They shoot out a minuscule amount of fuel mass, but they do it at [i]insane[/i] velocities. Around 40 [b]kilometers[/b] per second (90,000mph). This results in a force that is about the equivalent of lifting a piece of paper into the air. That's not very impressive, but they make up for it by taking their time with their fuel. Ion engines can "burn" for weeks, so this small force can add up to an extremely impressive delta-V.
This little satellite I made has a delta-V of 14,533 m/s and a burn time of about 72 hours.
Here are the details:
- Thrust: [b]0.050 kN[/b] (Yep, that's right, just fifty Newtons)
- Mass: [b]50 kg[/b]
- Price: [b]$100,000[/b]
- Specific Impulse: [b]11,515 s[/b]
- Fuel Type: [b]Xenon[/b]
- Electrical Consumption: [b]100kW[/b]
- Height: [b]0.25 m[/b]
- Diameter: [b]0.6 m[/b]
- Max Gimbal Angle: [b]0 degrees[/b]
