Resources

Oxygen

Half of what a throttled engine burns. A Fuel Tank holds half as much again of it as of methane, because that is the ratio the engines drink the two in.

An engine reaches only the tanks its own stage can be plumbed to, which is why the flight readout's fuel rows change as you drop stages. A fuel line changes both which tanks an engine reaches and which of them empties first: see Draw a fuel line. Two ships joined at a docking port become one ship, and then their tanks are one supply.

Methane

The other half of what a throttled engine burns. It runs out at the same moment the oxygen does, because the tank holds the two in the ratio the engines drink them.

Both halves live in the same Fuel Tank, so there is nothing to balance when you build: lengthen the tank and both go up together.

Solid fuel

The cast grain inside a solid booster. It is the heaviest resource in the game per unit, and the only one that is sealed into the part that burns it.

No joint on a booster carries fuel, so a booster can neither be topped up from a tank nor feed one, and each case burns only its own grain — two boosters on one rocket run down two separate clocks. It lights once, burns at the rate it was cast at, and is dead weight after that. It shows on the flight readout as SOLID FUEL while a booster that still has some is in the stage you are flying. How long a case lasts is set in the hangar: see Solid boosters.

Hypergolic

The propellant a thruster block vents and an Escape Motor burns. It ignites on contact with no spark and no pump, which is why the parts that use it are small and instant.

It runs along every joint on the ship, like electricity, so a hypergolic tank anywhere aboard feeds every thruster block and Escape Motor, across a pod, a beam or a booster alike, with no fuel line. It never mixes with the tank fuel: an engine that burns oxygen and methane is untouched by the hypergolic aboard, and a thruster block cannot drink from a Fuel Tank.

Xenon

The propellant an Ion Engine throws. The engine strips the gas of electrons and fires the ions off a charged grid, so a few grams a second go a very long way, as long as there is power to charge the grid.

It runs along every joint on the ship, like hypergolic and electricity, so a xenon tank anywhere aboard feeds every ion engine with no fuel line, across a probe core, a pod or a beam. It never mixes with anything else: only an ion engine burns it, and an ion engine burns nothing else.

Electricity

What keeps a pod alive, a wheel turning, an antenna talking and an instrument reading. It is the only resource that weighs nothing and the only one a ship can make more of.

A panel's figure is what it makes in full sunlight. Its output follows the light: it falls to nothing in a world's shadow, and a stowed panel makes nothing at all. Which way it faces never matters.

Running engines charge the ship as a side effect, from 0.01 u/s on the Lander Engine up to 0.06 u/s on the Heavy Engine. That covers an ascent and nothing beyond it, so anything meant to sit in orbit needs a panel or a big battery.

A flat ship is not lost, only stiff and blind: the reaction wheels make no torque and the instruments refuse to read. The radio keeps talking, and nobody aboard dies of it.

Food

The crew's rations. Only a seat with somebody in it eats, and an unmanned ship eats nothing at all.

Food runs along every joint like electricity, so a Passenger Cabin eats out of the pod's larder as readily as its own. That is what makes a long mission possible: add another pod or cabin and the whole ship gets its rations.

A pod's own larder is days, not months — 20 u is about twenty days for the one Meek in it. For anything longer, bolt on a Cargo Bay and load it with food: at its base length it holds 360 u, which feeds one Meek for roughly a year, and stretching it holds proportionally more.

A Greenhouse grows it back: every crop takes 5 u of waste and gives 5 u of food — 8 or 10 u with a second and third botanist aboard — as long as at least one botanist is aboard the ship and its grow lights never lose power. See Grow food in orbit.

Nothing eaten disappears. Every unit of food a crew eats leaves one unit of waste behind, and the two weigh the same, so a ship does not get lighter as its crew eats.

Waste

What the crew leaves behind. Every unit of food eaten becomes a unit of waste, and it has to go somewhere.

A waste store is room, not a load. Every one launches empty, so it adds nothing to the ship's mass on the pad, and it fills as the crew eats. Each pod and cabin keeps exactly as much room for waste as it keeps food, so a crew living off its own larder never runs out of room.

Waste runs along every joint, like food: it goes into whichever store aboard has room. Once every store is full, what the crew leaves behind goes overboard. Nobody is harmed by it, and the crew goes on eating. A long mission that carries extra food in a Cargo Bay should give the bay some room for waste too, or the ship ends the trip venting.

The flight readout's waste line works the other way round from the rest: it turns amber at three quarters full and red at nine tenths, because a waste store is in trouble full, not empty.

Ablation

The layer of char a Heat Shield boils away to carry a re-entry's heat off the ship. It is spent, not cooled, and there is no making more.

Nothing is spent while the disc is cool, and the hotter it gets the faster the layer goes. While any is left the shield shrugs off heat no other part survives. Once the last unit is gone it is a blunt plate that cooks like everything else, so a second re-entry on a spent shield is a lost ship.

Data

Raw measurements, waiting to be worked through. A store of it launches empty and it is never bought: the only source is an instrument taking a reading somewhere the ship's laboratory has not analysed before.

No cargo hold carries it — it takes no room. A reading taken where the lab's store is already full files nothing and the place is not marked as analysed, so the same reading still pays once there is room. See The Science Lab.

Discovery (aboard a lab)

Findings a laboratory has worked out and not yet sent home. It is the same discovery you spend on the tech tree, but it is not yours until you take the ship’s controls and transmit it: while it is aboard the ship it is a load like any other, and a ship that is destroyed takes it with it.

A full store stops the bench, which is what a laboratory nobody comes back to eventually does. You can pump it by hand to a docked ship with a better antenna: see Transfer resources between stores. See The Science Lab and Credits and discovery.

Helium-3

A rare gas baked out of the Moon's dark plains, and the only thing antimatter is made from. It is never bought or loaded: every store of it launches empty, and the only source is a Mining Rig working a deposit you have found.

It runs along every joint on the ship, so a rig fills any helium-3 tank aboard with no fuel line, across a pod, a beam or a docking port. Between two ships docked in orbit you pump it by hand: see Transfer resources between stores. It cannot be bought or sold, and recovering a full tank on Earth pays for the tank alone. See Helium-3 and antimatter.

Antimatter

What an Antimatter Converter makes out of helium-3, tens of micrograms a day. It can be kept in one part, in one kind of place: an Antimatter Container, powered, in space.

It runs along every joint, so a converter fills every container aboard, and a leak or a vent is taken from all of them together. It can be neither bought nor sold: a container launches empty, and every microgram is made by a converter from mined helium-3. Between two ships docked in orbit you pump it by hand, like any load: see Transfer resources between stores. Reactors burn it by the microgram and warp drives spend it by the day skipped.