Well, this certainly kicked off a lively discussion (full of nonsense in replies):
Your occasional reminder that physics PhDs are not engineers. The physics PhDs told us that we couldn't do missile defense. https://t.co/ra7Ybd82G0
— Rand Simberg (@Simberg_Space) August 31, 2026
So don’t engage. About a decade and a half ago there were plenty of people saying reusable rockets were, if not impossible, a waste of time. I assume some of them were probably PhDs…
I know some of them said, “You claim reusability will lower costs. Well, the Space Shuttle was reusable, and it didn’t lower costs. So there!”
Seemingly not realizing the government way of doing _anything_ increases costs.
And some of them were running ULA.
Just as clueless as Flerfs.
Some physics PhDs thought helping Stalin build atomic bombs would save the world.
Klaus Fuchs & Theodore Hall to name two… Although Hall was not a PhD during his time at Los Alamos, but later…
Michael Kelly did you know Ted Hall’s brother, Ed? Minuteman meets Peacekeeper?
No, Hall retired from the Air Force in 1959, when I was 5 years old, and worked 14 more years as an aerospace engineer before finally retiring. I was in my second year of engineering school at that time. He died in 2006, but I would never have had any opportunity to meet him.
Bummer. The stories you two could have shared. Ed Hall had to deal with the bomber pilots in the flag ranks. I envy his results not the path he had to take to get there!
Let’s give someone who makes Hitler look like a boy scout an atomic bomb, said no one with a brain ever!
LOL. I’m an engineer (or I was, Astro, UCLA undergrad), then med school
I am a PhD (Public Health).
They should have checked with me: I’d say look out your damned window.
Ahh! Dr. Banzai, tell us of your oscillation over thruster!
What was up with the watermelon?
You’ll have to ask Lord John Warfin.
You come here with a head full of mush and we send you home an arrogant asshole with a head full of mush. Not just lawyers, mind you….
I never made a paper airplane out of my grades letter. But I understood the principle. Never had Lindsey Wagoner as a girl friend in college either…
FWIW I always thought James Stephens made a more convincing Mr. Hart than Timothy Bottoms. But both the movie and TV series were very good thanks in no small part to Mr. Houseman.
Eh, add me to the list. Orbital data centers are definitely possible. All the hard problems are solvable. The real problem is that orbital data centers are competing with far cheaper and far simpler/less risky Earth-side data centers. The orbital market will be very niche. Even supporting Starlink, for example won’t be much better than supporting from ground-based data centers in terms of latency (even if we make each Starlink satellite its own data center, for example, we’re still just shaving milliseconds at considerable cost).
My view is that those 10,000 very smart people may well have a very different opinion in 5 years (at least for near future data centers)!
I tend to agree with you, however there is still the NIMBY factor. Strong and growing. Luckily for Elon, the astronomy crowd is small by comparison…
I used to think that actually updating infrastructure would be the cost prohibitive factor, esp. when compared to ground based centers. But Starship changes that equation drastically. I figure SpaceX/Starlink folk have figured that out as well… Esp. when one considers old hardware has little re-sell/re-use value. Quickly disposed of by de-orbiting. I suppose someday we may have to consider the pollution potential of hundreds of these satellites de-orbiting weekly. Nasty chemicals used in semiconductor mfg. etc. But we are a long way from that….
Yes, the anti datacenter people and all of the regulatory hurdles are what make space based datacenters attractive. It isn’t just cost in dollars but the costs of time and complexity.
The post Rand made a few days ago raises another uncertainty, open weights vs frontier models and how data centers fit into that. From that POV, it is an open question what the need for data centers will be vs the cost of adopting ai in a box where an individual or company controls both the data and hardware.
Looking a bit farther into the future, what will the ai needs be on the Moon and Mars and how does that some relationship play out?
Thing is, terrestrial data centers are not “far cheaper.” Possibly cheaper – the jury’s still out on that – but not “far.”
Terrestrial data centers should still be built – if only to poke sticks in the eyes of all of the progressives who have ginned up all of the current NIMBY angst at the urging of the PRC – but terrestrial compute faces limitations, and costs, space-based compute does not.
Thing is, terrestrial data centers are not “far cheaper.” Possibly cheaper – the jury’s still out on that – but not “far.”
What more evidence do you need? A terrestrial data center needs power. Everything else is relatively easy. Throw up a warehouse with some mildly esoteric internal infrastructure like cooling systems, fire suppression, and rows of racks. Simple process using infrastructure we already have.
Consider something simple like swapping out computer systems for better ones (every 3-5 years right?). In the terrestrial one, you’ve already hired staff who just take the new computers off the truck and install. In the orbital one, you’re either just leaving the data center alone because you can’t upgrade, or swapping out modules of computers robotically with a complex process (deorbiting or graveyard orbit) for disposing of the old module.
