Log in

View Full Version : Low-cost Access to Space



ÑóẊîöʼn
13th October 2008, 20:29
When I first intended to create this thread, it was going to be about a specific technology - the Slingatron (more on that below). But then I realised that it wasn't the only cheap way of getting into space. I also knew that there is a strong anti-space research sentiment among the left, and that in the event of a revolution such sentiments are likely to be reflected in the population at large - even today, ignorant people of all political persuasions piss and moan about the money being spent on space research, when in actual fact it is a miniscule proportion of the GDP of all countries, which spend far more on "defence". In fact the US spends hundreds of billions of dollars on it's imperialist military machine, while devoting less than 20 billion overall to NASA.

Currently, the only organisations with the resources and intellectual capital to perform serious research into space travel are organisations like NASA, ESA, JAXA, and the governments of China and India. But NASA is hidebound and unimaginative, and like the ESA and JAXA, criminally underfunded (not to mention that due in part to NASA's previously mentioned lack of imagination and also in part to the fact that NASA is used as a political football, too much of that money is wasted), while the Chinese and Indian space agencies are but in their infancy.

So it occurs to me that an essential component of any post-revolutionary body is a space program, but it seems likely that there will be significant popular sentiment against such a thing. Whatever the realities of resource allocation, space research advocates must provide results early and often to convince the masses that space research is vital and worthwhile. Any region larger than an island under revolutionary control will require orbital satellites for communication, weather monitoring, and scientific research. It may be possible to build a worthwhile space program on the back of such essentials, but then again it may not. So, resource allocation to space research is likely to be limited.

This is where the technologies I mentioned earlier come in. They will be able to demonstrate the worthiness of space research on a shoestring budget, which may be the catalyst for changing popular opinion on the importance of such research. If space research advocates can show what is possible on a limited allocation of resources, imagine what is possible if they had access to more!

So now I will show a brief run-down on low-cost and/or low-energy space access technologies:


The Slingatron (http://www.slingatron.com/index.html)

This is the technology which inspired this thread! I find it is very impressive for what it is; it uses no explosives, flammable chemicals, the energy required for launch can be built up slowly over time using flywheels (as opposed to railguns and gauss guns which require high-intensity bursts of electrical power in order to function), and it is based on simple physics and mechanical engineering principles that would have been familiar to Isaac Newton over 200 years ago. With modern day materials and engineering techniques, it is entirely possible to build one of these things capable of launching a vehicle into Earth orbit. Take a look at the website and be amazed.

The Slingatron could also be used a cheap but extremely powerful rapid-fire weapon system for defence against imperialist attack. Different Slingatron systems could be optimised for use as anti-aircraft platforms, anti-tank guns, coastal batteries, and ballistic missile defence systems. A sufficiently powerful Slingatron system would also be able to launch counter-strikes against aggressors on their own soil.


Launch Guns (http://orbitalvector.com/Orbital%20Travel/Launch%20Guns/LAUNCH%20GUNS.htm)

The types of launch guns listed in the above link that are of particular interest for this topic are the "Advanced HARP Launch Cannon" and the "Ram Accelerator Launch Gun". The Advanced HARP Launch Cannon is an option available to any moderately-industrialised country, and requires technology no more advanced than what was available during the Cold War. It would be entirely possible to launch microsatellites for various purposes using this technology. The Ram Accelerator is particularly interesting since it seems possible to build them as long as we like - which means that accelerations can be such that launching manned vehicles is possible. Further research is needed however.

Another type of launch gun is the Blast Wave Accelerator (http://en.wikipedia.org/wiki/Non-rocket_launch#Blast_Wave_Accelerator), which like with the Ram Accelerator it may possible to build it in lengths (and therefore accelerations) that make manned spaceflight possible. This could concievably be achieved having the initial rings made out of specially-formulated low-grade explosive, gradually increasing in explosive power as the launch vehicle goes along the tube.


Other Technologies

However, the above mentioned systems show only what is possible today. It may be that in the future more systems may be developed, advances made that make other space access technologies cheaper or more viable, and so on. Below are some technologies which I feel will become cheaper in the long run thanks to increasing technological development:


Space Elevator (http://en.wikipedia.org/wiki/Space_elavator) - If it ever becomes feasible to manufacture carbon nanotubes in the required lengths, then the construction of a Space Elevator becomes a distinct possibility. While the initial costs are likely to be high, the Space Elevator by it's very nature will very quickly pay off it's investment. Going up a Space Elevator takes significantly less energy than the same trip by a traditional rocket would, and the Space Elevator itself could be a source of energy - intertwine it's fabric with conductive materials, and as the Space Elevator moves through the Earth's magnetic field an electrical current is generated.

