A SpaceX  Falcon 9 rocket launched a cargo to the International Space Station today at 3:25pm ET, and then turned around and flew back to a soft landing in the Atlantic Ocean. The cargo, flown on a Dragon capsule, will reach the station on Sunday morning.

It’s the first time a booster rocket has made hypersonic reentry into the atmosphere intact and then splashed down gently without benefit of parachutes. Today’s flight was a major milestone in SpaceX’s quest for reusable orbital rockets. The company is already the cheapest launch provider in the world. Reusing its boosters, something no one else is able to do, would allow the company to radically change the spaceflight industry, essentially producing the iPhone of rockets, the machine everyone else will have to emulate to stay in business.

The first stage booster for today’s flight was equipped with landing legs, marking a first for an orbital vehicle. After SpaceX’s first attempt to bring a booster safely back after launch, in November, the booster safely reentered the atmosphere but began spinning, which ultimately resulted in a loss of control and break up on impact with the Pacific Ocean. After that flight, SpaceX CEO Elon Musk said he thought landing legs would have stabilized the vehicle enough to let it touch down gently.

The vehicle used for today’s flight had not only landing legs, but also more powerful thrusters for countering any spin, along with more nitrogen propellant on board. The safe reentry was accomplished by restarting three of the booster’s nine Merlin engines after the initial cutoff of the engines and separation from the rocket’s second stage. The gentle splashdown was enabled by restarting a single engine. The second stage of the rocket was not flown back.

About an hour and a half after today’s launch, Musk said in a press conference that the booster had reentered safely and, at last contact with a tracking station as it descended through about 27,000 feet, had no spin. It was left to an aircraft in the vicinity of the planned splashdown point to pick up the data stream from the booster as it descended. Musk and company were still awaiting that data at the time of the press conference, but about two hours later, Musk reported via Twitter that the booster had indeed touched down safely:

Data upload from tracking plane shows landing in Atlantic was good! Several boats enroute through heavy seas.


Flight computers continued transmitting for 8 seconds after reaching the water. Stopped when booster went horizontal.

Development will continue full steam ahead for the SpaceX flyback booster, dubbed the F9R. With ten more SpaceX launches planned for this year, there will be ample opportunity to continue refining the technology for reusable booster rockets. The company will also continue flight test at its McGregor, Texas proving grounds, as in the above video from a flight test that took place yesterday, as well as at Spaceport America in New Mexico. Musk said in the press conference:

Anything we can test at a relatively low altitude, so below around 10,ooo feet, we’ll continue to do in McGregor, and then the high-altitude stuff, where it’s going exoatmospheric, and going to 300,000 feet plus and that kind of thing, we’ll be doing in New Mexico because we just need a much bigger clear area. We’ll continue refining the technology over time because…reusability only matters to the degree that it’s rapid and complete. Otherwise its sort of reusability but you don’t get the equivalent economic benefit that has the huge potential to open up spaceflight.