Thruster

Screenshot assets/wiki-section-thruster.png A thruster burning, exhaust plume lit, ideally on a multi-thruster build.

The thruster produces forward thrust and drives the exhaust plume. Throttle is analog, so a build's thrust authority comes from each thruster's magnitude and how many you fit - more thrusters, more push. What that push is worth is the other half of it: a section weighs the box it is hit on, so a roomy hull is a slow one and no part of it says so anywhere. The skin plates that clad every base hull add weight of their own, so a clad ship is heavier than its sections alone.

Every drive here is a basic drive pushing the same 1.0. The Mining Tug and the Interceptor both fly on three of them. The tug's structure weighs 33.00, good for at most 58 m/s^2; the interceptor's weighs 41.25, good for at most 47 m/s^2, on the same three engines. The Training Picket has one drive fewer on a 20.13 frame: 64 m/s^2. Nothing authors that gap - a section's mass is the volume of the box it is hit on. These are upper bounds: the scope counts structure only, and the skin plates on a base hull make it heavier and slower. Bolting basic drives on closes the gap, with a tapering return: each one is a unit of mass as well as a unit of push, and no stack of them passes 640 m/s^2 - what a single drive would do carrying only itself.

A thruster bolts on by its forward end and by that end only. The rest of it is barrel, nozzle bell and exhaust, so the builder always seats it nose-in with the plume clear of the ship - you choose the face it grows from, not which way round it sits.

Balancing thrust through the hull

Because thrusters sit wherever you bolted them, an off-center burn would spin the ship. The flight computer prevents that: it sets each engine's throttle to deliver the commanded forward thrust while cancelling the twist through the live center of mass, recruiting off-axis thrusters purely for counter-torque when the firing set cannot balance itself. An asymmetric or battle-damaged ship still flies straight - any tiny leftover spin is mopped up by the steering - so a drive shot off one flank costs you push, not control.

What a hurt drive tells you

A hurt drive looks hurt. Past about a third of its health gone it cracks and throws sparks, and its exhaust runs short and guttering instead of steady. It never guts all the way out, because a dead plume means a shut-down drive and this one is not shut down: a damaged thruster delivers exactly the push a fresh one does. The plume tells you what a chaser has already taken off it, not what it can still do.

Loop capture assets/loops/loop-section-thruster.webm A short loop: throttle rolling up, plumes brightening, the ship pulling away.

Variants

Three drive grades ship, and they are priced by the space they take: the basic drive is a unit cube pushing 1.0, the vector drive is a 3x3x2 block pushing 9.0, and the capital drive is 5x5x3 pushing 75.0. Thrust per unit of mass is 1.0, then 0.5, then 1.0 again: the vector drive buys a hull fewer mounts to defend and a shorter drive bay, and the capital drive moves the largest hulls on one bell. All three bolt on by their forward face only, plume clear of the ship.

assets/icon-thruster.pngThruster - shipped prototypes

	Variant	Box	Thrust	Health
captureassets/catalog-basic-thruster-section.png	Basic Thruster Sectionbasic_thruster_section	1x1x1	1.0	70
captureassets/catalog-vector-thruster-section.png	Vector Thruster Sectionvector_thruster_section	3x3x2	9.0	480
captureassets/catalog-capital-thruster-section.png	Capital Thruster Sectioncapital_thruster_section	5x5x3	75.0	1250