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SpaceX Falcon Rocket Landed Intact

Irene Klotz, Spaceflight Correspondent
Apr 20, 2014, 4:38 UTC

Sen—Space Exploration Technologies (SpaceX) believes its Falcon 9 rocket’s first-stage  successfully touched down in the Atlantic Ocean Friday after sending a Dragon cargo capsule on its way to the International Space Station.

“Data upload from tracking plane shows landing in Atlantic was good!” company chief executive Elon Musk posted on Twitter Friday night.

At a post-launch press conference Musk downplayed the odds that the Falcon’s first-stage could be recovered intact. Recovering and reusing Falcon rockets are among the company’s long-term goals to cut launch costs.

SpaceX has been tackling the challenge with related programs, including flight tests with its experimental Grasshopper vehicle and operational Falcon 9 missions.

On Friday, after separating from the upper-stage and Dragon cargo ship, the Falcon 9’s discarded first-stage conducted two more engine burns. The burns slowed the booster’s fall back through the atmosphere and positioned it for a vertical touchdown on the ocean.

SpaceX figured it had less than a 40 per cent chance of success—and those odds didn’t take into account Friday’s unexpectedly rough seas.

Recovery ships were still making their way to the impact site on Saturday, but preliminary data shows the booster landed intact.

“Flight computers continued transmitting for eight seconds after reaching the water,” Musk posted on Twitter.

The data stopped when the booster went horizontal, toppled by the force of gravity.

Musk said the most important bit of data was that the rocket’s roll rate was close to zero.

The last time SpaceX attempted to recover a booster, centrifugal forces—caused by the rocket’s roll—choked off the flow of fuel, triggering the thrusters to shut down.

That rocket, like previous Falcon launchers, was destroyed.

"With more powerful thrusters and more nitrogen propellant, we were able to null the roll rate. So that's a bit of good news there,” Musk told reporters after Friday’s launch.

The Falcon that flew on Friday also was equipped for the first time with landing legs to help stabilize the rocket.

SpaceX will include landing legs to the next Falcon 9 mission, scheduled for May. That flight is to deliver six next-generation satellites for Orbcomm.

If the tests are successful, SpaceX may attempt a Falcon landing on the ground before the end of the year.

"We're really starting to connect the dots,” Musk said. "I think we've got a decent chance of bringing a stage back this year, which would be wonderful."