Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

dicktice · 2004-04-10 08:57:49

Going back to the begining of this thread and re-reading the ideas presented so far, I was struck with the difference between these and ideas being tossed about in other threads re. assorted launching methods proposed from Earth to LEO leading to human exploration of Mars and its eventual colonization. I'd like to suggest a rough scenario for a somewhat different approach--an amalgam of ideas derived from previous New Mars Forum topics--along the following lines:

Choose Ecuador as the country from which to launch, for reasons of its ideal location on Earth, mountainous terrain, seaboard, political stability and multicultured inhabitants. Initially, launch from sea level straight up to geostationary orbit, using single-stage H2/O2 rocket power, with cargos of fresh-water ice inside light-weight casings with partitions, etc. designed for eventual occupancy. This would avoid having to accelerate to LEO orbital speed, with the fuel saved to reach geostationary orbit at zero radial velocity. Each launch would carry one or more remote-presence robots (rebots) operated by one mission controller each per working shift, utilized for assembling space facilities from the conglomeration of launched hardware, and producing LH2 and LOX from the water-ice. Power from low voltage/high direct current, generated from solar-heated vs. shielded space-cooled dissimilar metalic junctions, would be changed to alternating current and transformed to the different voltages, etc. required to run onboard systems. The rebots would take the place of human astronauts in orbit and (once the first Mars Ship has been assembled and checked out) travel to Mars along with it. Rebot operators would work as a team, essentially in realtime while in Earth-orbit, under the watchful "eyes" of a mission director. While actual digital video monitoring would be availble from on-site camera, the actual rebot teamwork would be accomplished using virtual reality, exactly duplicating geometrically the habitat aboard ship. As the lightspeed communications delays increase with distance, the teamwork operates scene-wise, with the rebots kept stationary between the scenes, with durations dependent upon tasks, while virtual scenes rehearsals are carried out and debugged on Earth, before being allowed to take place aboard ship. Refueling en route, from electrolized melt-water obtained from the ice cargo, will enable mid-course burns to be carried so that Mars can be approached from behind, eliminating the need for aerobraking capture, the launching of survey and re-transmission satellites, and finally the vertical powered letdown to a surface location decided upon. The rebots would re-assemble themselves into various configurations as needed, set up atmospheric processing, deploy bladders, hoses and valves for gas, etc. storage, inflate workshop enclosures and set up the tool stations, assemble rover vehicles including a front-end loader for heavy-duty excavating and road making. Mars soil sample analyses would then be carried out, using the stop-motion-by scene scenarios, by the on-site rebot teams under scientist controllers on Earth. Nothing would be returned from Mars.
Meanwhile, back on Earth and in geostationary orbit, construction and processing would be ongoing to prepare for the second voyage, with or-without-human crew members and their special needs, along with the all-important rebots.
The Ecuador location takes advantage of maximum Earth's equatorial bulge, as well as maximum surface spin velocity, and proximity to the passive strato-volcano region reaching as high as 20,000 feet asl, for possible future maglev track launches for servicing LEO facilities, as necessary. The people of Ecuador who live out their lives above 10,000 feet, might profit by their ability to thrive with less partial pressure of oxygen in space work, eventually even becoming amongst the first settlers of Mars.

SBird · 2004-04-10 13:07:20

Having read some of the links on this thread, I'd like to revisit the whole rail launch idea.

On one side, I underestimated the benefit of a rail launch - I was forgetting to account for the gravitational losses from the slow inital moments of launch - you're constantly fighting 9.8 m/s^2 no matter how fast you're going so those first couple of minutes or two are very wasteful. It's not atmospheric drag as the people on the rail launch site seem to indicate - it's present but small beans compard to the other stuff.

On the other hand, their cost estimates are WAY off. 100 million of a completed stratovolcano launch rail? It takes $100 million to build a ski resort! The launch facility costs will be in the tens of billions at the least. In order for a launch facility to be justifiable, the cost of building it has to make up for the added costs of launchers and fuel you'll be saving. Unless your launch facility can be cheap, it's just cheaper to keep using the existing facilities.

