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Nuclear Conversion for Starship

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Re: Nuclear Conversion for Starship

#111

Post by ben_w »

flashback2199 wrote: post #108
ben_w wrote: post #90

Earlier quoted context omitted.

The sun is a giant fusion reactor known to cause cancer on a good day, and emit radiation bursts that can damage or disrupt power grids often enough that people can reasonably expect to read reports of them more than once in their lifetimes.

> The sun is a giant fusion reactor And chernobyl was a giant fission reactor. What's your point?

The comparison between the two is almost exactly the same as the comparison between a fart and a hurricane: 16 orders of magnitude, give or take.

Space is really hostile.

Re: Nuclear Conversion for Starship

#112

Post by amluto »

bluescrn wrote: post #80

Nuclear doesn't work with Elon's approach to development. You can't blow up multiple nuclear rockets within the atmosphere just to learn what needs fixing for the next attempt. Then again, it's looking like the whole 'fail fast' approach is over anyway, with Starship grounded by red tape. A full-stack Starship failure is seemingly too big/dramatic/risky to get away with doing repeatedly, especially admidst the politi…

I assume some of this is that the many early Falcon failures merely blew up the test vehicles. The starship test kind of blew up the launch site.

Re: Nuclear Conversion for Starship

#113

Post by SECProto »

idlewords wrote: post #38
maxcan wrote: post #9

AFAIK, the only nuclear rocket that makes sense is landing a reactor on an icy comet and using it to shoot super heated steam wherever you want thrust. #seveneves

The Project Orion design (shoot hundreds of fission bombs out the back and ride the shock wave on a reaction plate) is surprisingly practical, and probably our only way to get humans past Mars. It's just kind of terrifying.

> The Project Orion design [...] is surprisingly practical, and probably our only way to get humans past Mars.

I don't think this is the general consensus. It is seen as one of the only ways to get humans out of the solar system, but other nuclear rockets[1], and even chemical options[2], could get humans to eg the Jovian moons[3] with TRL's much higher than Project Orion.

[1] https://en.wikipedia.org/wiki/NERVA

[2] https://en.wikipedia.org/wiki/Interplanetary_spaceflight#Cyc...

[3] https://en.wikipedia.org/wiki/Exploration_of_Jupiter#Human_e...

Re: Nuclear Conversion for Starship

#114

Post by asdff »

sandworm101 wrote: post #109
asdff wrote: post #88

Earlier quoted context omitted.

It makes you wonder though, should you set up such space based infrastructure, is it even worth publicizing lest you trigger an arms race?

You couldnt do it without publicizing. Space stuff is big and loud. Space itself is transparent. Doing big secret stuff in space is extrodinarily difficult.

There are spy satellites that we know nothing about in orbit, only until someone like Trump leaks an image on twitter. Who is to say where that line of development ended, if ever, given so little is spoken publicly of these efforts? Perhaps others could detect some of your efforts, but you hold them to secrecy like you do other state secrets among allies out of mutual benefit. I'd expect there to at least be a well worked out plan for such an infrastructure along these lines by now, if not implementation. It's one of those things where the losing move is not to engage with it, for fear someone else is and making strides.

Re: Nuclear Conversion for Starship

#115

Post by p1mrx »

marcinzm wrote: post #74
idlewords wrote: post #69

Earlier quoted context omitted.

If someone siphons your gas tank, they're not going to be able to nuke Paris. But a nuclear pulse rocket needs thousands of bomblets the size of coke cans. That's the scary part.

> size of coke cans. Not really, each one would be 6 inches in diameter and weight over 300lbs.

Sounds impossible. A 6 inch diameter uranium sphere is only 80 lbs, and there are no materials significantly denser than that.

