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Our future, our universe, and other weighty topics

Tuesday, October 29, 2013

A New Space-based Plan to Minimize the Risk of Human Extinction

As discussed in my previous blog post Flavors of Doom: 11 Variations on the Apocalypse, mankind faces numerous risks to its survival. There is the threat of nuclear war, the threat of an asteroid collision, the threat of global warming, and the threat of a microbe that could wipe out all of us. There are also other more remote threats such as the threat that the Yellowstone volcano system may erupt in a way that might cover much of North American in ash, and leave human survival doubtful.

Many thinkers have long recognized that moving out into space offers a potential for lessening the risk that man may one day become extinct. The idea is that if we can create colonies in outer space, mankind will not have “all our eggs in one basket.” But discussion of space colonization tends to quickly become grandiose. People talk about colonizing a planet around another solar system (something that is very far in the future at best), or talk about terraforming Mars (which would take many decades). In this post I will take a very different approach. I will describe a new relatively low cost space-based plan to minimize the risk of human extinction, a plan that could be launched using only currently existing technology (with the possible addition of a few rather modest technical advances).

Recolonization Stations

At the heart of this plan is what I will call a recolonization station. A recolonization station is a space station that is capable of recolonizing planet Earth (re-establishing human life on it) after some disaster has wiped out all human life on it. About 30 people might live in each of these recolonization stations. A recolonization station might look something like the station depicted below. The flat gray surfaces are solar panels, which would provide energy for the station.

space station

This is mainly the classic ring-shaped design for a space station. The station is ring-shaped so that it can be rotated to produce artificial gravity for the people living in it, using simple centrifugal force. It requires no new technology to produce such an artificial gravity. Space station designers back way back in the 1950's realized that a simple ring-shaped space station would produce artificial gravity if it were rotated.

The main thing that is different about this space station are the three transport devices positioned at 3 points on the ring. These 3 devices are what I will call recolonization modules. Each recolonization module consists of a recolonization capsule designed to re-enter into the upper atmosphere, and a modest rocket unit designed to take the capsule from the space station to the upper atmosphere of the earth.

Ideally a recolonization station would be a closed system that would completely recycle all of its wastes, allowing the station to exist indefinitely with no need for new supplies sent from Earth. But something less than perfect recycling would probably be acceptable, because the station would probably still serve its purpose if it did not last independently for more than 50 years.

During any time in which human civilization was still fairly healthy on our planet, a recolonization station could be visited by spacecraft from Earth at intervals of once a year or once every two years, during missions that would restock its supplies and rotate its crew.

Handling a Threat of Human Extinction

In the case of a drastic decline of the human population, there might be no more resupply trips. Then the job of the recolonization station would be to survive as long as it could, sending its recolonization capsules only when there seemed to be no more human life (or very little human life) left on our planet. The recolonization station would need to have a good telescope capable of scanning the surface below for signs of human activity.

So, for example, here is one hypothetical timeline: a recolonization station is launched in 2030; it receives annual supply visits for 20 years until 2050; in 2050, a biological plague starts to wipe out mankind; after 30 years all humans are dead; then in 2085 the recolonization station (which existed independently for 35 years without being resupplied) finally decides there is no sign of human life below, and then launches its three recolonization capsules in an attempt to recolonize Earth.

The recolonization station would work well under this type of “rapid human collapse” scenario, but might not work well under a scenario involving a very long and slow decline and extinction of mankind.

The station's requirement for success can be symbolically described like this:

L > T

where L is the maximum length of time that the recolonization station could exist with dozens of crew members without being resupplied, and T is the length of time between the last time the station is supplied, and the time when human life no longer exists on Earth.

Admittedly there are many hypothetical cases under which this L might not exceed this T, but there are many cases in which it would. As the recolonization stations are a relatively inexpensive form of survival insurance for mankind, we need not worry too much about the fact that they won't work in every scenario. As the saying goes, some insurance is better than no insurance.

Recolonizing Earth

The recolonization capsules would be launched from the recolonization station in the event that human life had perished on Earth. Each recolonization capsule might carry about ten human beings, along with tools, seeds, and equipment needed for those humans to survive and begin reproducing once they arrived on the planet. The capsules would use parachutes to make sure they touched down safely on land or water. The Soviet Union often had astronauts return to Earth in capsules that used parachutes to land gently on firm ground. The entire population of the recolonization station (about 30 people) would be transported back to Earth in the three recolonization capsules, at which point the recolonization station would be abandoned.

