Routine launches to LMO - Volcano slope maglev launching ramps

dicktice · 2002-11-18 19:18:23

Having tried and failed to locate any proposals of systems for launching spacecraft routinely up to Low Mars Orbit, and noticing the location of the three Tharsis volcanos in the vicinity of the equator, I came to the conclusion that they might be ideal for supporting magnetic levitation, electromagnetic acceleration ramps. Given the heights of these peaks, which apparently penetrate the densest atmosphere, it might even be possible to gain LEO by launching eastward, without 2nd-stage boost! (I could be wrong.)
Olympus Mons, somewhat north of the equator, would appear to be ideal for polar orbits, being higher and having longer slopes for additional acceleration required without the planet's rotational assist.
I am not in favour of a "space elevator" on Mars, which would sacrifice Phobos and Deimos because they would get in the way. (They should be valuable as, eg. habitats, observatory platforms, freight and consumables depots....) Vocano acceleration launch-ramps would avoid the necessity of doing away with them, as well as provide ramps for mass-drivers of raw materials.

nebob2 · 2002-11-18 20:02:12

For rutine flights to LMO I would use compressed CO2 fueled NTR "shuttles". Fueling time is restained only by power constraints, it requires 84kWh to compress 1 ton of Martian atmosphere, so each shuttle could fly every couple of days if hooked up to a ground power source.

Tyr · 2002-11-26 07:44:42

Both ideas sound good to me. In his book,"The Millenial Project," M.Savage mentions using a mass driver on Pavonis Mons because it is just about on the equator. That mass driver could tak a while to build. NTR rockets using CO2 or H2O which seems to be very aboundant on Mars based on Mars Odyssey results, would be an excellent way to get exports from Mars going.

dicktice · 2002-11-26 14:11:57

Well, that's a relief! We've figured out a couple of ways of getting off the planet routinely...so the problem of how to get there in the first place routinely is pretty much all that's left, right? Let's see, now....

MarsGuy2012 · 2003-04-10 22:46:45

You could have your space elevator and keep the moons too, if you just oscilate it. Over its thousands of kilometers of length a little vibration of a few hundred kilometers won't be that hard to produce. If your going to use the moons for refueling or other industrial applications, I would suggest moving them into an aerostationary orbit above Pavonis Mons and extending the cable from them. You could use the moon material for the cable too. (once we figure out what to build it with.)

Shaun Barrett · 2003-04-11 01:28:59

I suppose if you have the ability to shift Phobos out to an altitude of 17000kms, you should be able to nudge its present orbit just sufficiently to make encounters with the elevator cable very rare.
Calculations could be done to find out almost exactly when the next encounter was due and you could simply nudge Phobos into yet another orbit as the need arose.
Such nudges may prove to be necessary only every century or so - probably easier than having the cable oscillating backwards and forwards to avoid impacts. Besides, flexing the cable too many times could eventually cause fatigue - if not in the carbon filaments themselves, then perhaps in the rails and cables attached.

Just a thought.

dicktice · 2003-04-11 07:42:33

Geeze, you guys ... I thought we'd disposed of the elevator, at least in the near term. Now, you're back at it again!
MarsGuy: Oscillate the Mars Space Elevator? How to keep it from oscillating would be the problem, not to touch on synchronizing it to avoid Phobos and Deimos--aptly named, I seem to remember: Greek, for Fear and Terror, or something like that. That's how you'd feel, riding the damn thing, anyway. Moving them (both?) to geostationary orbit, would take more effort energywise, and take such a long time to accomplish, I imagine, that mountain launch ramps used to support the programme would have by that time become so routine as to have made the elevator redundant. Come on--let's get on with the problems of getting Mars Direct "off the ground."
Shaun: One "rare encounter" would be sufficient. To "simply nudge" Phobos (forgetting Diemos) into another orbit, with the space elevator at stake? If, more likely when, that thing comes down...! You're not serious obviously, from your comment regarding bending fatigue, so what the hell ... having a little fun at MarsGuy's expense, right?

soph · 2003-04-11 15:31:29

dicktice, you factored out the space elevator, Highlift is actually picking up steam very well. And so are other ocean based companies, like Sea Launch.

