SpaceX just successfully launched its sixth resupply mission to the International Space Station, but its second attempt to land the reusable Falcon 9 rocket has failed. It's still unclear if it completely touched down, but excess lateral velocity caused the rocket to tip over in the last few moments. Judging from the picture the company just tweeted, it's another case of "close, but no cigar."

Before yesterday's scheduled launch, Musk tweeted that he still expected less than a 50 percent chance of success despite promising returns from the company's first few launches of the modified rocket. But shortly after today's successful launch, he and another SpaceX employee tweeted hints of the rocket's grim fate:

Ascent successful. Dragon enroute to Space Station. Rocket landed on droneship, but too hard for survival. — Elon Musk (@elonmusk) April 14, 2015

We falcon punched the barge... @SpaceX CRS-6 — SpaceX Engineer (@SpaceXEngineer) April 14, 2015

Hitting the barge is a tough task — SpaceX once compared it to balancing a broomstick on your hand during a windstorm — so it sounds like the company's attempt was accurate, even if something got in the way of a soft landing.

What SpaceX is trying to do is not easy

The company first attempted to land on the drone ship back in January. The rocket nearly hit its target, but the fins that are supposed to slow and guide its descent ran out of hydraulic fluid. The result was a descent that was so rapid and imbalanced that the entire first stage erupted in a massive fireball after it impacted the barge.

SpaceX had a second attempted landing scheduled for February. The launch was successful, but rough seas forced the company to bring the drone ship back to port. Instead of an attempted landing, the Falcon 9 lowered itself to where the barge was supposed to be, briefly hovered, and promptly sank.

While the company does have another Falcon 9 launch scheduled for late next week, that rocket will be delivering a communications satellite to a higher orbit, which means it won't be able to test the first stage landing. The next chance to get it right will likely come during the company's next ISS resupply mission, which is currently scheduled for June 22nd.