Practical High-Altitude Microgravity Experiment (PHAME)
Microgravity combustion experiments are of interest to NASA for applications to spacecraft fire safety. In an ideal world, materials would be tested in true microgravity conditions aboard the ISS to determine their safety, however that is obviously cost prohibited. Therefore, NASA is investigating improved simulated microgravity for these combustion tests and other experiments. Currently, NASA Glenn has a 550-foot drop tower that is capable of providing 5.18 seconds of microgravity. Unfortunately, each drop tower test costs about $7000, so it can only be used for a small number of experiments.
Therefore, a new microgravity system was developed over the summer of 2011 at the NASA Glenn Space Academy in which an experiment would be fitted inside of a drag shield and then raised to 110,000 feet by a weather balloon. Once at 110,000 feet, the system would be released, and an experiment package would begin to fall within the drag shield. Because the system is being released at such a high altitude, the drag shield will accelerate very closely to g for an extended period of time, thereby allowing the package inside an extended time in microgravity. Calculations indicate that the package could experience up to 12 seconds of microgravity, which would allow for longer microgravity experiments to be run than in the drop tower for about one tenth the cost.
This project was continued during the last two semesters at Case Western Reserve University where there were many improvements made to the experiment’s tracking, drag shield, avionics, recording capabilities, release mechanism, and overall systems integration. During the 9 weeks remaining in the Academy, continued improvements will be made to the avionics, tracking and drag shield. Additionally, a parachute release mechanism will be developed to increase microgravity time and ensure that there are no problems with tangling. There will hopefully be two balloon launches during these 9 weeks: the first to get the launch procedures confirmed and, more importantly, prove that the avionics, tracking, and parachute release mechanism work as planned. If successful, the drag shield package will be integrated, and we will attempt a microgravity proof-of-concept launch. Upon completion of the Academy, the experiment will be returned to Case for further development, ultimately concluding with an actual microgravity combustion experiment.