Search This Blog

Saturday, November 27, 2010

To Mars, by Conestoga Wagon

Several weeks ago I posted about Pete Worden at NASA Ames, and his announcement that the US would be revisiting the concept of the "100-year starship", or Project Orion. During the same announcement Worden also stated that NASA would be looking seriously into the "Mars to Stay" concept, which is to say, sending humans to Mars on a one-way trip. More on the merits and demerits of this concept in a minute. The first and most salient point is, these two projects are TWO SEPARATE PROJECTS. They have nothing to do with each other. Pillars of journalism and scholarship such as Fox News, the Daily Mail and Wikipedia have managed to conflate the two projects into a 100-year starship to Mars.

For the rocket scientists who look to Fox News, the Daily Mail or Wikipedia for information, please allow me to clarify.

Mars is not a star. It is a planet, somewhat like Earth. As planets go, Mars is pretty close to Earth. A currently existing chemical rocket such as the Saturn Vs which were used in the Apollo missions, using Hohmann Transfer Orbits (the "shortest" distance between to points orbiting the same body, in this case our sun) would get from Earth to Mars in about 214 days. A year on Earth is about 365 days, and a year on Mars is about 687 Earth days, so any way you slice it the trip to Mars is rather less than one year. Chemical rockets are the bottom baseline of speed for interplanetary voyages; every other propulsion system under consideration is faster, in some cases much, much faster.

To get from the Earth to Mars in 100 Earth years, you would have to average about 42 miles per hour.

If I were a bit skinnier and didn't insist on wearing so much protective gear and carrying so many books, I could do that on my 50cc scooter.


So, hopefully, we can dispense with the notion of a "100 year Starship to Mars".

That settled, what exactly is the idea behind a one-way trip to the red planet?

Setting aside for the time being the question of whether to build and launch a ship from Earth's surface, in orbit or on the moon, there are basically three ways of getting humans to Mars (alive).

The first is to do just what we did with the Apollo missions; take everything you need for the entire round trip with you. This is psychologically comfortable, but wildly impractical from the standpoint of serious exploration. None of the great expeditions on Earth would have succeeded without some degree of living off the land.

The second is to only take what you need to get there, and then make your fuel and water for your return trip while on Mars. This is called "Mars Direct", which I will be posting about in-depth at a later date.

The third option is to take everything you need for a one-way trip, plus everything you need to begin permanently colonizing Mars. This is the option Pete Worden was talking about. And because Pete Worden is talking about it, it would seem that this is the method NASA is most seriously considering.
I've seen a lot of ink (or bandwidth) spent in the weeks since Worden's announcement criticizing the idea of sending people to Mars with the intention of stranding them there. I have to say, I'm not sure I understand what the fuss is about. When the first European settlers crossed the Rockies in covered wagons heading west, they did not seriously imagine that they would ever see Boston again. It happens that due to the subsequent building of the transcontinental railroad some of the early pioneers were able to return east, and some analogue of this may prove true for our first martian settlers. Or, it may not. But I cannot imagine that on a planet nearing 7 billion people that we can't find a handful who would be more than happy to head to Mars (or Europa) with only their families and such possessions as they could stow in a backpack. The life they would find on an alien and hostile world would be more grueling than the most inhospitable climates on Earth. Prudhoe Bay or Death Valley would both seem like a tropical paradise by comparison. Some of the settlers would die. And some of the settlers would live, and have children, and build a life for themselves in this new wilderness.

Another thing Pete Worden mentioned was the possibility of genetically engineering the settlers to be better adapted to the environments they would settle. This makes sense. It is far easier to adapt an organism to a new environment than it is to adapt the environment to the organism, even though that's not the way modern humans typically do it. Frankly, even if we don't engineer our settlers' genes, Mars will engineer them for us via natural selection.

Yes, this means that some of your descendants will not live on Earth at any point in their lives. And, because they live on another world, they won't look like you, or me. That's okay.

The meek will inherit the earth. The rest, eventually, will inherit the stars.

3 comments:

  1. Reading your Posts has got me thinking about all this rather long distance travel. However the fact that our descendants "because they live in another world" will be different from us. But people here have looked the same for thousands of years. How will the generic markers change because they live in another world. Another point one can just imagine the religions going ballistic over the non-return policy volunteers or no volunteers. Somehow do not envision this happening for this century - but who knows?
    Good Watch.

    ReplyDelete
  2. Should that be 'genetic markers'? Whatever!!
    Good Watch.

    ReplyDelete
  3. The extraterrestrial environments we are most likely to end up attempting to colonize this century are very, very harsh. Far more harsh than the very most extreme environments on the earth's surface. We will either adapt as a species to these new environments, or we will fail to colonize them.

    For example, if we were to colonize the oceans below Europa's ice, we may benefit from additional fat and fur as other mammals which have adapted to icy waters have; if Europa's oceans turn out to have sufficient dissolved oxygen, gills might also be beneficial.
    Mars is very cold and its atmosphere very thin. Our current bodies cannot tolerate exposure to it, but they may be engineered to that environment as well.

    For brief periods of exploration, we can rely on pressurized environmental suits such as were used in the Apollo missions. But for people living out their lives on an alien world, we will need simpler, more robust and biological solutions.

    Much more on this later..

    ReplyDelete