launch in March was unsuccessful.

SpaceX has stressed that the landing attempt was experimental, and its success or failure had no bearing on the overall outcome of the mission, whose only primary objective is to place JCSAT-14 into its designated geosynchronous transfer orbit.

However, patchy webcam coverage from the drone ship saw the stage start to light up the deck, before suddenly showing the stage sat in the middle of the “X” – marking another major milestone for SpaceX.

The success was also aided by the multi-engine landing burn option, with three – as opposed to one – Merlin 1D igniting for touchdown.

This stage will now be safed and prepared to be returned to the coast.

外電報導：
https://www.nasaspaceflight.com/2016/05/falcon-9-jcsat-14-launch/