Update: Scratch that. The launch was scrubbed because of a helium leak. It's now rescheduled for April 18.
In 2011, Elon Musk’s SpaceX announced that one of its primary space exploration goals was to create a reusable rocket. After a series of successful launches using disposable versions of its Falcon 9 launch vehicle, the SpaceX ISS resupply mission launching today has a secondary goal of returning to Earth and landing in the ocean, where the company will recover it for re-use. This secondary goal is a lofty one, and SpaceX estimates that it only has about a 35 percent chance of success on the first try, but it’s the first time SpaceX is mission testing the rocket’s reentry guidance systems and fancy deployable landing legs.
SpaceX made its first delivery to the ISS in 2012, and this trip is its third supply mission. The company is slowly integrating their reusable rocket technology into their Falcon 9 spacecraft, making sure that none of the additions interferes with its ability to deliver its capsule to the space station. Today’s mission will include four landing legs on the rocket, and if successful, those legs will allow the rocket to undergo a landing maneuver after it re-enters Earth’s atmosphere before falling into the ocean. The company’s long-term mission is to land the rocket at a specified location on land, but SpaceX wants to make sure everything is working properly and safely first, and the ocean is a great place to have something go wrong. If everything goes well, the first successful landing on land should happen by the end of this year.
Even if it doesn't all go flawlessly today, SpaceX has plenty of time to get it right: its contract with NASA includes 12 supply missions to the ISS, so each mission will include other stages of the re-usable rocket technology. According to SpaceX, this technology, if successful, could save millions of dollars in launch costs, making space more accessible for organizations like NASA as well as commercial companies wishing to delve into the emerging space exploration market.