The Low-Density Supersonic Decelerator (LDSD), a new 7,000-pound test vehicle that many people compare to a flying saucer has been tested over the Pacific Ocean, with mixed results.
The LDSD, loaded with high-definition cameras, was lifted to the edge of space by a high-altitude balloon. The vehicle is designed to test technologies for spacecraft entering the Martian atmosphere. After release, the system fires rockets to accelerate the vehicle up to speeds which will create forces comparable to those during a Martian landing of a large payload. Once the LDSD reached its target velocity, it carried out a rapid inflation of the Supersonic Inflatable Aerodynamic Decelerator (SIAD). This doughnut-shaped device slows the vehicle down from 3.8 times the speed of sound to mach 2.
The Supersonic Disksail Parachute, the largest supersonic parachute ever deployed, slows the craft further for its final descent to the surface. The surface area of this device is more than twice the size of the parachute used to carry the Mars Science Laboratory (MSL) and the Curiosity rover to their destination. Tangling and tearing caused fragmentation of the parachute soon after deployment.
At the end of the test flight in June, the LDSD splashed into waters near Hawaii, where it was later recovered by divers. Despite the disintegration of the parachute, mission planners say the flight will still serve as a lesson for future research.
"A good test is one where there are no surprises but a great test is one where you are able to learn new things, and that is certainly what we have in this case," Ian Clark, principal investigator for LDSD at Jet Propulsion Laboratory, said.
The SIAD system, which provides the LDSD with its flying saucer-like shape, performed beyond specifications in the test, as did the ballute, which served to extract the parachute from its housing.
"We also got significant insight into the fundamental physics of parachute inflation. We are literally re-writing the books on high-speed parachute operations, and we are doing it a year ahead of schedule," Clark said.
This test of the LDSD was the first of three missions planned to examine new technologies needed to land large payloads on the surface of Mars. These capabilities will be needed to land habitats for human colonization of the Red Planet. The space agency is hoping to land humans on the surface of Mars sometime in the 2030's. The technologies tested aboard the LDSD could also allow robotic missions to Mars to land at higher altitudes than are currently possible.
A video showing the test from launch through re-entry is available on the Jet Propulsion Laboratory YouTube page.
