Arthur C. Clarke wrote about them in Fountains of Paradise, Kimberly Stanley Robinson in 2312, Heinlein in Friday and the list goes on and on. Space Elevators are an eventuality and fiction, in this case Sci Fi is the fore shadowing of what will be.
Arthur C. Clarke was asked if and when we might actually have space elevators and his response was ‘Probably about 50 years after everybody quits laughing’. Well, they are not laughing now, haven’t been for some time, they have been planning out every detail and getting it all together. There are meetings of a group (the ISEC) where papers are submitted, theories volleyed and a convention that is held each year, and there are countries, worldwide, working on the space elevator: NASA, the ESA, Japan, China and likely others. Several years back it was assumed that all this would come together by 2015, sadly that is not to be, but not because people have thrown their hands in the air and given up, but because they are moving forward full speed. Look for a space elevator to make its appearance around 2035. This actually makes so much sense and in my opinion will help place the needed politics in place as well. The LiftPort group is placing a space elevator on the moon in 2019. Consider that there will be a ton of activity in the years that follow 2019 – countries setting up colonies or observatories, mining, tons of needed supplies, and how will we get them there?
Probably at first SpaceX will launch them to one of the Lagrange points where it will then join up with the LSEI (Lunar Space Elevator Infrastructure). The frequency of the launches required will make the expense evident and so the Space Elevator will come off the back burner and take the forefront. (A recent report estimates the “old” way of using launches costing $20,000 per kilogram whereas with the Space Elevator it goes down to $500.) The technology, having been designed all along, will already be ready and so the countries together will bear the cost and the space elevator will be born.
Another bonus if it goes up in time for Mars, the cost of the launches for Mars can be calculated as starting above Earth’s atmosphere; Spacecraft taking off fromPais Unis, the station at the top of the world.
The technology was worked on all along? Yes, let’s review.
First, what is a Space Elevator? This can be explained two ways.
-First picture an elevator and no building around it. The elevator in reality is attached to a tether that disappears into the sky and the tether is in turn is attached to a counter weight. Not good enough?
-Remember the game tether ball? The ball is on a tether and the tether is attached to a pole. Picture the ball revolving around the pole. The ball is the counter weight in space; the tether is the tether (not a reach) and the pole, the pole is Earth.
The concept itself is relatively easy however there are concerns that come into play and hence these technologies are taking time to develop and so the reason for the year 2035.
We start with the Anchor. First there were two locations that were possible – a mountain top where one sees a reduction to the influence from the atmosphere, strength to density requirements for the tether cable etc., but there is the wind. However a location of the coast of Ecuador in the eastern equatorial pacific could offer the lack of Tornadoes and Hurricanes. There is another location being considered, the Indian Ocean, about 500km off of Perth – it offers one advantage, and that of course is shipping. Also, it lines up with geostationary orbits but then so does Ecuador. Throw on some Active Avoidance technology and it can move left or right a few miles should it become necessary – maybe incoming from outer space or response to something on Earth. This brings up protection from terrorists. While NOTHING can be 100% terrorist proof as once one decides die for a cause and eliminates having to escape they become a little more dangerous, having a sea location that is simple and very much like an oil rig without the oil, a simple platform floating in the ocean that can see all directions. But of course it would also become a shipping port of sorts with satellites deliveries or cargo for delivery to the Moon. Below the ocean there can be a sophisticated defense system or simply a depth charge or some combination of the two. It would require some sort of powering device. Albeit from the space side there will be a solar collector providing approximately half the energy requirements from the Earth there needs to be not only whatever form of energy is selected but also the transfer of that energy via photonic methods.
Next we go to the Tether. For the tether there are many considerations but not the least of which is the need to have strength. Strength for the weight that will be on it, the highest amount of stress is on the tether at the geosynchronous altitude and so it requires a cable that is its thickest at that height but tapers as it approaches Earth. A number of materials have been looked at from steel to diamond but all were tossed aside for various reasons from propagating cracks in the given situation to strength. Carbon Nanofibers a relatively young material is both 100 times stronger than steel as well as lightweight. A manner of gaining further strength requires the transformation into a nanoribbon. As the diameter will need to be approximately 10 meters and it needs to extend to about 35,786 km in altitude, this involves quite a quantity. Producing nanotube ribbon has presented a challenge at these lengths but one particular lab in Texas did have some success in continuing the knit past 2 meters. As that was a while ago odds are that amount has improved. If it has not there is a meta-material that was developed they started with this material and then treated it, breaking it down even smaller and the scientists found that when the material was smaller it became stronger. Counter-intuitive but true. It became bullet-proof. AND the Canadians have created a business suit out of it so we know it can be woven.
Another piece would be the Climber. The climber is little more than the elevator. An elevator but with a receiver that faces Earth for receipt of a laser transfer of an energy source; then another facing upward for transfer of energy from the solar collector up in space. There would be at least three different elevators that would be attached depending if there were human cargo, a satellite, or perhaps foods and other type cargo bound for the Moon and the colony there. The one for satellites might have a special robotic system that would enable autonomous release at the proper level, a release that would hurry it away from the tether.
The final piece of the space elevator is some sort of counterweight. Now certainly when the idea began a simple asteroid was considered as the counter-weight. At a cost of ~$800 million a launch, a space elevator would be more cost effective, launching from a platform already outside the Earth’s atmosphere. And so the space elevator ended at a parking lot, a place where the spacecraft is awaiting the astronaut’s arrival. Of course now it has expanded a bit more to include a cantina of sorts. When it is built who knows how much will have been added. Makes sense though. If the weights lifted changed to higher down the line then the counterweight would have to weigh more. IF one starts at a higher weight it avoids adding on later.
Now if you back out with your mind’s eye as so far this is a simple concept and what could possibly go wrong you start to realize the problems. First there is all the debris we have up in “space”. Those many satellites and pieces of rockets etc. that now just circle the Earth. Next we can foresee meteors coming through the atmosphere either reaching different levels before burning up (and the tether goes through all of them) or making it all the way to Earth. For this NASA has something up their sleeve.
In addition to the removal of various debris in space and every country is offering up a solution (Japan has it’s Tether, Swiss Space has the Clean Space option for new satellites to plan ahead, the ESA has the laser option, VASIMIR/Ad Astra Rocket has promised a space tug to clean the geosynchronous orbit and the list goes on) and in addition to extending the life of current satellites so they do not become space debris (NASA & Canada had the RRM mission and MDA has a refueling satellite as a result and NASA is testing something new along the same lines) there is the “bubble”.
Perhaps you have heard of it; maybe with regard to Warp Drive, perhaps with protecting a spaceship from cosmic radiation and micro meteors, even protecting a space colony. The same concept is also being planned to protect the space elevator.
So these are the basics and as you can see a lot of thought has gone into them. There are more details and those have been considered and worked out as well. So when we get to transferring cargo to the moon or we get to more frequent launches, we’ll need the space elevator. Currently, they are talking 2035. I think 2025 would be a better goal which means they probably should start assembly next Tuesday.