Approximately Up RCS Thrusters Setup

Main lifting thrusters push your ship up; RCS thrusters rotate it. In Approximately Up, rotation is not automatic — you bolt on small maneuvering thrusters, pair them with an RCS controller, and assign each thruster to a pitch, yaw, or roll channel. Get this wrong and your ship spins on the pad or drifts through lunar approach with no way to face your landing site.

This guide assumes you already have a flyable hull from Build Your First Ship and understand Power and Data Routing. For keyboard basics, see Controls.

Why you need exactly six thrusters

To rotate on all three axes you need two maneuvering thrusters per axis — one for positive torque, one for negative. That yields six thrusters total:

Axis	Thruster A	Thruster B
Pitch	Pitch A (negative input)	Pitch B (positive input)
Yaw	Yaw A	Yaw B
Roll	Roll A	Roll B

Each RCS thruster block has a small knob you turn to select its axis letter. The game does not know which way your ship faces when you build it — there is no command block or cockpit forward reference — so you tell each thruster whether it responds to pitch A, pitch B, yaw A, yaw B, roll A, or roll B.

A channels react to negative input values; B channels react to positive values. If two thrusters on the same axis both show red on the controller immediately at spawn, you likely assigned the same direction twice — change one knob.

RCS controller: wireless hub

Place one RCS controller on your ship and connect power from your router. The controller exposes three data inputs: pitch, yaw, and roll.

RCS thrusters do not need individual data cables. They pair wirelessly with the controller — think of them as bound radio endpoints. Mount thrusters on arms or corners with clear line-of-sight to the controller when possible; crowded frames still work but make replacement harder.

The controller’s indicator lights show each thruster’s built-in battery health:

• Green — healthy
• Yellow — draining
• Red — critically low or mis-assigned axis conflict
• Blinking red — depleted; thruster dead until replaced

RCS thrusters use single-use internal batteries. Long Moon trips can burn one pitch jet mid-flight — monitor lights during Moon Landing approaches.

Wiring the 3D joystick

Connect a 3D joystick to the controller’s pitch, yaw, and roll ports. Each stick axis outputs roughly -1 to +1, matching the A/B split on thrusters.

Simple layout:

1. Joystick pitch axis → controller pitch input
2. Joystick yaw axis → controller yaw input
3. Joystick roll axis → controller roll input

In fly mode, click the joystick, then use mouse or WASD to actuate. Mouse 3 resets neutral if you lose control.

Alternative: joystick splitter

For direct thruster control without the wireless RCS kit, some builders route joystick axes through joystick splitters into regular thruster data ports, splitting -1..0 and 0..+1 into separate 0..1 outputs. The wireless RCS path is simpler for beginners — use splitters only if you understand data scaling from Power and Data Routing.

Physical placement tips

• Mount opposing pairs on opposite sides of the center of mass
• Pitch thrusters: front/back or top/bottom pairs
• Yaw thrusters: left/right pairs offset from centerline
• Roll thrusters: top-left vs bottom-right diagonals often work well

After placement, enter garage mode (G) and verify knobs before fly mode (R). Fixing knobs on the ground beats debugging spin at 500 meters.

Test procedure on Earth

1. Hold R to launch with main lift at minimal throttle
2. Cut main thrust briefly in hover — rely on RCS only
3. Test pitch, then yaw, then roll separately
4. Watch controller lights during each axis burst
5. Land and end flight (R) if any axis feels weak or inverted — swap A/B on one thruster

If an axis feels inverted, swap which thruster is A versus B, or invert your joystick wiring with a remapper block from the logic palette.

Common failures

Symptom	Likely cause
Red light on pad	Duplicate axis assignment on two thrusters
One axis dead	Knob unset or thruster battery depleted
Violent spin on RCS tap	Opposing thruster missing on that axis
Works on Earth, fails at Moon	Battery drained mid-trip — carry spares

Integration with hover and missions

RCS keeps you oriented while Hover Logic holds altitude. For Moonstep cargo runs, stable roll control keeps freezers level — see Missions Walkthrough.

Co-op crews often assign one player to RCS joystick while another handles main throttle. Read Co-op Guide for split-cockpit layouts.

Related guides

• Build Your First Ship — frame and power baseline
• Moon Landing Guide — RCS during terminal descent
• Hover Logic — automate altitude while you steer rotation
• Tier List — RCS parts versus standard thrusters for early game

Six thrusters, six knob settings, one wireless controller, one 3D joystick — that is the full rotation stack. Nail it once and every future ship copy-pastes the same pattern.