Debug: Database connection successful
You are not logged in.
After reading all the fuelled rocket 1st-stage booster suggestions, I decided to google the subject of mountain launch tracks, especially up the slopes of the Andes mountain range, near the Equator...and I found the "Moon Miners' Manifesto." I've pasted the relevant article below.
[From: Moon Miners' Manifesto #99 / October 1996]
Mountains Made for Launchtracks
by Peter Kokh
When the idea of using an Earth-captive virtual first stage e.g. a spaceship-carrying rocketpowered dolly accelerating along a track up the western slope of some convenient mountain, first was published, I'm not sure. I first saw the idea drama-tically illustrated in the early 50s film "When Worlds Collide".
We are all familiar with the advantages of launching Eastward from low latitudes, as close to the equator as possible, to get a piggyback boost from the Earth's own angular momentum as it rotates on its axis. The maximum boost, at the equator, is 1,037.9 mph (1670.25 kph) = circumference of the Earth divided by 24 hours in the day. This boost diminishes as you move away from the equator to the north or south. The percentage of available boost at any latitude is given by the cosine of the latitude degree. For example, Cape Canaveral, Florida lies at at 28x N. The cosine of 28x is 0.88295 which gives the percentage [88.29%] of the boost available at the equator, or 916 mph.
We are also, most of us, aware of the penalty, in the form of drag, incurred by launching through a thick atmosphere. If we could launch not only from on or near the equator, but from high altitude as well, launch efficiency would be maximized (translatable into higher altitude, larger payload, or both).
Early '50s science fiction writers almost universally imagined that White Sands, New Mexico would be the major gateway to space. Eventually NASA decided for political, military, and, Oh Yes, range safety reasons that this country's major spaceport would be along Florida's Atlantic coast. But Wernher Von Braun, the make-it-happen guru of modern spaceflight, actually had had a better idea when he proposed that the World spaceport be located on a high mountain plateau in central New Guinea, 5x N. Von Braun, of course, was a multi-stage rocket man, and the idea of using an Earth-captive virtual first stage in the form of a mountain-slope climbing rocket sled dolly would have meant turning over an important part of launch operations to a separate team of scientists and contractors.
While the rocket sled idea remains "a path not chosen", prime fodder for the writer of "what if" alternate histories, the idea is essentially sound. Without discussing the technical and engineering features and merits of such a spaceship launch track, let's take a look at just what actual terrestrial mountains might make the final cut. Here is our short list of the top four, with some comments. We have them listed in order of their summit heights, even though a launch track might not reach it.
Mt. Cayambe, Ecuador
19,160 ft., 0x 40 miles NE of Quito, and 200 miles NE of the major Pacific coast seaport metropolis of Guayaquil. In the Andes, Cayambe is the only mountain on our list with neighboring peaks that might do just as well. The other three (Cameroon, Kenya, and Kinabalu) are stand-alone massifs.
Range Safety and clearance: best clearance is to the north for polar launches, for which Cayambe offers no advantage. 2,000 miles East to the Atlantic over the sparsely populated north Amazon basin.
Mt. Kenya, Kenya
17,040 ft., 0x. An extinct volcano with a beautiful and classic graduated slope. 300 some miles NW of the Indian Ocean port of Mombassa with a railroad connection. 100 mi. NNE of Nairobi and its major airport. The summit is sacred to some Kenyan tribes.
Range Safety and clearance: 300 miles west of the Indian Ocean coast (in southern Somalia) over sparsely populated terrain.
Mt. Kinabalu, Sabah, Malaysia
13,455 ft., 6+xN. Near the north east tip of the great island of Borneo. About 40 miles ENE of the South China Sea port of Kota Kinabalu, and 80 miles WNW of the Sulu Sea port of Sandakan. About 100 miles S of the southern tip of the Philippine island of Palawan.
Range Safety and clearance: 70 miles to open water to the East for eastward launches.
Mt. Cameroon, Cameroon 4.2xN
13,353 ft., 4+xN 60 miles from the border with Nigeria, 10 mi N of the port of Buea (former capital of the former British Cameroons), and 50 miles WNW of the major port city of Douala. The western slope is subject to torrential rains.
