Experiments in space can be expensive and infrequent, but Earth’s upper atmosphere is accessible via large scientific balloons, and can be used to address many of the same fundamental questions. Scientific balloons are made of a thin polyethylene film inflated with helium, and can carry atmospheric sampling instruments on a gondola suspended underneath the balloon that eventually is returned to the surface on a parachute. For stratospheric flights between 30 and 40 km above sea level, balloons typically reach the float altitude 2-3 hours after launch, and travel in the direction of the prevailing winds.
Autonomous technologies enabling stratospheric exposure experiments are lacking. As a result, a standalone enclosure system was developed that opens and closes at stratospheric altitudes, exposing experiments while sampling environmental data inside and outside of the enclosure. Strat-X is a stratospheric exposure technology that can carry experiments to the edge of space in a completely controlled manner when mounted on large scientific balloons. It is a fully self-contained system (autonomous avionics, power, environmental controls, and sensors) that attaches to the exterior of balloon gondolas. Strat-X has removable panels for hardware integration, and four independently rotating “skewers” that hold experimental samples.
Strat-X has a flexible design with removable panels for hardware integration, a control board for autonomous operations, and four doors for timed exposures aloft. The housing of the entire Strat-X system is composed of an 80/20 (aluminum alloy) frame and white powder-coated aluminum panels. The four independent skewers can rotate 180° to expose samples to the outside environment, or enclose samples and maintain ambient conditions inside Strat-X. Each cylindrical skewer is housed in a frame laced with Shuttle Nomex Felt Reusable Surface Insulation (FRSI) to shield the samples from light.
Its cube-like shape makes the technology easy to mount. Strat-X was built to operate in a near space environment (Earth’s stratosphere), and thus, is a very durable system capable of running tightly controlled scientific experiments in an extremely harsh environment.