What are the best ways to keep a spacecraft's propulsion system working in harsh environments?

1 Propulsion system types

There are two main types of propulsion systems for spacecraft: chemical and electric. Chemical propulsion uses the combustion of propellants to generate thrust, while electric propulsion uses electric or magnetic fields to accelerate ions or plasma. Chemical propulsion provides higher thrust and shorter burn times, but requires more mass and fuel. Electric propulsion provides lower thrust and longer burn times, but requires less mass and fuel. Depending on the mission objectives and constraints, systems engineers have to choose the most suitable type of propulsion system for their spacecraft.

2 Thermal management

One of the key challenges for propulsion systems is thermal management, which involves controlling the temperature of the components and the propellants. Too high or too low temperatures can affect the performance, reliability, and safety of the system. For example, high temperatures can cause thermal stress, degradation, or explosion of the propellants, while low temperatures can cause freezing, condensation, or sublimation of the propellants. Systems engineers have to design and implement thermal control systems that can regulate the heat transfer between the propulsion system and the environment. These systems can include passive or active elements, such as insulation, radiators, heaters, or coolers.

3 Radiation protection

Another challenge for propulsion systems is radiation protection, which involves shielding the components and the propellants from the harmful effects of cosmic rays, solar flares, and electromagnetic interference. Radiation can damage the electronics, sensors, valves, and other parts of the propulsion system, as well as degrade or ignite the propellants. Systems engineers have to design and implement radiation protection systems that can reduce the exposure and impact of radiation on the propulsion system. These systems can include passive or active elements, such as shielding materials, coatings, filters, or hardening techniques.

4 Debris mitigation

A third challenge for propulsion systems is debris mitigation, which involves avoiding or minimizing the collision or erosion of the components and the propellants by space debris. Space debris can include natural or artificial objects, such as dust, rocks, meteoroids, or satellites, that orbit the Earth or other celestial bodies. Debris can damage or destroy the propulsion system, as well as contaminate or leak the propellants. Systems engineers have to design and implement debris mitigation systems that can detect, track, or maneuver away from debris, or withstand the impact or abrasion of debris. These systems can include passive or active elements, such as sensors, cameras, thrusters, or bumpers.