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Partial ‘success’ for NASA’s LDSD on its second launch

Artist's rendering of LDSD test vehicle in flight. Image Credit: NASA

Artist's rendering of NASA's Low-Density Supersonic Decelerator (LDSD) test vehicle in flight.
Image Credit: NASA

For the second time, NASA has successfully launched the Low-Density Supersonic Demonstrator (LDSD ) from Kauai, Hawaii, but the supersonic parachute failed to fully deploy. The mission of this flight was to test a new technique for delivering large payloads to the surfaces of planets such as Mars or Venus. The spacecraft was carried to launch altitude by a large research balloon before being dropped and its main engine firing.

NASA's LDSD takes off from Hawaii while suspended under a giant helium-filled balloon. Photo Credit: NASA Technology

NASA’s LDSD takes off from Hawaii while suspended under a giant helium-filled balloon. Photo Credit: NASA Technology

The 39.57 million cubic feet (1.2 million m3) balloon lifted the LDSD into the morning sky at 7:45 a.m. HAST (1:45 p.m. EDT; 17:45 GMT) from the Pacific Missile Range Facility in Hawaii. The balloon and test vehicle combined stand is over 856 feet (261 m) tall. The balloon carried the craft to an altitude of 120,000 feet (36.5 km) before it was released into free fall.

The main rocket system fired shortly after release sending the LDSD skyward to an altitude of 180,000 feet (54 km) before it turned back to Earth to begin its descent. LDSD accelerated to a speed of just over Mach 4 (4,900 km/h; 3,045 m.p.h.) before the doughnut shaped Supersonic Inflatable Aerodynamic Decelerator (SIAD) deployed, slowing the craft to Mach 2.65 for parachute deployment. “It pops like the airbag in your car, but shaped like a donut,” said NASA spokesman Joshua Buck.

However, during phase two of the descent, where a 100 foot (30 m) diameter supersonic parachute was supposed to open and slow down the descent even further, the parachute only partially inflated in what NASA engineers call a “partial chute” deployment. Initial elation among the engineers quickly deflated into groans of disappointment as the parachute appeared to rip apart in the supersonic airstream.

NASA engineers have retrieved the craft and its “black box” – the information contained within, according to the engineers, will be invaluable for the improvement of the landing system.

Video courtesy of NASA

This was the second flight of the LDSD spacecraft. The first flight of the LDSD occurred on June 28, 2014, after enduring many weather related delays. While the primary mission of deploying the decelerator ring was a success on that flight, the parachute failed to deploy correctly. The parachute shredded when it was exposed to the stresses of the high speed environment. For this second test, the deployment of the parachute was the primary mission. Engineers redesigned the parachute to better handle the deployment stresses.

This new parachute NASA is testing is the result of studying the data from first flight of the LDSD. In that test, the supersonic parachute destroyed itself due to it not fully deploying on the descent phase.

In 2014, NASA created a parachute council known as SCOPE (The Supreme Council of Parachute Experts) to study the problems of the first flight and redesign the parachute. After five meetings where the team looked at everything from materials science to deployment of the suspension lines, the developed a new parachute and release mechanism. The new parachute system they created should eliminate many of the problems that plagued the first LDSD flight.

Low-Density Supersonic Decelerator (LDSD) launch to ocean recovery sequence. Image Credit: NASA

LDSD launch sequence. (Click to enlarge) Image Credit: NASA

The LDSD is a joint collaboration of several NASA facilities. The Jet Propulsion Laboratory is the lead facility. Langley Research Center Wallops Flight Facility and Ames Research Center are all providing logistics and development support. Langley researchers and engineers will provide trajectory simulations during the flight operations.

“During flight operations, Langley will provide trajectory simulations used to orient the test vehicle for flight and to position surface assets for the recovery of the test hardware,” said Eric Queen, the Langley LDSD lead who is in Hawaii. “We are also providing aeroscience and trajectory reconstruction analysis and support for LDSD. Plus Langley did the aeroscience and aero-database development for all flight test regimes and the flight dynamics simulation and pre-flight prediction of the flight test trajectory.”



Joe Latrell is a life-long avid space enthusiast having created his own rocket company in Roswell, NM in addition to other consumer space endeavors. He continues to design, build and launch his own rockets and has a passion to see the next generation excited about the opportunities of space exploration. Joe lends his experiences from the corporate and small business arenas to organizations such as Teachers In Space, Inc. He is also actively engaged in his church investing his many skills to assist this and other non-profit endeavors.

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