 Elon Musk and SpaceX continue their goal toward commercial space travel. I wonder what the in-flight movie will be? I'm Jake Kastronakis and this is 90 Seconds on the Verge. SpaceX launched its third supply mission to the International Space Station this afternoon. The Falcon 9 rocket and accompanying Dragon capsule took off from Cape Canaveral with the goal of rendezvousing with the space station on Sunday morning. The launch gives SpaceX a chance to test the next step in its plan for a reusable rocket. Once the Dragon capsule detaches, the rocket will attempt to slow itself and make a controlled return to Earth, where it will be fished out of the ocean and used again. To give you an idea of how expensive space exploration can be, a NASA space shuttle launch costs around $450 million per mission, and a lot of that money goes toward building rockets that just crash into the ocean afterward and are damaged beyond repair. But SpaceX has a chance to change that. Its launches cost about $56 million, and Elon Musk says that a reusable rocket could even cut that in half. While the chance of today's rocket landing successfully isn't great, it's put between about 30 and 40 percent, SpaceX and NASA will still be breaking new ground on the International Space Station. The Dragon capsule headed for the space station is carrying red romaine lettuce and radishes. These are being kept inside an experimental plant growth chamber. It's part of a test project meant to give astronauts a source of fresh food. Of course, all of this is just phase one for SpaceX. Musk's ultimate goal is to make commercial space travel not just a reality, but also an affordable one. For more on SpaceX, check out The Verge. Coming up, in an effort to add more fiber to the astronaut diet, NASA sends 40 tons of Metamucil to the International Space Station.