| The National Scientific Ballooning Facility (NSBF) is a NASA facility that provides for the launch, support, and retrieval of high-altitude balloon based scientific experiments. It is advantageous to do some experiments in the upper atmosphere, in the range of 100,000 ft. in altitude, as opposed to on the ground, and these include observations of cosmic rays and their atmospheric reactions, some measurements of the Cosmic Microwave Background Radiation, and atmospheric and weather observations. To reach the upper atmosphere, the experiments are attached to large helium balloons, some up to 400 feet in diameter, and consequently, a specialized launch site and apparatus are needed. The main NSBF base is located a few miles outside of Palestine, Texas, and the facility is managed by the University of New Mexico , under the guidance of NASA's Goddard Space Flight Center's Wallops Flight Facility.
The Palestine base consists of a large field, approximately two square miles in area, from which the balloons are launched, several large metal bays where experiment payloads are stored and assembled, a few large equipment sheds, and a small one story administration building. A water tower with the NASA logo is the only way a passer-by might identify the site. Balloon experiments are performed in the late spring, as this is the time of year that prevailing winds can be counted upon to take the balloon and payload over sparsely populated areas to the west, and are most often done in the late afternoon. Watching the launches is a somewhat popular activity with locals.
For launch, the experiment payload is dangled from the large crane of a specialized tank-like vehicle known as "Old Tim," while 500 ft. long tethers connect the experiment to the balloon, which is partially filled over the course of an hour and kept in place against the tremendous upward force via a giant mechanical arm. When the arm is retracted, the balloon begins its ascent, and while the tethers tighten, the crane vehicle maneuvers so that the payload will rise smoothly upward when the tension reaches it. For several minutes the balloon looks like a giant jellyfish against the blue sky as it fades from view. The experiment is then performed over the course of the night, and when it is over the payload is detached from the balloon and parachutes to the ground, most often over West Texas or western Oklahoma. Employees from the base then set out retreive the payload via a large pick-up truck. Experiments are ended early if the balloon is drifting toward major population centers.
An additional launch site is located in Ft. Sumner, New Mexico, wher launches can take place in the fall, and the NSBF provides support to launches in Antarctica and Australia.
Advertisement: Read all about the ARCADE experiment for an example of a high-altitude balloon based experiment. | 
