Physics / Math question

[manlymatt83]

I was reading this article:

http://www.time.com/time/health/article/0,8599,2099830,00.html?hpt=hp_t3

And it made me think....

Let's say the space elevator went 200 kilometers into the sky (double the height of which NASA considers you "in space"). If it was attached to the earth, therefore rotating directly related to the amount the earth was spinning, how fast would the top of the elevator (200 kilometers up) be moving through space? Would it be faster than the 17,000 miles per hour someone would need to maintain orbit? In other words, if they hopped out of the space elevator at 200 kilometers, would they immediately begin falling back to earth because they weren't moving faster than 17,000 mph?

 

[IronWing]

Look up "space tether", you should find the length needed for a self supporting space elevator where folks wouldn't fall back to earth.

 

[blinblue]

According to my calculations you be going about 1073 miles per hour. The speed required for orbit at 200 km above the earth's surface is closer to 17415 miles per hour.

So no, you'd fall back to earth, and it would be pretty painful

 

[Blackjack200]

Any space elevator would need to get to the same altitude as GPS satillites for someone to be able to step outside them and not fall to earth.

 

[ichy]

Any space elevator would need to get to the same altitude as GPS satillites for someone to be able to step outside them and not fall to earth.

No, it would need to be higher. GPS satellites aren't in geosynchronous orbit.

 

[Blackjack200]

No, it would need to be higher. GPS satellites aren't in geosynchronous orbit.

Weird, I had always assumed they were. I don't know why, but I'm really fucking annoyed that I thought that for so long

 

[IronWing]

Weird, I had always assumed they were. I don't know why, but I'm really fucking annoyed that I thought that for so long

It's okay. The WAAS satellite(s) is(are).

 

[Leros]

My biggest concern about this space elevator is the time it takes to ascend. From what I'm reading, the ascent will take a few days. That's a pretty long time.

 

[IronWing]

That's a pretty long time.

Particularly with that creepy guy who just won't shut up standing next to you the whole way.

On the positive side, the Bruce Willis movie with him crawling through the escape hatch in the ceiling of the elevator will be most awesome.

 

[ichy]

My biggest concern about this space elevator is the time it takes to ascend. From what I'm reading, the ascent will take a few days. That's a pretty long time.

For people it might be. For unmanned satellites it's not a big deal.

 

[DrPizza]

My biggest concern about this space elevator is the time it takes to ascend. From what I'm reading, the ascent will take a few days. That's a pretty long time.

Astronauts on the ISS spend a couple months up there. What's a few more days?

 

[Leros]

Astronauts on the ISS spend a couple months up there. What's a few more days?

Well, I was thinking more about mainstreaming space travel. Private operations, space tourism, etc.

 

[bobdole369]

According to my calculations you be going about 1073 miles per hour. The speed required for orbit at 200 km above the earth's surface is closer to 17415 miles per hour.

So no, you'd fall back to earth, and it would be pretty painful

Your speed does not negate gravity. The effect you are looking for - is the absence of centripetal force (the so called pseudo-force - centrifugal force). It tends to keep you moving outwards towards space. If I recall - a space elevator must be significantly longer than merely 200 miles. If I recall it must be geosynchronous so 36k miles.

 

[Puppies04]

A few days in an elevator, how many farts are you going to have to put up with. That is wrong on so many levels *badum tish*

 

[NuclearNed]

Slightly off topic, but Arthur C. Clarke wrote a great fictional story about a space elevator:

http://en.wikipedia.org/wiki/The_Fountains_of_Paradise

 

[silverpig]

Your speed does not negate gravity. The effect you are looking for - is the absence of centripetal force (the so called pseudo-force - centrifugal force). It tends to keep you moving outwards towards space. If I recall - a space elevator must be significantly longer than merely 200 miles. If I recall it must be geosynchronous so 36k miles.

Close. The centre of mass has to be at geosynchronous orbit. Adding up all the mass needed to support the cable and what not below geosync, you have to have a significant amount of mass past it in order to get the balance you need.

So a really long freaking cable of turbo high strength stuff is needed.

 

[Q]

I think the answer is yes.