Ion Thruster Simulator
Classroom worksheet · Interactive simulation: https://lkforge.com/tools/physics/ion/
Name: Date:
Learning objectives
- Explain how an ion thruster produces thrust.
- Contrast high specific impulse with low thrust.
- Identify suitable missions.
Variables to change
- Ion exhaust velocity
- Propellant flow rate
- Input power
Procedure
- Run the thruster and note the very high exhaust velocity but small thrust.
- Increase the propellant flow and observe thrust rise.
- Let it run continuously and observe the slow but steady speed build-up.
Observations
Record thrust and exhaust velocity, and how a small steady thrust accumulates large delta-v over time.
Questions
- How does an ion thruster work?
- Why is its specific impulse so high?
- Why is its thrust so small?
- What missions suit ion propulsion?
- Can an ion thruster launch from Earth’s surface?
Answer key (instructors)
- 1. It ionizes a propellant (e.g. xenon) and accelerates the ions electrostatically to very high speed.
- 2. The exhaust velocity is very large, so each unit of propellant gives lots of delta-v.
- 3. The mass flow rate is tiny, so the force (ṁ·v_e) is small despite the high speed.
- 4. Long-duration deep-space and station-keeping, where efficiency matters more than quick acceleration.
- 5. No — its thrust is far too weak to overcome gravity; it works in space over long times.
An ion thruster electrostatically accelerates ionized propellant to very high exhaust velocity, giving excellent specific impulse but tiny thrust (F = ṁ·v_e with small ṁ). Run continuously in space, that gentle push builds large delta-v — ideal for deep-space missions.