With cryogenics and faster-than-light travel still in the realm of science-fiction, the only way to overcome an inter-stellar distance would be to build a “generation ship” – a hypothetical type of spacecraft capable of hosting several generations of travellers on-board.
According to a new paper accepted for publication in the Journal of the British Interplanetary Society on 11 June 2018, a trip to Proxima Centauri b – the closest exoplanet to Earth – would take a crew of 98 people (equally split between men and women) and… 6,300 years of flight-time in space.
Discovered back in 2016, Proxima Centauri b, located in the orbit around the red dwarf Proxima Centauri, is roughly the size of Earth and has an average temperature of around -39 degrees Celsius, which makes it an attractive destination for future deep space missions.
In order to calculate the approximate duration of the hypothetical journey, two researchers from the University of Strasbourg – Frederic Marin and Camille Beluffi – used the estimated speed of the Parker Solar Probe, which is scheduled for launch on 11 August 2018 and expected to reach a speed of about 724,000 km/h, or 0.067 percent of the speed of light.
As for the size of the multi-generational crew, Marin and Beluffi employed a type of Monte Carlo simulation called HERITAGE, which allows for identifying the most likely scenario from countless others, achieved through numerous iterations.
To arrive at the specific number, the simulation had to include such factors as natural and accidental deaths, potential infertility, inbreeding (likely to occur at the beginning stages of the journey) and the chances of conception.
Sustaining the crew indefinitely wouldn’t be easy, though, as it would have to involve a number of carefully selected measures of social engineering, such as annual evaluation of the vessel population, offspring restrictions and breeding constraints.
In the future, the authors plan to make their calculations even more robust by controlling for random mutations, genetic drift and other biological factors.
Meanwhile, astronomers disagree over the habitability of Proxima Centauri b, given the occasional flaring events which can increase the brightness of the star by as many as 1,000 times in only 10 seconds, which would require the planet to have a powerful magnetic field and a dense atmosphere – just like our own home planet.