One of the big questions about the direction for our space program is why Mars?

Mars is actually a pretty good colonization target.

Ideal Gravity

Mars has about 1/3 the gravity of Earth.  This is enough so that humans who have shown severe health problems developing from too low gravity may be able to thrive.  We will have to see if a partial gravity of 1/3 Earth’s is enough to keep the joints, ligaments, muscles sufficiently engaged so they don’t become permanently damaged.  We will have to study the impact of Mars gravity on reproduction.

One-third Earth gravity makes it vastly cheaper and easier to escape its gravity well.   About 1/27th the energy is required to lift a weight into space from Mars’s gravity and a substantially lower escape velocity makes it easier for Mars to be a stopping point for us.

We can land supplies with considerably less thrust.  We can send return vehicles back to Earth much easier because Mars is also uphill from the Earth in the Solar System.  Coming back towards the sun is easier than going out to Mars.   Asteroid mining operations could use Mars as a waypoint to drop off for processing, gain supplies to make it to the asteroids cheaper.  We could run refueling ferries from Mars.

Fuel Supply Easily Available

Another really fabulous thing about Mars is that there is copious supplies of CO2, water and other materials that can be used to manufacture methane.

Virtually all missions to Mars plan to include methane production as part of the plan.  This is because spacecraft which will land on Mars doesn’t have to carry any fuel for the return voyage.  All of it can be manufactured easily on Mars either before the spacecraft gets there by robots or prior missions or by the mission when they get to Mars.

The availability of plentiful fuel also means that Mars can be used as a waypoint in missions to other planets or even to outside the solar system if we ever do this.

Materials Available to Eventually Terraform Mars

Mars contains at the poles enough CO2 and Water that we could eventually fill an atmosphere to comparable Earth density and temperature.

It has been known for a long time that Mars once had an Earth-like atmosphere.  Some of it has blown away into space but a lot of it is simply frozen or underground.   We do not know exactly how much water is on Mars but we have estimates from the poles alone that we could cover the entire surface area of Mars with 6 meters of water.  Of course, since Mars is varied in terrain if all the water was melted from the poles it would create rivers,  lakes, and oceans like on Earth.

It is only necessary to get to about 20% of the pressure of Earth’s atmosphere for humans to be able to operate fairly freely on the surface.  An atmosphere of this density would also allow for much more reasonable temperatures.  It would still be impossible to breathe without some assistance and to keep warm enough without significant protection but immediate loss of life could be avoided and some other living things may find it quite suitable to live on the surface within these constraints.

Terraforming is a long-term goal and not something that any colony could accomplish in the first 10 years or 20 years but it is important to note that it is possible on Mars.  Other planets or objects in our solar system do not have this capability except for very few moons and these are much more distant from the Earth.

Solutions to Radiation Exposure Problem

There may be some easy solutions to the radiation exposure problem.  Essentially living on Mars would expose people to dramatically higher levels of radiation of all types and to very dangerous special solar events which could injure you permanently from one incident.

There are several avenues of protection.  One is using the soil of the planet itself. 15 feet of soil produces about the same amount of protection as Earth.  It makes sense that a lot of habitats on Mars would be underground.

It will be necessary for colonists to spend at least 2/3 of the day in highly protected environments.  8 hours a day of relatively unprotected exposure to ambient radiation with only minimal protection would produce about 2-3 times the lifetime expected radiation on Earth.  It is thought that this is an acceptable level.

Other solutions are available.

Using a project already demonstrated in Europe we can fully protect people in transit to Mars using an artificial magnetic field created by superconducting magnets.  Such a system could be used on Mars as well to create overground areas with protected areas that could be essentially like Earth with windows and no special materials.

There are materials that can shield from radiation dramatically.  Simple plastic is somewhat effective as a radiation shield.  Plastic (Polyethylene) could line clothing, all walls and windows, etc of Mars habitats and living could be used to make the requirements for spending so much time protected much less.  We may develop even better materials.  It is noteworthy that polyethylene like methane would be trivial to produce on Mars from indigenous supplies.

