Select your propulsion system, enter your mass budget, calculate delta-v, check stability margins, and simulate your trajectory — a complete first-principles rocket design tool built on the Tsiolkovsky equation.
Work through each stage in sequence: choose a propulsion system, set your mass budget, calculate delta-v, then check stability and drag. The output gives you a complete first-pass rocket design with trajectory prediction.
Select your propulsion type. Each has distinct advantages and constraints that drive the rest of the design. The choice determines your Isp, thrust curve shape, complexity, and cost.
Simple, reliable, storable. Cannot throttle or shut down. Fixed thrust curve set by grain geometry. Standard for model rocketry and SRB boosters.
Highest performance. Throttleable and restartable. Complex turbomachinery and plumbing. Used on all orbital launch vehicles.
Solid fuel, liquid oxidiser. Throttleable, safer than liquid. Used in SpaceShipOne/Two. Intermediate complexity and performance.
Enter your rocket's mass components. The calculator applies the Tsiolkovsky equation: ΔV = Isp × g₀ × ln(m₀/mf). All mass values in kilograms.
Rocket stability requires the Centre of Pressure (CP) to be located behind the Centre of Gravity (CG). The margin of stability is measured in calibres (rocket diameters). A margin of 1–2 calibres is ideal for a sounding rocket.
Estimate the peak altitude (apogee) for a vertically-launched sounding rocket using a simplified ballistic trajectory with constant thrust and linear drag approximation. Uses outputs from Steps 2 and 3.
Reference specifications for real engines across all three propulsion types, from amateur model rocket motors to orbital launch vehicle engines.
Turbofan, turbojet, and rocket engine theory — Brayton cycle, specific impulse, nozzle design. The physics behind every engine in the builder.
Tsiolkovsky equation, staging, Hohmann transfers, and reentry — what happens once your rocket leaves the atmosphere.
Fin drag, body drag, and stability aerodynamics — the forces acting on your rocket during ascent.
Pitch, roll, yaw, and stability margins — the same principles that govern your rocket's trajectory.
Implement the Tsiolkovsky equation, propagate trajectories with ode45, and post-process flight data in MATLAB.
Rocket stability analysis, propellant comparison, and trajectory optimisation — all with defined methodologies.
SheCodes Lab teaches Python and C++ from scratch — side by side, free, no experience needed. Includes an engineering module covering NumPy, pandas, ISA models, cost index, and flight data analysis. The same tools used to build the calculators on this site.
shecodeslab.com →