They also mention safety which I find highly suspect. Adding a whole new layer of complexity to a launch system does not make it safer. Plus, you're now adding a very delicate rail track that a single launch failure will destroy. If a rocket on a launchpad blows up now, you have to rebuild the gantry facilities but otherwise, the nothing gets damaged - it's just big concrete slabs.

Also these folks seriously underestimate the weather on top of a big mountain. Winds at high summits regularly top 100 mph with little warning. They get hit with massive amounts of snow and the temperatures are low enough to cause all sorts of low temperature brittleness problems.

The only launch system that I could think of that would make sense would be one of the following two:

1: high altitude launch facility. There's some really high areas in Mexico that are fairly close to the equator. Over by Veracruz, there are 10,000 foot mountain plateaus that are right next to the Atlantic coast, solving the problem of downrange safety. Although a 20,000 foot launch base would be preferrable, the high altitude weather on exposed mountaintops is just too dangerous, IMO.

2: a vertical launch rail. Drill a big tunnel a half mile down into a mountain and have vertical steam catapults get the rocket moving vertically at a high altitude. Even a fairly slow 200 mph launch is as effective as a 30 degree launch at over 400 mph.

dicktice · 2004-04-11 09:44:36

SBird: Your opinion about a possible 3rd system, taken from my post just previous to yours, in addition to your Numbers [1:] and [2:]? I.e.,

3: "Initially, launch from sea level straight up to geostationary orbit, using single-stage H2/O2 rocket power, with cargos of fresh-water ice inside light-weight casings with partitions, etc. designed for eventual occupancy. This would avoid having to accelerate to LEO orbital speed, [using] the fuel saved to reach geostationary orbit at zero radial velocity. . . ."

I see this as a sort of a "pre-space elevator" approach, which I haven't seen posted before. It shouldn't even be here, I suppose, but wanted some critique before taking it any further. The remote presence robots, also, should be discussed elsewhere in a new thread, as astronaut substitutes perhaps?

SBird · 2004-04-12 12:16:15

The problem with that idea is that you've only got something like 450 m/s of rotational velocity from the Earth's rotation. At GEO, IIRC, it's something like 3,000 m/s. Plus, if you just rely upon vertical thrusting, you end up fighting gravitational acceleration the whole way. I'm not positive but I think that a direct vector to GEO would end up taking much more fuel than the current trajectories.

Bill White · 2004-04-12 16:03:36

For payloads that are not sensitive to gee-forces (water or peanut butter or fortified tofu paste) what about scram jet enhanced gun launched systems? John Hunter and Gerald Bull have done considerable work in this direction.

The US Army is looking into a scram-jet anti-tank missile capable of withstanding 60,000 gees that come from being fired from a tank gun. The Dr. Hunter idea is more like 1,000 gees. Astronauts would be rendered into a bloody goo but bulk goods should survive nicely.

Link:

[http://www.asc2002.com/summaries/c/CP-09.pdf]http://www.asc2002.com/summaries/c/CP-09.pdf

= = =

A plain old solid rocket booster appears to work as well.

= = =

Hunter's [http://www.astronautix.com/lvs/julncher.htm]Jules Verne gun. 3,300 kg to LEO at 60 degrees. An equatorial launch would improve those numbers.

dicktice · 2004-04-12 18:19:53

The problem with that idea is that you've only got something like 450 m/s of rotational velocity from the Earth's rotation. At GEO, IIRC, it's something like 3,000 m/s. Plus, if you just rely upon vertical thrusting, you end up fighting gravitational acceleration the whole way. I'm not positive but I think that a direct vector to GEO would end up taking much more fuel than the current trajectories.

