Thread: The Space Elevator

I don't think it would connect the Earth to the moon. The idea is just to have an easier way of escaping Earth's gravitational pull. It would just be connected to something out there orbiting in a geostationary orbit. This has been talked about and researched for a long time now, so I still wouldn't expect it any time soon.

Originally Posted by John11

I don't think it would connect the Earth to the moon. The idea is just to have an easier way of escaping Earth's gravitational pull. It would just be connected to something out there orbiting in a geostationary orbit. This has been talked about and researched for a long time now, so still would expect it any time soon.

Ah, I see. That makes much more sense. Heh.

The space elevator is literally the only way for us to truly become space-faring, and by extension, the only way for humanity to survive longer than a few hundred million years (that's when the sun starts boiling the oceans). And the only technology we don't yet have is a strong enough ribbon, but carbon nanotubes or some derivative will probably hit that mark very soon.

How I'd like to see a space elevator built while I'm still young.

I feel that our political differences will stifle the collaborative efforts that us, Russia, and other countries have put towards any BIG new developments for the space programs.

Hmm... what's the purpose? How is it more efficient than rockets? You still require the same amount of GPE..

Originally Posted by Xei

Hmm... what's the purpose? How is it more efficient than rockets? You still require the same amount of GPE..

Rockets usually get their potential energy from an extremely inefficient chemical reaction. If you actually took the time to calculate the potential energy of something the mass of the shuttle in orbit and compared that to the energy that the shuttle has in its tanks at launch, you would see that the initial chemical energy is an order of magnitude greater that the potential energy in orbit.

Fine, I'll do it. According to wiki, the specific orbital energy of LEO is 33 MJ/kg. I'm also going to assume the shuttle in orbit has the same mass it has on the pad, 109,000 kg, which is an overestimate. This means the GPE of the shuttle in LEO is 3.597x10^12 J

According to more numbers obtained from wiki, each SRB expends
1.55x10^13 J of chemical energy.

About 1.77x10^13 J for the LOX tank.

So in total, about 4.87x10^13 J expended for 3.597x10^12 J of orbital energy.

The advantages of the tether are two-fold:

1) energy can be used efficiently to reach orbit
2) energy can be provided from the ground via a visible or microwave laser, or from solar panels. Either way, the result is the fuel itself doesn't need to be carried on board. The advantages of this are obvious.

Hm, okay. I didn't realise it was possible to transmit large amounts of energy via lasers like that.

If we stopped wasting so much money on wars and stuff, and put it into space programs, we could have stuff like this.

Originally Posted by Alric

If we stopped wasting so much money on wars and stuff, and put it into space programs, we could have stuff like this.

So naive.

First of all, the money spent on wars is fiat money, not real money. Second, it will never be politically possible for a state to spend money on something that doesn't increase its own power. It just can't happen.

It's also true to say that military organisations can also invent technology that proves useful outside of a military use. The internet is the biggest example.

Peaceful scientific breakthroughs can be repurposed for war. But it is a 2 way thing.

Originally Posted by Photolysis

It's also true to say that military organisations can also invent technology that proves useful outside of a military use. The internet is the biggest example.

Peaceful scientific breakthroughs can be repurposed for war. But it is a 2 way thing.

Saying DARPA invented the internet is like saying Alexander Graham Bell invented the cell phone.

Well fiat money vs real money aside. If they are wasting resources, they might as well waste it on something like that instead of what they are currently doing.

Also being the only country with a space elevator, is very impressive. I would say more power and influence comes from something like that, than controlling iraq.

The first person to say "Beam me up Scotty" gets a bullet in their head.

Saying DARPA invented the internet is like saying Alexander Graham Bell invented the cell phone.

I didn't say they invented the internet as we know it. But it's true that the technology which was designed for a military use was repurposed.

In any case my point still stands.

Wow, that is so cool! Clean space travel as well! I hope I'm here to see it!
Wonder how safe it will be, could anything knock out the laser ribbon and
then would the elevator crash back to earth? I guess the designers would
figure all of that out. Very Cool!

