Estonia’s next satellite, ESTCube-2, is set to launch aboard Europe’s Vega VV23 launcher. Designed and built by undergraduate students, this shoebox-sized CubeSat has ambitious goals, including conducting surveys of Estonian vegetation and demonstrating the “plasma brake” technology in orbit.
The plasma brake technology, also known as electric sail or E-sail, was developed by Pekka Janhunen of the Finnish Meteorological Institute (FMI). If successful, ESTCube-2 will mark the first use of this technology, which uses charged microtethers to slow the CubeSat’s orbit. This demonstration could pave the way for keeping space free from dangerous debris in the future.
The plasma brake consists of a thin wire, or tether, that creates electrostatic drag in the ionosphere. By repelling the plasma in the ionosphere, the tether causes drag, slowing down the satellite and leading to a decay in its orbit. This technology offers a low-cost and low-mass method of deorbiting satellites and cleaning up the low Earth orbit environment.
ESTCube-2’s plasma brake E-sail is a 50-meter long interweaved aluminum tether line made up of hair-thick wires, each just 50 micrometers in thickness. To ensure reliability, the microtether design features redundancy with two parallel and two zig-zagging bonded wires.
Developed and built by a team from Tartu Observatory of the University of Tartu and student organization Tudengisatelliit, ESTCube-2 is a 3-unit CubeSat. In addition to the plasma brake technology, it carries student-built microcameras for vegetation surveys, a materials payload studying the corrosive effects of “atomic oxygen,” and a software-defined radio for amateur radio tests.
ESTCube-2 secured its place on the Vega launcher through the European Commission’s In-Orbit Demonstration/In-Orbit Validation program. Managed by ESA’s Small Satellite Platform Unit, this program allows for the early orbital testing of new technologies to enhance Europe’s space sector competitiveness.
The ESTCube-2 project has been eight years in the making and represents the ambitious efforts of over 600 university students. It aims to push the boundaries of what students can achieve and enable excellent science. If successful, ESTCube-2’s E-sail technology could revolutionize propulsion concepts for both Earth orbit and deep space missions.
The subsequent mission, ESTCube-LuNa, is currently being designed to further test the E-sail technology beyond Earth orbit and prove its usefulness in deep space exploration. Additionally, ESA has been studying E-sail technology as a cost-effective means of prospecting asteroids.