NASA’s next-generation spaceship has successfully completed its most challenging test to date: being dropped from a plane at 35,000 feet (6.6 miles) and parachuting to Earth safely.

The drop test of the Orion test vehicle was carried out over the U.S. Army’s Yuma Proving Ground in the Arizona Desert on Wednesday and was designed to give the vehicle’s three huge parachutes a trial run before another space-bound Orion test vehicle carries out an orbital test in December, called Exploration Flight Test (EFT)-1.

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During the Arizona test, engineers wanted to see how the vehicle’s parachutes coped with increased stresses. After being pulled from the C-17 aircraft, Orion was allowed 10 seconds of freefall before the entire sequence of parachute deployment was carried out. The freefall added extra aerodynamic pressure to the system, helping engineers ensure the descent will be safe for astronauts when Orion becomes operational.

“We’ve put the parachutes through their paces in ground and airdrop testing in just about every conceivable way before we begin sending them into space on EFT-1 before the year’s done,” said Orion Program Manager Mark Geyer in a NASA news release. “The series of tests has proven the system and will help ensure crew and mission safety for our astronauts in the future.”

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During the EFT-1, an unmanned Orion will be blasted 3,600 miles into space, reaching speeds of 20,000 miles per hour and will experience temperatures near 4,000 degrees Fahrenheit during atmospheric reentry. The vehicle will then splash down in the Pacific Ocean, after being slowed to just 20 miles per hour by the parachute system.

After the EFT-1 is complete, further tests of the parachute system will be carried out. One test will involve the Orion descending with just 2 of the three main parachutes deployed to simulate a ‘chute failure, making sure the vehicle can still land a crew safely.