Space (http://http://en.wikipedia.org/wiki/Space_fountain) Fountain (http://[/B]http://en.wikipedia.org/wiki/Space_fountain) - As with the Space Elevator, the Space Fountain requires a large initial investment of energy and materials that can be repaid over fairly rapidly over time. Unlike the Space Elevator, you would not need any presence in space - you could build it "from the ground up" - the ground station, the accelerator and the orbital station could be constructed at low cost on the Earth's surface, and the orbital station placed on top of the ground station. Then the Fountain is powered up slowly, the force of the pellet stream eventually lifts the station first a few centimeters, than a few hundred meters, and then is pushed up kilometer after kilometer.

[B]Space Tethers (http://orbitalvector.com/Orbital%20Travel/Orbital%20Tethers/Space%20Tethers.htm) - If the initial investment required of the Space Elevator is to hard to swallow, or if it turns out there is an upper limit on how long carbon nanotubes can be made, then the alternative may be a system of tethers. Like the Space Elevator, tethers can take advantage of the fact that moving conductive materials in a magnetic field can generate current, possibly making them self-powered.

Single Stage To Orbit (SSTO) vehicles (http://en.wikipedia.org/wiki/SSTO) - One of the major stumbling blocks with traditional approaches to reaching orbit is the complexity of the vehicles due to requiring multiple stages or booster rockets, the cost that such approaches incur, and the added cost of having to retrieve any re-usable stages. A working SSTO would eliminate the need for staging or booster rockets and would have lower operating costs, improved safety, and better reliability than current launch vehicles. Their lower part count would also lower their cost. The mass ratio of an SSTO could be reduced with a hybrid scramjet (http://en.wikipedia.org/wiki/Scramjet)/rocket engine, which would use the atmosphere as a source of oxidiser in the initial part of the launch, switching to it's rocket motor when it needs to exceed the speed limit of the scramjet in order to achieve orbital velocity.


Conclusion

Despite what the naysayers say, getting into space is vital, and I feel that what I have described and linked to above points the way forward if they have their way and limit the allocation of resources to space research. While I am hopeful that this will not be the case, there are no guarantees. It is my conviction that the only viable communist society will be high-tech, and constantly pushing back both the geographical and scientific boundaries of knowledge. The only alternative is stagnation and extinction, and that is why I consider space research to be so important. We need to get a foothold off of this planet as soon as possible, because as soon as we do, then when (not if!) disaster strikes the Earth, we will have a portion of our species not at risk of extinction from the resulting fallout.

Your thoughts, comrades?

AAFCE
13th October 2008, 22:39
I agree that space research is important. There is just so much out there, I dont see how people could find it unneccessary.

Pogue
13th October 2008, 23:06
I think its incredibly interesting and exciting and should one day be done, but like Bill Hicks said, we can only do it after we've fed and educated all the people of the world. Then we can explore space together. It can ony be justified in periods of great prosperity for all people due to its large cost and limited gains.

mikelepore
13th October 2008, 23:19
If the energy for the slingatron can be gradually accumulated over time into the flywheel, it seems to me like the same efficiency as gradually accumulating energy over time into the electrolysis of water to provide hydrogen. The main feature about today's missiles that I dislike isn't the main hydrogen-oxygen engine but the burning of aluminum in the solid rocket boosters.

While a jet propulsion method accelerates over a longer time, a projectile method has to impart all the initial velocity in the beginning. That amount of acceleration may be okay for cargo but not healthy for passengers. Even if it's just cargo, the viscosity of the air increases with the speed of the projectile, so a lot of heat will be dissipated at the lowest altitudes, which is energy subtracted from what's available for overcoming gravitational potential.

ÑóẊîöʼn
14th October 2008, 00:07
I think its incredibly interesting and exciting and should one day be done, but like Bill Hicks said, we can only do it after we've fed and educated all the people of the world. Then we can explore space together. It can ony be justified in periods of great prosperity for all people due to its large cost and limited gains.

This is a variant on the attitude I was talking about. The world has enough resources to feed, clothe, house and educate everyone as well as run a decent space program.

It'll be all well and good having worldwide prosperity, but all that will come to naught if human civilisation gets wiped out by an asteroid, an ice age, a supervolcano eruption or any of the other disasters that have befallen our planet in the past and almost certainly will happen again.

The sooner we start, the better our chances will be. We live in an indifferent universe that cares not for our nobility nor our foibles, but will unthinkingly laminate us all to the bedrock if the circumstances are right. Our primitive forays into space are but a step on a thousand mile journey.

