Run a reactor

Build an AR-8 Antimatter Reactor into a ship with the radiators and the nuclear scientist it needs, and light it.

You need this once you have antimatter to burn and something to power that the Sun will not reach. Reactors and heat explains why the plant is held down by its fins.

• You own Antimatter Power, which sells the reactor, and Heat Rejection, which sells the first two radiators.
• You have a Nuclear Scientist on your roster. They appear on the recruit board once the Astronaut Center reaches level 3. See Recruit a Meek.
• You have antimatter, in an Antimatter Container aboard. Containers launch empty, so it was made by your own converter: see Make antimatter.
• Your rocket can lift an 8 m stack: the reactor alone is 4.6 t.

Steps

1. Put the reactor in the stack. In the hangar, drag the AR-8 Antimatter Reactor out of the ‹ Electrical drawer onto an 8 m stack. It joins top and bottom and offers a rail down each flank, so the fins and tanks can hang on the reactor itself.
2. Add an antimatter container. Antimatter runs along every joint, so it can sit anywhere in the ship. The reactor burns 1 μg every twelve hours, and a full AM-8 is eighty-five days of running. A container launches empty: fill it in orbit from a converter, on this ship or across a docking port with Transfer resources.
3. Bolt on the radiators. From the same drawer, mirror a pair of fins onto the flanks. Three RW-3 Water Radiators carry the reactor's 60 kW under an open sky; one RK-6 Potassium Radiator carries it four times over. If the ship is also going to warp, read How many fins first, because the bubble's wall changes the answer.
4. Seat the crew. Tap the reactor and fill its one seat from the Crew row. The row lists only Nuclear Scientists, because that seat is theirs; with none free it reads No nuclear scientist yet - hire one at the Astronaut Center. Then give the ship somebody or something to fly it: an astronaut in the command pod, or a probe core such as a Sat Controller. A passenger rides only on a ship that can be flown.
5. Launch and get above the air. Leave the fins stowed for the climb: open they are rated for 2 g and nothing else on the ship is.
6. Deploy the radiators. Tap each one and tap Deploy, or put them in a stage and let staging do it. The vanes fan out over 3 s.
7. Start the plant. Tap the reactor and tap Start up. A line on the screen says AR-8 Antimatter Reactor started.
8. Watch the core come up. Tap it again. The greyed line counts Core coming up: 40 % for the first 180 s, then settles to the output and the name of the Meek on watch.

What you should see

The charge row in the readout climbs, and keeps climbing on the night side where the panels make nothing — and it keeps climbing after you leave, because a core that is up stays up until something puts it out. The reactor's sheet names the Meek on watch. Its vanes take on an orange glow as they carry heat, brightest at the root of each fin, which is the plainest sign from outside that the plant is working. The first time a reactor of yours makes power the First Light achievement pays.

If it didn't work

• The sheet says No nuclear scientist aboard. Nobody of that trade is alive on this ship. A scientist, an engineer or an astronaut will not do. Seat one and start it again.
• The sheet says No way to shed 60 kW: deploy a radiator. No fin aboard is out. Deploy them, or fit some.
• The sheet says held to 50 % by heat. Your fins carry only half the ship's heat, so the plant is held to half output. Add fins, or a hotter working fluid.
• The sheet says No antimatter. No container aboard has anything in it. The core goes out rather than idling hot, so it takes its 180 s to come back up.
• The hangar will not let you fly. Check what the seat rows say: the reactor's seat is reserved for a Nuclear Scientist, and the ship's pod still needs its astronaut unless a probe core is flying it.