Nuclear Fuel For Superfast Interplanetary Travel

jdoire writes: "Using a thin metallic film of americium-242m, a rocket could reach Mars in only 2 weeks. This is made possible because the nuclear material could be used both as a source of energy and as a propellent material, making the engine very efficient and light weigth. Check ScienceDaily for the full story."

Comments

Re:I honestly don't care

[styopa]

I see that you have been reading Zubrin, he a very convincing man, I heard him speak at a Mars Society talk here on campus. Unfortunately there are several problems with just packing up and heading off to mar right now.

• As one of the other replys mentioned, it takes time to build spacecraft, especially one that is supposed to make a 9 month journey. And right now it would actually take longer than that because we are not in the proper alignment with mars for the shortest possible trip.
• It also takes money, and right now the government of the United States has this policy of supporting only ONE big science project. I am helping out with research in High Energy Physics, and everyone knows in that field knows that the ISS was choosen over another particle accelerator. Those were the two choices at the time.
• The level of technology is not suffecient.
  1. Currently the only reliable engines that we have are chemical fuel rockets. All of the other ideas out there whether it be plasma, solar sails, Hall-effect engines, etc... are either not ready, not properly tested, or have major problems that need to be sorted out. Plasma is one of the better ideas and it is years away. Solar sails have an interesting problem with a harmonic ripple effect on the edge of the sail which doesn't damp out in space and causes the sail to collapse. Most of the other engines would take extremely long amounts of time, like the Hall-effect. Although this nuclear engine sounds really nice, I seriously doubt that it has been properly tested.
  2. Also we really don't have a good way of protecting the travelers from the large amounts really nasty radiation that they will have to deal with. Not only will they have to worry about the radiation while enroute, but also while on the planet. Mars does not have a magnetosphere like Earth does, nor does it have a suffeciently thick atmosphere. Both of those things are why we don't have to worry too much about solar flares completely fscking us up. Currently the best way we have to deal with radiation is lead. It will be a real pain to get enough lead up into space to protect the astronouts. Frankly the last thing we need to have is our heros coming home completelyl sterile and then dieing of cancer shortly after returning.
  3. Living quarters are still being tested for the Mars direct plan. They have their tunafish can living quarters in Canada right now. They are always looking for help in testing it.
  
  
• As mentioned before we are not in position for shortest travel time to Mars. I forgot the exact number but it is either 12 or 20 years from now. If I remember correctly almost all of the figures that are given for enroute times are calculated assuming that the Earth and Mars are in proper alignment so as to give the shortest possible time.

I want to see us go to Mars, but I don't want us to rush it. I am sure that you have taken note to the backlash that NASA took when it lost several probes in a row. Those were unmanned and they got reamed big time. Imagine what the public would do if NASA lost six astronouts while enroute to or on Mars. Chances are good that NASA would either get axed or be so horribly crippled from budget cuts that it might as well be dead. Although the technology we have currently is capable of sending manned missions to Mars, we need to do more research and more testing and patience before we can achieve a SAFE mission to Mars. I am sure we will get there, and within my lifetime. Why, because it is one of NASA's priorities. Right now they are spending most of their budget on the ISS, as you know, which IS necessary. I personally believe that having a working space station is as necessary as sending someone to another planet. Once they are done with the ISS then they can move onto providing more time and funding to the Mars project.

Re:G force issue!

[mghiggins]

The G-force isn't that bad, actually.

brittanica.com tells me that the distance from Earth to Mars is between 56M km and 400M km, depending on the relative position of the orbits.

Assuming constant +ve accn for the first half of the journey and constant -ve accn for the second half, and a two-week journey in total, this means an acceleration of between 0.15 m/s^2 and 1.1 m/s^2.

Since 1g = 9.8 m/s^2, these accelerations are tiny, and you'd safely avoid being pureed.

Orbital Mechanics is not quite that simple....

[DG]

Your calculations would be great if you were flying from point A to point B in a straight line, but unfortunatately it's not that simple.

Firstly, you're moving about in Sol's gravity well, so you can't just point at Mars and pull the trigger. Instead, what you want to do is move into a higher (faster) orbit around the sun.

Secondly, Mars moves! :) So not only do you have to worry about the eccentrities of getting into a Solar orbit at Mars' distance, but you have to time the process such that Mars will be there when you arrive. Depending on the positions of Mars when you leave terrestial orbit, this can be non-trivial.

I Am Not An Orbital Mechanic, and perhaps someone who is could do the real math, but I think that the distance covered is far greater than you've assumed.

However, it seems to me that the accelerations involved are still not extreme. I may be wrong, but I think that a 1G acceleration gets you to Mars in ~ 2 weeks, taking orbital mechanics into account. 1G is a magic number, as it would simulate the gravity you're experiencing now - good for bone mass retention. :)

Re:Neat Idea

[Paul Dirac]

It's amazing what one neutron will do....

Am242: fuel to mars

Am241: Smoke detectors!

Paul_D

Neat Idea

[cluge]

The really neat thing about this is that it would allow us to make rescue attempts if something goes wrong. If something went wrong on a MOON mission, we would ahve left our astronauts out there to die. There would have been no way for use to rescue them. The president even had a speech written just in case. Starving to death or slowly running out of air doesn't sound like a good way to go.

If this can be made praticle (and lord knows getting americium is damn near impossible!) it make the possability of space exploration more inviting and less risky. The time to arrive at our destinations is greatly decreased and the saftey factor goes up. Just think, a trip to the moon could turn into a "three hour tour".

I for one hope they make it work.

Re:Just say no to Mars Direct

[plsander]

Sure, we can go to Mars in a year or two with Mars Direct... but consider:

Fourty some years ago there were several methods for getting to the moon under consideration - among them were:

• Assembly in Orbit -- building the infrastructure to dock sufficient resources together in earth orbit and from there go to the moon.
• "Moon Direct" -- a single rocket that could deliver two people to the moon. No in-space infrastructure needed, relativly cheap and fast.

We went with Moon Direct - and sent 12 (14 if you count Apollo 13) people to the moon. Since then nothing.

Perhaps if we had gone the other way, we would have built the space station in LEO first. Used it as a staging point for missions to the moon and been left with an easy jumping off point for further missions to the moon, mars, and beyond.

I fear that if Mars Direct is the way we get to mars, you will be able to count the missions to mars on the fingers of one hand.