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SpinLaunch is building a centrifuge to launch satellites into orbit

wired.com

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Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#111

Post by fanf2 »

nitrogen wrote: post #86
piker wrote: post #62

Earlier quoted context omitted.

> The total amount of radioactive waste on the earth is about the size of a swimming pool (or was that the total amount of gold? I forgot, either way in terms of quantity it's not that much) This seems wrong in both places. There are probably enough gold rings manufactured per year to fill a swimming pool. In pictures: Fort Knox itself seems to have at least a swimming pool of gold [1] and Thailand a swimming pool of…

Those piles of bars are shallow, and those barrels are probably mostly non-spent-fuel by volume.

In the 1930s they put about 13,000 tonnes of gold in Fort Knox. (It now has about 4,500 tonnes). Density of gold is about 20g/cm^3, or 20 tonnes per cubic metre. So Fort Knox held up to 650m^3 of gold.

A normal swimming pool is about 25m x 12.5m x 2m which is 625m^3.

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

This page indicates Sellafield has 2000m^3 of high level nuclear waste.

https://ukinventory.nda.gov.uk/site/sellafield/

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#112

Post by mhandley »

viraptor wrote: post #102
noitpmeder wrote: post #96

Earlier quoted context omitted.

From the article " a counterbalance spinning opposite the rocket gets released at the same time, preventing the tether from becoming unbalanced and vibrating into oblivion "

Yes, but where is it released? Because if it's at the same time and the rocket goes up, the counterbalance goes down. And that means a big explosion right under your infrastructure.

Exactly - the energy of the released counterweight will inevitably produce an explosion as it's stopped pretty quickly by something. My question was how big an explosion. The answer is pretty big, but this probably isn't their biggest problem.

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#113

Post by brohee »

absolutelyrad wrote: post #78
martey wrote: post #46

The Wired article that this SyFy blurb is based on has more details (and more criticism) - https://www.wired.com/story/inside-spinlaunch-the-space-indu... > One former employee, who spoke on condition of anonymity due to their nondisparagement and nondisclosure contracts, acknowledged the gulf between theory and reality. They described SpinLaunch’s prototype centrifuge as a relatively unsophisticated machine that “an…

Thanks, this is what I was looking for. I didn't want to dismiss them fast, but it did sound like the founders don't know what they're up to. Maybe they figured out some advanced materials science we don't know about, but that seems unlikely from this article. > Over the next few years, the team ran hundreds of high-speed tests. Most of them were to study and improve the system, but some were to mollify skeptical inv…

How many G is a drop on concrete?

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#114

Post by heelix »

absolutelyrad wrote: post #90
londons_explore wrote: post #88

Earlier quoted context omitted.

Assume the screen and top glass of an iPhone are 40 grams. 10000g's will make the effective mass of them 400kg. Could an iPhone survive 400kg sitting on top of it? It's definitely within the realm of possibility...

The force is acting on internal parts too. I don't think the silicon microchip inside can survive those forces. There is just too much that could go wrong here. I would be positively shocked if this thing works. I'd have to rethink a lot of things I hold an opinion on.

Electronics are usually the key payload - but things like water, fuel, and other 'potential solids' could use a cheap way to get them out of the gravity well.

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#115

Post by mech422 »

krasin wrote: post #32
nohat wrote: post #13

Put this on the moon and we are talking. I'm not sure I see this being too useful otherwise, considering how much extra fairing mass those gforces are going to require

Yes, SpinLaunch on Moon launching ore concentrates. No housing needed, g-forces irrelevant; gravity well is smaller. Obligatory link, "Moon is a Harsh Mistress", by Heinlein: https://archive.org/details/TheMoonIsAHarshMistress_201701

I loved Heinlein as a kid...

I wonder how many geeks today realize he's the origin of the term 'grok' ?

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#116

Post by graderjs »

mhandley wrote: post #112
viraptor wrote: post #102

Earlier quoted context omitted.

Yes, but where is it released? Because if it's at the same time and the rocket goes up, the counterbalance goes down. And that means a big explosion right under your infrastructure.

Exactly - the energy of the released counterweight will inevitably produce an explosion as it's stopped pretty quickly by something. My question was how big an explosion. The answer is pretty big, but this probably isn't their biggest problem.

Liquid back stop? Ballistic jello?

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#117

Post by [deleted] »

brohee wrote: post #113
absolutelyrad wrote: post #78

Earlier quoted context omitted.

Thanks, this is what I was looking for. I didn't want to dismiss them fast, but it did sound like the founders don't know what they're up to. Maybe they figured out some advanced materials science we don't know about, but that seems unlikely from this article. > Over the next few years, the team ran hundreds of high-speed tests. Most of them were to study and improve the system, but some were to mollify skeptical inv…

How many G is a drop on concrete?

[deleted]

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#118

Post by extraduder_ire »

Cthulhu_ wrote: post #58
blackrock wrote: post #49

Earlier quoted context omitted.

Raw metal powder for 3D printing laser sintering. Or plastic pellets. Water. Fuel. Clothes. Maybe this is what can kick start the 3D printing in space revolution. Maybe it can also launch radioactive waste into space? One bucket at a time. Then a space towtruck can be launched to hurl it into the sun. But it’ll likely just part a naive investor from their money.

Not sure how serious you are with the radioactive waste thing but I'll do the HN thing and bite (nerdsnipe!), because that's not going to work. You can't launch things into the sun, you need to decelerate objects. The earth travels at 30 km / s (70K MPH) around the sun, so you need to decelerate about that much the other way. And orbiting radioactive waste is just asking for trouble. The total amount of radioactive w…

> burying it deep and forgetting about it for the next 100.000 years is the way to go I think.

Is there a problem with burying it in a subducting plate boundary, so it is eventually pulled back into the earth's mantle? There's already fission going on down there.

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#119

Post by 1958325146 »

blackrock wrote: post #50
DennisP wrote: post #4

I hope it works because it'd be rad, but at $500K per 200-lb payload, they'll cost $2500/lb. That's only half as much as SpaceX Rideshare for the same size payload, today. If Starship works out, then SpaceX costs will drop enormously. Fuel is a minor portion of launch cost. SpinLaunch is saving fuel but throwing away rockets; it's going to be hard to compete with someone who throws away more fuel but saves the rocket…

How is Starship going? Are they still trying to “sweat” the fuel out of the skin, to give it an active cooling layer?

The latest we have is that it will sweat only where the heat shield can't hold up on its own: https://twitter.com/elonmusk/status/1107380559834046465 .

Re: SpinLaunch is building a centrifuge to launch satellites into orbit

#120

Post by jl2718 »

Havoc wrote: post #97
Cthulhu_ wrote: post #58

Earlier quoted context omitted.

Not sure how serious you are with the radioactive waste thing but I'll do the HN thing and bite (nerdsnipe!), because that's not going to work. You can't launch things into the sun, you need to decelerate objects. The earth travels at 30 km / s (70K MPH) around the sun, so you need to decelerate about that much the other way. And orbiting radioactive waste is just asking for trouble. The total amount of radioactive w…

>The earth travels at 30 km / s (70K MPH) around the sun, so you need to decelerate about that much the other way. Surely you’d just need enough to end up in a decaying orbit? Then it’ll eventually reach the sun

All you need to do is hit the Lagrange point.
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