Rocket Thrust Calculator

Calculate rocket thrust using the rocket equation with exhaust velocity and mass flow rate

Calculate Rocket Thrust

Speed of exhaust gases relative to rocket

Rate of fuel consumption

Cross-sectional area at nozzle exit

Environmental pressure around rocket

kPa

Static pressure at the rocket nozzle exit

Example Rocket Engines:

Rocket Thrust Equation

F = ve(dm/dt) + Ae(Pe - Pamb)
F: Total thrust
ve: Effective exhaust velocity
dm/dt: Mass flow rate
Ae: Nozzle exit area
Pe: Nozzle exit pressure
Pamb: Ambient pressure

The equation consists of momentum thrust (first term) and pressure thrust (second term).

Newton's Third Law

Action-Reaction

For every action, there is an equal and opposite reaction

Rocket Propulsion

Exhaust gases pushed down create upward thrust

Conservation

Momentum is conserved in the rocket-exhaust system

Rocket Facts

Rockets work in vacuum unlike jet engines

Higher exhaust velocity = better efficiency

Thrust increases with altitude due to lower pressure

Specific impulse measures propellant efficiency

Understanding Rocket Thrust

How Rockets Work

Rocket propulsion is based on Newton's third law of motion. When a rocket expels mass (exhaust gases) at high velocity in one direction, it experiences an equal and opposite force (thrust) that propels it forward. This works in the vacuum of space because rockets carry their own reaction mass.

Thrust Components

Rocket thrust consists of two components: momentum thrust and pressure thrust. Momentum thrust comes from accelerating the exhaust mass, while pressure thrust results from the pressure difference between the nozzle exit and ambient environment.

Momentum Thrust

F₁ = ve × (dm/dt)

Thrust from accelerating exhaust mass to velocity ve

Pressure Thrust

The pressure thrust component becomes significant when there's a pressure difference between the nozzle exit and the surrounding environment. At sea level, this can reduce total thrust, but in space (vacuum), it maximizes performance.

Pressure Thrust

F₂ = Ae × (Pe - Pamb)

Thrust from pressure difference across nozzle exit

Applications

  • Spacecraft propulsion and orbital maneuvers
  • Launch vehicle design and optimization
  • Satellite attitude control systems
  • Rocket engine performance analysis