Astrobiology Talk: ESTCube-2: A stepping stone for interplanetary and astrobiology nanospacecraft missions

Here we present the mission analysis for the ESTCube-2 three-unit CubeSat, which is designed to test Coulomb drag propulsion. The primary mission is to deploy and charge a tether in low Earth orbit to decrease the altitude of satellite. The negatively charged plasma brake tether interacts with the ambient ionospheric plasma ram flow to slow down the satellite. To test this concept, ESTCube-2 will deploy a 300 m tether and subsequently charge it to 1 kV. Such a tether could deorbit ESTCube-2 from an altitude of 700 km to 500 km in half a year. The plasma brake is a lightweight, efficient, cost-effective, and scalable deorbiting system with a potential to address the space debris issue at critical altitudes of 1200 km and less. The ESTCube-2 platform is designed to accommodate the future Coulomb drag propulsion experiments. One example is the demonstration the electric solar wind sail (E-sail) outside the Earth’s magnetosphere, which would enable interplanetary travel for nanospacecraft with, in principle, unlimited delta-v. The satellite bus and deorbiting module occupy around 1.5 CubeSat units, providing the rest for payloads.  The ESTCube-2 platform can be reused to conduct exposure experiments (e.g. biological) in the higher orbital altitudes (up to 1200km) where deorbiting system will be required making it impossible for nanosatellite employing traditional propulsion. Significant time spent in the Inner Van Allen belt (0.1-450 MeV photons) will increase total ionisation dose and decrease mission time dramatically in comparison with one conducted on the ISS presently.