We must carry on.


If the energy for the slingatron can be gradually accumulated over time into the flywheel, it seems to me like the same efficiency as gradually accumulating energy over time into the electrolysis of water to provide hydrogen. The main feature about today's missiles that I dislike isn't the main hydrogen-oxygen engine but the burning of aluminum in the solid rocket boosters.

The Slingatron is more efficient because there are fewer "steps" in the energy usage process. Electric motors spin the flywheels, which directly power the Slingatron via drive shafts. Hydrogen however must be produced by electrolysis at a production facility, then shipped via road or rail to the cosmodrome where it is stuck into the fuel tanks. A Slingatron can avoid this by running directly off the grid, and since it can do it gradually, it does not cause brownouts or power surges by doing so.

Chemical rockets are also notoriously inefficient. They require multiple stages to get into orbit, and have ludicrous mass ratios - just look at the Shuttle on the launch pad, and see how it is dwarfed by the collective mass of it's boosters and that detachable fuel tank. Slingatrons and Launch Guns, however, stay on the ground while their payload is sent into orbit. It takes a lot of preperation before you can send another Shuttle up, but Launch Guns and Slingatrons can do it in a tiny fraction of the time.


While a jet propulsion method accelerates over a longer time, a projectile method has to impart all the initial velocity in the beginning. That amount of acceleration may be okay for cargo but not healthy for passengers.

Certain designs, such as the Ram Accelerator and the Blast Wave Accelerator, can be made longer so that they can use more gradual accelerations. Tolerance varies, but the typical person can withstand about 12 gees if the axis of acceleration is perpendicular to the spine before losing consciousness - but in a launch-gun type arrangement accelerations are only experience for a relatively short amount of time (meaning that G-forces can be up to 35 gees for short periods of time), and mitigation of G force effects can be achieved through immersion of the crew in a fluid medium, placing the crew in a backwards position, High-G training, and the wearing of G-suits.

It may be possible to launch manned vehicles in such manner - but I would need to do some serious calculations in order to be sure.


Even if it's just cargo, the viscosity of the air increases with the speed of the projectile, so a lot of heat will be dissipated at the lowest altitudes, which is energy subtracted from what's available for overcoming gravitational potential.

Put enough energy into the projectile and it will overcome that "friction debt". The Ram Accelerator dodges the whole air friction problem by actually using the carefully chosen atmospheres within it's sealed sections as a source of thrust. It is therefore possible to make a Ram Accelerator long enough so that when the projectile leaves the end of the barrel, it doesn't matter about air friction because it's muzzle velocity is so high.

al8
14th October 2008, 00:19
I don't think one should need to feed all and educate all people of the world, then divest attention to space exploration and settlement. These objects don't need to be mutually exlusive. I think it important not to find endless excuses to not do it.

It like saying "we wont pay any heed to making instruments" until we eliminate world hunger. It is ludicrous because society consists of many individuals that have different interests and talents, and can therefore have different goals. Are we going to hinder a flutemaker from making flutes because there is a water-shortage on the other side of the globe? A diverted flutemaker dosn't nessisarily have the expertice needed to solve the problem in the first place or have any materials direly needed to stave of a food crises.

ÑóẊîöʼn
14th October 2008, 00:22
I don't think one should need to feed all and educate all people of the world, then divest attention to space exploration and settlement. These objects don't need to be mutually exlusive. I think it important not to find endless excuses to not do it.

It like saying "we wont pay any heed to making instruments" until we eliminate world hunger. It is ludicrous because society consists of many individuals that have different interests and talents, and can therefore have different goals. Are we going to hinder a flutemaker from making flutes because there is a water-shortage on the other side of the globe?

Let's not forget that all those housed, clothed, well-fed, and well-educated folks are not just going to be eating and sleeping - they're going to be working as well. Why not have some of them work in space research?

Vanguard1917
14th October 2008, 03:16
I agree that space research is underfunded and probably affected by the same lack of imagination and narrowmindedness, as well as risk averseness, which pervades Western society currently, particularly its elites, but also its opponents in the so-called 'left'. But i don't think we can assume that there will be mass opposition to space research in socialist society based on that. The way i understand it, socialist society, much to the chagrin of reactionaries, seeks to unleash humanity's potential for progress in all spheres of life, whether economic, cultural, technological or scientific.

