CS272 – Tech A

A key question when proposing a mission to Mars is the notion of coming home to Earth. This notion would not be viable with the resources available on Earth, such that the amount of fuel required for a round trip to Mars would be very hard to handle for such a long distance. Thus, the only feasible option for such a return would be to find or manufacture the fuel for the home trip while on Mars. With articles discussing the technologies and resources for fuel on Mars, it seems like this will be the way to go when planning a Mars trip, and making it not just a one-way grave for astronauts.  There are two major possible options for the creation of fuel on Mars. One using the Martian atmosphere, and the other using nuclear elements found on the planet’s surface.

While the Martian atmosphere is quite different from our own (not to mention much thinner),  and is mostly comprised of carbon dioxide (CO2). There are two different methods that fuel can be produced by this. One is the electrolysis of the CO2 into carbon monoxide (CO) and oxygen (O2). The carbon monoxide is used as a fuel and the oxygen could be used elsewhere. This is a fairly simple method of making fuel with only the elements of the atmosphere. The other method would be to create a Sabatier reaction, “reaction of hydrogen with carbon dioxide at elevated temperatures and pressures in the presence of a nickel catalyst” (“Sabatier Reaction”, Wikipedia), which would output methane (CH4) and water (H2O). This method seems to be a little more involved but also produces water in the end, which is crucial for sustaining life on Mars. One rover, from a proposed NASA mission, was designed to used the first method to create a “self-refueling hopper” to sustain itself on the planet. I believe that this could be the method to get home from Mars.

The nuclear option for harnessing fuel on Mars would be through its rich Thorium (Th) deposits. “Any cubic meter of Earth, Moon or Mars has enough Th-232 to run a profligate American’s energy life for several years” (Alexander Cannara, IEEE Life Member). There are also detailed maps of the Martian surface noting the Thorium density in parts per million. Thus the quantity of the Thorium cannot be disputed, unlike the method required to create a nuclear reaction with it. Thorium is not inherently fissile, meaning it cannot start or sustain a nuclear reaction. It would require some “weapons-grade material” to start the reaction. This is something such as Plutonium-239 or Uranium-239, which we might have to bring with us from Earth. The unique part about this process is that Thorium will decay into Uranium-233 from the nuclear reaction which is a fissile material. Thus, once the Thorium decays to a certain point the external Plutonium and Uranium becomes unnecessary, and the process becomes self-sustaining. This would all be great in theory, and possibly even for fuel on Earth, but at the current time it seems that the technology is not there and much more complicated than methods using the Martian atmosphere.

In the end I feel that using the CO2 from the atmosphere will prove to be the ideal way to fuel both living on Mars and the trip home, and the notion of it being a one-way trip should seem out of the question even with today’s technology.

Sources:

• http://www.lpi.usra.edu/meetings/robomars/pdf/6098.pdf
• http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1559325
• http://www.geoffreylandis.com/propellant.html
• http://spectrum.ieee.org/tech-talk/energy/nuclear/is-thorium-the-nuclear-fuel-of-the-future
• http://energyfromthorium.com/forum/viewtopic.php?f=6&t=759
• http://www.ieer.org/fctsheet/thorium2009factsheet.pdf

Even if humans are able to make it to Mars there are still many unanswered questions. The most controversial issue that arises with a mission to Mars is the idea that it might have to be a one-way mission. The United States already possesses the beginnings of the needed technology to send man to Mars; we have already sent robots there. However, in the case of a manned mission, that is only half of the issue. Once an astronaut’s time on Mars is complete how are they supposed to get home? Since the actual spacecraft that carries man to Mars will need to be small, there is no viable way to launch from the surface of Mars with significant force to send it back to Earth. Even if it was decided to send a larger spacecraft to Mars in an attempt to allow for a launch off of the surface, the price would be astronomically large.

This issue has put a major damper on the whole prospect of manned Mars exploration. However, many scientists have argued that sending one man on a one-way mission to Mars would be the best solution. Critics of this idea state that this mission would indeed be a suicide mission and funding for such missions should be cut immediately. Many proponents of this idea argue that this would not be a suicide mission at all; it would be more a “lone-wolf” mission in which all of human civilization would be watching one man set foot on the moon. Still, many view this as an unacceptable mission.

In order to please all those opposed to this notion of a suicide mission, many have argued that the one-way mission of a single man would only be the beginning of many more to come. Many scenarios have been revealed that seems to solve many of the issues. One such scenario consists of sending a single man to Mars to begin setting up the beginnings of a colony. 26 month later (this is the window for launching Mars missions based on orbital physics) another spacecraft would be sent to Mars containing another individual to help with the construction of a biosphere. So the idea is that there will be only one person there for a short period of time. This pattern would continue until the technology existed to send multiple people per spacecraft to Mars.

Another scenario builds off of the above. In this situation, a man and a woman of reproductive age would be sent to Mars together. The idea is that they will create an “Adam and Eve” situation and create the beginnings of a civilization in Mars. Some years later, another “couple” will be sent to Mars to aide in the population of Mars.

Yet another scenario that combines the above is one in which many individuals would be sent to Mars in either single-manned missions or multiple-manned missions and create a population of roughly 150 people. This should allow for a significantly diverse gene pool and the population of Mars would grow quickly and diversely.

The ultimate goal in all of these situations is to find a way to populate Mars and create a livable colony on the Red Planet by using the least amount of money. By sending humans on a one-way mission, the need to launching from Mars is eliminated and instead of trying to cram enough supplies in a small ship to launch from Mars, we can provide the travelers with more supplies they might need on the Red Planet.

The simplest and most cost-efficient way of populating Mars is a series of one-way manned missions. It is up to each individual to determine if they believe these missions are suicide missions or “lone-wolf” exploration.

Sources:

http://www.universetoday.com/13037/a-one-way-one-person-mission-to-mars/

http://www.wired.co.uk/news/archive/2010-10/20/the-case-for-a-one-way-manned-mission-to-mars

http://www.huliq.com/8738/nasa-contemplates-manned-mission-mars-one-way

http://cosmiclog.msnbc.msn.com/_news/2010/10/18/5312576-going-to-mars-on-a-one-way-trip

http://www.mobilemag.com/2010/02/25/nasa-to-send-man-to-mars/