Rocket Engine Works: How a Rocket Engine Is Built

Shopidle

Station0 / 15

Parts fitted0

Launched0

Details

idle

Press Build to start the line

The floor is idle. Give the engine a serial number below and watch one unit go from powder to orbit.

reading stop: press Space to hold it here

Flight ascending

Engine data sheet computed live

Materials share of what is fitted so far

Fills as the engine is built up.

Traveller

Launch board

nothing launched yet

Stations click to fly there

What this is

Rocket Engine Works is an isometric factory where every machine is one step in building a liquid<br>rocket engine — a methalox, full-flow staged-combustion engine of roughly the class that flies<br>today. A carrier rides the main belt through fourteen stations. It leaves goods-in as bar stock<br>and canisters of metal powder, is printed, machined, given cooling channels and a jacket, gains a<br>nozzle, an injector, turbopumps, valves and a controller, is assembled, inspected and fired on a<br>test stand — then rides a transporter out to Launch Complex 1, is bolted into a rocket, and<br>launched.

How much of it is real

Genuinely computed, live, in your browser: the exit Mach number, solved<br>numerically from the area ratio you choose by bisecting the isentropic area–Mach relation; exit<br>pressure and temperature from it; exhaust velocity; characteristic velocity and mass flow from<br>chamber pressure and throat area; thrust from the momentum and pressure terms at whatever ambient<br>pressure the vehicle is currently at; and specific impulse from those. Move a slider and the<br>numbers move because the gas dynamics changed.

Also computed: the ascent. Altitude and velocity during the launch are integrated<br>from thrust, falling vehicle mass as propellant burns, and gravity falling off with altitude. The<br>readout is not a script — it is why the rocket is slow off the pad and quick two minutes later.

Modelled, not measured: combustion. Chamber temperature and exhaust molar mass<br>come out of an equilibrium solver in real life; here they are fitted curves against mixture ratio,<br>which puts the peak in the right place and moves the right way but is not a chemistry calculation.<br>The ratio of specific heats is held constant, which it is not. The gravity turn during ascent is a<br>crude pitch schedule, not a trajectory optimisation.

Indicative: the materials split, the part counts, the tolerances quoted in the<br>station write-ups, and every dimension of the machinery on the floor. Engine builders do not<br>publish process sheets or bills of material. Treat the numbers on the panel as the lesson and the<br>factory itself as an illustration.

Pacing

The first time the carrier reaches a station it stops long enough to read that station's write-up,<br>between 9 and 28 seconds depending on how much there is to say, with a progress bar under the<br>panel text. Once every station has been explained the line runs at a watchable pace instead of a<br>readable one. Space holds any stop indefinitely, S steps one station at a time, and<br>the Speed slider scales everything, reading stops and the launch included. Reset (⟲)<br>replays the slow tour from the beginning; Build keeps what you have already read.

Controls

Space play / pause · S advance one station · R reset and replay the tour ·<br>F follow camera · L labels

Drag to pan, scroll to zoom, click any station for its write-up.

The view starts close on the carrier and rides along with it. The ⤢ button on the left<br>(or a double-click on the ground) pulls back to the whole site; turning off Follow lets<br>you wander. During the launch the camera climbs with the rocket whether you are following or<br>not.

A companion piece to EngineWorks, which lays out a Formula 1 power unit the same way.<br>All code, art and copy here are original; no game assets are used.