A reusable SpaceX rocket that launched a year ago has lifted off again this evening from the Space Coast.

SpaceX also successfully landed the first-stage booster on the barge in the Atlantic.

CEO Elon Musk is excited this "flight proven" booster flew and landed again.

The booster rocket lifted off Thursday night from Kennedy Space Center Pad 39A with an SES communications satellite that will provide HD television, maritime and data service for Central and South America.

This is the same Falcon 9 rocket that launched in April 2016 that delivered cargo to the International Space Station. As the cargo capsule headed to space, the first-stage booster used thrusters, grid fins and landing legs landed on a drone barge platform off the coast of Cape Canaveral.

Experts say reusing rockets will make launches more affordable and will expedite missions to space.

This success sets the stage for the next goal.

"Now our aspirations will be zero flight-ware changes, re-flight within 24 hours and and the only thing that changes is we reload propellant," said Musk at a post-launch news conference.

Musk says 70 percent of a flight's cost is the first stage booster. Saving it to fly again and again is where spaceflight must go.

"It means that humanity can become a space-faring civilization and be out there among the stars," he said.

Will this booster fly again? Musk says it will be given to the Cape as an historic gift to display. 

Historic spacewalk

Meanwhile, hundreds of miles above, a 57-year-old woman set the record for most spacewalks by a female astronaut. 

Peggy Whitson is currently on her eighth spacewalk of her career. NASA TV is covering the 6 1/2-hour spacewalk outside the International Space Station.

Officials have been tweeting updates of the Expedition 50 spacewalk, saying the spacewalkers are installing shields and computer relay boxes.

Whitson and Commander Shane Kimbrough are reconnecting cables and electrical connections on a docking port.

Midway through the spacewalk, an important piece of shielding needed for the ISS floated away.

NASA will monitor the shield to make sure it doesn't come back and hit the station.

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