SNORT partners with JPL for groundbreaking test
News Review Staff Writer
A groundbreaking test on Friday propelled forward technology used in the Mars landers and secured a historic achievement along the way for teams from NASA’s Jet Propulsion Laboratory and China Lake’s Supersonic Naval Ordnance Research Track.
While the sights and sounds captivated many Indian Wells Valley residents as the roar of the rocket motors firing resounded clearly through the crisp, early morning and a parachute more than 100 feet in diameter could be seen hanging in the air, the success of the test was celebrated by dozens of collaborators from the rooftop of the SNORT facility.
At least three iterations of the Mars landers have included contributions from Naval Air Warfare Center Weapons Division employees. Mike Meacham, a mechanical and aerospace engineer at JPL and the parachute verification lead for Mars landers, said that while previous tests have focused on narrowly defined goals, the most recent test was an attempt to take current technology a leap forward.
“This time we are actually developing new technology to get us to Mars,” said Meacham. “We haven’t done anything this big in 40 or 50 years.”
Landing modules now face extremely narrow constraints on mass, since the current ability to slow things down without crashing into the planet are extremely limited. Although each generation of the lander has been improved in its efficient use of space and in landing precision, the current technology has basically hit a ceiling.
“We are basically aiming to do three big things on Mars — we want to land heavier things, and for that we need a bigger parachute,” said Meacham.
“We want to improve our landing accuracy. We have a large, but shrinking, ellipse for service landings. That means if a scientist says, ‘We want to land on this exact rock,’ we can’t do it. We have to rover our way over. Our concept is that if we can start slowing down higher up in the atmosphere, that will shorten that ellipse quite a bit and give you the ability for more precision landing.
One concept JPL has come up with to face this particular challenge is designed an inflatable donut that is deployed ahead of the craft, essentially increasing the size and effectiveness of the heat shield.
“The last limitation we are working on is our landing altitude.” The tallest mountain on Mars is more than 90,000 feet — more than three times the height of Mt. Everest. “That means you have to slow down even faster, because you’ve lost that many miles of atmosphere.”
The expense of sending anything to space increases the pressure to ensure integrity before launch, although testing equipment presents a challenge when you are working with the noncomparable conditions of Earth’s gravity and atmosphere.
When JPL first started thinking of ways to test chutes, it considered vertical drop tests. “That would have cost millions of dollars and it wouldn’t have been a great test. You need constant wind to test parachutes. Even dropping it from a high altitude doesn’t create the resistance you need.”
So the brainstorming continued. “Then we started thinking about using SNORT to test the parachute.” But given the scale of the parachute, modifications were necessary to prevent the chute from simply dragging across the ground during the test.
Many, many generations in, the JPO and SNORT team settled on a hybrid test that uses a helicopter to lift a chute to altitude. The chute is deployed and 4,000 feet of rope are pulled in by a 300-horsepower winch. After the parachute is inflated and all slack in the line is removed, the rope is passed to a rocket sled. The rockets fire, pulling the chute with 90,000 pounds of force around a 50,000-pound tripod and pulley structure bolted to 2 million pounds of concrete.
And until Friday, the team still didn’t know for sure if the system would work.
“The structure is a civil engineering project in and of itself,” said Meacham.
“Just the sheer scale of this structure is pretty amazing, and I know we’ve captured people’s attention with what we are doing. I’m told all the big things we are building in the machine shops are SNORT projects,” said Ben Marti SNORT test engineer.
“But really it just gives me a lot of faith in what our teams can accomplish.”
A peek inside the control room on the day of the test would reveal evidence of the evolving demographic of contributors to the modern space program. In place of the buttoned-up, gray-haired men whose images were captured by the media at the height of the space race, the headsets are worn by 20- and 30-somethings who donned T-shirts proclaiming their professional associations when they arose hours before dawn to see if their custom-designed system worked like they hoped it would.
On Friday morning scores of men and women watched the helicopter pick up the pre-rigged chute and cable and climb to altitude. Shortly after the handoff, the line was tightened and the rocket sled lit up, lighting up the morning and announcing its presence with a thunderous, if delayed, clamor. The chute maintained its altitude, hanging nearly unmoved in the air despite a resistance that would normally be zipping the sled across the track at thousands of feet per second.
“The test was successful beyond any of my expectations,” said Meacham. That success will ultimately redefine the way we test Mars technology on Earth, he added.
“We consider this first test to be a ‘shakeout’ of the system in order to learn what areas need tweaking or fixing. However, the architecture that the team has constructed worked perfectly. With just this one run, we have learned key information about the next Mars parachute that we could not have learned any other way.”
When local engineers and scientists track the chute that bears their fingerprints as it enters into Mars atmosphere, many of those will be following along via the national media.
Meacham said that for the JPL team, watching the Mars landings is an exciting climax to years of intense labor. While the labs are filled with Washington VIPs, the nearby bars are temporarily packed with “space geeks” and the televisions switched from sports coverage to NASA TV.
Friday’s success gives locals a similar ownership of future events that will someday be watched by millions.
Elsa Hennings, who as project manager at China Lake has been working with JPL on Mars projects since 1994, said that Friday’s exercise represented a first full-system test and worked perfectly.
“After two years of hard work, we were ecstatic when everything went as planned in this brand-new test technique, which brings a new capability to China Lake.”
She also noted that the effort included the collaboration of many WD employees in addition to those at SNORT and her parachute team, including the Michelson Laboratory machine shop, the helicopter crew from VX-31, the range team and many others.
“The JPL team was also wonderful to work with. They are a group of creative, talented engineers who come up with out-of-the-box ideas that fit right in with the China Lake how-can-we-make-this-work attitude,” said Hennings.
“This has personally been one of the most exciting programs I’ve ever worked on, and it was literally breathtaking to watch it all come together after working so long to make it happen.”
“I think this has also kind of brought our little SNORT team back into the limelight at China Lake,” said Marti, adding that even among China Lakers the SNORT operations have been mostly under the radar in recent years.
SNORT Branch Head Eric Laskey said that as a space buff and NASA enthusiast, he found the test a fun change of pace from the SNORT team’s normal fare.
But Laskey pointed out that SNORT celebrates its 60th anniversary of virtually continuous operations next month. The first test in November 1953 was a Tiny Tim with an unknown payload.
In the intervening years, SNORT has tested all manner of weapons and payloads, establishing firsts and setting benchmarks along the way. The world record for speed is held by the track at Holloman Air Force Base in New Mexico — the only track in the world longer than the one at China Lake. But local engineers say the fact that the chute kept the sled’s pace to a slow crawl during the test could have actually set a record for how slowly something could move down the track.
But Laskey points to one distinction of this test — “It is certainly the most unique test we have ever conducted on the SNORT track.”
And like all outside-the-box firsts at China Lake, there is no telling how this innovative test will evolve the way the SNORT team approaches creative solutions to other problems.
“You can look through our archives and see that pretty much everything out there we have tested at some point,” said Laskey. “But JPL is doing work that has never been done before anywhere. It’s exciting to be a part of that.”Story First Published: 2013-10-16