Space Elevator

I guess that in this community, there’s no need to explain what a space elevator is, and how much it would advance space exploration if we could actually build one.

So - should we launch a competition around building a space elevator? Or maybe just some parts of it?

What do you think?

Maybe part of it, e.g. demonstrating that using nanotubes can build a long bridge?

This would be fantastic. I can only see a sustainable future of space exploration that is built around an extensive space elevator infrastructure. We cannot keep using massive chemical rockets. That’s too much of an unsustainable brute force approach to escape Earth’s gravity.

There is already quite some work that is being done on the topic. Japan has been investing heavily in space elevator research. And there’s organizations like the International Space Elevator Consortium (ISEC) and the Space Tethers Technical Committee. However, we’re nowhere near close to even a working small-scale prototype. It would be good to use XPRIZE to boost concrete technical development.

@AngeloVermeulen -
I like @crointel 's idea of separating the problem into smaller parts - for example, demonstrating that one can build a long bridge (or similar structure) with the tensile strength needed.

You seem knowledgeable on this subject, so I would love to hear your ideas on how we can break this challenge down into its individual components.

Where’s the space elevator going to?

Shouldn’t we built (more) space stations first?

I don’t consider myself a real expert on the topic. It would probably be best to bring people into the conversation who actually work on space elevator technology. They could help define a very concrete challenge. I must admit I have some reservations about predominantly employing an approach of breaking down the challenge into smaller parts. Yes, we need concrete experimentation to move forward. But we also run the risk of losing the more holistic perspective that is really needed to get this idea off the ground. Personally, I always to try to present such a challenge as a larger idea, a larger image of the future that people get excited about. And then I try to get that supported by specific prototypes and experiments while permanently keeping the larger idea sharply in focus.

This is simply an alternative access to space. It literally brings people and technologies into LEO, just like rockets do on an almost daily basis. It’s not restricted to access to space stations. Here’s an interesting paper about the orbital mechanics of space elevators and the consequences for launch capabilities: https://www.sciencedirect.com/science/article/abs/pii/S0094576520306275?dgcid=rss_sd_all

Orbital rings and launch loops are additional concepts that take the space elevator idea even further. The entries on Wikipedia are pretty good introductions:


If we group these ideas and maybe more to, e.g. non-traditional delivery system to space, a more flexible prize design will be definitely needed. Breakthroughs in material science seem not required for certain idea(s), so a milestone challenge for material breakthroughs may not be necessary.

@crointel, @AngeloVermeulen -
Maybe we can indeed group all of these potential solutions together under a common theme: “dramatically (99%) lowering cost to reach low-Earth orbit”.

What do you think?

Yes, I think they can be grouped together. “Dramatically” is a good term used here, sounds cool and ambitious. Considering that SpaceX charges more that 60 million USD per launch and CERN is spending 21 billion EURO on a new particle accelerator, spending the same amount of budget as CERN’s project have or more on implementing a "dramatically (99%) lowering cost to reach low-Earth orbit” system, it makes very much sense, if a well-done proof of concept can be provided.

“Dramatically” works almost as well as “exponentially” :slight_smile:

Many years back, I wrote an internal paper on this subject. The concept I presented was a large spinning satellite at about 1000 miles up. A cable was extended from it that rotated in the direction to cancel forward motion of the satellite as the tip approached close to the ground, low enough to rendezvous with a high-reaching plane. Travelers would hop on the cable tip at the near-earth position, then let go near the opposite side. The release velocity would be very high, sufficient for rapid flight to the planets. The launch energy comes from kinetic /potential energy of the massive satellite. Exciting to me was the concept that the trip was “reversible,” a returning voyager could return his energy of re-entry back to the satellite. At the time, I concluded that available materials had a specific strength about ten times too low.

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Yes: a space elevator is worthy of an XPRIZE - it’s audacious and the future impact could be very significant!

An interesting read on Space Elevator:

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It sounds like some of those same ideas are being revisited, @ErnieRogers! More like a station at GEO, but with the tether extending to the atmosphere. I’m really excited to see where this technology goes. With the future of space travel hinging on reliable and inexpensive transportation, it seems like this idea has some promise and isn’t just science fiction anymore.

Some people are also thinking that a material like Kevlar could handle the tension/shear forces if an elevator is executed in this way.

Question: Is this the transportation breakthrough (even if it is still decades away, at least) that you’re most excited about? If not, what would your ideal transportation breakthrough be?

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Hi @buzlityr, @RobertB and @derleth - Curious to here your thoughts on Space Elevator being a breakthrough solutions to increase access to space.

The space elevator has some serious problems to implement that I don’t think many people realize. As you go vertically upwards there is a force that drags the object backwards ( with respect to the earth’s rotation). This is simple orbital dynamics. For example if you are in orbit around the earth (which is what you would be if you were going up or down on a space elevator), if you go up you will be drawn back away from the vertical and if you are coming down the elevator you will be pushed forward perpendicular to the radial direction. To counteract this “force” you would have to provide an equal and opposite force accelerating in the forward direction JUST TO STAY IN A VERTICAL PATH. This would add a lot of extra mass to every payload equivalent to the fuel necessary to put the object into orbit. There is no free lunch and the common assumption of the space elevator is that you just ride up and when you get to the top you are in orbit. That is not how orbital dynamics work (physics 101). You have to put energy into the system in the horizontal direction as the object rides up to maintain the constant rotational velocity. The second issue is that you would be putting a conducting path (even if your elevator material was not conductive) short circuiting the ionosphere vertical electric field to ground. Not a good idea. The same issue exists with any gravitationally weighted tether. It will discharge the local vertical electric field. The space shuttle tether team experienced this when they extended a tether out of the space shuttle bay only a few hundred meters causing a lot of physical and electrical damage to the shuttle.

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@jmcc1 - Welcome to the XPRIZE Community James!
Thanks for sharing your thoughts on the workability of space elevator.
What are your thoughts on democratizations of space? What breakthroughs could open up space? You can share your thoughts here.

Hi, @jmcc1! Welcome to the community! Glad to have you here!

I think that the idea that more people have been “gravitating” toward (ha!) is an elevator that starts with the tether attached to an object in geostationary orbit. That way the tether wouldn’t be attached to the Earth at all.

Do you have any comments on this type of approach?

@ErnieRogers do you have any response or input to these ideas?