PATRIOT

PATRIOT [University of Michigan]

PATRIOT (Plasma Ambipolar Thruster for Rapid In-Orbit Transfers) is a 3U CubeSat developed by the University of Michigan's Plasmadynamics & Electric Propulsion Laboratory (PEPL) and Michigan Exploration Laboratory (MXL).

PATRIOT is a mission to demonstrate a CubeSat Ambipolar Thruster (CAT) plasma source/engine in Low Earth Orbit (LEO) which will be the first flight tets of a nanosatellite with significant delta-V capability. If will also conduct scientific research that will address the fundamental question of how plasmas expand in freespace.

The CubeSat Ambipolar Thruster is a new design for a permanent magnet helicon generated plasma thruster. Its small plasma volume (~10 cm³) and low power requirements (<100 W) make it ideal for propelling nanosatellites (<10 kg). The source is powered by a novel DC to RF oscillator with air-core inductors suitable to be flown on small spacecraft. Specifically, the CAT is being made to fit the CubeSat form factor. Permanent magnets generate a converging-diverging magnetic nozzle with a magnetic field that decreased to the strength of earth's magnetic field within 50 cm. In the CAT, the plasma is generated continuously using a Radio Frequency (RF) antenna to launch a helicon wave. This type of plasma wave is extremely efficient in ionizing the gaseous propellant. The wave also heats the electrons, which are insulated from the walls of the plasma liner by a magnetic field generated by rare earth magnets. The electrons stream out of the plasma liner through the magnetic nozzle, dragging the ions with them. The thermal energy of the electrons is converted to kinetic energy in the ions to generate thrust.

PATRIOT was selected in 2014 for launch with NASA’s ELaNa program.

The development of the CAT propulsion development migrated from the University of Michigan to Phase Four and the PATRIOT mission is being repurposed for other technology demonstration.