The cable would weigh virtually nothing. CNT is ridiculously light, strong, and thin. If the cable were hit, it could easily be replaced. The base is the real cost, and that doesn't just come down.

But mountain launches making the elevator redundant? The elevator could be used to bring its payload capsules back down, and send them back up, for $100/kg. There's no way vehicles that actually have to be launched will replace the elevator, more likely they will be used for different purposes (i.e. space elevator cargo, mountain and other launch types for people.)

Routine? The elevator would use lasers and capsules-you can launch every day or two, for the same $100/kg. Just load your capsule, and send up. Two elevators could get up to 1.4 kilotonnes to orbit a week for $140 million.

dicktice · 2003-04-11 17:11:22

What happens to the two Mars moons in your scenario, Soph?

soph · 2003-04-11 17:25:17

They should never hit the elevator. Both orbit at an angle of over a degree (at closest, .89 degrees) to the Martian equator. The elevator would be on the equator. They stay in their happy orbit.

Shaun Barrett · 2003-04-11 18:56:17

Hi Dicktice!
Yes, I was serious. No, I wasn't joking at anybody's expense. And yes, if anything I said was stupid, it was genuine, 100% guaranteed, homegrown stupidity!!

Your idea of using launch ramps up the sides of mountains is an excellent one. In fact, it may prove to be the only way to bring the cost of launches to LMO or LEO down to reasonable levels, using current technologies.

It may be a bit of a stretch to drag elevators into this thread, although you could classify regular transport up and down a 'beanstalk' as "Routine Launches". But elevator technology is really not that far away from present levels and should become feasible in the next decade or two. So I don't think it should be dismissed too lightly as an alternative to ramps.
You must admit, the sheer elegance of, say, half a dozen space elevators reaching up to geo(areo)synchronous orbit like the spindly spokes of a wagon wheel, with Mars or Earth as the hub, is breathtaking! The enormous tonnage of material we could "launch routinely" into high orbit, or even sling-shot off towards the other planets, would completely revolutionise our space exploration/exploitation capabilities.
I find it a mesmerising prospect - and I know Phobos does too! :;):

The concept of causing a deliberate oscillation of any Mars elevator, to avoid collisions with Phobos, was first postulated by Arthur C. Clarke (I believe but could be wrong) and was used by Kim Stanley Robinson in his Mars future-history trilogy.
I've always thought it was an awkward way to get around the possibility of a calamitous encounter, which is why I put forward the idea, above, of nudging Phobos into a 'safer' orbit instead.
I didn't forget Deimos in all this. Deimos is in a fairly circular orbit with an altitude of 23,000 kms. This is some 6,000 kms higher than areosynchronous orbit. This allows for plenty of 'cable' above the centre of gravity of the elevator, to enable sling-shot launches of payloads back to Earth or elsewhere, and room also for the counterweight which would be necessary, without any risk of a collision with Deimos. It's only Phobos we have to worry about.

But if ramps prove to be the way to go ... bring on the ramps!!

soph · 2003-04-11 19:37:23

Phobos is some 9,000 km up.

dicktice · 2003-04-12 09:07:31

They should never hit the elevator. Both orbit at an angle of over a degree (at closest, .89 degrees) to the Martian equator. The elevator would be on the equator. They stay in their happy orbit.

That's crazy, Soph: The orbits of both moons, regardless of what their respective orbital inclinations happen to be, cross the equitorial plane of Mars. So what you're proposing is a "roulette situation," and the inevitable payoff is ... ka-powee!

soph · 2003-04-12 09:17:31

Not according to the Smithsonian Book of Mars, dicktice.

