Lawrence Livermore National Laboratory



Matthew Horsley

Overview

Collecting relevant physical dynamics data of the upper atmosphere, stretching from the stratosphere to the thermosphere, is difficult. Instrumented balloons and airplanes cannot reach extreme altitudes, and sounding rockets can only collect the relevant data for short periods of time, typically minutes (Oberheide 2011, Wharton 2018). Satellites, however, can provide global coverage with rapid update rates. Advances in nanosatellite capabilities offer the possibility of hosting atmospheric sensors on these platforms, providing an inexpensive option for monitoring the Earth's upper atmosphere, if feasible.

In this study, we investigated technologies for remotely sensing the Earth's upper atmosphere using methods and instruments compatible with the small form factor of a nanosatellite. We performed a detailed assessment of stellar occultation and its applicability to estimating properties of the upper atmosphere. We determined that telescope design, platform stability, focal plane performance, data storage, and radio communications were important factors determining the success of the mission. We developed a conceptual design for an optical telescope that provides sufficient light gathering power, significant baffling for rejection of stray light, and a compact, robust mechanical design small enough to fit on the nanosatellite while being strong enough to survive launch. As platform stability is a critical factor when considering optical observations, we investigated methods for precise stellar centroiding using instruments readily available and compatible with currently available nanosatellite Attitude Determination and Control System. The results of our study indicate that remotely monitoring the Earth's upper atmosphere is possible with nanosatellites hosting commercially available instruments. This approach will significantly reduce the cost of acquiring the data necessary to develop models capable of describing the physical dynamics of the upper atmosphere.

Impact on Mission

Demonstrating the capability of small satellite-based sensing platforms to perform missions normally reserved for large, expensive satellites provides an inexpensive, robust sensing approach that would be advantageous in meeting national defense and science goals. Developing a small, satellite-based sensing platform as a cost effective technology to monitor Earth's upper atmosphere helps broaden and deepen Lawrence Livermore National Laboratory's expertise in both space security as well as atmospheric science. The research also supports many Livermore mission areas such as stockpile stewardship (hypersonic flight), multi-domain deterrence (space system development), and energy and climate security (advancing atmospheric science). This work further supports Department of Defense and NASA interests.

References

Oberheide (2011) "Climatology of Upward Propagating Diurnal and Semidiurnal Tides in the Thermosphere." J. of Geo. Res.: Space Physics, 116.

Wharton, S. (2018). Evaluation of the Development of a Whole Atmosphere Model Capability (WAMC). LLNL.