totm nov 2023 SpaceX Discussion Thread

[RKunze]

1 minute ago, darthgently said:

That is over a 30% difference.  When has a 30%+ efficiency increase ever been considered insignificant by any power engineer? 

When taking advantage oft it means you have to pay way more than for just building and running 30% more generators...

Don't get me wrong, there's a lot of interesting stuff that could be manufactured  in orbit zero g. But running data centers in orbit is just plain stupid because you can do it easier and cheaper down here.

[darthgently]

7 hours ago, JoeSchmuckatelli said:

One concern is latency, though. (I started speculation about large scale geosynchronous data farms and then realized that would only be good for relatively static data given signal travel times) 

Why geostationary?  Put them at near Starlink altitudes, or even on Starlink next  gens?

2 minutes ago, RKunze said:

Don't get me wrong, there's a lot of interesting stuff that could be manufactured  in orbit zero g. But running data centers in orbit is just plain stupid because you can do it easier and cheaper down here.

I guess we'll just see what happens.  I certainly don't know the future or what will cease to be an obstacle or become an obstacle in the future

[JoeSchmuckatelli]

14 minutes ago, RKunze said:

just plain stupid because you can do it easier and cheaper down here.

...can be said about a lot of things.  Most every thing, anyway.

What we need is something that can be made better in space - something we need down here, but also need to go up there to get the most out of.  I'm tired and can't possibly think of what that thing would be.  Should be fun to watch what happens (hopefully within my cognitive lifetime!)

[Hotel26]

1 hour ago, RKunze said:

If you want to use the most expensive way to generate the needed electrical energy, go ahead.

Certainly true in the West for non-scientific reasons.

"China plans to build as many as thirty nuclear power reactors in countries involved in the Belt and Road Initiative by 2030."

"Advanced pressurized water reactors such as the Hualong One are the mainstream technology in the near future, and the Hualong One is also planned to be exported."  And, no doubt, financed.

Consider any country that is a) developing with determination, b) low on population, c) stable geologically, and d) has plentiful water (e.g. large lakes).  Start a candidate search with e.g. the Stans...

Don't be surprised if other countries begin making the scientific and economic determination that nuclear power is both safe and economic.  YMMV.

Edited November 27, 2023 by Hotel26

[NFUN]

An industry that famously produces a ton of waste heat that needs to be removed is about the worst possible choice for one to be moved to space

[darthgently]

5 minutes ago, NFUN said:

An industry that famously produces a ton of waste heat that needs to be removed is about the worst possible choice for one to be moved to space

Unless the heat is the point

https://en.m.wikipedia.org/wiki/Kilopower

 

[AckSed]

I can think of a reason: If a computer server is in orbit, it's a little harder for an authority - any authority - to shut it down.

[tater]

14 minutes ago, NFUN said:

An industry that famously produces a ton of waste heat that needs to be removed is about the worst possible choice for one to be moved to space

Wonder about sinking conductors to do it on the Moon. Or use waste heat for water extraction in shadowed craters.

[NFUN]

16 minutes ago, darthgently said:

Unless the heat is the point

https://en.m.wikipedia.org/wiki/Kilopower

 

then by definition it wouldn't be "waste heat" would it

[darthgently]

16 minutes ago, NFUN said:

then by definition it wouldn't be "waste heat" would it

Exactly

[RCgothic]

6 hours ago, RKunze said:

 

If you want to use the most expensive way to generate the needed electrical energy, go ahead.

There's a reason almost nobody is building commercial fission power plants anymore. Those things are just too expensive to build, to expensive to run, and too expensive to get rid of after they go out of service...

 

As someone who used to design wind turbines and is now designing a commercial fission plant for the upcoming nuclear renaissance, hard disagree.

If you think wind and solar are cheap now, just keep giving them a bigger share of the grid and see what happens. As their share goes up, productivity drops due to oversupply and the price per kWh goes up massively.

Nuclear is as cheap to build as anything else when you commit to having a lot and a lot cheaper than trying to transition entirely to wind and solar, or even worse continuing to burn carbon. Nuclear also has an enormously longer lifespan, is vastly more reliable, and uses far fewer resources and land.

PWR nuclear plants are easy to decommission and spent nuclear fuel is such a valuable resource that it should be a crime to waste by burying it. Nobody has *ever* been seriously harmed by spent nuclear fuel from a commercial power plant, and if we absolutely must bury it it'd be no more dangerous to future generations than anything else we routinely put in industrial landfills, like mercury.

 

[Scotius]

In other words: Diversification is the key. Let's not put all our eggs in one basket.

Time and practice will show which method of producing energy is optimal.

[JoeSchmuckatelli]

4 hours ago, RCgothic said:

is now designing a commercial fission plant for the upcoming nuclear renaissance

Sounds interesting! 

 

Fair winds and following seas! 

[darthgently]

7 hours ago, RCgothic said:

As someone who used to design wind turbines and is now designing a commercial fission plant for the upcoming nuclear renaissance, hard disagree.

If you think wind and solar are cheap now, just keep giving them a bigger share of the grid and see what happens. As their share goes up, productivity drops due to oversupply and the price per kWh goes up massively.