Risk is lower. The terrestrial center doesn’t have to worry about a paperclip-massed object or large solar flare ending the data center. You can legally keep potential hostile entities outside of an exclusion zone.
And of course, cooling. It remains easier to cool things on Earth – even if you have to air cool them and do so quietly.
The people who have actually built terrestrial data centers – one of whom is Elon, by the way – would beg to differ with you as to the ease with which such projects can be done.
No offense, but you sound, here, more than a bit like Michael Bloomberg “explaining” how easy farming was a yew years back.
“Mildly esoteric” understates it a bit too (I’ve built data centers). Thing is that a terrestrial data center is not much safer from solar flares than ones in LEO. Also, you have to junk/recycle the contents of terrestrial data centers at some cost, rather than just dropping them over Point Nemo. Finally, my last air-cooled data center sounded like a low-flying C-130. Maybe that tech has gotten better in the intervening years?
The people who have actually built terrestrial data centers – one of whom is Elon, by the way – would beg to differ with you as to the ease with which such projects can be done.
They will have to beg a lot more than that. There’s well over ten thousand serous data centers worldwide with a variety of owners which is clear evidence of the low barrier to entry of the field and the relative ease of building more data centers.
No offense, but you sound, here, more than a bit like Michael Bloomberg “explaining” how easy farming was a yew years back.
By the same metric, there’s something like 600 million farms. That’s a problem that’s been figured out the better part of a billion times.
Sorry, I don’t buy your argument!
Terrestrial data centers depend on electricity from the grid or by their own gas turbines. Grid capacity is already stretched, and it will take some time to improve. Gas turbines not only have high acquisition and operations costs, but there’s also a big backlog. It can take years to get a gas turbine operational.
Orbital data centers depend on electricity from their own solar arrays. Those are comparatively cheap and easy to produce. In addition to eliminating the NIMBY factor of terrestrial data centers, SpaceX is gearing up to mass produce these things at rates even higher than Starlink. Add to that the fact that SpaceX is building their own mass launching capability like the world has never seen. In the end, this may be less expensive than terrestrial data centers. Time will tell.
Musk said they might have to build their own turbines in an interview. Not sure if they ever followed through. But XAi are taking a dual track approach with terrestrial data centers and space based ones.
Anyone know the daily mass of meteorite infall? I have some wildy disparate numbers. If satellite re-entry mass becomes a significant fraction of this, satellites may need heat shields and be deorbited into some useless piece of desert like Australia.
Getcher catcher’s mitt Mike, they’ll be comin’ atcha. 🙂
I’ll add landing de orbited satellites to strip mining, storing nuclear waste and keeping the coasts apart, to the uses for most of Australia.
It isn’t called the GAFA for nothing – Great Australian F… All.
Supposedly a hundred tons a day is what I got. 36,500 tons a year? Might actually be worth it to drop the leosats on Oz as opposed to Point Nemo. Here’s Ayers Rock, and right next to it, Mt. Elon.
The downside is a miss of the GAFA is likely to hit someone.
A miss at Pt Nemo will likely hit ….. somewhere else in the Pacific Ocean
Huh. I’d heard GABA, but maybe Bugger was a euphemism.
I made note of that in here:
https://www.thespacereview.com/article/5226/1
My apologies. I need to read this…
That was really interesting.
I asked Grok about heatshield emissions and it noted that N0x was the primary worry and didn’t think the heatshields would be that worrisome. Did you look into pollution from heatshields?
Yes, NOx emissions impact on ozone generated by heating in the plasma sheath. I am working on a NOx-specific follow-on piece that will hopefully run before Thanksgiving. Going to have to crunch that one finely before it goes out the door.
I did find some good modeling data don on Space Shuttle Orbiter re-entry back in the late 70s that gave me what I needed to underlie my estimated scenarios.
The good news is I don’t think Starship is going to be as bad as I feared. The bad news is Boom is going to cause more issues than Starship et al if it’s successful. I am considering re-entry and SSTs, anything above the Troposphere.
I think you may be greatly underestimating the NOx impact. Many of the Starship onboard views looking down the plume show a red-brown trail behind the launcher as the hot plume interacts with the air during ascent.
Even as a callow undergrad, close contact with people who had PhDs quickly taught me that possession of an advanced degree was no imprimatur of superiority or even a guarantee of basic good sense on the part of their holders. I’d have to rate acquiring that particular bit of wisdom as a definite plus of going to college.
