In what was the 10th in a series of 17 tests to be conducted to develop the capsule's parachute system, a nearly full-size replica of it was dropped from a U.S. Air Force C-17 from an altitude of 35,000 feet, which is the height commercial airlines typically fly at, over the base's Robby/Lapoza drop zone at about
"In this case, we had the computer command one of the three main parachutes to fail, by firing the riser line cutter, and intentionally separating it early," McClung said. "It separated when it was supposed to. We had timed it to happen once all three chutes deployed and was starting to inflate and catch some air, which put a load into it."
McClung said engineers have already proved that Orion can land with just two of its three main parachutes, but the importance of this test was to study how one parachute pulling away in mid-flight might affect the remaining two, and if any other damage was caused as a result. The parachute separated from the others approximately 8 seconds after they were deployed.
"This type of failure should never happen. The probabilities of it are pretty low," McClung said. "From a parachute perspective, it is important for us to know that if we have that bad day, and something unexpected happened, did it cause any other failures? The unknown unknowns, that is one of the reasons to do this kind of test."
Previous drop tests have been conducted form an altitude of 25,000 feet, with the parachutes deploying at 22,000 feet. McClung said having the 10,000 additional feet allowed engineers to actually begin the test at 25,000 feet, which better reflects the altitude the capsule would normally deploy its parachutes at when coming back from a mission.
"You have to let the vehicle fall to get it into test conditions. Previously we always had to start at 25,000 feet, so we were testing lower than we desired," McClung stated. "So it was important to us to test like you fly. And one of the ways you do that is to try and match your entry conditions as closely as you can."
McClung said the test appeared to have been successful and everything had gone as planned.
"We expected that the (parachute) would cut cleanly, and that it would pull away. Now we will see if it propagated any other failures," McClung said. "And, even if we get in there and find some damage, it is still a success because we will learn from it, and be able to modify the design if we have to."
The C-17 flew over the drop zone three times before dropping the replica capsule out its back cargo doors on its second pass. Once on the capsule had landed,
"I understand they are the largest parachutes ever made,' Wullenjohn said.
In addition to being the highest altitude
Wullenjohn continued by saying
The EFT-1 flight will take Orion to an altitude of more than 3,600 miles, more than 15 times farther away from Earth than the
(c)2013 The Sun (Yuma, Ariz.)
Visit The Sun (Yuma, Ariz.) at www.yumasun.com
Distributed by MCT Information Services