Starfield Ship Builder Guide: Module Placement and Flight Checks

Starfield's ship builder will eat whole evenings once it hooks you. You start with the Frontier, a tired little hauler with weak engines and a hull made of soggy cardboard, and sooner or later you end up parked at a Ship Services Technician bolting on better parts. The catch is the flight check. The game flat-out refuses to save or fly a build that breaks its rules, and a few of those rules hide in weird places. So here's the rundown on part unlocks, reactor power, hab connections, mass, and the errors that stop a build from ever leaving the pad.

Unlocking Better Ship Parts

First, where you can even build. Any city spaceport has a Ship Services Technician who'll open the builder for you, and so will the manufacturer staryards floating out in space. Outposts work too, but only with the full-size landing pad. Once you're in, the parts list you see gets filtered by three separate gates, and all three have to line up.

The first gate is your character level. Parts trickle in starting around level 3, get decent in the teens (the 360T Stellarator reactor shows up at 14), and the endgame gear lands in your 50s and 60. The best reactor in the game, the Pinch 8Z, doesn't appear on shelves until level 60. If a part you've read about simply isn't in any shop, your level is usually the reason.

The skill gates

Two skills matter here, and they do different jobs.

Starship Design is an Expert Tech skill, which means you have to sink 8 skill points into the Tech tree before you can even buy rank 1. From there, rank 1 gets you "improved" modules, rank 2 "superior", rank 3 "cutting-edge", and rank 4 "experimental". Each rank has a challenge attached: install 5 unique ship modules for rank 2, 15 for rank 3, and 30 for rank 4. The cheap trick is that structural junk counts as a module. Twenty minutes and maybe 20,000 credits of random greebles glued onto your hull will carry you most of the way to rank 4.

Piloting is the other one. Rank 3 lets you fly class B ships, and rank 4 unlocks class C. The reactor sets the ship's class, so a class C reactor sitting on a pilot without rank 4 is a very expensive paperweight.

Where the good parts live

City technicians stock a grab-bag mix of brands. The dedicated stuff lives at the source:

• Deimos Staryard, in orbit over Mars in Sol
• Stroud-Eklund Staryard, orbiting Dalvik (a moon of Deepala) in Narion, where Havershaw runs the counter
• HopeTech in Hopetown, on Polvo in the Valo system
• Taiyo Astroneering in Neon, Volii system, up the elevator from Ryujin Tower
• Nova Galactic parts at New Homestead on Titan, since the Nova Galactic staryard itself is a wreck after The Old Neighborhood
• The Key, if you're on friendly terms with the Crimson Fleet

Vendor stock is partly random and level-gated on top of that, so if the shelf is empty, come back after a few in-game days.

A few parts are quest-locked instead. The SAL-6830 engine, arguably the best engine in the game, only shows up after you finish Walter Stroud's All That Money Can Buy in Neon, and you want to play that one diplomatic. It's a class C engine with 18,000 thrust that only draws 2 power, which matters way more than it sounds. (More on that in the mass section.)

Reading Reactor and Power Limits

One reactor per ship, no exceptions. That single part decides two things: the class ceiling for everything else bolted to the hull, and your total power budget.

Class first. Parts come in A, B, and C flavors, and nothing on the ship can outrank the reactor. A class B reactor accepts A and B parts. A class A reactor accepts A only. Break that rule and you get the "Ship Contains Modules That Exceed Reactor Class" error. Flying the result is a separate hurdle, since class B hulls need Piloting rank 3 and class C hulls need rank 4.

| Reactor | Class | Power | Appears at level | Skill needs | | --- | --- | --- | --- | --- | | 114MM Toroidal | A | 16 | 3 | none | | 360T Stellarator | A | 20 | 14 | none | | 101DS Mag Inertial | B | 16 | 12 | Piloting 3 | | Fusor DC403 | C | 38 | 49 | Piloting 4, Starship Design 3 | | Pinch 8Z | C | 40 | 60 | Piloting 4, Starship Design 4 |

One reactor deserves a callout even though it's not on the table: the SF40 Sheared Flow hits 40 power on a class A frame at level 57. That's max reactor power without touching a single Piloting rank, which is why shipbuilders who never dogfight love it. The Pinch 8Z matches that output with better reactor health and repair, but it wants both skills at rank 4 and runs 85,200 credits.

