Getting up into space is expensive and difficult. Think about it. Some of it comes to mind quickly, tons of fuel, expensive rockets, a huge launch crew. But there is more:

someone has to recover the rocket boosters

replace the heat shield tiles after every launch

transport and store all that fuel

many years of training for the pilots

the weather has to be right

refurbish all the rocket parts

very inefficient energy use

and on and on and on…

Currently, it costs about $10,000 per pound to get something into orbit! That cost is for low Earth orbit, which is the cheapest.

All the above is to show you that our method for getting into space is horribly inefficient and will need to be replaced if we want to have practical space flight.

Technology for flying into orbit is improving, better rockets, lighter systems, and even planes that can fly from the atmosphere into orbit are being worked on right now. But there are even better methods that could be coming over the horizon.

What if we were to build a skyscraper that was 22,000 miles tall. To get into space, all you would have to do is take an elevator ride to the top. This was the idea of Konstantin Tsiolkovsky in 1895. Over the years the form has changed from a tower to a cable suspended from the sky but it was firmly in the realm of science fiction. Like many ideas, it has refused to stay in there.

How high can you jump up? A few feet at most. How high can you climb a rope? 10 ft? 50 ft? If it is not more than you can jump you need to get off you computer now and do some pushups…I will wait.

It is much easier to gain altitude climbing up an object than it is to fly up.

So what is it? It has 4 main parts. A cable, a counterweight, a base, and a climber.  A counterweight is in orbit around the earth outside of geostationary orbit. (the point were an object in orbit stays above the same place on Earth.) A cable extends down from the counterweight to the base on earth. The climber then climbs the cable taking people and cargo into orbit.

This works because of centripetal force, the same thing that keeps water in a bucket when you swing it over your head. As the bucket spins, you have to pull on the rope to keep it moving in a circle (It wants to move in a straight line from inertia) If you pull on the rope too hard the bucket will move toward you. If you don’t pull hard enough the bucket will fly away.

The space elevator will work the same way. The Earth is rotating and pulling the cable, swinging it and the counterweight around in a circle. Unlike you, the Earth has enough mass to have gravity. If the balancing act is done correctly the force of gravity on the cable and counterweight will be the same as the force needed to keep the cable/weight moving in a circle so the Earth does not even need to be attached to the cable!

This is what a Nano-tube looks like. Each sphere is one carbon atom.

The hardest part of the elevator is the cable. The material has to be strong enough to hold up thousands of miles of itself. Think about it. If you have a rope hanging off a cliff, the top of the rope has to hold up the weight of all the rope hanging below it. It was only recently that a material that might be strong enough was created. The material is carbon nano-tubes or a similar material called graphene. These are made from carbon sheets. While they seem to be strong enough to make the cable, we currently don’t have the technology or know-how to create long cables of the material.

The counter weight is easy. It can be anything. Most likely this object will be a space station and dock for trips to and from the elevator.

The base station could also take many forms. While the cable could be designed so it did not need to be attached to anything, it would be easier to have it attached to an anchor. Several forms have been proposed. Some are stationary bases that would act like an airport for people traveling into space. Others have proposed that the base station should be a large ship. This would allow the elevator to move to dodge bad weather and space debris.

 

This is one artist’s concept of a climber

The last piece is the climber that goes up the cable. It could also take many forms depending on if it was carrying cargo or people. Energy would most likely be sent to the climber through the cable or by using lasers to send energy. It would also need to carry anything the passengers would need for the trip. This would include an air supply and food. Even if the climber gets moving at 200 mph the trip to geostationary would take 4.5 days. We will have to develop better elevator music!

Dr. Michio Kaku Explains the Space Elevator

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We still have a lot of work to do before this can become a reality, but it seems like it is coming.  A company in Japan says that they want to build one by 2050 and several others are also working on it, such as Google. There are also several prizes being offered for those who can develop technology for the elevator.

Will we be able to climb into space someday? No one knows for sure, but it is clear that mankind wants to move into outer space so something must be created to make it easier.  Maybe in your lifetime you will say ”Will you please hit the geo orbit button for me?”

 

–Jay Murphree

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