Can we refuel in space?

Yes! In-Situ Resource Utilization (ISRU) means making fuel on the Moon or Mars from ice. This breaks the tyranny of the Rocket Equation.

Why not nuclear engines?

Politics. Nuclear Thermal Rockets (NERVA) are 2x as efficient as chemical ones, but nobody wants to launch a nuclear reactor over Florida.

It's the 'currency' of space travel. It means 'Change in Velocity.' If you have 100 m/s of Delta-V, you can change your speed by 100 m/s.

Spaceship Fuel Planner

Plan your interstellar fuel loadout.

📜 The Origins

Tsiolkovsky's Rocket Equation is a cruel mistress. The more fuel you carry, the more fuel you need just to move that fuel. This planner helps you find the 'sweet spot' for your mission.

🚀 Master the Tool

Input your ship's dry mass and your target Delta-V (change in velocity). We'll tell you exactly how much fuel you need to reach your destination without becoming a permanent satellite.

Fuel Logistics

Plan energy requirements for your interstellar voyage.

Origin

➜

Destination

Vessel Class

Distance: 0.000023 Light YearsTotal Energy: 5.44e+2 MJ

Fuel Type

Mass Required

Volume

Kerosene (RP-1)

15.9 M kg

Liquid Hydrogen

3.8 M kg

Nuclear Fission

6.6 kg

Fusion Plasma

0.00181 kg

Antimatter

6.11e-9 kg

Tsiolkovsky's Tyranny

The Rocket Equation is the cruelest law in physics: $$ Delta v = ve ln rac{m0}{m_f} $$ Translation: To go faster, you need more fuel. But fuel has mass. So you need more fuel to lift that fuel. It's an exponential curse.

The "90% Fuel" Rule

Look at the Saturn V rocket. 90% of it was just fuel tank. The astronauts, the ship, and the lander were a tiny speck on top. To get to Mars, we need better engines (higher Specific Impulse, or $I_{sp}$), not just bigger tanks.

Getting to Orbit is Halfway to Anywhere

Robert Heinlein famously said: *"Once you get to earth orbit, you're halfway to anywhere in the solar system."* It takes ~9.4 km/s of Delta-V to reach orbit. It only takes another ~3.6 km/s to escape Earth's gravity entirely and head to Mars.