Nuclear is as cheap to build as anything else when you commit to having a lot and a lot cheaper than trying to transition entirely to wind and solar, or even worse continuing to burn carbon. Nuclear also has an enormously longer lifespan, is vastly more reliable, and uses far fewer resources and land.

PWR nuclear plants are easy to decommission and spent nuclear fuel is such a valuable resource that it should be a crime to waste by burying it. Nobody has *ever* been seriously harmed by spent nuclear fuel from a commercial power plant, and if we absolutely must bury it it'd be no more dangerous to future generations than anything else we routinely put in industrial landfills, like mercury.

 

Agree.  The huge elephant in the room is the woefully inadequate grid worldwide.  Most people have no clue how much lead time, treasure, and sweat go into growing and maintaining the electrical distribution grid no matter what the source of the juice is.  Maintenance alone is astronomical on its own. 

If all the money, and I mean all, that goes into centralized solar facilities were to be put instead into decentralized rooftop solar with local storage it would dovetail with the current grid somewhat better but big centralized solar, given the grid problem, is the worst "solution" possible.

Small neighborhood state of the art nukes would be the best solution, imo

[Ultimate Steve]

Given that we are talking about solar's flaws...

This is definitely a tangential comment, but when discussing space based solar, something that isn't talked about often enough is that it gets rid of solar's biggest disadvantage, which is that it can't act as a baseload power source. There are no no clouds in space, there is no snow in space, there is (almost) no night in space (high orbit), you aren't tied to a peak at a certain time of day, and in the event of overproduction you can either rotate the satellite slightly or beam the excess into deep space.

Granted, there's still a bajillion other problems with space based solar, of which the biggest is probably economic, but a guy can dream!

[AckSed]

As I think SpaceX might have alluded to once or twice, they have a modest heavy-lift vehicle in the works. That would make for a fair delivery system for a SBSP system. It wouldn't even need to be that lightweight, so it could be constructed on the ground. Hell, take some domestic panels, add what shielding and hardening you think it might need, boost and see what breaks. Repeat a few times, and see if they work or they need to be built specially.

[CBase]

Are there  yet any rumors about the FAA mishap report on IFT-2 ?

I would love to see an IFT-3 this year and for sure SpaceX would have the vehicle ready in time. So any news on bureaucracy ?

[JoeSchmuckatelli]

SBSP... Whatcha'll smokin? 

 

[RCgothic]

15 hours ago, darthgently said:

Small neighborhood state of the art nukes would be the best solution, imo

Traditional grids generate their power close to where it is needed, and long-distance power transmission is fractional amounts for rural purposes and load balancing.

Decentralised grids to support unpredictable power sources need to be able to send large fractions of national consumption over long distances and have many more connection points. This also adds to the price per kWh, which will soon become apparent.

Large nukes use fuel more efficiently than small nukes (it's a function of the surface area to lose neutrons from vs volume - another square cube law), but as fuel is a relatively small proportion of the lifetime costs this isn't necessarily a huge deal if you can make other savings with economies of scale on smaller plants, but this would rely on there being enough permissible nuclear sites. The current policy of reusing existing sites (in the UK at least), tends to favour large plants.

Small plants close to where the power is needed would be particularly effective for using the by-product heat for heating and industrial process heat. By using this heat it's possible to triple the fuel efficiency of nuclear plants (any thermal plant actually).

It's bizarre we don't do this already.

Edit: It's even more bizarre 6 of you liked this post before I corrected all the word substitutions autocorrect snuck in that I didn't immediately notice yesterday. I'm amazed anyone understood what I was on about. 

Edited November 28, 2023 by RCgothic

[tater]

 

[Pthigrivi]

The funny thing about all this is the solar/wind folks assume we'll be building a smart grid capable of managing dynamic energy loads, and the nuclear folks assume we'll be spending oodles more money and convincing the masses that its no biggie to have a nuclear plant next door. Neither of which will happen because it's cheaper and easier to just let the planet boil. 

[darthgently]

30 minutes ago, RCgothic said:

Small plants close to where the power is needed would be particularly effective for using the by-product heat for heating and industrial process heat. By using this heat it's possible to triple the fuel efficiency of nuclear plants (any thermal plant actually).

It's bizarre we don't do this already.

Cogeneration is key to nukes.  In northerly climes heating greenhouses to grow crops year round for local fresh produce could be a big deal, for example.  Pump sequestered CO2 in to really boost production.  We will need this in the next glacial, ha!

[Minmus Taster]

1 hour ago, tater said:

 

Great animation, maybe they could extend the header tanks to also use for the start of the boostback?

[Piscator]

I guess they could either keep more engines burning during separation or delay the full restart until the fuel has had time to settle again. Might be easier to just change the flight profile than rearrange the plumbing. Might be not though, in the long run.

[SunlitZelkova]

3 hours ago, JoeSchmuckatelli said:

SBSP... Whatcha'll smokin? 

 

http://spaceflighthistory.blogspot.com/2016/12/energy-from-space-department-of.html?m=1
 

It’s actually really feasible, especially with Starship coming online. Starship is basically just a scaled down version of the Space Freighter proposed by Boeing.