Space Elevator Vehicle: Acceleration After Cable Release

In summary, the conversation discusses the concept of a space elevator and its potential for travel beyond Earth's gravity. It is noted that as the vehicle travels up the cable, it will slow down due to gaining potential energy and losing kinetic energy. The conversation also clarifies that the vehicle will never truly leave Earth's gravity but will reach a point where the rate of deceleration becomes almost zero. This point is known as escape velocity. The conversation ends with a request for a link to a NASA pdf discussing the concept of space elevators.
  • #1
nuclear tan
2
0
Say you have a space elevator 47000 km* long (well past the point where centripetal acceleration cancels out gravity)

There is a vehicle traveling up the cable with a pretty high velocity, and instead of braking it just shoots off the top. (assume the counter weight allows this)

At the instant the vehicle leaves the cable, itwould be traveling at the magnitude of the normal and tangential velocity... I think.

Would it slow as it escapes Earth's gravity, or has that already been taking care of?


Now I apologize if this is the wrong forum.

This isn't homework, it's just something I have been thinking about.


*fyi I read about this enormous length in a NASA pdf...
 
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  • #2
Space elevators are very interesting. Could you post a link to the NASA pdf?

Thanks
Matt
 
  • #3
nuclear tan said:
Would it slow as it escapes Earth's gravity, or has that already been taking care of?
Yes it will continue to slow down.
Every metre higher it gets it gains potential energy - it must pay for this with kinetic energy by reducing it's speed.
As it gets further away the extra energy in going each metre is less (because Earth's gravity is progressively weaker) so the amount of slowing down is less with each metre.

It never leaves Earth's gravity - there is no limit to gravity (it goes on forever) but eventually it reaches a distance where the gravity is so weak that there is very little difference in potential energy at each extra metre and so the rate of deceleration goes to almost zero.

Escape velocity is the speed you would need to start at so that when you got an infinite distance from Earth you would still have some kinetic energy (and hence speed) left.
 
  • #4
mgb_phys said:
Yes it will continue to slow down.
Every metre higher it gets it gains potential energy - it must pay for this with kinetic energy by reducing it's speed.
As it gets further away the extra energy in going each metre is less (because Earth's gravity is progressively weaker) so the amount of slowing down is less with each metre.

It never leaves Earth's gravity - there is no limit to gravity (it goes on forever) but eventually it reaches a distance where the gravity is so weak that there is very little difference in potential energy at each extra metre and so the rate of deceleration goes to almost zero.

Escape velocity is the speed you would need to start at so that when you got an infinite distance from Earth you would still have some kinetic energy (and hence speed) left.

Ha! Thank you.
 

1. What is a space elevator vehicle?

A space elevator vehicle is a proposed type of spacecraft that would travel along a long cable extending from Earth's surface into space. It would use the Earth's rotation and centrifugal force to lift payloads into orbit without the need for traditional rockets.

2. How does a space elevator vehicle accelerate after cable release?

After the space elevator vehicle detaches from the cable, it would accelerate using its own propulsion system. This could be achieved through the use of ion thrusters or other forms of electric propulsion, which would gradually increase the vehicle's speed until it reaches the desired orbit.

3. What are the potential benefits of using a space elevator vehicle for space travel?

The use of a space elevator vehicle could significantly reduce the cost and environmental impact of space travel. It would also allow for larger payloads to be lifted into orbit, making it easier to construct and maintain space stations or launch missions to other planets.

4. What are the challenges of building and using a space elevator vehicle?

One of the main challenges is the development of materials strong enough to support the weight of the cable and the space elevator vehicle. Another challenge is creating a stable structure that can withstand the extreme forces and conditions of space. Additionally, there are safety concerns and potential hazards to consider, such as collisions with debris in orbit.

5. Are there any ongoing projects or plans to build a space elevator vehicle?

There have been several proposals and conceptual designs for space elevator vehicles, but no major projects have been started yet. Some companies and organizations are conducting research and testing materials for potential use in a future space elevator. However, the technology and infrastructure needed for a fully functional space elevator are still in the early stages of development.

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