SpaceX's Falcon 9 rocket successfully launched and delivered it's Dragon capsule to the International Space Station. Rather than a hard landing back into the ocean (like normal rockets do), the Falcon 9 rocket attempted a soft landing on a barge floating in the Atlantic (the first attempt of its kind). Initially, CEO Elon Musk said there was a 50:50 chance the landing would be successful.
The attempt was, in fact, nearly a home run. However, mere seconds before landing, the rocket ran out of hydraulic fluid in the fins that steer the rocket as it descends. This caused it to hit the barge and perform a Rapid Unscheduled Disassembly (aka explosion). According to Musk, the next launch is scheduled for the next 2 to 3 weeks. This new rocket will have 50% more hydraulic fluid. So at least it should "explode for a diff [sic] reason."
Musk hopes that successful soft landings will allow for quick and cost-effective reuse of rockets, making space travel significantly more affordable and feasible.