There's no way with current and near-term technology that a group of 10,000 people on Mars could survive for a few hundred years and come back to re-populate Earth. That size colony is not large enough to sustain a high-tech industrial base.As soon as the spare parts ran out, the life support systems would fail and everyone would die.
There's no way with current and near-term technology that a group of 10,000 people on Mars could survive for a few hundred years and come back to re-populate Earth. That size colony is not large enough to sustain a high-tech industrial base.As soon as the spare parts ran out, the life support systems would fail and everyone would die.]/b]
12/ Because source will be defense budget and the goal will assure continuity of USA, I think Congress will be OK to approve it.
Quote from: ChrisWilson68 on 03/21/2018 05:40 amThere's no way with current and near-term technology that a group of 10,000 people on Mars could survive for a few hundred years and come back to re-populate Earth. That size colony is not large enough to sustain a high-tech industrial base.As soon as the spare parts ran out, the life support systems would fail and everyone would die.Tech aside, the population needed to maintain genetic diversity is known as the Minimum Viable Population, and for humans it was estimated by Traill et al. to be about 4,169. Or thereabouts.We've come close before, one being an alleged genetic bottleneck about 50-70,000 years ago, the population declining to about 10,000 individuals.
Quote from: ChrisWilson68 on 03/21/2018 05:40 amThere's no way with current and near-term technology that a group of 10,000 people on Mars could survive for a few hundred years and come back to re-populate Earth. That size colony is not large enough to sustain a high-tech industrial base.As soon as the spare parts ran out, the life support systems would fail and everyone would die.]/b]I think that end result is model dependent. If a single settlement is established and the supplies sent from Earth are uniquely manufacturable on Earth, and the people sent are simply users of the equipment, then you are correct... no matter how large the population. This is the ISS model.On the other hand, if a self-sufficiency model is established from the beginning, the infrastructure to build critical items on Mars is delivered (along with early supplies) and the components of the equipment are specifically designed to be manufacturable on Mars, then a different outcome becomes possible at some point. A second aspect of this model is that technicians would be a significant part of the early population sent there, not just operators and users of stuff. In this model, industrial laser printers and shop tooling will be delivered to build spare parts (and developmental/prototyping parts) and the equipment/spare parts sent will have been built by equivalent machines.We have never attempted such a model. As a more concrete example, batteries and solar cells will be needed by the hundreds of tonnes. All can be shipped from Earth, with unique-to-Earth fabrication detail. This is the first model. The alternative is to send equipment to find and process needed raw materials, fabricate the cells, and assemble the solar panels or batteries needed -- along with the early supply of finished product. One day, Mars could be independently producing all the solar power and storage devices they need. The latter approach is much more challenging at first, but opens the possibility of self-sustainment down the road. Agriculture and fertilizer manufacture is another example, propellant and the means to collect/process/etc. is another. Water collection, purification, and hydrolysis is probably one of the first needed to be self-sustaining.The number might not be 10,000, but whatever the number, the prospects of eventually becoming self-sustaining is completely model dependent.
If enough radiation is released or nuclear winter is bad enough to cause a mass extinction event, why go back to Earth? It will take thousands or even millions of years for the ecology to recover and it won't be the same.Expand the Mars settlement and build orbital settlements. Spread across the solar system.If the war or disaster collapsed civilization and left survivors, then the Mars Plan B can help rebuild civilization.
Quote from: raketa on 03/21/2018 03:46 am12/ Because source will be defense budget and the goal will assure continuity of USA, I think Congress will be OK to approve it.If congress has this kind of foresight, they would be funding BFR right now, not just for this wacky plan B, but for the obvious military application, a super cheap fully reusable SHLV would have. Since they are not doing this, the conclusion is they lack the foresight you're hoping for.
Its cheaper just to build and provision bunkers here on Earth for a subset of the population. Also has a higher chance of successfully being built and working should the need arise.
8/I think we could decide use 2% of Arms budget, to have a permanent contingent of 10k young people on Mars. In the case of earth devastation war, they will stay on Mars and in several hundred years come back to Earth and repopulated it.
Quote from: ChrisWilson68 on 03/21/2018 05:40 amThere's no way with current and near-term technology that a group of 10,000 people on Mars could survive for a few hundred years and come back to re-populate Earth. That size colony is not large enough to sustain a high-tech industrial base.As soon as the spare parts ran out, the life support systems would fail and everyone would die.]/b]I think that end result is model dependent.
On the other hand, if a self-sufficiency model is established from the beginning, the infrastructure to build critical items on Mars is delivered (along with early supplies) and the components of the equipment are specifically designed to be manufacturable on Mars, then a different outcome becomes possible at some point.