Equations

This is the master list for equations!

Δ v

Where:

• M _t is total mass.
• M _d is total mass minus fuel mass.
• "In" is a natural logarithm.

See the Δ v page for a comprehensive explanation of Δ v.

Rocket Efficiency 

According to Stef:

Top to Bottom

Where

• E_r is Efficiency of the rocket, and

• M_n < is Mass in tonnes of the succeeding stages.

Bottom to Top

, which simplifies to:

Exhaust Velocity of Propellant

, where

$V_{e}$ is the exhaust velocity of your propellant, and

$g_{0}$ is the standard gravity, which on Earth  is: 

$9.8m/s^{2}$

Thrust to Weight

, where

• $F$

is force of thrust in kilonewtons (kN) and

• $M$

is your rocket's mass in metric tons (t).

$g$ is the force of gravity. For example, on Earth , it is 9.8 m / s ² .

If the TWR is greater than or equal to 1 your rocket will lift off the ground. 

Average ISP

, where

• $F_{total}$

is the sum of all the forces, and

• ${\dot {m}}_{total}$

is the fuel consumption rate in kg / s.

Average ISP can also be calculated from each engine:

, where

• $F_{n}$

is the force in kilonewtons of the n th engine, including duplicates, and

• $ISP_{n}$

is the ISP of the n th engine.

Fuel Consumption Rate

The same fuel flow rate.

Burn Time

Mass for that Time

Suicide burn

Orbital Velocity

Orbital Period

Kepler's Third Law of Planetary Motion

SOI Radius

Max Payload 

R = Required Δ v for Mission

X = Max Payload in tonnes

Eccentricity

E = Eccentricity

r_max = Apoapsis

r_min = Periapsis

Please allow a margin of error of 10% as well as user errors.