Range Safety and clearance: Open water 25 miles to the south for southward launches only, a major drawback. Some 2,000 miles from the East African coast (in Somalia).
Excluded from this list are active volcanoes, and mountains that lack good seaport access. Arthur C. Clarke fictionalized ("Fountains of Paradise") a space elevator from a mountain in Ceylon (Sri Lanka) at 6xN. In truth, Mt. Pidurutalagala, the highest peak, is only 8,281 ft. and nearby Adam's Peak a thousand feet less. Both, however, have good eastward clearance over the southern Bay of Bengal.
Any effort to pick a site and build a mountainslope launch track would also have to factor in local political stability or the lack of it. If we were to pick just one such facility, serving all the world, my vote would have to be for Mount Kenya. It is tall, smack on the equator, central to the world's popula-tion, has fair weather, good access to a major port, and arguably acceptable range clearance.
[End]
I would like to expand on the subject to include investigations of Mt. Kilimanjaro, in Tanzania, Africa. (And later perhaps, Mt. Alpamyo and other 20,000-foot massifs, in Peru--which are nearer the West Coast of South America than the massifs of Ecuador.) But taken overall, it would seem the almost-ideal location for the first International Mountain Space Launch Facility is Mt.Kilimanjaro (see below):
Mt. Kilimanjaro, Tanzania
Mount Kilimanjaro rises majestically from a rolling plain close to the Indian Ocean from hot savanna to a barren and frigid 3-1/2 mile high peak. It's the highest mountain in Africa and one of the largest free standing mountains in the world. Climbing Kilimanjaro is a must-do challenge for almost every trekker and mountaineer in the world.
Kilimanjaro National Park takes in the area above the 8,850 feet, or 2,700 meters, on the mountain. It includes the moorland and highland zones, Shira Plateau, Kibo and Mawenzi peaks. In addition, the Park has six corridors or rights of way through the Kilimanjaro Forest Reserve. The Forest Reserve, which is also a Game Reserve, was established in 1921; the Park was established in 1973 and officially opened in 1977.
Kilimanjaro stands a scant 205 miles south of the equator, on the northern boundary of Tanzania. Its location on an open plain close to the Indian Ocean, and its great size and height strongly influence the climate, vegetation, animal life and the climbing conditions. It is made up of three extinct volcanoes: Kibo 19,340 feet (5,895 meters), Mawenzi 16,896 feet (5,149 meters); and Shira 13,000 feet (3,962 meters).
It's great to get away from the "is it feasible" stage, and start in on the "location/elevation/velocity/acceleration" stage!
I won't deny, I'm an enthusiast for mountain launch-rails as the least expensive means of reaching low Earth-orbit using present day technology. I first thought of using the Peruvian 20,000 ft. stratovolcanos on my own, with the launch sled Rogallo-wing-supported landing in the Atlantic (2,000 mile glide!) and towed back through the Panama Canal to the Pacific coast of Peru for reuse. Pretty silly, that retrieval!
Then I googled by accident upon the Moon Miners Manifesto (look it up, it's got a lot about Mars as well). They had already proposed the Andean mountain massifs of Equador, for the same reasons as I, right on the Equator, mentioning Mt. Kenya and others, around the World. In choosing Mt. Kenya, I considered its isolation from other mountains, allowing polar launch tracks as well as equitorial ones, right on the Equator for least acceleration to LEO velocity, undeveloped surroundings except national parkland, no religious significance (Mt. Kenya is "sacred" to the natives), and capable of transforming Tanzania from the poorest per capita African nation, to like Guiana, a prosperous, technically savy one.
Greatest possible height, next to nearness to the Equator, is essential to eccononic launching up the mountain slope. Also, the gradually increasing slope from flat, plateau land surrounding the base, allows long-duration accelerations comparible to air transports taking-off, with near vertical releases near the top. I would assist separation by decelerating the maglev sled a couple of thousand feet before "end of track," bring it to a stop (many ways), and let it slide down backwards returning electrical energy to the powerhouse. Less-than-sonic speed simplifies aerodymics of separation from the sled, while height reduces atmospheric drag on the fuel-bearing spaceplane/booster airframe.
