The CUA Monofilament Vaporization Propulsion (MVP) system is an electrothermal thruster that uses a space-rated plastic as propellant. This approach enables CUA to deliver competitive delta-V to CubeSat customers at a substantially lower cost and dramatically lower risk profile than traditional liquid or gaseous propulsion systems having pressure vessels. In a 1U form factor, MVP provides a total impulse of 271 N-s with a peak continuous thrust of 4.5 mN. A flight-like MVP passed environmental and subsystem qualification testing on a NASA Phase II SBIR program.

TYPICAL OPERATION AND INTERFACE

MVP draws from 3D printing technology to feed propellant. A preheat is required before firing (~3 minutes), but once warmed the “ready” state is maintained with minimal power draw and thermal loading. When firing, the system uses approximately 45 W (duty cycled average is only 13.5 W). Propellant fiber is mechanically drawn from a fixed spool into the extruder where it evaporates. Propellant metering is precise, but evaporation time results in “softer” starts and stops. As a consequence, minimum impulse bit is inherently much larger than gaseous propulsion systems with fast-actuating valves; this represents the largest trade-off for the reduced system cost, complexity, and risk.

Developmental 1U MVP system interface:

• Unregulated battery voltage line (for resistojet and preheat, will be stepped down)
• Regulated 12 V line (< 2 W when firing)
• I2C communication protocol (other options available on request)
• Mounting interface designed for typical CubeSat via external enclosure adaptable to customer requirements