How power actually works

Power moves in single pips. You feed pips to five places: engines, shields, grav drive, and up to three weapon groups. Each system caps at 12 pips no matter how fancy the reactor is. Run the ugly math and you'll see even a 40-power plant can't run everything. Twelve pips for engines, 12 for shields, 12 for grav, and 12 apiece for three weapon groups is 72 pips of demand against 40 pips of supply. Choosing what to power is half the minigame.

In flight, the power bars sit at the bottom left, and you can shove pips between systems live. Pulling a pip costs that system a slice of its max, not a flat amount. The wiki's example: a shield system with 5 pips, yank one out, and the shields can only charge to 80%. Weapons need at least 1 pip parked in them or they lose their charge. Power feeds weapon recharge speed, engine top speed, shield capacity, and grav drive spin-up time.

The habit worth building early: strip the grav drive the moment a fight starts and pour those pips into shields and guns. The grav drive is your escape button. Spin it back up if things go sideways, not before.

Building Valid Hab Connections

Habs are the walkable part of the ship, and a legal build needs at least one. The bare skeleton goes like this: landing bay on the bottom, a hab sitting directly on top of it, and the cockpit attached to that hab's side or top. The hab over the bay is where the entry hatch appears, and it's where you load in when you board.

The interior has to form one connected chain. Stacked habs link with ladders, and side-by-side habs link with doors. Here's the annoying part: you don't place any of those. The game picks door and ladder spots when you finalize the build. If a ladder lands where a workbench was supposed to go, the workbench quietly disappears. Infirmary habs are the famous victim, since they're meant to hold both a research station and a pharmaceutical lab, and plenty of builds end up missing one because a doorway ate it.

So the loop is build, exit, walk the inside, adjust, repeat. Kind of a pain, but the builder never shows you the interior, so your feet are the only preview that exists.

Picking hab types

Select a placed hab and tap left or right to cycle its variant. That swap is free, and it works even at a yard that doesn't stock the brand. What each type gives you:

• Workshop: weapon, spacesuit, and industrial workbenches, plus a research station
• Infirmary and Science Lab: research station and pharmaceutical lab
• Control Station: 4 crew stations, while Battle Station bumps that to 6
• Armory: weapon and suit displays, mannequins, chest storage
• All-in-One Berth: bed, galley, research, and a couple of passenger slots
• Mess Hall: galley plus 3 passenger slots
• Companionway, Storeroom, and Cross habs: nothing inside, pure structure

Crew stations matter more than they look. More seats means more of your crew's skill bonuses running at once, and passenger slots are what let you take the gigs where you ferry people around.

A note for the aesthetics-minded: Deimos and Stroud-Eklund habs share the same interior layout in different colors, HopeTech and Taiyo share theirs, and Nova Galactic is the only truly unique one. Mixing brands builds fine, the inside just won't match.

Two connection rules trip people up. The docker has to mount on a hab and stick out past everything else on the ship, because the spinning blue ring marking its range has to stay clear of the hull. And the cockpit has to be reachable from the landing bay through habs. Put a solid wall of structure between them and you'll catch "Cannot Reach Cockpit from Landing Bay" at the flight check.

Balancing Mass and Mobility

Mass is the tax on everything else. Pile it on and your mobility drops, your top speed drops, and your jump range shrinks. Mobility is the big one for combat: it caps at 100, and once you slip under 70, the flight check itself starts nagging you. A ship at 100 mobility turns on a dime. A ship at 40 handles like a bus full of wet cement.

Engines carry two thrust numbers. Engine thrust drives your top speed, and maneuvering thrust drives mobility. Each engine draws 2 to 4 pips, all your engines combined can't exceed 12 pips, and you can mount up to six engines if the hull has the hardpoints.

| Engine | Class | Pips | Engine thrust | Maneuvering thrust | Mass | | --- | --- | --- | --- | --- | --- | | White Dwarf 3015 | A | 3 | 20,460 | 3,150 | 95 | | Dunn-71 | B | 3 | 26,580 | 5,250 | 144 | | SAL-6830 | C | 2 | 18,000 | 8,800 | 330 |

Here's why those pip numbers matter so much. Say you've got the full 12 pips for engines. SAL-6830s draw 2 each, so six of them fit: that's 52,800 maneuvering thrust. Dunn-71s draw 3, so only four fit, for 21,000. Same power budget, two and a half times the turning force. Heavy engines with fat thrust but greedy pip draws lose that fight pretty much every time.