The astronauts riding in the recolonization capsules would need to be mainly young and female, to assure that the population of a newly established colony would grow as quickly as possible. An ideal average age would be only about 21 years, to allow for a maximum number of child-bearing years. Such a young population would be possible if certain measures were taken. One such measure would be rotating the crew in the recolonization station (prior to any disaster putting mankind in danger) to assure a young crew. Another such measure might be having the station crew (after some disaster that put mankind in danger) mate onboard the station to add new station crew members who could one day serve as earthly colonists by traveling down to Earth in the recolonization capsules. In the latter case, techniques might be used to assure a great likelihood of female offspring, as the recolonization capsules would need to be populated mostly by young females.

To assure the rapid growth of the newly established colony on the surface of Earth, it would probably be necessary to abandon conventional reproductive habits. There would probably initially be only two or three males among the recolonization capsule crew of ten. After adequate shelter was established, each man would probably need to quickly impregnate three or four consenting females, to assure that the colony started to grow quickly.

To assure adequate genetic variation in the new colony, it might also be necessary for the colony to make use of frozen sperm and possibly also frozen embryos brought with them in the recolonization capsule. Each recolonization station could initially be supplied with a repository of frozen sperm and frozen embryos, consisting of the genetic material of hundreds of carefully selected people. Such a genetic bank (which would not weigh very much) could be split up among the recolonization capsules, and used in the newly established colonies on Earth. This might require sophisticated medical training for the crew, and might require that some sophisticated medical equipment be included in the recolonization capsules. The technology for artificial insemination (and the implant of thawed frozen embryos) has been around for a long time, so this aspect would require no technical breakthrough.

Once they had landed, how could there be shelter for the crew members who landed somewhere on Earth in these recolonization capsules? They could start out by simply living in their capsule. Under most apocalyptic scenarios (such as the death of everyone on Earth because of global warming or a biological plague or a comet collision or a small asteroid collision or nuclear fallout or a super-volcano) there would still be many surviving human houses and buildings all over the globe. So the most likely way for the crew to acquire shelter would simply be to find a previously built building, and make use of that. Only the most extreme apocalyptic event (such as the collision of a giant asteroid which buries everything on the planet) would destroy all human buildings.

Each recolonization capsule would also carry with it electronic storage devices that would store a huge amount of useful technical information, as well as a huge number of cultural, historical, and artistic treasures in digital form. We can currently store the equivalent of a 20-volume encyclopedia (including all its pictures) on a single small disk. It would not add much weight to the recolonization capsules to have them include digital archives that included items such as the 1000 greatest books in digital form, the 1000 most useful books in digital form, the 100 greatest movies in digital form, and the 1000 most useful instructional videos on www.youtube.com. Such an archive would help insure that the recolonization capsules would be the seeds of communities that would become technically proficient relatively soon, without having to pass through centuries of “re-inventing the wheel” in a thousand different ways. 

The Relatively Low Cost and High Feasibility of This Plan

Perhaps the main attraction of the plan discussed here is its low cost (compared to other space-based plans), and the fact that it requires few or no technical breakthroughs. The plan could be put in place for a small fraction of the cost of colonizing the moon or terraforming Mars. We already know how to build space stations. Although the International Space Station currently in existence does not have a ring shape that allows for artificial gravity, it would require no big technical leap to construct a station that had such a shape. The technology for re-entry capsules that land with parachutes has been around for decades, and we also have had reproductive technology using frozen embryos and artificial insemination for decades. Probably the one technical advance needed for this plan is additional closed-system and resource recycling technology, which would allow a recolonization station to exist for a few decades independently. But that would be a relatively easy hurdle to jump.

As for the cost of the plan, assuming a somewhat lower cost of space flight because of recent launch vehicle advances, I estimate that several recolonization stations could be built and maintained for an annual cost of about 100 billion dollars (which would need to be shared by the world community). That's a significant cost, but not much of a price tag for helping to insure the continuation of a civilization which has a current net worth estimated at 223 trillion dollars. Any insurance agent will tell you that an insurance rate of a tenth of one percent is a huge bargain (by comparison, homeowners routinely pay an annual charge of about 1 percent for homeowner's insurance).

As for when such a project should be launched, the answer would seem to be: the sooner, the better. If various types of apocalyptic threats were to suddenly arise, it might be too late to get started on recolonization stations that might take 20 years to implement. The safest situation would be to have some recolonization stations already in existence, ready to respond to any existential threat to humanity that rapidly developed.