A new propulsion system combines the power and speed of conventional chemical thrusters with the precision and fuel-efficiency of electrical thrusters. The system could enable small satellites capable of both fast, powerful maneuvers and slower, precise adjustments.

…The key to the new system is a special propellant that can power both chemical and electrical thrusters…

…a type of “green monopropellant” originally developed by the U.S. Air Force for use in chemical propulsion in space can also effectively power tiny “electrospray” thrusters. Electrospray thrusters are dime-sized rockets that use electric fields to charge up a liquid propellant’s particles, which are then shot into space as a thrust-generating spray…

  • Delta_VOPEnglish
    8·
    10 days ago

    The paper linked to in the article says the thrusters have a specific impulse of 600s, and a thrust-to-power ratio of about 50 mN/kW.

    Compared to the xenon ion thrusters used on the Dawn spacecraft, these new multi-mode thrusters produce more thrust, but are significantly less efficient. Dawn’s thrusters have a specific impulse of 3,100s and a thrust-to-power ratio of about 36 mN/kW.

    Even so, it means satellites can be built with one small fuel tank that can power high efficiency electrospray thrusters to make slow maneuvers, or use the same fuel as a monopropellant to quickly get out of (or into) the way of something. ASCENT monopropellant thrusters can have a specific impulse slightly better (240 Isp) than traditional hydrazine monopropellant thrusters (235 Isp).