With its first flight into space scheduled for December and the first manned mission slated for 2021, the National Aeronautics and Space Administration (NASA) is excited about the next generation of spacecraft.
“Today’s test is a key moment in a well-orchestrated plan to take humans to deep space,” said William Hartwell, Deputy Program Executive for the Orion spacecraft. “Getting the crew home safely is one of our biggest challenges, and the parachute system is critical to accomplishing that, for there are many systems that have to function correctly. We are very pleased to have the expertise of the Air Force, Army, and YPG to help us ensure this crucial system will bring our crews home safely.”
Wherever in the heavens they may go, the crew’s home will be the Orion Multipurpose Crew Vehicle, 16 feet wide and 10 feet tall, capable of taking astronauts to multiple destinations in our solar system and returned to Earth by a trio of large parachutes. The robust capsule parachute assembly system (CPAS) is designed to slow the hurtling capsule to a languid 17 miles per hour upon splashdown in the ocean.
But what if something unexpected requires the capsule to come back shortly after lifting off from the launch pad, or from altitudes and speeds lower and slower than what would occur from an ordinary mission? This is the scenario NASA and YPG test officers were testing in late April during the 13th of 17 tests of the CPAS system at YPG.
“Typically in a re-entry from deep space, the vehicle is coming at high speeds and essentially vertical so when the parachutes deploy, you’re deploying into an air stream coming from below the vehicle,” said Chris Johnson, project manager for the CPAS system. “For pad abort scenarios, the spacecraft speeds are much slower and because of the trajectory the vehicle will be flying somewhat sideways, or what we call a shallow flight path angle. We want to test the parachutes in those different conditions to understand how the shallower flight path angle changes the deployment performance of the parachutes, including the timing differences in how long it takes the parachutes to get out.”
To create the proper conditions for the test, the mock Orion capsule had to be dropped from an altitude of 13,000 feet, whereas all previous ones have been conducted from at least 25,000 feet. This created new challenges for the YPG test officers coordinating the test.
“One of the easier things about the high altitude drops is that we’re high above everyone else, so you don’t have to worry as much about de-conflicting airspace and shutting down other tests’ safety fans,” said Ryan Fraser, test officer. “An elevated low velocity drop is typically conducted at 2,000 feet or lower. This one is at 13,000 feet, and the object coming out of the aircraft is a lot bigger.”
The test drop occurred without a hitch, however. Once the capsule’s four minute descent to the ground had occurred, YPG personnel fanned out and carefully recovered the massive deployed parachutes and lines from the desert floor. The recovery crew needs to gather the fabric from each of the 10,000 square feet of canopies slowly and methodically so testers can evaluate any damage that may have occurred to the chutes during flight, and know that it was not incurred from the recovery efforts. This time, the Kevlar lines and some fabric from one of the chutes were snagged in a tall creosote bush, necessitating long polls to ease it out of the crooked branches. As they trucked the packed parachutes back to the Air Delivery Complex, where the parachutes were suspended from a high ceiling and carefully studied, workers from YPG’s motor pool used a large crane to lift the heavy capsule onto a lowboy trailer for transport back to Yuma.
YPG testing has already resulted in design changes that improve the Orion capsule. The risers on the parachutes have been changed from steel to Kevlar, which reduced the overall mass of the system and made it easier to route them from where they attach to the capsule.
“Every change that we do to the parachutes, we test here,” said Johnson. “Testing in a full scale environment is very important to not only identify changes that need to be made, but test the implementation of those changes. YPG is unique in that advanced capabilities exist here in terms of doing low velocity air drops, and we build on the type of test techniques that have been developed over the years with the military to do the testing.”