Can you Throw a Payload into Space??

[Yazata]

Sure, on one of those tiny asteroids like Bennu. But what about Earth?

Here's a company called Spinlaunch that hopes to do it.

They propose to build a giant vertical wheel, attach a payload to its edge and then spin it really fast. Then release the payload at precisely the right time when it's headed up and fling it into space.

There are big technical challenges.

For one, the wheel will be a giant centrifuge and the payload will experience something like 10,000 Gs before launch. So this definitely isn't for human spaceflight. Any payload it flings will have to be hardened against high G forces. Solid state electronics should be able to take it.

Another challenge is that the payload will emerge from the wheel at very high mach numbers and will face all kinds of atmospheric heating and weird hypersonic aerodynamics. It will glow incandescent as it ascends.

A third challenge is that a wheel spinning that fast needs to be precisely balanced. If it's balanced with the payload attached as it gradually spins up, it needs to keep from tearing itself to pieces when the payload is released.

But by all accounts they have very good engineers and some ideas about how to solve the problems that impress other engineers.

What's the advantage of doing this? One word, cost. !t's cheap. Cheaper even than reusable rockets. All it uses is electricity to spin up the wheel.

When people first heard it proposed to throw payloads into space, the response was "Yeah, right". But opinion is moving toward "OK, maybe it's possible." The biggest question now is whether a business case can be made for it. Will it ever be practical?

https://www.spinlaunch.com/

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

Scott Manley has done a video on them

https://www.youtube-nocookie.com/embed/JAczd3mt3X0

Here's their "small" sub-scale suborbital test wheel they've been using to test their concept

[Image: ?u=https%3A%2F%2Fcdn-blog.adafruit.com%2...f=1&nofb=1]

[confused2]

The failure modes are potentially so spectacular and catastrophic that .. well, that.

[Yazata]

Real life video of where they are now: their October 22, 2021 first spin of their new mexico test wheel. The payload for this was just a dummy mass. I don't know how high it reached.

https://player.vimeo.com/video/640160330...nch.com%2F

And this artist's conception video showing how the concept is supposed to work. The kinetic energy launcher will be 3x the size of the test wheel. It only replaces a rocket first stage and there is still a second and a small third stage that are hurled into space in a protective aeroshell to protect them from the hypersonic transit up out of the atmosphere like a meteor in reverse. One it is up in near vacuum the aeroshell is jettisoned and a conventional rocket engine is lit.

https://player.vimeo.com/video/646339783

[Zinjanthropos]

Why not build it in space (Or get it there somehow) and launch craft from there?

[Yazata]

Why not build it in space (Or get it there somehow) and launch craft from there?

Scott Manley points out that it would be a great concept for launching stuff from the Moon. Low gravity, no atmosphere, and it will probably be easier to produce electricity on the Moon than rocket fuel. So speculatively, if there are ever Moon mines, bulk cargo won't care about high Gs, so fling it from the Moon's surface and, if the orbital dynamics work out, into orbit around the Earth. Most of the speculation I've heard about mass drivers on the Moon envision some kind of electromagnetic rail-guns, but this might conceivably be competitive too, provided that it can launch enough mass.

[confused2]

Why not build it in space (Or get it there somehow) and launch craft from there?

It needs to keep its feet on the ground - otherwise the flinger gets flung too. Action and reaction.