From CNN: SpaceX rocket explodes after launch:

An unmanned rocket by Elon Musk's SpaceX on a resupply mission to the International Space Station exploded Sunday just minutes after launch.

SpaceX said that an "anomaly" had caused the spaceship, named Dragon, to fail and was investigating. NASA is set to hold a press conference later Sunday.

"It is not clear what happened," NASA said initially. "The vehicle has broken up."

SpaceX -- which is headed by Musk -- has made seven trips to the ISS under a contract the company has with NASA. It is the first company to complete a return trip to the space station, a feat previously achieved by only governments.

The failed cargo flight was carrying more than 2 tons of supplies, including 1,500 pounds of food and provisions for the crew aboard the space station.

Mark Polansky, a former NASA astronaut, tweeted that the failure will not immediately affect those aboard. "ISS priority is crew safety," he wrote. "Though tragic, @SpaceX cargo failure doesn't pose immediate impact to that."

Three space station astronauts, two Russians and NASA's Scott Kelly, were awaiting the arrival of SpaceX's shipment, which was meant to arrive on Tuesday.

In a tweet from space, Kelly, who is the brother-in-law of former Arizona Congresswoman Gabrielle Giffords, said he watched the launch. "Space is hard," he wrote. Read on...