SF24B-T008 - Self-Regulating Heaters for Satellites

Self-regulating heaters are heaters with a designed-in temperature setpoint that exists as a property of the resistor material. They are ‘smart’ heaters, automatically and independently warming each region of the heater circuit to the designed setpoint without a temperature sensor. The electrical resistance of the heater material jumps substantially at the setpoint, inhibiting electric flow and production of heat above the setpoint temperature. However, the current self-regulating heaters used in the petrochemical and automotive industries are not suitable for space  propellant system heating. Conventional solutions to space propellant system thermal control are resource intensive, requiring much engineering design and touch labor as well as much hardware and burdening the flight computer to control the circuits. In this STTR program, ACT and UCSD propose to develop an innovative self-regulating heater that reduces all the above-mentioned resource demands for space application. The proposed self-regulating heater is flexible, lightweight and has an ultrafast response to temperature change. The setpoint of this self-regulating is tunable and an ultrahigh turndown ratio between the electrical resistances above and below the setpoint temperature can be achieved. The heater can be operated under any voltage between 12 and 100 VDC, and is capable of generating 1 to 10 W/in^2 heat flux at the fully ON condition. The proposed self-regulating heater can also handle the harsh space environment, specifically: vacuum, intense UV radiation, atomic oxygen, ionizing radiation and wide thermal cycles.