NASA's astronaut selection process evaluates roughly 18,000 applicants to select 10 to 12 candidates. The selection criteria are well-established for ISS missions of 6 to 12 months. But a permanent lunar settlement is not a mission. It is emigration. The psychological profile of someone who can thrive on a 6-month rotation is fundamentally different from someone who can thrive in a closed environment indefinitely, 384,000 kilometers from everyone they have ever known.

The Mars-500 isolation study confined six crew members in a simulated spacecraft for 520 days. The data showed progressive decline in activity levels, disrupted sleep cycles, and increasing interpersonal tension after month 8. One crew member became effectively nocturnal. Another essentially withdrew from social interaction. And they knew they could walk out the door at any time. On the Moon, there is no door.

The submarine community has the most relevant analog data. Nuclear submarine crews operate in confined, isolated environments for 90-day patrols. The U.S. Navy screens for "submarine personality": emotional stability, low need for external stimulation, high tolerance for routine, and the ability to maintain professional relationships without close friendship. But even submariners know they are coming home. A permanent settler does not have that psychological anchor.

The initial crew of 20 must be selected as a system, not as individuals. Group dynamics modeling suggests optimal composition includes a range of personality types that create functional tension without destructive conflict. You need leaders who listen and followers who challenge. You need introverts who recharge alone and extroverts who energize the group. The crew manifest is as much a social engineering document as a technical one.

Communication delay is only 1.3 seconds each way, which is manageable for conversation unlike the Mars scenario. But bandwidth is finite. Real-time video calls with family on Earth require significant allocation of the communications budget. My calculations show the initial communication architecture supports approximately 4 hours of personal video communication per crew member per week. Is that enough to maintain the relationships that keep people psychologically whole?

There is a selection criterion that no one discusses openly. The crew must include people who are willing to die on the Moon. Not from recklessness, but from acceptance. Equipment will fail. Medical emergencies will exceed the settlement clinic capacity. Someone will have a condition that cannot be treated without return to Earth, and return may not be available. The informed consent for this mission includes acknowledging that the Moon may be where you are buried.