LDSD (Low-Density Supersonic Decelerator) - Launch test

The objective of this brief flight was to perform a launch test of a mockup capsule of the Low-Density Supersonic Decelerator (LDSD) test vehicle. The project was a NASA initiative aimed at testing new atmospheric entry technologies for future Mars missions. It focused on two key innovations: the Supersonic Inflatable Aerodynamic Decelerator (SIAD), a Kevlar inflatable device designed to slow spacecraft by increasing drag, and the Supersonic Ring-Sail (SSRS), a large parachute capable of handling supersonic speeds.

The vehicle to be used as a test platform featured a rocket-powered saucer-shaped design which was carried to high altitudes by a stratospheric balloon and then released, reaching speeds of Mach 4 to simulate Mars reentry conditions. At the inception of the LDSD project, NASA's safety policies did not allow the balloon launch staff to stay near a payload carrying a large armed rocket motor, ruling out the use of a conventional dynamic launch for the test flights. Initially, there was an idea to build a remote-controlled launch vehicle, but that concept was discarded in favor of a completely new approach: a tall tower (nearly 25 meters high) with a lift to bring the payload to the top at a safe height above the launch ground. The payload hung from an arm about 5 meters long, which held it until the balloon lifted it away. The arm included a mechanism to swing to one side to ensure the payload did not hit the arm. The launch tower did not require anchors or a special type of surface to function. It was equipped with outriggers and accommodations for ballast to provide the required stability for large balloons and heavy payloads.

Two other elements were part of the launch system. One was a movable table, based on a modified rotating irrigation system, to carry the laid-out balloon and align it with the wind in azimuth. The other element was a new spool vehicle that could contain the inflated balloon bubble and adjust azimuth in concert with the table.

All components of the system were portable and could be transported to other locations, although the launch tower platform was not self-propelled and required a truck for movement. The tower and spool vehicle were built by Foremost, an engineering firm from Canada, meanwhile, the rotating table was built by an agricultural firm specializing in circular sprinkler systems, which designed and modified one of their commercial systems to meet the requirements.

NASA's Columbia Scientific Balloon Facility also developed a new computer simulation system that, based on low-level wind data, calculated where the spool vehicle needed to be placed to ensure the top of the balloon rose directly above the launch tower.

Balloon launched on: 9/3/2013
Launch site: Scientific Flight Balloon Facility, Fort Sumner, (NM), US  
Balloon launched by: Columbia Scientific Balloon Facility (CSBF)
Balloon manufacturer/size/composition: Zero Pressure Balloon  
Flight identification number: 644NT
End of flight (L for landing time, W for last contact, otherwise termination time): 9/3/2013
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): 15 m
Landing site: A few miles NW of the launch base

The test consisted in the launch of a mockup of the real LDSD gondola. After the succesful launch and release of the model from the tower, the balloon was let to ascend to 8000 feet and then terminated, landing a few miles NW of the city.

• Low-Density Supersonic Decelerator NASA website
• High Altitude Supersonic Decelerator Test Vehicle AIAA Aerodynamic Decelerator Systems (ADS) Conference, 25-28 March 2013, Daytona Beach, Florida
• Launch Tower for LDSD NASA website