True, I wasn't thinking beyond just getting up to GEO, in order to propose the remote presence robot idea for the first and second Mars expeditions as a way to simplify the long-term logistics. I wonder, in my ignorance, if the fuel per Mars expedition from GEO might not be comparable with that from LEO, or even Mars Direct? Leaving that aside (I'm good at that), remote presence robots on Mars, using the teamwork-by-scene-stop-motion scheme to combat lightspeed control loop delays, still interests me. I have full confidence in our ability to accomplish the most complex work in Earth-space, realtime. The human operators in conjunction with virtual reality could have this capability within the decade (that has a nice ring to it, ahem). The "stop scene motion" can be tested by Mars Society by e.g., tape delays, in order to prove-out the scheme on Mars. What fun, to be able to sidle up to one of these, as a "Martian" and shake its hand! But seriously, mightn't a method something like this for carrying out human-quality explorations on Mars initially--without the complications and traumatic, sidetracking worries that flesh and blood out-and- return crews would present--worth some more discussion, as a topic in itself? The idea is so new to me, I haven't given it much thought myself yet. . . .

SBird · 2004-04-13 01:23:42

Having read a bit more about the superguns, I'm intrigued. It seems that they're limited to small cargo masses but offer the best cost to orbit for just about any technology available.

It appears that all of the major technical hurdles were within current day technology. For things like carrying fuek up to LEO, this technique has potential. It's probably not practical in the Mars Direct timeframe but worth looking at for a cheap future launch system.

Also, there's a company that's also actively working on the technology for mini sounding 'rockets' up in Canada. [http://www.columbiad.ca/index.html]Here.

Rxke · 2004-04-13 02:16:57

SBird, heehee, yes the Columbiad guys, are silently just doing what a lot of people are talking about... Looks like they are progressing steadily.

Columbiad, BTW was the name of the vessel that brought the men to the moon in Jules Verne story, and they were launched with a big cannon...

Bill White · 2004-04-13 06:32:49

Having read a bit more about the superguns, I'm intrigued. It seems that they're limited to small cargo masses but offer the best cost to orbit for just about any technology available.
It appears that all of the major technical hurdles were within current day technology. For things like carrying fuek up to LEO, this technique has potential. It's probably not practical in the Mars Direct timeframe but worth looking at for a cheap future launch system.
Also, there's a company that's also actively working on the technology for mini sounding 'rockets' up in Canada. [http://www.columbiad.ca/index.html]Here.

In my opinion, work on this has stopped for lack of demand.

Without a genuine push for colonization, there simply is no need to lower launch costs so significantly.

SBird · 2004-04-13 10:42:10

Well, the Columbiad folks to seem to think othewise and I agree with them. There's a big market for small suborbital and orbital payloads. University research teams that are looking for microexperiments at under $1 million a pop are going to be a constant source of income.

The whole micro/nanosat market seems to have been a bust so let's assume that's not something that can be counted upon.

That leaves fuel/water/etc as a payload. NASA is already proposing LEO refuelling depots - the ability to get material to these depots for as cheap as possible would be a wise investment. As long as you can get more than a few kg per launch, a low cost per kg makes this system a great one for a slow, steady trickle of consumables to orbit.

The mistake that Dr. Hunter made was to try and convince the gummint to scale up from the SHARP gun to a billion dollar orbital capacity gun. Had he pushed for an intermediate gun as a proof of concept, there's a good probability that the project would have continued.

These Columbiad folks in Canada (I wonder how many old Richard Bull collaborators are on that team) seem to be working on getting lots of experience with their small guns and slowly working their way up towards more advanced models. Right now, they're competing with the sounding rocket market.

Bill White · 2004-04-13 11:01:35

Okay, I stand corrected. Drats, wrong again. ???

If these Canadians can get this project to work that would be waaay cool.

A security question, however. If this thing is portable, why isn't it an effective tool for anti-sat work, at least against targets in low orbit?

Rxke · 2004-04-13 12:23:36

If this thing is portable, why isn't it an effective tool for anti-sat work, at least against targets in low orbit?

*Splendid idea! Muahahaha!

