How much would it cost to build a space elevator?
How much would it cost and how much resources would it take to construct a space elevator from a fixed point on earth to a geosynchronous orbiting space station?
Would it be feasable to do this in say the next 20 years?
The reason I ask is because a Fixed space elevator capable of taking up tonage of material into space would have a far less cost then say normal rocket propelled methods of transportation. Thus reducing the cost to get into space for ALL mankind! Huzzah!
Here is some information for you – A circular geosynchronous orbit in the plane of the Earth’s equator has a radius of approximately approximately 35,786 km (22,236 statute miles) above mean sea level.
A statute mile is 1,760 yards – or 5280 feet
so to get to a geosynchronous orbit it would take a distance of 188,950,080 feet
What Diamiter should the cable fixing the stationt to the planet be? Use algebraic functions to figure out a volume– then figure out how much it cost in volume units to create cable made of a material that has a unknown strength.
How much strength should the cable have?
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Comments on How much would it cost to build a space elevator?
It would take BILLIONS(possibly trillions) of dollars and resources to build such an elevator. Also, much notably research has to be done to accomplish that feat.
If we could use a special type of fuel for it like all solar powered then it would be a LOT cheaper
Trillions just do to the research needed to make the necessary
construction materials but could we yes if we wanted to bad enough and in 20 years.( i have faith in the ingenuity of the human race when it really wants to do something.)
It would cost quite a bit. However if it is paid by private entrepreneurs rather than thru tax monies the burden on the economy for its construction will be negligable.
I bid the job for $8.93…checks, cash or money orders accepted.
They’ve estimated somewhere between $5-10 billion dollars. Not too bad when you come to think about it:):)
Okay. Let’s see. The Saturn V weighed about 6.7 Million lbs and could lift about 200 thousand lbs into LEO. That is about 3%. Yes, a tether should be much more efficient. If it were practical.
The greatest tensile strength material that is commonly available is Kevlar. The problem is that if we take any thickness of Kevlar cord it will reach breaking strength in 400 miles. In other words, when the cord gets 400 miles long the weight of the cord equals the breaking strength of the Kevlar. If you taper the cord you can reach 800 miles. However, 800 miles is quite a bit short of the necessary 22,000 to reach geosynchronous orbit.
Okay, now let’s look at gravity. Gravity decreases with the square of the distance. The Earth’s surface is about 3,500 miles from the center. If you go up 3,500 miles above the Earth’s surface the gravity is only 1/4. At about 1,500 miles up the gravity is about 1/2. This is why the tether concept is so frustrating.
With the gravity at 1/2 and decreasing to nothing as you go out toward geosynchronous orbit Kevlar is strong enough. So, the last 20,500 miles is no problem. The problem is the first 1,500 miles where gravity is 1/2 and increases to 1. The Earth’s gravity is still at 80% at 400 miles so you do get a littel help. However, even taking into account the reduction in gravity the Kevlar will still break at about 1000 miles. However, if a material is developed that is twice the strength per weight of Kevlar then a tether could reach to about 4,000 miles. If you can increase the strength by about 3 then you would have some left over for payload.
There are other practical considerations like how you would pull against the tether to raise the car without abrading the tether. Also, in space temperature would be a problem because Kevlar would melt if got too hot and would risk being brittle if it were too cold.
A more practical near term vehicle might be something like a linear accelerated vehicle that would essentially be shot out of a magnetic canon. For example, you put one in the Rockies and you can clear one mile of atmosphere and have plenty of time to accelerate to a nice speed. This would also relieve the inefficiency of having to carry the weight of the reaction fuel. The downside is that I’m not so sure about hitting the atmosphere at hypersonic velocities as you exit the barrel.
Third on the list is an air breathing lifter. The reason why this is nice is because with typical liquid hydrogen/liquid oxygen rockets the oxygen weighs 8X as much as the hydrogen. If you could get the oxygen from the atmosphere the efficiency would go up tremendously. This has been done with a bomber with the X-15′s and more recently with the lifting craft on Spaceship 1. However, the ultimate would be a SCRAMJet engine which would allow you to get higher and boost the space vehicle to a higher initial speed.
It would probably cost tens to hundreds of billions of dollars. The problem is finding a material strong enough to support itself without breaking. Kevlar is not strong enough with a tensile strength of about 3.7 gigapascals. Carbon nanotubes are strong enough with a tensile strength of 63 gigapascals.
The idea would be to tether a very small asteroid at the top just a few kilometers PAST geo synchronous orbit to keep the space elevator cable under tension at all times. Because the asteroid is tugging on the cable, it should stay put, despite being a few kilometers past geo synchronous orbit.
To make this a reality in 20 years, we will need to be able to produce carbon nanotubes in large quantities. This feat has yet to be achieved.