Other sleds bearing boosters and spaceplanes would be switched, as in railway switchyards, enabling follow-on launches, as needed by a spacefareing World.
Other locations, by all means ... but to get there, perfect the procedures, not the least of which will be convincing the United States to accept the fact of international commercial space enterprise...!
Offline
Like button can go here
BDG: Responding to your points--
If you object to track friction--I agree--not feasible.
Acceleration to reach Mach 0.9 at the end of the track could be kept down to airline runway acceleration jsimply by making the track long enough.
A torus-like "slingshot" accelerator thus wouldn't be required.
Magnetic levitation on the other hand, makes feasible high subsonic rail-guided velocities.
If you object to aerodynamic friction--modern airframe design copes rutinely with that.
Maglev suspension, with linear ac-motor acceleration, would truly revolutionize the boosting of spacecraft to LEO by eliminating the fuel-burdened 1st-satge liftoffs.
Pollution yes, in the form of contrail proliferation, due to multiple launches of one-or-more per day (say), even with otherwise benign, hydrogen/oxygen rocket burns within the atmosphere.
No shockwave booms, during the (subsonic) acceleration of the vehicle assembly to the end of track.
Possible new and creative contributions from interested Mars Society members, might now bring the original "Moon Miners' Manifesto" up to date.
Offline
Like button can go here
Any numbers on mass ratio capacity?
How about combining this with ramjet + scramjet systems, to get a real kick?
The problem I see is that this would have to be used primarily for payload launch, and could never fit the mass market (i.e. good for satellites and space stations but not for people transportation). So, it could do very well for its role, but it would have a specific role.
Offline
Like button can go here
The mountain launch track, ending at (say) 20,000 feet and a 70-degree angle...atmosphere-dependent drive would probably not be essential.
The launch might comprise a tandem, two-stage rocket assembly, with the fuelled rocket-powered spaceplane in front of a 1st-stage hydrogen/oxygen booster rocket. Different-sized flyback spaceplanes could be launched (including small relief-crew transport/lifeboat craft) using standardized 1st-stage boosters. And the boosters need not be wasted, but collected in orbit for future use....
Offline
Like button can go here
Right, but the thing is, you have very specific launch and land points, which would not be suitable to commercial activity.
However, this has great potential for launches. Why not use a steam driven catapult to jumpstart it, and then run it through a maglev track? You could significantly truncate the track, and get the same benefits.
Offline
Like button can go here
So, what are we trying to achieve here?
Are we looking at releasing a 50 tonne rocket(fuel and payload) from the track at an altitude of, say, 5 kilometres and a speed of Mach 0.9?
If so, what will be the final mass to reach LEO?
And will this be cheaper in electricity and amortised infrastructure costs than, say, the Soyuz workhorse - pound for pound or kilogram for kilogram?
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
Offline
Like button can go here
Soph:
Commercial operations would be facilitated by using mountain launch tracks to boost a variety of vehicles, similar to the flexibility of railway cars.
Specific launch points as close as possible to the Equator, but located around the World--wherever suitable mountain massifs exist--to reach LEO.
To be commercially applicable, boost acceleration should be no greater than the airlines. Track-lengths to achieve this need not be truncated, since the chosen western mountain approaches would be sufficiently long.
Steam-driven shoves, or rollercoaster type down-hill brake releasing, for the initial (wheeled) acceleration, would be followed as soon as feasible by maglev suspension to reduce track friction.
Offline
Like button can go here
The potential i see in this is for payload launches.
I think RBCCs and similar designs, that could launch from airstrips, would be more viable for commercial applications (convenience, flexibility, existing infrastructure).
Thus, I think that you would want to truncate the runway, because for payload, g load is less important, and a shorter runway means less maintenance, and greater launch rates.
Offline
Like button can go here
Shaun:
What we are trying to achieve here, is (1) elimination of fuel-carrying boost, substituting maglev/mass driver acceleration to just under supersonic velocity at 15- to 20-thousand feet (2) second-stage burn to present shuttle fuel-tank release point (3) spaceplane orbiter acceleration to LEO.
Final mass to reach LEO would depend upon the mission, e.g. ISS crew-transport spaceplane (like X-38 et al.), pilotless consumable delivery and refuse carrier (like Soyuz/Progress), materials/subassembly/satellite transportation spaceplane (like Space Shuttle Orbiter).
