After successfully delivering a satellite into a geosynchronous transfer orbit, SpaceX attempted to land its Falcon 9 booster on a seabarge, the "Of Course I still Love You," in the Atlantic Ocean. The video feed cut out at the last instant, keeping everyone guessing as to the fate of the unmanned first stage rocket, but SpaceX founder and CEO Elon Musk has now confirmed in a tweet that the landing attempt was unsuccessful.
At 6:35 pm EST, the booster lifted off from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida and then delivered the SES-9 mission into orbit. After lifting off, the nine-engine Falcon 9 rocket reached its moment of peak mechanical stress or Max Q at the one minute mark. The Falcon 9 shut down at two minutes 36 seconds into the flight with stage separation four seconds later followed by the second stage ignition at the two minute 47 second mark.
The second stage fired for about five minutes, then coasted until 27 minutes into the mission, when it refired to put the SES-9 satellite into a transfer orbit that will place it 22,236 mi (35,786 km) above the Earth as part of a 50-satellite constellation. There it will provide coverage for up to 26,000 surface vessels annually on high-traffic maritime routes in the Asia-Pacific region over the next 15 years
Meanwhile, the Falcon 9 first stage, instead of crashing into the ocean, re-oriented itself and executed a "boostback" burn to kill its suborbital hypersonic velocity, followed by a re-entry burn three minutes later to further slow it down. As it re-entered the atmosphere, A set of vanes deployed on the top of the booster and acted as rudders to guide the rocket down. As it approached the barge, the engines fired for a final time before touching down nine minutes after liftoff.
The purpose of the barge landing was to develop the technology needed to further SpaceX's goal of creating a completely reusable launch system. Part of this strategy involves the use of drone barges, which will allow the Falcon 9 booster to land downrange from a variety of trajectories that would prohibit a touchdown on dry land.
The launch took place under clear skies after four previous launch aborts due to problems with the supercooled liquid oxygen on February 24 and 25, followed by a dramatic last-second abort on February 28 just as the engines were firing due to a combination of a low-thrust warning, high liquid oxygen temperature, and helium bubbling. Then the March 1 launch window was canceled due to prolonged high winds.
In a statement prior to the launch, SpaceX said that it was not optimistic about the chances of success for the landing. The Falcon 9 uses fuel left over from the launch to slow itself down and maneuver to its landing target, but because geostationary payloads are large, high-energy shots, very little was left over for today's attempt.
Because of the loss of direct video feed and telemetry, as well as the distance of the seadrone from land, information as to the fate of the booster was unknown until Musk made the following tweet, "Rocket landed hard on droneship. Didn't expect this one to work ([very] hot renetry), but next flight has a good chance."
Source: SpaceX
