NASA’s Low-Density Supersonic Decelerators (LDSD) team stands ready to attempt the second flight test of a rocket-powered, saucer-shaped test vehicle into near-space from the U.S. Navy’s Pacific Missile Range Facility on Kauai, Hawaii.
Depending on weather conditions and other factors, the test vehicle will begin its flight from a starting point of 120,000 feet over the Pacific Ocean — a little over 22 miles high, deep in Earth’s stratosphere. There, its booster rocket will ignite, pushing it to supersonic speeds as it ascends to approximately 180,000 feet — a little over 34 miles high, penetrating the lower mesosphere. A series of precision steps will take place for the 6-meter supersonic inflatable aerodynamic decelerator (SIAD) and the supersonic parachute to slow the vehicle as it descends through the atmosphere.
This ascent, and its subsequent fall back into the ocean, will simulate the kind of supersonic entry and descent speeds a similar vehicle would face in the atmosphere above the planet Mars.
So NASA’s first major hurdle is to get the test vehicle to that altitude. How is that accomplished? By use of a large scientific balloon that’s over 600 feet long!
Bringing in the Balloon Experts
NASA scientific balloons are a proven way to quickly and efficiently launch even large-scale science payloads into Earth’s stratosphere — between 7 and 31 miles up — to undertake missions lasting mere hours or more than a month.
For the LDSD flight test, NASA will employ a balloon 34.4 million cubic feet in volume, its helium contained by 22 acres of plastic roughly the thickness of a sandwich bag. When fully deployed, the entire apparatus plus test vehicle stands a towering 980 feet tall.
NASA’s Wallops Flight Facility in Wallops Island, Virginia, will oversee its deployment, bringing to bear its extensive expertise in scientific balloon test operations. They’re aided by a team from NASA’s Columbia Scientific Balloon Facility in Palestine, Texas, (operated by Orbital ATK) and Foremost Industries LP of Calgary, Canada, who built a special launch tower to safely launch the balloon used to carry the LDSD test vehicle to its target release altitude.
In this video, a scientific balloon lifts the test vehicle during the 2014 LDSD test flight from the island of Kauai, Hawaii. (NASA/Bill Rodman)
Stay with us for more fascinating insight into the project as we count down to launch!