Errr... No. Good point, Accuracy shouldn't be too big an issue actually, with some radar and a good computerprogram on a powerful laptop with GPS etc to set launchtimes/inclination/whatnot, you just launch the little rocket *approximately near* the sat you wish to get down, and let your rocket explode (nail-bomb style) Should be enough...

SBird · 2004-04-13 12:24:56

Quick follow-up, I was browsing the Columbiad site and their plans are for a 100kg to LEO gun as their initial orbital launcher. According to other cost estimates of the Bull launchers, $500/kg to orbit is not an unreasonable figure.

Columbiad is claiming (Of course these figures have to be taken with a grain of salt until they demonstrate an actual working full scale gun) that they will be able to do up to 6 launches per day or up to 100 launches per month. Assuming that figure holds true, that's 10 MT / month / gun. If a set of these were operating in tandem, it's not unrealistic to assume that it would be possible to get the equivalent to a couple Shuttle launches a month in fuel to orbit or an HLV launch every few months.

Assuming that we can loft these cargo at $500/kg including gun and vehicle failures, the 100 MT of fuel I proposed to loft to a modified Mars Direct spacecraft (basically the empty shell of Mars Direct w/o fuel/water or air that would nearly triple the Mars delivery payload) results in $50 million in launch costs. Considering that's less than one Delta launch, that's a pretty good deal.

Of course, there's the issues of how to control and dock all these space-borne artillery shells but that's nothing that we couldn't probably reuse old SDI technology for. Additionally, recovering the shells after they drop off their fuel payload should be fairly simple as long as they land on a soft target. Assuming a fairly accurate reentry capability, one could aim the shells for a patch of ocean and design the shells to be buoyant. A radio transponder can then be used for ship recovery. The shells themselves should be nearly completely reusable as they're hardened to easily be able to shrug off high velocity atmosphere crossings and large G-forces.

Since air density affects this launch system particularly acutely, you want the launchers to be as high in altitude as possible. Again, I'll stump for Southern Mexico. The location is fairly close to Mexico city, located in a nearby country with close ties to the US and reasonably stable. The Tlaxcala/Puebla region is fairly sparsely populated and largely agricultural so launch noise problems won't be quite such an issue. Also, the position of the Mexican highlands is fairly close to the standard orbital track out of KSC, at 20 degrees lattitude. Combined with a number of high plateaus at >3000 meters in elevation, it's a good place to place lob NASA support payloads.

Alternately, such a gun could be used from a large floating platform like Sea Launch for getting a 0 degree orbital inclination launch. The only problem is that I can't see having more than one launcher per platform, making it problematic to get a decent mass rate to orbit. Perhaps an old WWII battleship could be recommissioned for such work but I've got doubts that even those monsters could withstand the launch forces generated.

Bill White · 2004-04-13 12:52:41

SBird, in my developing book, I have people build a gun like this in Ecuador, with a fixed inclination. Rather than bore into a mountain, they lay high grade petroleum pipe in segments up the side of Mt. Chamborazo.

Pipe sections can be swapped out as needed and lasers are used to assure alignment. Basically, its Hunter's Jules Verne gun assembled on the side of a mountain rather than bored into a mountain.

As far as recovery goes, since JDAM technology seeks to put "warheads on foreheads" I figure putting "foreheads on foreheads" can only be easier.

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#26 2004-04-10 08:57:49

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#27 2004-04-10 13:07:20

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#28 2004-04-11 09:44:36

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#29 2004-04-12 12:16:15

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#30 2004-04-12 16:03:36

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#31 2004-04-12 18:19:53

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#32 2004-04-13 01:23:42

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#33 2004-04-13 02:16:57

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#34 2004-04-13 06:32:49

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#35 2004-04-13 10:42:10

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#36 2004-04-13 11:01:35

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#37 2004-04-13 12:23:36

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#38 2004-04-13 12:24:56

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

#39 2004-04-13 12:52:41

Re: Mountain launch tracks revisited, - Alternative to fuelled rocket boosters.

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