Looks like early liquid oxygen depletion caused engine shutdown just above the deck pic.twitter.com/Sa6uCkpknY— Elon Musk (@elonmusk) June 17, 2016
Elon Musk has released footage of yesterday's attempt to land a Falcon 9 rocket booster on a drone ship at sea. It was SpaceX's eighth attempted sea landing, and the fifth time that the rocket didn't survive. The payload for this mission — two communications satellites — was successfully delivered to space shortly after the attempted landing.
High orbit missions make it hard to land
Before this mission, the company had been on a bit of a streak, having landed three Falcon 9 boosters in a row over the course of the last three months. The strange thing about this most recent attempt, though, was that no one could immediately tell whether or not the rocket survived the landing. SpaceX was live streaming the entire mission, but the drone ship's camera feed kept cutting out during the landing attempt, and the images that did make it through showed the booster apparently standing upright but engulfed in fire and dark smoke.
Shortly after that confusion, we learned on the broadcast (and from Elon Musk on Twitter) that the Falcon 9 first stage didn't make it, and now we see why. The rocket made what appears to be a careful descent down to the ship, but it never truly settled after it landed. Amidst all that smoke and fire, the rocket eventually tipped over. Unlike SpaceX's other landing attempts gone sour, we don't see an explosion — the video that Musk posted cuts off right before the rocket fully tips over. (Here's hoping we get more angles in the coming days.)
While SpaceX had been on a roll with these landings, it's not a total surprise that the rocket landing wasn't successful. This particular rocket delivered its payload to a very high Earth orbit known as geostationary transfer orbit, or GTO. Falcon 9 missions to GTO require more fuel and higher speeds, meaning there is less fuel left to slow the rocket down to land. That wasn't a problem during the last two GTO missions — both rockets landed successfully — but it appears to be the cause this time: yesterday, Elon Musk tweeted that the thrust was low on one of the rocket's three landing engines, a result of burning up too much fuel.
Because of this, Musk said that the Falcon 9 landed hard enough to destroy part of the rocket's frame, and the impact also knocked a few of the engines around, presumably upsetting the rocket's balance. He added that he only expects 70 percent of this years attempts to succeed, calling 2016 "the year of experimentation." He also tweeted yesterday that the company is working on upgrading the landing system of the Falcon 9 rockets to prevent these kinds of close-call failures in the future.