NASA parachute engineers have appetite for destruction

October 9, 2014 by Dc Agle, JPL/NASA
The tools of the rocket sled trade can be seen in this nighttime shot from the Supersonic Naval Ordnance Research Track (SNORT) at the Naval Air Weapons Station China Lake in California. Credit: NASA/JPL-Caltech

Engineers from NASA's Jet Propulsion Laboratory in Pasadena, California, are bound and determined to destroy a perfectly good parachute this week during the latest test for the Low-Density Supersonic Decelerator (LDSD) project. The parachute to be tested at the China Lake Naval Air Weapons Station in California is the same 100-foot (30.5-meter) parachute design that flew during the first supersonic flight of LDSD this past summer. That test took place in June in Kauai, Hawaii, at the U.S. Navy's Pacific Missile Range Facility.

The upcoming test, employing a Navy Seahawk helicopter, almost 4,000 feet (1,200 meters) of synthetic rope and a rocket sled packing four solid rocket motors with 280,000 pounds (127,000 kilograms) of thrust, is scheduled to take place on Thursday, October 9, weather permitting.

"Whenever you get to see a rocket sled in action, that is a good day," said Mark Adler, project manager for NASA's LDSD project at JPL. "When you watch the sled rip apart something you worked very hard in creating, and be happy about it, that is a great day."

The goal of the LDSD project's Parachute Design Verification test 1-1B is to place stresses on NASA's Supersonic Disksail Parachute that will cause the 8,000 square feet (740 square meters) of synthetic fiber and ripstop nylon to fail structurally. It is the latest in a series of tests developed to evaluate two new landing technologies for future Mars missions.

"Our has a not-to-exceed load during normal operations of 80,000 pound-force of pull," said Adler. "Then there is another load rating well beyond that, where we expect the chute to fail. That is 120,000 pounds-force of pull. Well, to ensure we get to see how the chute fails and at what load, we configured the sled so it can get up to 162,000 pounds-force of pull when all the rockets kick in. The details of the failure will be used to calibrate our models, and if the failure is earlier or in a different place than expected, we will address that in the parachute design before our supersonic flights this coming summer."

When the test begins, a Navy helicopter crew will lift the still-packed parachute, trailing on a very long, very sturdy rope and a chunk of ballast known as the "bullet," to about 4,000 feet (1,200 meters) and then drop it.

At this point, a 300-horsepower winch—connected to the other end of the rope—begins pulling. The parachute inflates, and the whole setup—rope, bullet and inflated parachute—descends toward the surface and the rocket sled at about 15 mph (24 kilometers per hour).

Near the surface, the bullet will enter a funnel, which guides it into a latching mechanism on the rocket sled. When this latch-up occurs, the first two of four 70,000-pound (32,000-kilogram) thrust solid rocket motors fires. A few seconds later the second set of rockets kicks in. The test is expected to apply the full load on the parachute canopy in about five seconds.

The parachute is the same design used during the first high-altitude supersonic flight test of the LDSD project last June, which was launched from Kauai. During the Kauai test, which was a shakeout flight designed to explore the capabilities of LDSD's saucer-shaped test vehicle, the test parachute shredded during its deployment at nearly 2,000 mph (3,200 kilometers per hour).

"That test was such a blessing to this program," said JPL's Ian Clark, principal investigator for the LDSD project. "We got an early look at the parachute we were going to test in 2015 and found we needed to go back and rethink everything we thought we knew about supersonic parachute inflation. When we combine what we learned there with the data set from this test, we should have a new working model on how to build large supersonic parachutes."

A new supersonic parachute design is expected to be ready in time for the next round of Kauai flight tests scheduled for the summer of 2015.

"This is going to be fun," said Adler. "Basically, we are going to watch this with every instrument we can get our hands on and then watch the parachute be destroyed. Then we will apply what we learn to our future parachutes."

Explore further: Ride shotgun with NASA saucer as it flies to near space

Related Stories

Ride shotgun with NASA saucer as it flies to near space

August 11, 2014

NASA's Low-Density Supersonic Decelerator (LDSD) project successfully flew a rocket-powered, saucer-shaped test vehicle into near-space in late June from the U.S. Navy's Pacific Missile Range Facility on Kauai, Hawaii. The ...

NASA's 'flying saucer' readies for first test flight

June 3, 2014

(Phys.org) —It only sounds like science fiction. To test a new technology for landing heavy payloads on Mars, NASA is about to drop a flying-saucer shaped vehicle from a helium balloon high above Earth's surface.

First LDSD test flight a success

June 30, 2014

NASA representatives participated in a media teleconference this morning to discuss the June 28, 2014 near-space test flight of the agency's Low-Density Supersonic Decelerator (LDSD), which occurred off the coast of the U.S. ...

JPL tests big with a supersonic parachute for Mars

April 11, 2014

"You wanna go to Mars, you wanna go big? Then you gotta test big here," says mechanical engineer Michael Meacham, and testing big is exactly what he and other engineers at NASA's Jet Propulsion Laboratory have done to develop ...

NASA's saucer-shaped craft preps for flight test

May 19, 2014

(Phys.org) —NASA's Low-Density Supersonic Decelerator (LDSD) project, a rocket-powered, saucer-shaped test vehicle, has completed final assembly at the U.S. Navy's Pacific Missile Range Facility in Kauai, Hawaii.

JPL to test new supersonic decelerator technology

December 18, 2013

(Phys.org) —A giant crane will tower above NASA's Jet Propulsion Laboratory in Pasadena, Calif., shooting out of a hilly mesa like an oversized erector set, ready to help test components of NASA's Low Density Supersonic ...

Recommended for you

Fish-inspired material changes color using nanocolumns

March 20, 2019

Inspired by the flashing colors of the neon tetra fish, researchers have developed a technique for changing the color of a material by manipulating the orientation of nanostructured columns in the material.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

EyeNStein
not rated yet Oct 09, 2014
Failure test of a known to fail chute..
Couldn't they save money by getting Mythbusters to do this type of test ;-)

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.