Regardless, Phobos is 3,000 km above geosynchronous orbit.

dicktice · 2003-04-12 13:00:49

Soph: I really wanted to begin discussing practical deas for economical, alternative launch methods today--both from Mars and from Earth. But your Phobos comments have got me stumped ... so I took time to "google" the facts, just now, and guess what I came up with...?
The mean distance of Phobos from Mars is only 9,380 km, which is a lot lower than the geostationary orbital height (17,100 km).
Its orbital inclination (1-degree) causes Phobos to cross the plane of Mars's equator, whose centre it shares, twice each orbit.
The space elevator, of course, sweeps its overall length (twice 17,100 km) 360-degrees, once each Mars day.
Since Phobos revolves in less than a day, coincidence between the the moon and the elevator must eventually occur, resulting in a catastrophic collision.
Not only that, but with Deimos orbiting at 23,460 km, the opposit end of the elevator, roughly 35,000 km high, is bound to collide eventually, too. Shucks, Soph, y'can't win for loosin' in planetary roulette....

soph · 2003-04-12 13:41:56

Yes, I made a mistake about geosynchronous orbit. However, the chances of Phobos or Deimos ever coming near the elevator are extremely slim, and perhaps even impossible if the elevator is put in the right locations (for example, the equatorial crossovers may be limited to certain regions).

Russian Roulette has risky odds-these aren't really that risky.

dicktice · 2003-04-12 14:05:48

I didn't forget Deimos in all this. Deimos is in a fairly circular orbit with an altitude of 23,000 kms. This is some 6,000 kms higher than areosynchronous orbit. This allows for plenty of 'cable' above the centre of gravity of the elevator, to enable sling-shot launches of payloads back to Earth or elsewhere, and room also for the counterweight which would be necessary, without any risk of a collision with Deimos. It's only Phobos we have to worry about.
But if ramps prove to be the way to go ... bring on the ramps!!

Shaun: It would almost seem feasible to bring down Deimos's orbit--to geostational height--so it could become the central station for the Mars Space Elevator. Otherwise, you know, it'll collide with the upper part of the elevator....
But, there's still good old Phobos in the way. As an aside: In a recent novel ("Mars Underground"), a Clarke-style rotating wheel space station was attached to one of the poles of Phobos, and the whole collectively spun-up to provide Mars-gravity in the outer ring. Brilliant! In other words, Phobos is worth keeping!
I'm of an age, with a terrific urge to see this Mars Direct and follow-ons happen--which is what fuels my ambition to brainstorm the (now do-able) Mountain Launch Track scheme. Not my idea, of course, but when I read about the concept (Mars Miners) and the immense equatorial stratovolcanos--the Tharsis peaks of Mars, Kilamonjaro of Earth--together with recent maglev/electric-propulsion disclosures, on the Internet ... well, it just seems to be "Mountain Launch Track time" now!

dicktice · 2003-04-13 12:08:16

Yes, I made a mistake about geosynchronous orbit. However, the chances of Phobos or Deimos ever coming near the elevator are extremely slim, and perhaps even impossible if the elevator is put in the right locations (for example, the equatorial crossovers may be limited to certain regions).

Oh, Soph, you are a stubborn cuss.... When you have two oscillating systems, that aren't frequency-related in any way and therefore cannot be phase-locked with respect to each other, they are bound to coincide from time-to-time.... Which, in the case of Phobos or Deimos and your hypothetical Mars Space Elevator, would be a very spectacular, one-time-only event--to be viewed as far as possible from the equator, I might add!

soph · 2003-04-13 12:55:52

Do you know how thin the cable is? It wouldn't do any damage if it were destroyed, even if it somehow came crashing down in one piece.

Shaun, do the Martian Moons have a certain area in which they make their equatorial passes, or are the passes random?

Shaun Barrett · 2003-04-13 17:12:53

I have to admit I've made an error.
I stated that Deimos orbits at an altitude of some 23,000 kms (23,460 kms to be exact). In fact, the figure I was relying on refers to Deimos's distance from the centre of Mars! This was not apparent to me at the time I looked it up - I was too hasty to read the data properly.

So, in fact, Deimos's altitude is only slightly over 20,000 kms. This brings it to only 3000 kms above areosynchronous orbit and allows us much less room for manoeuvre between the elevator and Deimos! In fact, it may prove necessary to nudge Deimos into a higher orbit while we're nudging Phobos into a different one!!

I apologise for my error and I do regret any confusion I may inadvertently have introduced into the debate.

soph · 2003-04-13 17:51:54

Shaun, sorry if you missed it, but could you tell me if the orbits of the moons cross the equator at specific areas, or in random areas?

MarsGuy2012 · 2003-04-13 22:41:00

Well guys,

I say if you have the technology to build a space elevator you have the technology to do whatever the heck you want with those pesky little moons.