Offline
Like button can go here
Soph:
I noticed a proposal for Boeing 747-towed spaceplane launches, to 40,000 feet and 500-plus mph. I would think that fly-back spaceplanes, of whatever size and purpose, could be designed capable of being launched from mountain tracks as well as by airplane-tow.
Any savings obtained by scrimping initially on ground facilities that would obviate passenger carrying, would seem "penny-wise and pound-foolish," compared with the expense of present-day launching. As a glider pilot, I appreciate the advantages/disadvantages of aerial towing, and believe me, it's not an all-weather proposition. Mountain track launces would be all-weather capable.
Regarding launch-rates: The mental image I get is of mission-bearing spacecraft of every description, on sidetracks, waiting to be slotted into various low Earth orbits, or beyond (sigh).
Offline
Like button can go here
What do you mean by very specific land points ?! Obviously, once you reached LEO you can land just about anywhere you want with the vehicle.
Sorry, you are right, I meant very specific launch points, which is not in any way desireable for passenger flight.
Offline
Like button can go here
BDG: We shouldn't contemplate supersonic speeds in the lower atmosphere for reasons (as they say) too numerous to mention....
"Specific points" was in reply to Soph. I meant, points in the vicinity of the Equator where suitable stratovolcano massifs are located.
On Mars...yes! Mountain launch tracks would seem to be ideal...maglev single-stage boost...right up to LMO, Phobos or Deimos.
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 same 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.
Olympus Mons, somewhat north of the equator, should appear to be ideal for polar orbits, being higher and having longer slopes, for additional acceleration required without the planet's rotational assist.
Offline
Like button can go here
I dont base my history on sci fi tv shows.
Offline
Like button can go here
I dont base my history on sci fi tv shows.
But, Soph, that's where this all is coming from. Most of what we/you-all are proposing and arguing about in these forums began back when fans like me were ridiculed...by mystery story fans (ugh) I might add. (It's very hard to write believable scifi-stories, by the way.) But seriously...remote space-ports were conceived as necessary for reasons of (a) range safety (b) noise reduction (3) operating and servicing the huge SSTO ships.... Commercial economies of getting to LEO will demand Equatorial region sites. Now if you move to Tanzania, you can get in on the ground floor regarding real estate, and not have to take a trip to get there when they/we start launching. How about that?
Offline
Like button can go here
Right, but there are other alternatives, already being R&D'ed, that would allow commercial passenger flights from airports, which is more convenient for the "customers."
Since mountain tracks are less likely to be as ubiquitous as airports, they may be better served towards devoting themselves to the payload launch markets.
Offline
Like button can go here
Umm...Hi, actually I was just thinking about this, and i wonder if anyone could help me.
I worked out the figures, but i want to see what answers others get ok,
Question;
To maintain an orbit of +200km you need a launch speed of 8.063 km/s. No when you launch from surface eastwards can use the earth's rotational velocity as part of you launch velocity, so at the equator you will only need a launch velocity of aroung 7.57 km/s.
Would it be possible to launch with an acceleration of 3g on a mountain track and how long would the track need to be?
Just want to see if your answers come close to mine.
And answers/theories/suggestions would be helpful. I will tell you my answers later if anyone wants them.
Every instant is a pin prick of eternity! All things are petty, easily changed, vanishing away!
There must be no exception to the rule, but you need the exception to prove it!
Cognito Ergo Sum
I've had eighteen straight whiskies, I think that's a record.
Offline
Like button can go here
kseiII: A favourite site of the "Moon Miners" (google that, for details), is the stratovolcano, Kilimanjaro, in Northeast Tanzania, with a height of 19,300-odd feet, about 200 miles from the Indian Ocean. I haven't got the altitude of the surrounding plateau, which is not mountainous, so the track approaches to the ideally-increasing slope of this peak can be as long as you need, to accelerate at no more than a transport plane at takeoff. If you depart the maglev sled at no more than 0.9 Mach (to avoid supersonic shockwave sled-design complications and sonic bangs from what is a nature reserve) when the sled brakes--as it approaches end-of-track near the summit--the booster first-stage burn can then take you up to near-orbital velocity over the ocean. The sled will then be allowed to roll back down and switch to a sidetrack, clearing the launch track for the next vehicle. The spaceplane, second- stage burn will take it up to LEO or beyond. The first stage can be retrieved from the ocean, eventually even orbited for storing leftover fuel in space, as well as used to assemble further space platforms....
