NASA's "flying saucer" completes second test
NASA has put a new supersonic parachute design through its paces in the second test of its flying saucer-like Low Density Supersonic Decelerator (LDSD). The technology is being developed for future exploration of Mars, where it would allow NASA and its partners to land heavier payloads on the surface.
The idea behind theLDSD is to dramatically increase the amount of drag created by the vessel as it approaches the surface. Its saucer-like form is equipped with a 6-meter Supersonic Inflatable Aerodynamic Decelerator(SIAD), which increases the surface area of thevehicle when inflated. This is designed to reduce velocityenough to deploy the supersonic parachute that is packed into therear of the craft.
In order to simulatethe effects of the Martian atmosphere, the capsule has to besubjected to supersonic speeds at dizzying heights. This is as closeas we can get to the conditions above the Red Planet, where theatmosphere is only 1 percent as thick as the Earth's.
Last year's maiden LDSDtest proved to be a frustrating affair – in the SIADinflated perfectly only to see the supersonic parachute torn toshreds before it had a chance to fully deploy.
For new the test, theLDSD was equipped with the same model of SIAD as before, but had amodified parachute with the center constructed fromconcentric rings. It was hoped that the new design would deliver amarked improvement in strength over the solid center used in the original Supersonic Parachute.
Monday's test hadpreviously been postponed multiple times due to poor weatherconditions. The team needed to wait for calm weather to deploy the giant atmospheric balloon that would bring thecraft up to a suitable height to initiate the test, and to be certainthat the conditions at sea would allow for a swift recovery once theordeal had come to a close.
The most recent provingflight, which kicked-off at the US Navy's Pacific Missile RangeFacility in Kauai, Hawaii, saw the 7,000 lb (3,175 kg) LDSD strappedto the colossal balloon, and carried an impressive 120,000 ft (36,576m) into the air – three times the height that a commercial Boeing 747operates.
At this point, the LDSDwas dropped, and began a controlled spin to aid stability. Shortlyafter, the test vehicle's Star 48 solid-fuel rocket engine ignited,and burned for around 70 seconds, accelerating the saucer to Machfour, and pushing it just above the 180,000 ft (54,864 m) mark.
During the flight, fourGoPros streamed live, albeit low quality footage of the test. Throughthe stream, viewers could see the SIAD deploy flawlessly soon afterthe thruster's fuel was spent, producing a ridged, stable deceleratorthat succeeded in slowing the test vehicle to around Mach 3.
This brought the teamto the moment of truth – the deployment of the SupersonicParachute. Unfortunately, almost immediately after the 100 ft (30 m)parachute had fully deployed, it appeared to rupture,failing under the immense pressure exerted upon it.
Looking forward, LDSD scientists will examine testcapsule once it's salvaged from the Pacific Ocean off the coast of Hawaii where it splashed down, as well as the high definition footage contained in itsblack box in an attempt to improve the design of the parachute aheadof next year's test, where another SIAD design will be tried. The new iteration is larger in design, and features integratedair intakes that will be used to inflate the decelerator.