Development of a Venting/Termination System for Altitude Flight Control and Stability of High Altitude Balloons on Near-Space Missions

Abstract

Hypersonic flight dynamics are complex and certain important issues, such as what can trigger laminar hypersonic flows to become turbulent, are not well understood; thus new advances in science need to be made before aircraft can be designed that can safely and routinely fly at many times the speed of sound. A team of undergraduate and graduate student researchers in the Aerospace Engineering and Mechanics (AEM) Department, working on an AFOSR-funded MURI grant, are using optical particle detectors flown on weather balloon missions to characterize the particulate content of the stratosphere. Data collected will be used in computer simulations that study the onset of turbulence in hypersonic flows. This poster discusses the MURI Project's progress, as of April 2021, in creating a venting/termination system that can ideally 1) provide "slow-descent" capability for Hwoyee 1600g weather balloons from 80,000 to 120,000 feet altitude (thereby providing optimal conditions for stratospheric particulate measurements), 2) extend the "altitude floor" of our stratospheric ballooning flights so that those altitudes can be consistently achieved without the balloons prematurely bursting, and 3) provide a reliable termination mechanism so that vented flights can consistently terminate at the end of slow-descent and return to Earth in a timely manner. As of April 2021, an easy-to-build and reliable vent/termination system has been constructed and successfully tested with Hwoyee 1600g weather balloons on slow descent flights from 111,000 to 80,000 feet, with successful flight termination at 80,000 feet. Future test-flights, beyond April 2021, demonstrated that slow-descent from 120,000 feet to 80,000 feet is possible with this balloon and venting configuration.