Offline
Like button can go here
Theoretically would it be possible to dispose of the first stage. So that you only need the maglev and the space plane engines (eliminating the need to collect anything from the see.)
And at what speed would you need to leave the maglev track at?
Every instant is a pin prick of eternity! All things are petty, easily changed, vanishing away!
There must be no exception to the rule, but you need the exception to prove it!
Cognito Ergo Sum
I've had eighteen straight whiskies, I think that's a record.
Offline
Like button can go here
Theoretically would it be possible to dispose of the first stage. So that you only need the maglev and the space plane engines (eliminating the need to collect anything from the see.)
And at what speed would you need to leave the maglev track at?
Too damn fast, I'm afraid. Two stages give mission flexibility, and the spaceplanes can be any size--from single-seat (Buck Rogers style) to replacement crews for the ISS. As stated, the 1st-stages ideally could be designed light enough to make it into orbit, with fuel to spare for storage. Engines could then be detached where not needed for orbital construction, and returned to Earth by the larger, otherwise empty-of-payloads spaceplanes.
Offline
Like button can go here
This may not be imprtant exactly, but all the best sites for volcanoes are in unstable countries, politically i mean. I mean, Kenya, Tanzania and Malaysia (to it is the best of the three by far), are not exactly the baskets you want to place all you eggs.
Though I may be mistaken, I sometimes can jump to conclusions.
But, could it be possible to build a track in a more stable country (a western country).
Would'ny you just need a longer track and a different launch angle?
My ideas for possible sites are;
Monte Amaro, Italy. 2793m high, 50km to the Aegean sea for eastward launch, but 42 degrees N.
Serra de Cadi, Spain. 2567m high, 175km to Ligurian Gulf, but again 42 degrees north.
Cerro-Pena Nevada, Mexico. 3644m high, 150km to Gulf of Mexico (but not sure), 24 degrees north, but the problem is it's in an earthquake zone.
Another possibility would be to built a launch track in French Guiana, with is only 4 degrees North, but there is no mountain, but is a mountain necessary, how much of a rise is need at the end of the track?
I know none of these come to being anywhere near are useful as Mt. Kenya would be, or Kilimanjaro, but all four sites are in more politically stable environments, so the investment would be safe.
What does anyone think? Personally out of the four ideas i think the Italy one would be best, or possibly French Guiana.
Every instant is a pin prick of eternity! All things are petty, easily changed, vanishing away!
There must be no exception to the rule, but you need the exception to prove it!
Cognito Ergo Sum
I've had eighteen straight whiskies, I think that's a record.
Offline
Like button can go here
Umm...also is Mach 0.9 and acceleration of about 300m/s/s That's like 30g. No-one could launch with that accerleration comfortably could they, though i may have worked all that out wrong and may now look inceedibly stupid. But, isn't it?
Every instant is a pin prick of eternity! All things are petty, easily changed, vanishing away!
There must be no exception to the rule, but you need the exception to prove it!
Cognito Ergo Sum
I've had eighteen straight whiskies, I think that's a record.
Offline
Like button can go here
Sorry, just went back and read the post. So, u meant the sled can never go faster than 0.3km/s/s. Isn't that a bit slow?
Every instant is a pin prick of eternity! All things are petty, easily changed, vanishing away!
There must be no exception to the rule, but you need the exception to prove it!
Cognito Ergo Sum
I've had eighteen straight whiskies, I think that's a record.
Offline
Like button can go here
hey guys, though id announce my presence.
I was thinking about this last year and found this handy website detailing the efforts of a group of engineers in exactly this field. They lay the maths and the concept out pretty clearly and make a convincing case.
I always liked Ascension Island in the atlantic. Its peak is only 2600 ft but it is close to the equator, already has extensive facilities and is a UK dependancy making all companies based there tax free
Offline
Like button can go here