The Lofstrom Loop | Hacker News Reader

The Lofstrom Loop

en.wikipedia.org

30 pointsbeernutz19 comments

It's frustrating that many of these alternative approaches to accessing space (e.g. the space elevator) are "all or nothing", i.e. they require a massive investment just for performing preliminary experiments. Rockets (and to some extent space guns) can be built up incrementally, in range and capacity, which is probably a major reason they're so far ahead.

I'm not sure if miniature launch loops would be viable (i.e. self-supporting), but it should certainly be possible to build a space fountain up from the ground, at a very small scale. I'm still waiting to see it done though :(

Maybe this would be a project Gulf countries could blow their money on rather than supertall buildings.

Maybe the supertall buildings are designed to be adapted into space elevators? See also: Empire state building as dirigible mooring station.

If they want to go higher they'll have to do something brave at some point: https://en.wikipedia.org/wiki/Space_fountain

I think there have been space tourism projects pitched to Dubai and Saudi Arabia, but they haven't taken off.

It would be one natural path towards actual spacefaring.

That may be underestimating the cost of a loop by three or four orders of magnitude.

I can't help to think that given the size of the structure it would be almost impossible to guard, and would be highly susceptible to sabotage. (by groups against space colonization ?)

I like this list:

https://en.wikipedia.org/wiki/Non-rocket_spacelaunch

Some ideas seem rather sci-fi :D

Back when the web was relatively new (say 1998), NASA's Institute for Advanced Concepts (NIAC) had a great page that enumerated most of the exotic alternative launch ideas and presented simple graphics and short formulas on what their problems were.

It was back when a much higher portion of people browsing the net could be expected to be relatively technically competent and to care about content and not gloss. Maybe it was removed since it didn't come up to some visual standard. Sadly I haven't been able to find it on archive.org

Some ideas seem rather hard to erect and maintain...

https://en.wikipedia.org/wiki/Space_fountain

Cool idea... though, along with the space fountain, it seems to have no non-cataclysmic failure modes. Though, there are proposed safety features to dump the cataclysm somewhere relatively safe.

How big and powerful would a catapult have to be to shoot several tons into orbit?

A catapult might be a more compact solution :)

Here is a list of space launcher design :

https://en.wikipedia.org/wiki/Non-rocket_spacelaunch#Project...

Slings might work well on the moon and asteroids.

The high gravity and atmosphere becomes a problem for all such stationary schemes here on earth.

Are there any small scale working models of Lofstrom loop, space fountain or even maglev trains?

its an old idea and until my last search around two years ago I've found almost nothing.

In my infinite spare time (in retirement or something) I plan to build one of a scale large enough to launch something like a water balloon or maybe paintball payload a couple feet. I'm well aware there are simpler and more efficient ways to toss a water balloon ten or twenty feet, but its unlike there exist any cooler ways to do it. I would take it to the local maker faire and set it up next to the guy with the pumpkin trebuchet (every faire seems to have one of those guys).

It turns out that shock loads can be significant and dynamic stability is not exactly guaranteed, which makes it a cool engineering project. Also for small ones either the payload has to be extremely small (resulting in the paintball payload) or the loop has to be extremely heavy (probably not insurance approved, although it would be cool to spin up a length of hoist cable).

The one thing I have found is a cat or kid toy implementation radius about one foot. Its moderately cool. In order to eliminate or cut down on medical bills it has some elaborate and extremely fast motor current monitoring, which is usually the downfall of the toy.

If you're thinking the same thing I'm thinking, I wish you good luck. Its a cool project idea.

This topic comes up almost like clockwork on HN every couple years. Eventually I'll have something cool to demo.

"The one thing I have found is a cat or kid toy implementation radius about one foot."

- Citation please :)

I am unsuccessful at finding the kids toy. I owned one, maybe ten years ago. Hand held, black plastic...

An artist named Paolo Salvagione made an arduino controlled "string fountain" a bit less than a year ago on this principle. It would have to be dramatically up scaled to launch a paintball or similar. His artistic interpretation was the vibration modes of the string look nice and artsy, whereas the engineering launch device I'm thinking of would be a perfectly non-vibrating circle.

Awesome. Putting something on this string that tries to passively slightly bend the string while allowing the string to pass through should be enough to have it lifted and kept up.

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