This is an old revision of the document!
Table of Contents
Space Propulsion
In space, the only real option for propulsion is pure thrust. Drives of these sort fall into two categories: reaction drives, which rely on Newton's third law of motion, and reactionless drives, which do not.
Reaction Drive
“For every action, there is an equal and opposite reaction.” Newton's third law is the fundamental concept behind the reaction drive: If you throw something out the back of your ship, the ship will go forward.
Chemical Rockets
These work by burning a propellant of some sort, and then exhausting the resulting hot gasses and particles out the back of the ship. They are extremely simple in concept, and nearly foolproof as a result.
| TR | Type | Mass (kg) | Cost (₠) | Fuel (lph) |
|---|---|---|---|---|
| -2 | Solid Rocket | Thrust ÷ 10† | Mass × 2.5 | – |
| -1 | Solid Rocket | Thrust ÷ 36† | Mass × 2.5 | – |
| 0 | Solid Rocket | Thrust ÷ 60† | Mass × 2.5 | – |
| -1 | Liquid Fuel Rocket | Thrust ÷ 650 | Mass × 10 | Thrust ÷ 11 |
| 0 | Liquid Fuel Rocket | Thrust ÷ 1,000 | Mass × 10 | Thrust ÷ 15 |
| +1 | Liquid Fuel Rocket | Thrust ÷ 1,200 | Mass × 15 | Thrust ÷ 18 |
| +1 | Metal Oxide Rocket | Thrust ÷ 400 | Mass × 10 | Thrust ÷ 15 |
†per minute of burn-time
Mass is per Newton of thrust (and per minute of burn-time for solid rockets). Cost is per kilogram. Fuel is in liters per hour. Volume for all engines listed above, in cubic meters, is equal to their mass divided by 150.
Thermal Rockets
Similar in concept to chemical rockets, thermal rockets heat up a reaction mass and then fire it out the back of the ship. The principal difference is that chemical rockets combust their reaction mass to impart energy on it, whereas thermal rockets use an external source of energy. Thermal rockets are less powerful than their chemical counterparts, but frequently more efficient.
| TR | Type | Mass (kg) | Cost (₠) | Fuel (lph) | Power (kW) |
|---|---|---|---|---|---|
| 0 | Electric Rocket | Thrust × 2 + 10 | Mass × 10 | Thrust ÷ 4 | Thrust × 350 |
| +1 | Electric Rocket | Thrust + 10 | Mass × 10 | Thrust ÷ 8 | Thrust × 350 |
| 0 | Fission Rocket | Thrust ÷ 60 + 450 | Mass × 50 | Thrust ÷ 160 | – |
| +1 | Fusion Rocket | Thrust ÷ 200 + 20 | Mass × 50 | Thrust ÷ 800 | – |
| +2 | Fusion Rocket | Thrust ÷ 400 + 10 | Mass × 50 | Thrust ÷ 800 | – |
| +2 | Antimatter Rocket | Thrust ÷ 500 + 500 | Mass × 50 | Thrust ÷ 350 | – |
| +3 | Antimatter Rocket | Thrust ÷ 500 + 50 | Mass × 50 | Thrust ÷ 350 | – |
Mass is per Newton of thrust (and per minute of burn-time for solid rockets). Cost is per kilogram. Fuel is in liters per hour. Volume for all engines listed above, in cubic meters, is equal to their mass divided by 100, and includes limited access space for maintenance to be performed, typically to the heating elements.