Parachutes of Nasa’s Orion space capsule have undergone the most complex series of tests to verify the system is ready for its maiden space flight in December.
The tests, carried out at the US Army’s Yuma Proving Ground in Arizona saw Nasa engineers dropping the capsule from a C-17 aircraft at the altitude of about 10.5km after performing a series of ground-based tests. It was the first time Orion’s parachutes have been tested at such a high altitude.
"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 Exploration Flight Test (EFT)-1 before the year's done," said Orion Program Manager Mark Geyer. "The series of tests has proven the system and will help ensure crew and mission safety for our astronauts in the future."
To maximise the load on the parachutes, engineers left the capsule in free fall for ten seconds to increase the vehicle’s speed and aerodynamic pressure.
After Orion's free fall, its forward bay cover parachutes deployed, pulling away the spacecraft's forward bay cover, which is critical to the rest of the system performing as needed. The forward bay cover is a protective shell that stays on the spacecraft until it has re-entered Earth's atmosphere. The parachutes that slow Orion to a safe landing speed are located under the cover, so the cover must be jettisoned before they can be unfurled.
Engineers also rigged one of the main parachutes to skip the second phase of a three-phase process of unfurling each parachute, called reefing. This tested whether one of the main parachutes could go directly from opening a little to being fully open without an intermediary step, proving the system can tolerate potential failures.
The complete parachute system won’t be tested again until Orion’s first space flight, currently scheduled for December 2014. During the flight, the unmanned capsule will travel some 3,600 miles into space, farther than any spacecraft built to carry humans has been in more than 40 years. Orion will travel at the speed necessary to test many of the systems critical to NASA's ability to bring astronauts home safely from missions to deep space, including an asteroid and eventually Mars.
During its return to Earth, Orion will reach a speed of up to 20,000 mph and experience temperatures near 4,000 degrees Fahrenheit. Once Orion has made it through the atmosphere, the parachute system, with two drogue parachutes and three massive main parachutes that together cover almost an entire football field will be responsible for slowing it down to just 20 mph for a safe splashdown in the Pacific Ocean.
Orion's next parachute test is set for August and will test the combined failure of one drogue parachute and one main parachute, as well as new parachute design features. It is one of three remaining tests needed to demonstrate the system's capability for human missions, but does not need to be completed before Orion's first flight later this year.