Originally Posted by supreme

Wow, that is so cool! Clean space travel as well! I hope I'm here to see it!
Wonder how safe it will be, could anything knock out the laser ribbon and
then would the elevator crash back to earth? I guess the designers would
figure all of that out. Very Cool!

Here's an example of the environmentalist left brainwashing our youth. The space shuttle main engine combines hydrogen with LOX to produce water steam, the cleanest chemical reaction imaginable.

Thank you Nasa I choose to believe. All hail Nasa and also our new useful space elevator project! As we sure ain't getting off this planet lately. Nasa and our evolution. The private sector. With money we can do it. Believe it, support it. Progress it. You'll be off the planet in no time with Nasa, ready to explore the universe. And if not Nasa, pay someone else to screw you over. All we need is some fancy music and some more broken promises. This will delay your yearning for space travel for atleast another generation before we can come up with some other excuse to keep you grounded. It's a new project, it's different. You can believe in this one, unlike the Apollo missions. By the time you don't believe in this project hopefully you will have a short enough memory span that you can just forget about all the other times you got screwed over. That way we can start a new lie and start it all over again.

Originally Posted by supreme

Wow, that is so cool! Clean space travel as well! I hope I'm here to see it!
Wonder how safe it will be, could anything knock out the laser ribbon and
then would the elevator crash back to earth? I guess the designers would
figure all of that out. Very Cool!

Originally Posted by drewmandan

Here's an example of the environmentalist left brainwashing our youth. The space shuttle main engine combines hydrogen with LOX to produce water steam, the cleanest chemical reaction imaginable.

So...

Professor Fraser said: "The classic example of environmental impact is in Kazakhstan at the Baikonur launch site, where there are reports of quite serious environmental damage."

For most shuttles, the damage comes from the solid rocket boosters, or SRBs, require at shuttle launch to provide 71.4% of the thrust at lift-off and elevate the shuttle to an altitude of 45km (28 miles).

As a shuttle launches, a "cloud" becomes visible which contains SRB exhaust products, either dissolved or as particles in the water vapour released by the main engines.

Hydrochloric acid formed in this launch cloud leads to acidic deposits in the surrounding area, a phenomenon which may also be observed some distance away if exhausts are carried on prevailing winds.

Dead fish
The scenes of dead fish in Spain could be repeated next to launch sites
John Pike, president of Global Security.org, and an expert on the US space programme says: "The hydrochloric acid can pit the paint on your car if it is too close to the launch site."

http://news.bbc.co.uk/2/hi/uk_news/magazine/4130980.stm

...with the scrapping of the need for SRB's, is the shuttle not even cleaner than it previously was?

Originally Posted by Oneironaut

...with the scrapping of the need for SRB's, is the shuttle not even cleaner than it previously was?

I can't decipher the meaning of this sentence, but the shuttle gets most of its orbital energy from its main engines, which do produce pure water. NASA didn't use that reaction because of the environment; it just happens to be a very energetic reaction. The reason SRBs are used are purely economical. There's no physical reason the shuttle couldn't go on H+LOX alone.

Originally Posted by drewmandan

I can't decipher the meaning of this sentence, but the shuttle gets most of its orbital energy from its main engines, which do produce pure water. NASA didn't use that reaction because of the environment; it just happens to be a very energetic reaction. The reason SRBs are used are purely economical. There's no physical reason the shuttle couldn't go on H+LOX alone.

I just re-read it, and realized that what I meant to say was:

"...in scrapping the SRB's, wouldn't the space elevator still be a cleaner way into orbit than the present boosters?"

(Sorry. Smoked a bowl as soon as I got home. )

Originally Posted by Oneironaut

I just re-read it, and realized that what I meant to say was:

"...in scrapping the SRB's, wouldn't the space elevator still be a cleaner way into orbit than the present boosters?"

(Sorry. Smoked a bowl as soon as I got home. )

Dude, I like your style.

I suppose if you consider all the maintenance and the low efficiency of the rocket, one could argue that a tether might have smaller lifecycle CO2 emissions, but that's assuming producing either the H, LOX, or laser energy produces CO2 emissions at all. Bottom line, the main concern is energy usage, not environmental bullshit.