Extended Lifetime of CubeSats in the Lower Thermosphere with Active Attitude Control

Abstract

A wide variety of missions could be enabled by extended orbital flight in extreme low Earth orbit, defined as an altitude range of 150–250 km. This study investigates the feasibility of a nanosatellite (mass ) using a propulsive, attitude control system in conjunction with a primary propulsion system to extend mission life. The primary propulsion system consists of a pair of electrospray thrusters providing a combined thrust of 0.12 mN at 1 W. Pulsed plasma thrusters are used for attitude control. The mission consists of two phases. In Phase I, a 4U CubeSat is deployed from a 414 km orbit and uses the primary propulsion system to deorbit to an initial altitude within the targeted range of . Phase I lasts 12.73 days, with the propulsion system consuming 5.6 g of propellant to deliver a of 28.12 m/s. In Phase II the mission is maintained until the remaining 25.2 g of propellant is consumed. Phase II lasts for 30.27 days, corresponding to a of 57.22 m/s with a mean altitude of 244 km. Using this approach, a primary mission life of 30.27 days could be achieved, compared with 3.1 days without primary propulsion.