Computing the minimal crew for a multi-generational space travel towards Proxima Centauri b

TL;DR

This paper uses Monte Carlo simulations to determine the minimal crew size needed for a sustainable multi-generational space mission to Proxima Centauri b, ensuring genetic health and mission success over 6300 years.

Contribution

It introduces a simulation-based method to estimate the minimal viable crew for long-term space travel considering genetic and social constraints.

Findings

A crew of 98 people is required for guaranteed mission success.

A starting population of 25 breeding pairs often leads to extinction without inbreeding restrictions.

Adaptive social engineering can sustain a healthy population indefinitely.

Abstract

The survival of a genetically healthy multi-generational crew is of a prime concern when dealing with space travel. It has been shown that determining a realistic population size is tricky as many parameters (such as infertility, inbreeding, sudden deaths, accidents or random events) come into play. To evaluate the impact of those parameters, Monte Carlo simulations are among the best methods since they allow testing of all possible scenarios and determine, by numerous iterations, which are the most likely. This is why we use the Monte Carlo code HERITAGE to estimate the minimal crew for a multi-generational space travel towards Proxima Centauri b. By allowing the crew to evolve under a list of adaptive social engineering principles (namely yearly evaluations of the vessel population, offspring restrictions and breeding constraints), we show in this paper that it is possible to create and maintain a healthy population virtually indefinitely. A initial amount of 25 breeding pairs of settlers drives the mission towards extinction in 50 +/- 15% of cases if we completely forbid inbreeding. Under the set of parameters described in this publication, we find that a minimum crew of 98 people is necessary ensure a 100% success rate for a 6300-year space travel towards the closest telluric exoplanet known so far.