During the final qualification trial an Orion test capsule was dropped from a Boeing C-17 Globemaster III military transport aircraft at an altitude of 35,000 feet to verify the reentry system.
Three main parachutes, each almost as large as a football field, bring a mock-up of the NASA Orion space capsule to a safe earth landing at U.S. Army Yuma Proving Ground. (Image source: U.S. Army)
The aptly named “Assembly System” is an assortment of 11 parachutes, cannon-like mortars, and pyrotechnic devices that deploy sequentially slow the Orion capsule's descent to Earth – from 325 miles per hour (mph) to 17 mph.
Although this system is pretty fancy, the Orion’s aeroshell does most of the heavy-lifting, reducing the capsule’s initial entry speed by about 19,675 miles per hour as it enters Earth’s atmosphere. Check out our article on NASA’s new expanding aeroshell design.
Orion’s FBC, drogue and main parachutes are packed with a hydraulic press to the density of oak. (Image source: NASA)
The breakdownAt 26,500 feet and 325 mph, three seven-foot-diameter Forward Bay Cover (FBC) parachutes deploy in conjunction with pyrotechnic thrusters to launch the FBC off the top of the capsule.
One of the other interesting challenges faced by parachute developers involves the harsh, unforgiving conditions of outer space. Temperatures range from plus 270 degrees in the sun and minus 270 degrees in the shade. The FBC protects the drogue, pilot, and main Orion parachutes from the heat generated during reentry. While the rest of Orion’s parachutes are made from a Kevlar/Nylon hybrid material, the FBC parachutes are made entirely out of Kevlar for added heat resistance.
As the FBC lifts off, two 23-foot-diameter Kevlar/Nylon drogue parachutes deploy at 25,000 feet to decelerate the capsule to 130 mph and orient it, so the main parachutes can operate effectively.
Five chutes gone. Six to go.
So, the main parachutes get their own parachutes, which is fun – but also critically important. Three 11-foot pilot parachutes deploy at 9,500 feet and then help lift the 116-foot-diameter main parachutes at approximately 265 feet.
From there, the Orion capsule decelerates to 17 mph, and during an actual Orion mission, the capsule will make a water landing. From FBC deployment to landing, the entire process takes under three minutes.
To get to that three minutes, it took more than 12 years to provide design, development, and test for various circumstances, including normal landing sequences, several failure scenarios and a variety of potential aerodynamic conditions to ensure the safe return of astronauts from deep space missions. Nearly every parachute failure mode imaginable was replicated and studied during these years.
Next stepsAstronaut Randy Bresnick, a 14-year NASA veteran, was among those who witnessed the dramatic test. Earlier this year he returned from a 139 day stay on the orbiting International Space Station where he served as crew commander. He explained that NASA chose to conduct the parachute tests at Yuma because of the drop zone's great expanse, as well as the high-altitude restricted airspace above it.
"This is one of the few places in the United States NASA can do this," says Bresnick.
He believes the past 12 years of testing was critically important.
"We can conduct a great future exploratory mission in space, but if the parachutes don't work on earth re-entry, it was all for naught," he said. An unmanned Orion mission will take place in June 2020 and the first manned mission two years later. The Orion will use the largest and most powerful rocket engines ever developed,” continues Bresnick.
"Orion is our new human exploration spacecraft, and this is a spacecraft that will take people farther in space than we've ever gone before," says Orion program manager Mark Kirasich.
Orion will launch on a NASA Space Launch System (SLS) launch vehicle.
<<This Friday post is part of our “Composite coverage: real lightweight stuff” series and a departure from SAE International’s traditional reporting approach. Let us know if you like our fun, conversational, and most likely irreverent coverage of legitimate news and notable events.>>
A new expanding NASA aeroshell could mean larger planetary payloads
JAXA launches HTV7 unmanned cargo spacecraft on resupply mission to ISS
NASA selects Frontier Aerospace to continue development of new deep space thruster
William Kucinski is content editor at SAE International, Aerospace Products Group in Warrendale, Pa. Previously, he worked as a writer at the NASA Safety Center in Cleveland, Ohio and was responsible for writing the agency’s System Failure Case Studies. His interests include 'literally anything that has to do with space,' past and present military aircraft, and propulsion technology. And also sportscars.
Continue reading »