Space Elevators: Absolutely Crucial?

EarthWolf · 2004-08-08 19:48:18

Hello,

Is a space elevator absolutely crucial to the economic well-being of a potential Martian economy? I would think that the lower escape velocity would make off-Mars export practical. What's your thoughts?

Cordially,

EarthWolf

Martian Republic · 2004-08-08 20:50:07

Hello,
Is a space elevator absolutely crucial to the economic well-being of a potential Martian economy? I would think that the lower escape velocity would make off-Mars export practical. What's your thoughts?
Cordially,
EarthWolf

A space elevator is not absolutly necessary for the economic well being of the Martian economy, but it would defenetly help the Martian economy. Any time you can bring the cost down doing something in an economy, it will ultimately help improve the viability of that economy. Once the space elevator been built and paid for and we have a sufficient number of people using it with sufficiently large enough masses, it will potentially be the price of an air line ticket or possibly a train ticket.

Of course if we have fewer than a few hundred thousand people on Mars using the space elevator, it could be more expensive because your still going to have the maintaince cost and the cost to build that space elevator or possibly have enough people that could be put to the task to build it either.

???

Larry,

Grypd · 2004-08-09 04:43:17

From an economic and colonisation point both Mars and the Earth will need elevators it is the only reasonable way to keep costs down. With technology that we can envision for the future. Short of antigravity being developed we will be stuck with beanpoles.

Course with technology we have now we can start, but just not as cheap.

Omer Joel · 2004-08-13 14:40:42

As Grypd and Martian Republic have already said,
A space elevator will make Martian exportation to the rest of the solar system viable; Otherwise, the cost will be prohibitive. Most exports, I suppose, will be technological and agricultural products - mining would most likely be done on astroids.

And could an orbital elevator be built for Earth? one article I've read refers to the problems inherit to its annoyingly strong gravity field...

SpaceNut · 2004-08-13 20:30:29

So what is the base power system for such an elevator?

On the Moon such a modified system more like a rail gun or magnetic rail system cold be used to launch payloads to Earth or to mars.

Martian Republic · 2004-08-13 21:22:50

So what is the base power system for such an elevator?
On the Moon such a modified system more like a rail gun or magnetic rail system cold be used to launch payloads to Earth or to mars.

Electro-magnetic propulsion from the elevator as it goes up the space tower. It would be a variation of the super train idea, but going up and down instead of across land on a levitated rail system. So you would have to have put in place an electrical system it to generate the magnets and/or put permanent magnet in place to get your elevator to go up and down the tower.

I think it would be wise to put into the system a safety locking method encase of a power failure. You would want the elevator to come crashing down from space.

Larry,

dicktice · 2004-08-14 10:58:06

Other than an interesting thought problem, the space elevator idea is just a nonsensical waste of brain power better devoted to how to get out and back usefully to low-Earth orbit and beyond "within this decade"--as JFK might have proclaimed in today's circumstances.
Regarding KISS engineering for space, I would attach an additional pair of letters to the acronym: FS (for fail safe). A space elevator project can never satisfy the constraints imposed by KISS/FS, so why not drop it (whoops, sorry).

Gennaro · 2004-11-28 06:42:58

Where it's relatively easy to build a space elevator because gravity is low, like on Mars or some moon, you don't really need it.

When fusion powered SSTO's come on line we might not need space elevators on Earth either, but can instead rely on the flexibilty of numerous rocket ship flights.

John Creighton · 2004-11-28 13:05:39

An amount of mass up the elevator per year that is equal to 10% of the mass of the space elevator. If the space elevator is made from space resources it may be economical for it to have a lower mass transfer rate. However, the question will always arise why not just make whatever we are shipping up in space? Do we have enough demand for things that cannot be made without shipping stuff off a planet to justify the cost of the elevator. For space elevators Mars may have an advantage if one of it moons is high in carbon.

RobS · 2004-11-28 13:34:49

The velocity to put something into Mars orbit from the surface is about 4 kilometers per second or 8,000 miles per hour. In contrast, it takes 22,000 miles per hour to put something into Earth orbit (4500 mph to get it up to orbital altitude and overcome air friction, plus 17,500 mph minimum orbital velocity). In contrast, Spaceship 1 achieved 5,000 mph. The exhaust velocity of methane/oxygen is 3.8 kilometers per second or 8,000 mph; hydrogen/oxygen is 4.5 km/sec or 10,000 mph.

So as you can see, a simple single-stage to orbit spacecraft can rather easily be built for use on Mars. Getting stuff to low Mars orbit from the surface is relatively simple.

Phobos and Deimos are a lot higher than low Mars orbit, but fuel made on them can be partially aerobraked down to a low orbit refueling station, so a shuttle with cargo in low orbit could refuel to continue up; to the moons, to Earth (about 6,000 mph from low Mars orbit) the asteroid belt, etc.

So I think chemical rockets can be pretty effective and cheap for transportation to and from Mars. It might be a long time before an elevator is cheaper, and the elevator will have to avoid the two moons.

-- RobS

John Creighton · 2004-11-28 13:35:25

When fusion powered SSTO's come on line we might not need space elevators on Earth either, but can instead rely on the flexibility of numerous rocket ship flights.

Agreed, this is the real secret of a space faring nation. Lots and lots of energy. Everything else is secondary.

srmeaney · 2005-07-21 11:21:23

Space elevators have their flaws. Singular location for movement of goods being one of them. If a colonist must move a load around the planet just to launch into orbit, then the concept is a fail. You would be better off with an orbital hook designed to retrieve goods moving on an equatorial rail way...

New Mars Forums

Announcement

#1 2004-08-08 19:48:18

Re: Space Elevators: Absolutely Crucial?

#2 2004-08-08 20:50:07

Re: Space Elevators: Absolutely Crucial?

#3 2004-08-09 04:43:17

Re: Space Elevators: Absolutely Crucial?

#4 2004-08-13 14:40:42

Re: Space Elevators: Absolutely Crucial?

#5 2004-08-13 20:30:29

Re: Space Elevators: Absolutely Crucial?

#6 2004-08-13 21:22:50

Re: Space Elevators: Absolutely Crucial?

#7 2004-08-14 10:58:06

Re: Space Elevators: Absolutely Crucial?

#8 2004-11-28 06:42:58

Re: Space Elevators: Absolutely Crucial?

#9 2004-11-28 13:05:39

Re: Space Elevators: Absolutely Crucial?

#10 2004-11-28 13:34:49

Re: Space Elevators: Absolutely Crucial?

#11 2004-11-28 13:35:25

Re: Space Elevators: Absolutely Crucial?

#12 2005-07-21 11:21:23

Re: Space Elevators: Absolutely Crucial?

Board footer