There is another option which is even more exciting and may be possible.   It has been shown that if we could place a significant but not that difficult electromagnetic field in space in front of Mars orbital path around the sun we could effectively perform the same function as the Earth’s magnetic field.  This is actually practical and doing it would eliminate almost all of the problems above.

There is no doubt that we will need to do all of the above for a colony but it is good to know there are reasons why Mars is a good candidate.  It may be possible to eliminate the radiation problem but there is also other ways to produce acceptable radiation exposure without breaking the bank.

Energy

It is assumed that we would have solar arrays on Mars.   The lack of storms, clouds means that these arrays will be very productive but they produce about 1/2 the energy they do on Earth due to less intensity due to the distance from the Sun compared to the Easrth.  Nonetheless, it should be reliatively easy and dependeable to use solar energy for a lot of energy.

Solar has problems though because it is heavy to transport and we would need a lot to keep a colony of significant size in operation.  Also, solar cells are complicated not easily produced on Mars so it would be difficult for some time for Mars to become self-sufficient in producing them.

Occasionally sandstorms last for weeks even months on Mars.  This implies we would also need large storage of Energy and probably the second source.  We’ve already mentioned the ability to produce methane easily.  There could certainly be some backup methane generators.  However, another approach has come about recently.

NASA has announced a nuclear option.  A 10kw reactor that would nominally last for 10-20 years would produce a massive amount of energy and several of these units are lighter than solar panels and batteries.   I expect we will have all 3 forms of energy in any colony.  Nuclear which could last a long time and be extremely reliable.   Solar for the main energy requirements and Methane as a backup if some serious issues arise.

Potential Habitats and incredible natural environment

If we are able to solve the problems of radiation exposure then many more options for habitation become possible.  Mars is a fascinating planet with a varied geography.  Tall mountains taller than on Earth.  Deep crevices deeper than the deepest ocean on Earth.  Holes and various regions with different characteristics because of Mars history lends to the idea that lviing on Mars might not be as dreary as some think.

Some have suggested that initial colonies will have to find places in holes that we can find.  That was we don’t have to dig our own holes to put habitats.  We can also use the canyons and caldera to form natural shielded formations that can be sealed with much less material.

Other Resources to build sustainable colony

Mars has a plethora of chemicals.  We will have to explore to find them but like Earth, we may find virtually all the elements we need there to build a sustainable colony.

Proximity to Earth

An obvious but important point is that Mars is closer to the Earth than any other planet going outward from the Sun.   This makes the trip for communication feasible.  (2-4 minutes each way depending on the point in our orbit.  This is not good enough to control some robot for instance in real time but it is possible to have a back and forth conversation over a period.

It is close enough to be practical for us to travel there with significant mass from the Earth.  I estimate we will need to have 5-10 million kg of  materials of various types to bootstrap a colony on Mars.   This is practical in 100 reasonable missions from Earth.  Going to farther destinations would thus be much harder.

Summary

I believe we are at the cusp of the technology needed to endeavor on this goal.  To build a colony on Mars with the goal to eventually become self-sufficient or at least to very minimally depend on the Earth.

The reason this is possible is due to many very convenient facts about Mars.  Whether we are lucky or not it turns out Mars is a pretty good candidate to colonize.

It has a convenient gravity.  It has materials in quantity.  It may eventually be terraformed into a livable world without instant death from exposing yourself to the elements.  It is a very convenient and promising candidate for the human race to get a second redundant instance of ourselves.

Certainly, it seems like somebody is tempting us to try.  The fact Mars has these features is quite improbable as we can see just looking at our own solar system and what is available.  We are being lured out.  I hope we take the bait.

Please read some of my other Mars and Space blog entries to get my plan to go to Mars and why.

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