Research Objectives:
NASA's National Scientific Balloon Facility (NSBF), based in Palestine Texas, operates the Long Duration Balloon (LDB) program at Williams Field near McMurdo Station. NSBF staff work with researchers to launch, track, and recover high-altitude balloons carrying scientific payloads into the stratosphere.
Each year the air in the stratosphere over Antarctica forms a stable vortex--a high altitude jetstream with a circular pattern. A balloon launched in these conditions will circumnavigate the continent between 77 and 80 degrees south latitude and often land near where it was launched. If it stays aloft for one revolution, the scientific instruments aboard operate for 10 to 15 days. If all is well with the balloon and its science payload, a second revolution may be attempted. The vortex is stable from mid-December to mid-January providing a month-long launch window.
Every austral summer the NSBF launches two long duration balloons, each with a volume of 28.42 million cubic feet and capable of ascending to a float altitude of up to 42 kilometers (137,000 feet or 26 miles). Standard NASA scientific balloons are made of polyethylene film, the same material in plastic bags. It is only 0.002 centimeters (0.0008 inches) thick, about the same as an ordinary sandwich wrap. The helium-filled balloons can carry a payload weighing as much as 3,600 kilograms (8,000 pounds).
Balloon-borne science payloads in Antarctica offer advantages as a means of high-altitude exploration: They remain at altitude much longer than long duration balloons launched in other locations. They cost far less and can be configured and launched much faster than satellites. The instruments in the payload can be recovered and flown again.
During flight, the balloon is controlled by satellite-relayed commands from NASA's Wallops Flight Facility in Virginia. The sensors in the science payload collect data and sends it to the researchers' home institutions and to McMurdo Station where the instruments are monitored by project team members. To terminate the flight, an aircraft flies within line-of-sight of the balloon and sends a command to the payload. When “cut down,” the payload descends with a parachute and recovery operations begin.
This year the science payloads are BESS-Polar (Balloon-borne Experiment with a Superconducting Spectrometer) event number A-140-M, and CREAM (Cosmic Ray Energetics and Mass) event number A-137-M.
