Energy savings with space elevator

In summary, the conversation discusses a paper on the energy saving of taking a payload to geostationary orbit using a space elevator. The formula given is incorrect and the premise is questioned. The paper cited is "The Physics of the Space Elevator" by P.K Aravind and explains the percentage of energy saved compared to using rocket propulsion. It is suggested that the paper may focus on alternative energy sources rather than fuel.
  • #1
bksree
77
2
Hi
I read in a paper that the enrgy saving in taking a payload to geostaionary orbit with a space elevator is (R/Rg)*(2-R/Rg) where R- radius of earth, Rg - radious of geostaionary orbit.

How is this obtained ?

TIA
 
Physics news on Phys.org
  • #2
bksree said:
Hi
I read in a paper

Please make a complete citation of the paper!

Zz.
 
  • #3
It's easy enough to calculate, and the formula you give is wrong, but more importantly the premise is wrong. Reaching orbit requires an increase in potential energy and an increase in kinetic energy. These are the same regardless of how you get there, whether you use a rocket ship or a space elevator.
 
  • #4
Thanks for the replies. The paper is : P.K Aravind, 'The Physics of the space elevator', Am. J. Phys., 75(2), Feb 2007.
The eqn actually gives the percentage saving of energy w.r.t that required if rocket prpoulsion is used. I think it is related to the energy required to accelerate to escape velocity with rocket propulsion wheras the space elevator uses the centrifugal force ofthe rotating Earth to accelerate the satellite.

TIA
 
  • #5
You don't need escape velocity to put a satellite in geostationary orbit. If it has this much velocity it won't be neither geo- nor stationary.

The paper may be about the energy "saved" from the point of view of not using fuel but rather some other way to get the energy required.
Similar to the energy "saved" by connecting an appliance to a solar cell or wind generator rather than the wall plug.
 

1. How does a space elevator save energy?

A space elevator is a proposed method of transportation that would use a long cable or tether anchored to the Earth's surface and extending into outer space. This cable would allow for objects and people to be lifted into space using much less energy than traditional rocket launches. The energy savings come from the fact that the majority of the work is done by the Earth's rotation rather than the rocket's propulsion.

2. How much energy can be saved with a space elevator?

The exact amount of energy that can be saved with a space elevator is still being studied and debated. However, some estimates suggest that a space elevator could save up to 96% of the energy currently used for rocket launches. This would have a significant impact on reducing our carbon footprint and dependence on fossil fuels.

3. What materials would be used to build a space elevator?

The two main materials proposed for building a space elevator are carbon nanotubes and graphene. These materials are incredibly strong, yet lightweight, making them ideal for supporting the weight of the elevator and its cargo. However, further research and advancements in material science are needed to make this technology feasible.

4. How would the space elevator affect space travel and exploration?

A space elevator would greatly reduce the cost and energy required for space travel, making it more accessible and affordable. This could lead to more frequent and extensive space exploration missions. Additionally, the space elevator could serve as a launching point for spacecraft, allowing for easier and more efficient travel to other planets and beyond.

5. Are there any potential risks or challenges associated with a space elevator?

While the concept of a space elevator is promising, there are still many technical challenges and potential risks that need to be addressed. The main challenge is developing a cable strong enough to support the weight of the elevator and its cargo. Other concerns include space debris, weather conditions, and the potential for sabotage or accidents. These challenges will need to be carefully considered and addressed before a space elevator can become a reality.

Similar threads

Energy savings with space elevator
    • Astronomy and Astrophysics
Replies
19
Views
6K
A Continuity of a quantity in a conical system to determine the velocity
    • Classical Physics
Replies
0
Views
165
How does the addition of a lift affect the forces on a space elevator?
    • Classical Physics
Replies
9
Views
1K
I Rosetta orbits and phase space
    • Classical Physics
Replies
20
Views
1K
Space elevator minimum initial speed
    • Introductory Physics Homework Help
Replies
3
Views
1K
Questioning the Solution for Elevator vs Rock Problem
    • Introductory Physics Homework Help
Replies
7
Views
1K
I Space elevator and Coriolis force
    • Astronomy and Astrophysics
Replies
6
Views
2K
I I need some support, please, for a gravity assist analysis
    • Classical Physics
3
Replies
86
Views
4K
B What is the total kinetic energy of the Earth relative to the Sun?
    • Classical Physics
2
Replies
40
Views
2K
A Confused about multipole expansion of vector potential
    • Classical Physics
Replies
4
Views
691

Hot Threads

Recent Insights

Back
Top