You could push them into Earth-Mars cycling orbits to use as transports. You could send them off to Jupiter with a thousand colonists aboard. I say push them into Aerosynchronus orbit and use their material for the elevator itself. You have to use something to build it, might as well use what's already up there.

By the way, sorry to get off topic. I like the Mountain track launch idea...this space elevator stuff is just funner.

Shaun Barrett · 2003-04-14 01:23:54

Hi Soph!
I have tried to track down the information you need about Phobos and Deimos, without success.
They both have stunningly circular orbits - Phobos has an eccentricity of 0.01% and Deimos zero% ! And they have only tiny orbital inclinations - Phobos 1 degree, and Deimos 0.9-2.7 degrees.
But whether or not the point where they cross the equator is constant (which seems unlikely to me) or gradually migrating around Mars' circumference, is not clear from the information I've been able to locate so far.

The fact that people like Clarke and Robinson have seen fit to devise complex oscillations of their fictional elevators, indicates to me that migration of the equatorial crossing points is most likely. Otherwise, we could simply erect our 'beanstalk' at an equatorial position which would forever be out of harm's way.
And life, unfortunately, is rarely that simple!!

Palomar · 2003-04-14 11:01:56

*I think most of you know me well enough by now to know that I rarely -- if ever -- drop a damp blanket on the interesting fires of conversation here...but I must say I'm a bit perplexed and blown away by this easy talk of moving a moon here, nudging it over there, etc., as if Phobos and Deimos are chess pieces on a game board. I'm a bit shocked by the blasse nature this conversation is rapidly developing. I'm -not- saying such notions/plans are right or wrong...I'm simply wondering if any of you are taking into consideration the fact that there would be enormous amounts of protest by various environmental groups and the like, perhaps even within the scientific community (likely, I'd say), against playing checkers with moons.

Of course, I doubt I'll live to see any such plans actually proposed and then protested against.

How can you know whether or not moving a moon here or there is a good idea? Are we in a position to begin to even try and ascertain the possible repercussions? What about unknown variables at stake?

"Phobos is worth keeping..." My jaw dropped. Yes, it's worth keeping...I'm stunned.

--Cindy

Shaun Barrett · 2003-04-15 06:57:07

I think I understand your point of view and consternation at people seeming to play God. But I think it's all a matter of degree in this case rather than anything absolute and fundamental.
Earth's Moon is a monster! As you know, it's way bigger by comparison with its primary than any other moon in the solar system. In addition, it has played a pivotal role in the development of life here on Earth. It still largely controls our ocean tides, lights our dark nights, beautifies our skies, and provides a romantic backdrop for courting couples! We need and love our Moon!

The moons of Mars are comparative tiddlers - small bits of cosmic detritus which happen to have found themselves orbiting a planet in a region of the solar system far from their point of origin. They raise no tides - even if there were seas again on Mars, they still wouldn't raise tides! They may help to make the skies marginally more interesting but they provide little light and are too small to have played a part in the development of any Martian life-forms. From large areas of the Martian surface, you can't even see Phobos!
If you are prepared to fundamentally alter the environment of a whole planet (terraforming Mars), can moving a couple of stray asteroids from one orbit to another really be such a moral watershed? I'm not trying to be facetious or scathing in any way, I assure you, and I'm perfectly willing to listen to arguments contrary to this line of thinking. (Remember I've been married 23 years ... I'm more than used to the airing of arguments contrary to my own!!! )

Some people here at New Mars have advocated mining Phobos and Deimos for volatiles - using them as 'gas stations' for our inner solar system transportation needs. Some have suggested hollowing them out for space stations and living inside them!
Up until now, nobody has expressed any regret at the thought of exploiting them mercilessly. Given their insignificance and apparent interloper status, it's actually quite surprising to hear a voice raised in their defence!

I, personally, don't have a problem with utilising or shifting the Martian moons to achieve our ends but I'm sure there will be others not so cold-blooded about it. I guess I'm addressing one of them right now?!!

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Re: Routine launches to LMO - Volcano slope maglev launching ramps

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Re: Routine launches to LMO - Volcano slope maglev launching ramps

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Re: Routine launches to LMO - Volcano slope maglev launching ramps

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