
The Lofstrom Loop - beernutz
https://en.wikipedia.org/wiki/Launch_loop
======
chriswarbo
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 :(

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

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

~~~
scotty79
If they want to go higher they'll have to do something brave at some point:
[https://en.wikipedia.org/wiki/Space_fountain](https://en.wikipedia.org/wiki/Space_fountain)

------
seren
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 ?)

------
k__
I like this list:

[https://en.wikipedia.org/wiki/Non-
rocket_spacelaunch](https://en.wikipedia.org/wiki/Non-rocket_spacelaunch)

Some ideas seem rather sci-fi :D

~~~
Gravityloss
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

------
mikevp
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.

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

A catapult might be a more compact solution :)

~~~
seren
Here is a list of space launcher design :

[https://en.wikipedia.org/wiki/Non-
rocket_spacelaunch#Project...](https://en.wikipedia.org/wiki/Non-
rocket_spacelaunch#Projectile_launchers)

------
scotty79
Are there any small scale working models of Lofstrom loop, space fountain or
even maglev trains?

~~~
VLM
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.

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

\- Citation please :)

~~~
VLM
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.

~~~
scotty79
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.

