May 2, 2013
Simulated Parachute Failures Can’t Keep NASA From Landing Orion Test Version Safely
April Flowers for redOrbit.com - Your Universe Online
During a simulation of two types of parachute failures this past Wednesday, a test version of NASA´s Orion spacecraft made a safe landing.
The mock capsule was traveling approximately 250 mph during the test in Yuma, Arizona, when the parachutes were deployed. This is the highest speed reached by the craft as part of a series of tests designed to certify the parachute system for carrying humans.
The mission´s engineers rigged one of the two drogue parachutes on the capsule not to deploy. They also fixed one of its three main parachutes to skip its first stage of inflation after being extracted from a plane 25,000 feet above the ground. Main parachutes inflate in three stages to gradually slow the capsule further as it descends, and drogue parachutes slow and orient the Orion during this process.
This week´s failure scenario is one of the most difficult simulated so far. It will provide data that the engineers need to rate the parachute system for human use.
"The tests continue to become more challenging, and the parachute system is proving the design's redundancy and reliability," said Chris Johnson, NASA's project manager for the Orion parachute assembly system. "Testing helps us gain confidence and balance risk to ensure the safety of our crew."
The canopies of the three main parachutes can cover almost an entire football field, making Orion´s parachute system the largest ever built for human-rated spacecraft. The astronauts aboard will use the parachutes to slow the spacecraft for a splashdown in the Pacific Ocean after reentering Earth´s atmosphere.
Irregularities in testing allow the engineers to verify the reliability of the parachutes when something goes wrong. The information gathered during these tests will be employed to refine models used to build the parachute system and Orion. The work done to validate Orion´s systems will also benefit other government or commercial spacecraft using a similar parachute system.
"Parachute deployment is inherently chaotic and not easily predictable," Stu McClung, Orion's landing and recovery system manager, said in a statement. "Gravity never takes any time off -- there's no timeout. The end result can be very unforgiving. That's why we test. If we have problems with the system, we want to know about them now."
The next Earth-based test of Orion´s parachutes will take place in July, when the test capsule will be released from 35,000 feet. The first space-based test will be during Exploration Flight Test-1 in 2014. An uncrewed Orion will return from 3,600 miles above Earth´s surface, traveling at about 340 mph when the parachutes deploy.