Introduction

The primary mission of the LionSat nanosatellite is to perform in-situ ionospheric plasma diagnostics.  These measurements will entail mapping the ram/wake structure of plasma and also ambient, undisturbed plasma density measurements.  There are a myriad of techniques for doing this from retarding potential analyzers to floating potential probes.  Due to the limited size and power constraints of a nanosatellite, an efficient method of conducting plasma diagnostics is needed.  Past research at Penn State University has been moving toward the development of a hybrid plasma probe (HPP) for gathering these in-situ plasma measurements, while also conforming to the size, power, mass and expense constraints of a nanosatellite. 

The objective of our team, the LionProbe hybrid probe design team, was to design and, time permitting, build a hybrid plasma probe that is to be used as the main scientific payload of the LionSat nanosatellite.  The hybrid plasma probe is a combination of Langmuir (LP) and plasma frequency probes (PFP). Also, the circuitry enables the probe to operate as a biased probe (BP) and fast temperature probe (FTP). [1]  Utilizing these features, the HPP will be able to measure electron and ion density, spacecraft relative potential, and electron temperature.  These capabilities coincide with the scientific goals of the mission. This combination of plasma sensing techniques is a reflection of the need for accurate plasma diagnostics using a small size, power efficient, low cost, low mass probe.

 Past work on plasma probes has been done in theses and sounding rocket missions at Penn State.  Resulting data and probe design from these past missions has served as input to our hybrid probe design.

This document describes the design, testing, and conclusions/future considerations of the project as well as an introduction to plasma probe theory and the ethical impact of the developed science.