The Nuclear Podship

This is the workhorse rocket ship of the Earth-moon system. It’s principal characteristics are as follows: 

  • Uses a rotating particle bed nuclear reactor to heat hydrogen, as researched in the Timberwind program
  • Uses liquid oxygen injected into the engine nozzle for greatly increased thrust, which is the LANTR design
  • In normal operation, 97% of the mass of propellant is oxygen, and it provides most of the thrust. The nuclear reactor can be smaller and operate at a lower temperature because of this, reducing cooling needs and increasing operational life span.
  • Normally does rendezvous with one of the skyhooks orbiting the moon, which either brakes it for landing, or flings it towards Earth or another destination after launch. This greatly reduces the amount of delta V that must be achieved by its engine
  • Normally carries one to four pods, which slot into berths on its spine. These pods are standardized like shipping containers. There are passenger pods and cargo pods. If transport of special cargo is needed, the ship’s spine can instead be fitted with purpose-made adapters.
  • The nuclear reactor is surrounded with enough shielding to pose no radiation danger when the ship is standing vertical. When lowered to horizontal for loading and unloading, a plug is placed in the engine bell, after which there is also no danger due to radiation.
  • Propellant tanks can be swapped instead of being refilled. To achieve mission requirements, extra tanks can be added or the ship can be reconfigured to accommodate larger tanks. Sizing and systems to be determined.

Maneuvering thrusters

4 pairs, to assist in docking

Cargo pod

Similar in construction to a passenger pod, but with a cap at one end that unscrews and is set aside for loading and unloading. May hold an extremely thin atmosphere, have refrigeration, supply power, or other custom adaptations for the sake of the cargo - which is often food. All pods have 2 standard connection points that the ship latches onto, and a 30 cm port at the aft end for transfer of air, water, power, and data, which connects to pipes running to the midship housing.

Midship housing

Holds everything for the thrusters, for passenger pods air and water (loaded frozen so it can be a heat sink), air scrubbers, reaction wheels, etc.

Nuclear Reactor

Shielded heavily enough to not present a radiation risk, and uses only hydrogen fuel, meaning the exhaust is not radioactive as hydrogen doesn't emit radioactive particles. Design operating temperature is low enough for long life, as most thrust comes from the afterburner. Interior built of sapphire and titanium carbide produced on the moon, for good durability. At the spaceport, the entire engine can be swapped out for another if needed.

Liquid Hydrogen Tank

Designed for swapping tanks rather than refilling. Ship can be reconfigured to use a cluster of up to 3 tanks. This is rare but might be done if the decision is taken to use a podship to go to Mars or Venus.

Solar Panels

Fold out once coasting and turn towards the sun

Grapple Point

Where skyhook grappling systems grab the ship while swinging it into a new trajectory


Single hatch, no airlock. EVA is not possible. A service robot stored in the midship housing does work in the rare event it's needed.

Passenger Pod

Exterior dimensions 8 m in diameter and 27.5 m long, maximum capacity 80 passengers, for a trip of up to 4 days. Trips to and from Earth orbit to the lunar surface normally last 40 hours. Pods are built on the moon from lunar glass, lunar fiberglass, and titanium fibers, with an offset aluminum skin for heat rejection and as a Whipple shield. Windows are laminated quartz. In the event of a solar flare, the ship turns its tail to the sun, trying to shade passengers using the bulk of the fuel tanks. cargo, and engine shielding. Prediction of these events has come a long way and so trips with passengers are delayed when the risk is too high. If one happens during transit anyways, sometimes a high-power emergency ship can race to rendezvous and deploy extra shielding around the tail on time.

Ship spine

The core structural element of the ship. The extension that allows 3 pods to be attached at the nose can be retracted, or removed and replaced with a custom scaffold for large, odd-shaped cargo. Strongback trucks take hold of the spine to lower the ship to horizontal and move it for unloading, and to raise it again for launch. This piece is made of lunar glass reinforced with titanium fibers.

Liquid Oxygen Tank

A small one for a run to Earth orbit, carrying one cargo pod loaded with around 200 metric tons of stuff, and 3 empty passenger pods. Most of the delta V is provided by skyhooks in lunar orbit and Earth orbit. LOX tanks come in longer and fatter versions, and can be clustered. Tanks can be swapped out for full ones, while docked at the skyhook station in low Earth orbit.

Afterburner oxygen injection

Liquid oxygen is sprayed into the engine nozzle where it mixes with the super-hot hydrogen blowing past, greatly increasing thrust as it combusts with it and expands - this is the LANTR design. Where possible, oxygen is used for fuel instead of hydrogen. Oxygen is cheap and plentiful because it is a byproduct of most lunar refining processes. The more oxygen is used, the less efficient the engine is, but there is so much usually that's still cheaper. Plus, the more thrust comes from oxygen, the cooler the nuclear reactor can run, extending its life.

Current 3d models:

A version of this model to serve as a basis for development is available in 3 formats. OBJ is the format that should import properly into any 3d software. FBX and GLB are formats best suited for games. 

There is a channel on our Discord server for discussion of the design of this equipment. Come join if there is anything you’d like to comment on or ask –

Also see the Projects page for general guidance on designing for Moonwards – materials, infrastructure, transport, practices, and main reference works.