Description: The Open Source Platform for Remote Experiment deploYment (OSPREY) will be built upon a flight-tested breadboard prototype. This work will design the Printed Circuit Board (PCB), and open-source the existing code and interface to the Iridium module. The flight controller provides GPS position/clock, basic environmental data, absolute orientation, and context images. A standard interface is adapted for the sensors in such a way that dedicated instruments using serial, I2C or USB protocols could be seamlessly added to the system. A Wave Front Sensing measures the wavefront aberration at high speed and performs a modal decomposition allowing to estimate the Kolmogorov atmospheric turbulence parameters. An off-the-shelf Thorlabs Shack-Hartmann wavefront (WFS) sensor is used that has a sensitivity of L/150 that, at 405nm wavelength, is equivalent to approximately 3nm RMS and is capable of measuring very small wavefront perturbations caused by the atmosphere. The WFS with a collimated laser source at 405nm is illluminated, held on a source payload using a rope in order to sample large scale turbulence structures. Nighttime and daytime measurements are considered and a narrow band notch filter is used to mitigate the background light noise.

Benefits: The lack of precise turbulence property data in the stratosphere limits our ability to predict the performance of new advanced instrumentation that could operate on stratospheric balloons for demanding applications, such as exoplanet detection using high-contrast imaging. If turbulence proves to be limited, there is an opportunity to search for rocky planets around the closest FGK stars by flying telescope with moderate apertures (1-1.5m) on balloon platforms. Current balloon-borne exoplanet missions such as Picture-C, Maple and HCIBAS are not designed to detect rocky planets. The objective here is to design, and calibrate an instrument capable of retrieving in-situ the Kolmogorov atmospheric turbulence parameters over large distances (>10 m) in the stratosphere.