Facing Higher Odds, SpaceX Scores Second Successful Ocean Landing

SpaceX achieved its second consecutive successful landing at sea overnight as a part of the JCSAT-14 satellite launch to Geostationary Transfer Orbit.

Coming less than one month after the first successful drone ship landing which took place during the NASA CRS-8 resupply mission to ISS on April 8, last night’s achievement was even more challenging due to the inherent requirements of a GTO launch. Facing the need to accelerate its payload to a much greater velocity than required to achieve low Earth orbit where the International Space Station resides meant the Falcon 9 first stage would be moving faster, higher and hotter following second stage separation, and all that energy would need to be negated to bring it safely down to its target.

To accomplish the task, SpaceX changed its return profile to include a last second 3 engine landing burn which had the effect of more quickly negating the unavoidable gravity loss working against the booster than the single engine landing burn which had been employed on previous landing attempts both successful and failed. The change, which came in the form of a tweet from company founder Elon Musk, might seem counter intuitive given the fact that the booster was already operating with minimal propellant remaining, but it also demonstrates the impossibly fine margins SpaceX is exploring with each flight in the effort to recover as many first stages as possible.

In this case, it may have taken advantage of the fact that each of the 9 first stage Merlin 1-D engines would necessarily have had some minimal amount of residual propellant remaining in the maze of lines which supply the first stage. With the stage reduced to its dry mass, plus whatever bit of propellant was still present, the sudden thrust of 3 engines would have resulted in a high acceleration, sudden screeching halt taking place at the exact second necessary to land the booster. That it happened over the deck of a drone ship  operating several hundred miles down range from the launch site in the Atlantic Ocean is simply stunning.

The primary goal of the launch, as SpaceX was quick to remind, was the successful deployment of the JCSAT-14 and a proper sendoff on its way to geostationary orbit. That too was completely successful, becoming the 9th SpaceX mission to be launched to GTO or beyond, with 8 being commercial, and one, the DSCOVR satellite, which was sent to deep space.

In other stats, SpaceX has now compiled an overall Falcon 9 launch record of 23 out of 24, with a near even balance of governmental and commercial missions. Of the total, one was a demonstration launch of the Falcon 9 in June 2010. Ten, including the failed CRS-7 flight in June 2015 have been a part of NASA’s COTS/CRS programs, with two others being multi-agency scientific missions. The remaining eleven have been commercial missions, including the first launch of the Falcon 9 V1,1, which carried the Cassiope satellite for MDA on behalf the Canadian government. JCSAT-14 was the fourth launch of the year and the third since December 2015 to see a first stage recovered intact, one by land and two by sea.

While SpaceX has indicated that its very first stage to be recovered will be sent to its Hawthorne, California headquarters for permanent display, it is worth noting that the company has now safely landed what amounts to the entire first stage assembly of the triple core Falcon Heavy booster which will round out its commercial portfolio and support its recently announced Red Dragon mission to Mars. Although these will not be the specific stage segments to launch that mission, it offers one possible glimpse into the economics of how the company may be able to afford a robust program of planetary exploration, made possible by the re-use of of booster segments which have already fully returned their initial investment.