There's a speed trade hiding in the same table. Light class A engines like the White Dwarf line push a ship to the 150 top-speed cap, while big class C iron tends to settle around 130. Corner like a fighter or fly fast in a straight line. Pick one.

Landing gear scales with mass too. The rule is 1 lander thrust per 200 ship mass, so a 1,600-mass build needs gear adding up to at least 8 thrust. Different gear pieces carry different thrust values, so check the stat before bolting them on instead of counting legs.

Grav drives care about weight as much as engines do. Jump range is grav thrust against hull mass, the floor is 15 LY before the flight check fails you, and the cap sits at 30 LY. A heavy hauler fixes a shrinking jump range with a bigger drive or a lighter ship, and there's no third option.

The practical version of all this: cargo holds and habs are where mass piles up fastest. A build that needs 3,000 cargo is going to be heavy, and that's fine, because that's exactly what class C reactors and six-engine layouts exist for. Just don't expect a freighter to dogfight. If mobility keeps sagging on something that's supposed to be nimble, the fixes are lighter habs, fewer cosmetic cowlings, better engines, or more engines.

Fixing Flight Check Errors

The Flight Check button lives at the bottom of the builder. Red text means error: you can't save it, you can't fly it, and if you try to back out with errors present, the changes get tossed. Warnings are the softer tier. The ship will fly with those, you'll just feel it later.

The errors you'll actually hit

Unattached modules. Every part has to link to the rest of the ship through the blue attach-node circles. The classic trap is swapping a part for a newer model that doesn't have the same nodes. A new grav drive with no side mounts leaves whatever was hanging there floating in space. The community trick for finding the culprit: double-click the ship and drag the whole thing, and whatever gets left behind is your loose part.

Missing or extra cockpit, missing or extra landing bay. Exactly one of each per ship, and the bay sits on the bottom.

Cannot reach cockpit from landing bay. Your entry hatch is on the hab above the bay, and there has to be a walkable hab chain from there to the cockpit. Break the chain, catch the error.

Landing gear errors. Three flavors here. Missing gear, meaning you need at least one. Minimum gear count, meaning 1 lander thrust per 200 mass. And misaligned gear, meaning the bay and all the gear have to sit flush with the ground. Each piece's ground marker glows green when it's level and red when it isn't. On top of those, nothing can hang below the bay-and-gear line. No underground modules.

Docker errors. Missing docker, or a docker in an invalid position. It has to sit on a hab, out at the ship's edge, with its blue range ring clear of every other part. Dockers come in up, sideways, and forward variants, plus a small hatch model that fits on hab tops, so there's usually one that works for your hull.

Grav drive errors. Missing drive, or a jump range under 15 LY. Bigger drive or less mass, pick one.

Reactor errors. One reactor only, and no part can outrank its class. The fix is a bigger reactor or smaller parts.

Engine errors. At least one engine, and the combined pip draw can't pass 12. Most engines pull 2 or 3 each, so count them up before wondering why the check is mad at you.

Minimum fuel tank count. One fuel tank minimum. Cheap, easy to forget in the middle of a rebuild.

Weapons not assigned to a group. If there are guns on the hull, every single one needs a slot. Open Flight Check, flip to the weapons tab, and assign each weapon to group 1, 2, or 3. Three groups max, 12 pips per group. This is probably the single most common error in the game, and it looks way scarier than it is.

The warnings

Three warnings exist, and none of them block the build. No shield installed, which is legal but a genuinely bad idea unless you enjoy paying for hull repairs. Fewer than three weapon types across your three groups, which is you leaving tools on the table, since lasers strip shields fast and ballistics chew hull. And mobility under 70, the game's polite way of saying the ship is too heavy for its engines.

A workflow that saves pain

Run Flight Check after every major change, not once at the end. Build the spine first, meaning bay, hab, cockpit, gear, reactor, engine, fuel tank, grav drive, and docker, and pass the check before adding anything fun. When a swap breaks something that used to work, undo the swap first and rebuild around it second. Nine times out of ten the new part is missing a node the old one had.

Once the errors are gone, the whole thing is mostly a money problem. Six SAL-6830s plus a Pinch 8Z reactor runs right around 505,000 credits (420,000 for the engines, 85,200 for the reactor), and that combo passes every check in the book with power to spare.