Human Space Flight

[Sparko]

The moon does rotate. I rotation = 1 revolution. It would be a really long elevator, though.

well yeah.

I was also thinking maybe the other end of the elevator might be just in a longer orbit around the earth, but like you said it would have to be pretty long for the centrifugal force to overcome the pull of the lunar gravity if it were anywhere close to the moon. I think the same if you tried to put it in a shorter orbit, or even in front of or behind the moon in the same orbit.

[Christianbookworm]

What if you could connect an indestructible(so space junk doesn't destroy it), elastic(handle orbit distance irregularity) space elevator from Earth to the Moon? And then attach all the planets with an infinite stretchy cord. What's the worst that could happen?

Wait, the Earth rotates every 24 hours, but the Moon takes a month. Oops. We'll need a never ending space elevator!

[37818]

What if you could connect an indestructible(so space junk doesn't destroy it), elastic(handle orbit distance irregularity) space elevator from Earth to the Moon? And then attach all the planets with an infinite stretchy cord. What's the worst that could happen?

Wait, the Earth rotates every 24 hours, but the Moon takes a month. Oops. We'll need a never ending space elevator!

They might build one by 2050.
http://www.seeker.com/next-floor-the...769119212.html

[Jedidiah]

They might build one by 2050.
http://www.seeker.com/next-floor-the...769119212.html

The earth end would have to be on a globe circling track.

[Carrikature]

Space elevators continue to be one of the dumber sci-fi ideas.

[Leonhard]

I don't think you can really build a space elevator on the moon. It requires a geostationary (or in this case lunarstationary) orbit, which you can't have on the moon because the moon doesn't rotate.

You're right that you can't do a geostationary orbit around the moon, however you can still build a space elevator. There's a specific point between the earth and the moon called a lagrange point, where the attraction from the earth and the moon combines to make possible an orbit which stays at the same distance between the two. Its roughly 65000 km above the surface of the moon, and acts a bit like a pseudo geostationary orbit.

Due to its low gravity building a space-elevator on the moon would be possible using fibers of kevlar or spectra, or some other strong fiber thread. The cable would extend up to the L1 point and a little further out to a heavy counterweight on the other side pulling towards Earth, that counterbalances the forces from the weight of the cable trying to pull everything towards the moon. It would be a difficult construction, but possible if we ever need to routinely send huge amount of cargo to the moon or back. It would also mean we'd only have to send ships to the L1 lagrange point and not to the moon itself, saving a bit of fuel.

Its interesting that there are five of these orbits. With one lying on the opposite side of the moon.

[Leonhard]

Space elevators continue to be one of the dumber sci-fi ideas.

For Earth its definitely a stretch.

[Leonhard]

They might build one by 2050.
http://www.seeker.com/next-floor-the...769119212.html

Its hard to make future predictions on a space-elevator since the substance we require (strong carbon nanotube fibers) hasn't been developed beyond microscopic laboratory samples, and there isn't a clear path to producing industrial quantities.

[Cerebrum123]

For Earth its definitely a stretch.

I remember them using one in Generator Rex, and it was on Earth.

[Leonhard]

I remember them using one in Generator Rex, and it was on Earth.

There's nothing wrong with the concept per say. It just relies on materials we can't build with the technology we have. Its stuff that does exist, but we can only make microscopic quantities of it at the moment. This makes space elevators speculative. We can study all theoretical aspects of its construction, but whether we build it depends on a breakthrough that may or may not come.

The more interesting question for me is whether there's a need for one.

A space elevator has to be maintained once its built; Its pelted by micro and not-so-micro meteorites, hard radiation, an ionic and corrosive upper atmosphere, and even stress and strain from oscillations when things on in the atmosphere moves, or climbers ascend. It would have to be maintained. New layers of substance would have to be laid down repeatedly and that means there's a cost in just having it standing around. Whether its sending people and cargo to space or not.

So if a space elevator is to make sense, it could only make sense if we have enough of a need to send people and things into space, to outweigh the maintenance costs. Without a high level of traffic, a space elevator isn't worth building. Rockets would be cheaper and simpler, reusable or not.

The deep hard question for those proposing more extreme ways to orbit is: Why need do we have to send lots of stuff into space?

[Cerebrum123]

There's nothing wrong with the concept per say. It just relies on materials we can't build with the technology we have. Its stuff that does exist, but we can only make microscopic quantities of it at the moment. This makes space elevators speculative. We can study all theoretical aspects of its construction, but whether we build it depends on a breakthrough that may or may not come.

The more interesting question for me is whether there's a need for one.

A space elevator has to be maintained once its built; Its pelted by micro and not-so-micro meteorites, hard radiation, an ionic and corrosive upper atmosphere, and even stress and strain from oscillations when things on in the atmosphere moves, or climbers ascend. It would have to be maintained. New layers of substance would have to be laid down repeatedly and that means there's a cost in just having it standing around. Whether its sending people and cargo to space or not.

So if a space elevator is to make sense, it could only make sense if we have enough of a need to send people and things into space, to outweigh the maintenance costs. Without a high level of traffic, a space elevator isn't worth building. Rockets would be cheaper and simpler, reusable or not.

The deep hard question for those proposing more extreme ways to orbit is: Why need do we have to send lots of stuff into space?

Well, a few reasons it was a "doh" moment for the cartoon IMO. 1. Their technology seemed to only be a little more advanced than ours in a few areas, and one example of super secret[1] technology much more advanced than us. They likely didn't have massive quantities of rare material to use. Especially with the crisis[2] Earth had been in for some time. 2*. It was supposed to have been out of use for a long time. Likely no repairs for a long time either. Looked and worked as if it was brand new. 3*. They sent the main character up there on the elevator without any kind of special suit or anything. Sure he has special powers, but they have limits. Did I mention this one was only built to send up supplies, and not people. Apparently most people would die from the G forces involved. It could get stuff from Earth to space in like 30 seconds or less.

I think they only threw it in the episode because they thought it sounded cool, and to add to the sense of urgency for what Rex had to do.

* Been a long time since I saw the show and episode in question, so certain parts might not be 100% accurate.

1.Well the nanotech was a secret until it was released all over the world and started mutating living creatures at random.
2. The mutated people/creatures were often violent, and much stronger than anything natural. Everyone was infected too. Only a matter of time before you changed unless they developed some sort of cure.

[Sparko]

They might build one by 2050.
http://www.seeker.com/next-floor-the...769119212.html

yeah that is a typical sci op piece by someone who has no idea what they are talking about.

First, the moon is 238,900 miles, not 59,651 miles. Second, you can't run a tether to the moon. It would wrap itself around the Earth in a day.

A space elevator has to be in geosynchronous orbit with the earth. Or sort of. Basically the other end has to be just beyond the geosync orbit which is about 22,236 miles. That would keep the tension on the line via centrifugal force. Too far out and the tension would snap the line to Earth. After you have an Elevator, You could then have another line extending beyond the endpoint to launch payloads into space easily. That is where the 59K mile length probably comes in on the story. So
like this:

EARTH---------------------22K Miles ----(elevator top) ----------------- line to launch payloads--> [empty space for 200K miles] (Moon)

[Carrikature]

The deep hard question for those proposing more extreme ways to orbit is: Why need do we have to send lots of stuff into space?

Because we want to move there. And that means, at least at first, making a ton of stuff down here and putting it out there. Once we can get manufacturing going out there, life gets easier. A lot of the silly gravity well issues go away.