Crew
Crew refers to the humans required to run habs and ships. They are similar in principle, but have some mechanical differences.
Hab Crew
Each hab module has some number of crew, with the exception of "Automated" modules. The crew values for each hab module are detailed on the Habs page.
The largest values at each tier are from the Quarters family, with a tier-1 Quarters using 50 crew, a tier-2 Residential Module using 500 crew, and a tier-3 Civilian Complex using 2500 crew.
Upkeep Costs
Each crew member of a hab module will consume resources for their upkeep, unless those costs are offset. Every crew will consume a base of 0.35 
Water, 0.35 
Volatiles, and 0.1 
Money per year.
The water and volatiles upkeep costs may be offset by agricultural modules:
- A Hydroponics Bay offsets 120 crew, for a monthly savings of 3.5 units each of water and volatiles.
- A Farm offsets 600 crew, for a monthly savings of 17.5 units each of water and volatiles.
- An Agriculture Complex offsets 3000 crew, for a monthly savings of 87.5 units each of water and volatiles.
These offsets only work for the upkeep costs of crew, and not for the upkeep costs of any other modules. However, they work for all crew on the entire hab.
There is no general way to offset the money costs of crew upkeep. However, the Quarters family of modules charge no upkeep costs for their own crews.
Body Population
The population of a body (other than Earth) is equal to the total population of all human habs on or around that body. Alien habs have no crew, and thus do not increase the population of a body. When the population of a body reaches certain milestones, new modules become available for habs on or around that body.
| Module | Tier | Required Population |
|---|---|---|
Research Campus  |
2 | 10,000 |
| Research University |
3 | 50,000 |
Social Science Lab  |
1 | 10,000 |
| Social Science Research Center |
2 | 50,000 |
| Social Science Institute |
3 | 50,000 |
| Tourist Berth |
1 | 50,000 |
| Space Hotel |
2 | 50,000 |
| Space Resort |
3 | 50,000 |
| Medical Center |
2 | 10,000 |
| Space Hospital |
3 | 10,000 |
Broadcast Outlet  |
1 | 10,000 |
| Communications Hub |
2 | 50,000 |
| Media Center |
3 | 50,000 |
Note that these values are required to construct/upgrade the modules, but the modules remain even if the population later falls (due to module changes, or due to hab deactivation/destruction).
Ship Crew
Some module on ships will require crew. Each crew member required adds 4 tons to the mass of the ship. Ship crew require no upkeep, aside from this mass.
Some officer promotions require a minimum crew on a ship to be possible. These minimums range from 10 to 40 crew members - see Spaceships#Officer for details.
When scuttling a ship, the crew will be rescued. The cost of rescue is zero in any Earth interface orbit, and costs 
Boost equivalent to the cost of moving 0.1 units of material from Earth to the location of the scuttled ship. This cost can be avoided by using surviving ships of the same fleet to rescue the crew - each ship can carry 25% more than its standard crew complement safely.