What i'd warn against, though, is using the language of fear in order to win support for space research. We need to put forward the positive case for why space research is important - that advancing human knowledge of the universe is a good enough reason in itself. Evoking visions of apocalypse only adds to and helps reinforce the timid and fearful climate which is helping to hold back progress in the first place, i think.

ÑóẊîöʼn
14th October 2008, 03:33
I agree that space research is underfunded and probably affected by the same lack of imagination and narrowmindedness, as well as risk averseness, which pervades Western society currently, particularly its elites, but also its opponents in the so-called 'left'. But i don't think we can assume that there will be mass opposition to space research in socialist society based on that. The way i understand it, socialist society, much to the chagrin of reactionaries, seeks to unleash humanity's potential for progress in all spheres of life, whether economic, cultural, technological or scientific.

Well, I hope you're right and that my fears turn out to be unfounded. But I still think it is prudent to have some kind of back plan/strategy.


What i'd warn against, though, is using the language of fear in order to win support for space research. We need to put forward the positive case for why space research is important - that advancing human knowledge of the universe is a good enough reason in itself. Evoking visions of apocalypse only adds to and helps reinforce the timid and fearful climate which is helping to hold back progress in the first place, i think.

Well, I like to think my approach is different from that of the doom-mongers - more pro-active, IE actually enouraging that we do something about it other than just tightening our belts. It's probably just a sign of my passion that I've somewhat unconsciously started to follow the apocalyptic mode of thinking, as it seems to be the only thing that really garners attention these days.

But you are right - good research is it's own justification. But the problem of all scientists seeking funding is that research for it's own sake is not good enough for the grant committees. And my fear is that anti-science types will play on popular sentiment to withhold resources even in a communist society.

Vanguard1917
14th October 2008, 03:59
It's probably just a sign of my passion that I've somewhat unconsciously started to follow the apocalyptic mode of thinking, as it seems to be the only thing that really garners attention these days.

I know what you mean. I think it's important to go against the tide, though, so to speak. We need rational public debate about these things. While it's good to highlight why advancing human knowledge is so important, it's also important to rise above the language of fear which seems to permeate any discussion nowadays. Accepting their terms only helps add to the problem.

Plagueround
14th October 2008, 04:56
Anyone who doesn't think humanity reaching out into space is beneficial and crucial to our existence as a species needs to read some Freeman Dyson (some of the atheist members might want to skip his feelings on God though ;)).

mikelepore
14th October 2008, 17:33
A lot depends on the acceleration time. On earth escape velocity is about 11,000 m/s. Assuming the path is long enough to accelerates a projectile to that final velocity in five seconds, that's an acceleration of 2,200 m/s^2, which is about 220 g.

mikelepore
14th October 2008, 17:37
You're right about the inefficiency of rockets. The main cause of that is, not only you use fuel to accelerate the payload, you also use fuel to accelerate that portion of the fuel that haven't consumed yet and are still carrying.

Dust Bunnies
18th October 2008, 02:54
I believe that the current NASA goal (colonizing the moon) is incorrect. I am for any Stark Trekian research (warp drives anyone?). With each little science project or weapon we make, we increase the chance of wiping out the human race, therefore we need to learn how to make a decent propulsion system, then run to Alpha Centauri like the wind.

I would rather they make warp drives than more nukes IMO.

ÑóẊîöʼn
18th October 2008, 03:56
I believe that the current NASA goal (colonizing the moon) is incorrect. I am for any Stark Trekian research (warp drives anyone?). With each little science project or weapon we make, we increase the chance of wiping out the human race, therefore we need to learn how to make a decent propulsion system, then run to Alpha Centauri like the wind.

Actually, almost all propulsion systems are also capable of being used as weapons, or have military applications.

We must face the facts - we can't have advanced technology without also having advanced weaponry.

Colonising the Moon is a far more sensible goal than trying to build something that onyl has an outside chance of working (and how do you know that warp drive technology doesn't have any military applications?) - not to mention we must learn to walk before we run. We need practical experience of how to build self-sustaining habitats in space and on airless worlds like the Moon before we can even think of heading to Alpha Centauri.

Revy
18th October 2008, 05:15
A space elevator would be scary. What happens if the elevator breaks and falls down into Earth :eek:

Revy
18th October 2008, 05:17
I think it would cost less and be a much easier and faster process if all the nations of the world , worked together, and created an International Space Agency. Because the space race is really dumb, it always was.

ÑóẊîöʼn
18th October 2008, 05:36
A space elevator would be scary. What happens if the elevator breaks and falls down into Earth :eek:

Not a lot, actually. Most of it would burn up in the Earth's atmosphere, while the rest would whip into space, depending on exactly where the break occurred.