SpaceX's winning streak came to an explosive end with one of its rockets blowing up during its attempted landing.

The Falcon 9 rocket has - as its name suggests - nine rockets to take off, but uses just three to land. One of those failed to deliver full thrust on landing, causing it land very hard on the company's drone ship.

That lead to, in Elon Musk's words, a Rapid Unscheduled Disassembly.

Despite it being fourth time unlucky, the main mission was successful however: SpaceX successfully delivered two satellites into geostationary orbit.

The rocket lifted off on schedule from Space Launch Complex 40 at Cape Canaveral Air Force Station at 1029 ET (1429 UTC) carrying two satellites, both built by Boeing. The EUTELSAT 117 West B satellite will carry video and data services for Latin America and was released 30 minutes into flight. The ABS-2A satellite, which will handle similar traffic over Africa, the Middle East, Russia and Asia, was delivered five minutes later.

Second of two satellites being deployed into proper orbit with today's launch https://t.co/XcHFBPEyfk — SpaceX (@SpaceX) June 15, 2016

But the fate of the Falcon 9's first stage was uncertain for a while. The rocket was shown approaching the drone ship Of Course I Still Love You before the picture was obscured by large clouds of smoke. SpaceX has now confirmed that the rocket has been declared a loss.

Ascent phase & satellites look good, but booster rocket had a RUD on droneship — Elon Musk (@elonmusk) June 15, 2016

A RUD, Rapid Unscheduled Disassembly, is a geeky way of saying it is currently in pieces in the North Atlantic. There won't be video of the event until staff get aboard the drone landing ship, but Musk said that one of the Falcon's rocket motors had been faulty.

Musk explained one of them had developed low thrust during the landing, causing the rocket to crunch down hard on the drone ship, fall over, and undergo RUD.

The fix would be to adapt the three rocket motors so that they could increase thrust to compensate if this happens again. It's a complex job but Musk said the redesign should be done by the end of the year.

Landing video will be posted when we gain access to cameras on the droneship later today. Maybe hardest impact to date. Droneship still ok. — Elon Musk (@elonmusk) June 15, 2016

Today's landing was always going to be tricky. Deliveries to low-Earth orbit – like space station missions – are easier because less fuel is needed and, in many cases, the rocket can carry enough fuel to make it back to land and SpaceX's facilities.

But geostationary missions push the limits of what the Falcon can handle and return from. The rocket burns up so much fuel on takeoff that a water landing is a must, and even then, the rocket is reduced to using the last dregs of propellant, leaving very little margin for error.

Elon's Musketeers will be disappointed that they couldn't make it four successful landings in a row, but the primary satellite delivery mission was accomplished and the company will be getting paid.

Musk said he'd know SpaceX was successful when rocket launches became boring, but there's no sign of that happening quite yet. ®