New Mars Forums

Let's talk about the power source for these Martian trains.

I am pretty sure future Martians will be quite pro-nuclear and all, but I still don't think they would prefer to power their land vehicles with a nuclear reactor like Robs mentioned.  The idea of beaming the power from the lead car to other cars with microwaves is possible but just sounds to inefficient. I'm no expert on these matters, but I don't think I'd like to be playing cards in a vehicle while it was being bombarded by not only nuclear radiation but also microwave energy.

I say keep the nuclear reactors back at the bases and use them to produce chemical propellants for the land vehicles.

Here's an interesting fuel that would work for a Martian train:  Silane.  Methane, Ethylene, Hydrogen, and most all other fuels burn in oxygen, so you'll have to store the oxygen (about 75% of the propellant weight) on the vehicle in tanks.  Silane, on the other hand, burns in carbon dioxide.  You can get it from the air as you travel.  It is liquid but produces solid exhaust, so it is no good for internal combustion.  But, it would work great to heat the boiler of a steam locomotive.

With steam locomotives all we need now are some bionic horses with people riding them wearing cowboy marsuits and we'd have a good martian western. :;):

Silane (SiH4) can be produced locally as silicon (Si) makes up most of the regolith all over Mars.

The only thing I don't know is how expensive it would be to produce.

Since this seems to show that life and intelligence are rare in the universe or rather that this universe with life is a rare universe, it makes me think that it was not all by chance.  Every new discovery confirms my belief that there is a creator.

Hey I'm all for nuclear power, but personally I wouldn't want to drive around with radiation leaking through the back seat.  I haven't studied nuclear powered rovers too much, so I might not know what I'm talking about.  I just think you would have too much of a problem with radiation shielding.  I mean you already have to be concerned about the cosmic radiation and occasional solar flares -- the Martian atmosphere blocks some but not all of it.  Why would you want more radiation coming from your own vehicle?

     "Nuclear power or fuel cells are the logical power plants..."

What about internal combustion?  Fuel cells are nice but combustion is much more powerful -- something like 50 times more power per kg.  Why do engineers that make things for space automatically discount "old technology"?  For example:  if you had two bases a couple hundred miles apart you could lay some rail between them and use a silane powered steam locomotive.  Silane burns in CO2.  Old technology isn't cool but it works.

Well, I was going to compliment you, Earthfirst, on your spelling and grammer, but near the end you kind of lost focus.  Hey, at least I know you can spell and speak correctly if you want to. :;):

As for your arguments - the only thing that struck me was a lot of name calling.

I'm not a Green Peace activist.  I am an environmentalist, though.  One thing I find strange is how some people think that to save the environment you have to sacrifice people.  You know, we could all coexist nicely if we just gave it a try.

Algol,

    "However the tether idea does fill me with unease due to possible complications involving letting the tether out and being seperated from your engine, as well as the stopping it all at the end."

I know the Mars Direct plan by heart.  'The Case for Mars' is my favorite book.  I've read/studied it five to ten times.  So trust me when I say your unease is unfounded.  First, the counterweight at the other end of the tether is just the burnt out upper stage that threw you to Mars.  It has no fuel and is useless except as dead weight.  Your engines for orbit correction and landing are on the Hab itself.  Second, to stop the rotation and get ready for Mars aerocapture all you have to do is cut the line.  The counterweight will fly off and the rotation will stop.

The tether system is extremely simple, but if for some unexpected reason the counterweight can just be cut off and the mission can continue in zero-g.  I suggest testing the tether on the first ERV that is sent out 2 years before the first manned mission.  That will help work out any bugs.  With the manned mission I say hope for the best and prepare for the worst.  Try the tether and if something goes wrong and you have to cut it just use the excersize equipment that you brought along as a backup.

I'm an American, but I'm not proud to be an American.  What did I do?  I just had the luck to be born here.  I am GREATFUL to be an American, but not proud.

Now who should be proud to be American?  How about people that have actually done something to create America or people that have done something to get here?  These are the people who can be proud:

Immigrants who have suffered hardship to come here.
Those that fought in the Revolutionary War.
Civil rights activists.
Womens suffrage activists.
Abolishonists.

This is the kind of people that can be proud.  But are/were they proud?  I don't think so.  I would bet they were humble.

I agree dicktice.

I can't remember anything worthwhile from PaganToris either.  I wish he would at least type well.  Maybe he could use a little grammer sometime as well.

Pagan,

Come on man!  Give us something we want to read.

I'll take a shot at your chicken eg question Bill.

A Mars colony or at least a base will be built before an elevator.  Why, because it will use proven technology.  We have sent probes to Mars with rockets before, so we can build bigger ones and send people.  Banks and politicians can both understand that so the funding will be more readily available.

Transportation to Mars with rockets will cost in the millions.  Let's say you can build a 100 tonne capacity Earth to Mars vehicle for a billion dollars.  That would cost $10 million per tonne.  Once an elevator is built you don't have to get the cost into the thousands you just have to beat the $10 million dollar price.  If say you offer your elevator services at 1 million dollars per tonne, any government/company sending explorers to Mars will jump all over it.  You will be the exclusive transportation provider to Mars.

gotta go...I'll be back.

Well,

You guys sure are busy!  Five pages in just one day!

Anyway, I'm all for the elevator.  I'm sure the demand will increase when it is built - especially if there is a colony on Mars to go to.

Just got a few questions and suggestions:

1.  What do we do about all the space junk floating around between LEO and GEO?

2.  Why would we beam power from a SPS to Earth with microwaves if we can just string a cable down the elevator?  As I understand about 50% of the power is lost in the atmosphere with a microwave system.

3.  I just don't see the point of using disposable capsules if you can bring them down on the elevator.  Remember, most of them will be empty so you won't loose capacity at a one to one ratio.

4.  I'd make the Elevator with two ribbons up to GEO for up and down travel, then one extra long ribbon extending out from GEO to slingshot vehicles out to Earth/Mars cyclers, Saturn, or whatever.

5.  How fast could a vehicle go if you put it in the slingshot ribbon and just let the sucker go - no brakes?

6.  How fast would you get loads to GEO if you had a constant excelleration - say 1.5 gs all the way there?

Welcome Trevor,

Animals could exist anywhere that people could exist.  If they had to be in a cage they could just be under the dome or in the underground tunnels or whatever we build to live in.  You might want to make the cages pretty big though, they would be able to jump very high and would hit their heads alot in a small Earth-sized one.  :;):

Don't worry about the lunar dust - you're on Mars remember.  There is Martian dust, but if people can live there animals should be just fine.

If you are going to design a shuttle like system to replace the shuttle I would also be in favor of a spherical ejection capsule.  I suppose the OSP would have the same kind of launch abort system as in the Saturn V/Apollo system, right?

I just don't understand why some people insist on sending cargo and people together.  If I understand correctly the Buran had the same capabilities as the shuttle but could be operated completely by remote control.  I think it actually flew into space twice with no crew.

I say stick with small ships for people and large unmanned vehicles for cargo.

I would definitely advocate using fusion to power the freighters, but I would still use a Hohmann transfer.  You will be able to move much more cargo.  They say time is money, but a few months savings probably won't outweigh the extra cargo you can carry with a slower trajectory.

If you're moving colonists to Mars I'd still suggest the six month trip because you can move many more people and it will cost less per person.  A long boring one way trip for a colonist will be forgotten after living decades on Mars.

I would only use a fast transit for executives, politicians, rich turists, etc. who wouldn't be staying at their destination for the rest of their life.