Re: Nuclear Conversion for Starship

#116

Post by bunabhucan »

bluescrn wrote: post #80

Nuclear doesn't work with Elon's approach to development. You can't blow up multiple nuclear rockets within the atmosphere just to learn what needs fixing for the next attempt. Then again, it's looking like the whole 'fail fast' approach is over anyway, with Starship grounded by red tape. A full-stack Starship failure is seemingly too big/dramatic/risky to get away with doing repeatedly, especially admidst the politi…

You can. You just can't legally do it in Texas. Maybe SpaceY will be based in North Korea or somewhere to escape the burdensome regulatory regime in the USA.

Re: Nuclear Conversion for Starship

#117

Post by sandworm101 »

asdff wrote: post #114
sandworm101 wrote: post #109

Earlier quoted context omitted.

You couldnt do it without publicizing. Space stuff is big and loud. Space itself is transparent. Doing big secret stuff in space is extrodinarily difficult.

There are spy satellites that we know nothing about in orbit, only until someone like Trump leaks an image on twitter. Who is to say where that line of development ended, if ever, given so little is spoken publicly of these efforts? Perhaps others could detect some of your efforts, but you hold them to secrecy like you do other state secrets among allies out of mutual benefit. I'd expect there to at least be a well w…

Except we know when they were launched, thier general orbital parameters, and what they are generally doing. We dont know the specifics but their existance as spy sats is well understood. There is even an online community of enthusiasts looking for and tracking them. Wikipedia is full of data.

https://en.wikipedia.org/wiki/Orion_(satellite)

https://en.wikipedia.org/wiki/Lacrosse_(satellite)

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

https://www.nro.gov/launches/

Re: Nuclear Conversion for Starship

#118

Post by dr-detroit »

asdff wrote: post #114
sandworm101 wrote: post #109

Earlier quoted context omitted.

You couldnt do it without publicizing. Space stuff is big and loud. Space itself is transparent. Doing big secret stuff in space is extrodinarily difficult.

There are spy satellites that we know nothing about in orbit, only until someone like Trump leaks an image on twitter. Who is to say where that line of development ended, if ever, given so little is spoken publicly of these efforts? Perhaps others could detect some of your efforts, but you hold them to secrecy like you do other state secrets among allies out of mutual benefit. I'd expect there to at least be a well w…

[dead]

Re: Nuclear Conversion for Starship

#119

Post by nradov »

bunabhucan wrote: post #116
bluescrn wrote: post #80

Nuclear doesn't work with Elon's approach to development. You can't blow up multiple nuclear rockets within the atmosphere just to learn what needs fixing for the next attempt. Then again, it's looking like the whole 'fail fast' approach is over anyway, with Starship grounded by red tape. A full-stack Starship failure is seemingly too big/dramatic/risky to get away with doing repeatedly, especially admidst the politi…

You can. You just can't legally do it in Texas. Maybe SpaceY will be based in North Korea or somewhere to escape the burdensome regulatory regime in the USA.

Countries with less burdensome rules are subject to ITAR restrictions.

Re: Nuclear Conversion for Starship

#120

Post by idlewords »

SECProto wrote: post #113
idlewords wrote: post #38

Earlier quoted context omitted.

The Project Orion design (shoot hundreds of fission bombs out the back and ride the shock wave on a reaction plate) is surprisingly practical, and probably our only way to get humans past Mars. It's just kind of terrifying.

> The Project Orion design [...] is surprisingly practical, and probably our only way to get humans past Mars. I don't think this is the general consensus. It is seen as one of the only ways to get humans out of the solar system, but other nuclear rockets[1], and even chemical options[2], could get humans to eg the Jovian moons[3] with TRL's much higher than Project Orion. [1] https://en.wikipedia.org/wiki/NERVA [2]…

It's not just about propulsion, but radiation. The radiation environment in space is awful and you need thousands of tons of shielding to effectively screen a crew from cosmic rays. Moreover, because of secondary radiation, partial shielding from energetic cosmic rays is worse than none.

A unique property of nuclear pulse propulsion is that the engineering gets easier the more massive the spacecraft. That leaves lots of room for radiation shielding and consumables, and makes it the only halfway practical choice for multi-year missions into the outer solar system.

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