Human factors for a lunar lander

A lander is judged on mass, propulsion and landing accuracy. What decides whether a surface mission works is a crew getting in and out of it, in a suit, twice a day, for weeks.

TypeDesign study

Year2026

FocusSurface operations · Crew interface

StatusOpen study

A vehicle you live inside

Apollo’s lunar module gave two crew roughly 6.65 cubic meters of habitable volume for stays measured in hours, with no seats. The landers now being built carry more people, for longer, and the human factors question changes with the duration: a cabin that is tolerable for a day becomes the limiting factor over a week.

In one sixth gravity the body is light but the suit is not. Mass still has inertia, so a suited crew member is hard to start and hard to stop in a small volume, and every handhold, corner and hatch edge is something to collide with.

L-01 · Standing crew, suited and unsuited, with the reach envelope and the volume suiting actually needs

The egress sequence is the mission

Each surface excursion runs the same sequence: prebreathe, don the suit, depressurize, clear the hatch with a backpack on, descend the ladder, and return covered in dust. Twice a day, for weeks. Every step is crew time, and crew time is the scarce resource on the surface.

The design question is which steps the vehicle can absorb and which the crew must carry. A suit port removes donning assistance and most of the depressurization. A wider hatch removes a collision risk. A dust mitigation strategy decides whether the cabin stays habitable in week three.

L-02 · The sequence that sets the rhythm of a surface day

What we would measure

Time to egress. From the decision to go outside to boots on regolith, measured with a suited subject rather than estimated.

Assistance required. How many of the steps need a second crew member, and what happens when that person is unavailable.

Collision and snag events. Counted, not judged. Where the cabin is too tight is an empirical question.

Dust carried inboard. Mass and distribution after each cycle, and what it does to seals, optics and air.

Sleep and recovery. Whether the cabin lets a crew member rest between excursions, which is what makes week three possible.

How it connects

This study sits between the training work and the habitation work. MEK is where a crew learns to move in a suit before they fly; the lander is where that movement meets a real volume on a real schedule; the surface habitat is where they go when the lander is no longer home.

Figures here come from public Apollo documentation and should be checked against current vehicle data before use in a proposal. If you are designing a lander, a suit or the operations between them, we would like to compare notes.