99% of the replies are about missile defense. Many don’t know the historical debate about missile defense and shift to cost without knowing about layered missile defense, advances in technical capabilities, or how the rapid change we are seeing is leading to cost reductions and increased production of interceptors, development of interceptors that are not missiles and drones, EW, and offensive capabilities that are the overlooked aspect of missile defense.
They see Iran land a few hits while ignoring not just how many are blocked but also how many hits the USA has landed. Their fallback position is that Iran still exists. Destroying Iran could be done at any moment and was never the objective. Well, the USA still exists and our ability to conduct operations hasn’t been halted. In the real world, the scope of our operations has expanded.
Oil coming out of the GCC states is about 70% of prewar levels. The GCC are developing alternate routes to move oil. The USA is developing affordable means of protecting convoys that will also increase missile defense capabilities. Sieges are slow, this one is doing a lot of damage to Iran, and every month that passes our capabilities grow stronger, more effective, and ultimately cheaper. Which isn’t to say there is no cost, just that a given amount of money will be able to accomplish more things.
This is happening as Iran’s proxies are getting hammered and while Iran can still squeak out some launches, they can’t do the volume they did at the beginning of the war. People talk about Iran being able to overwhelm our defenses but notice they aren’t. They can’t sustain a launch cadence that would allow them to do that or they would be doing it.
Next year a new pipeline should become active with hopefully more over the next five years. Over the next two years, the USA will field hundreds of autonomous boats similar to the Marauder with that number growing each year after. Shahad type drones will be easier to knock down for less money and the same goes for ballistic missiles. All of this will take place while Iran’s capabilities are continually degraded. It will be a state like the Clinton era no fly zone over Iraq.
The luddites always default to the obsolete strawman arguments of thirty and forty years ago.
They argue against things like Mars missions on cost per ton numbers that are decades out of date, like SpaceX never happened or against so-called assault rifles like Americans buying forty million since the 94 ban never happened.
They can’t acknowledge current reality without admitting that reality undermines the entire premise of their argument.
Late-stage socialism and late-stage socialists.
Oh! And a missile defense must be 100000% perfect or it’s not worth doing. That’s another one.
Yeah that one never made much sense. Any enemy with missiles would be shooting mainly at ours and they’re all in barely-populated parts of the rectangle states. We used to cork off nukes outdoors within sight of Las Vegas to test them and there were a lot more of those than there would be leakers with a decently implemented Golden Dome. Other than giving most of the cast and crew of The Conquerer cancer, we didn’t take much damage from all of that.
There are, of course, a few bomber and naval bases in less-deserted parts of the country that would be targets too. And there would be DC. Again, with a decently implemented Golden Dome we wouldn’t lose more than a small fraction of such targets. If the bad guys smeared DC I would miss the National Air & Space Museum but would otherwise consider DC’s loss a net plus.
There would be no real military value in nuking large cities, but if we lost one or a few of those, well, they’re all blue-majority places anyway. Net plus again.
And I say that as a resident of one of them.
It would damage transportation hubs and nodes of communications. Even a small nuclear exchange would make the Covid supply chain disruptions look like a spilled kiddie meal at the Sizzler by comparison.
Still, less is better and uncertainty in targeting screws the enemies ability to plan a strike.
I used to think my first inkling of WW3 would be looking toward a far-away flash of light and saying, “What was that?” Then I found out my cell phone will give me a head-up, sort of like a silver alert…
When you get that far off flash of light, I know it sounds trite, but Duck and Cover.
The people of Chelyabinsk learned that first hand when a small chunk of asteroid slammed into the atmosphere and destroyed itself in such a flash. A lot of people were just standing there mouths agape staring out the window wondering “what was that” when the blast wave followed, giving them a faceful of glass shards.
Then I found out my cell phone will give me a head-up, sort of like a silver alert…
Not sure what you mean. My cell phone only alerted me on 9/11/01 when I tried to use it. Not before. Was trying to call my wife at the time and all I could get was a fast busy signal. After a couple of attempts I thought to myself: “Sh*t I must’ve forgotten to pay my bill”. Figuring I could get through to my carrier, I called them and sure enough after some menu options got ahold of a live person and told them I’m getting a fast busy signal and wanted to pay my bill. Before the guy said anything else he said everyone is getting that. Their circuits are all tied up and didn’t I know about one (at that time) of the WTC Towers being hit by an airplane? So yeah my phone alerted me. But only when I tried to use it. Probably less effective than CONELRAD. If you don’t what that means consider yourself a youngster.
It’s 25 years later. Now the alert system can switch on my turned-off phone, make a shrill alarm, and then turn on the speaker to make its announcement. The first time that happened was a 2am Amber Alert.
As far as flashes of light and blast waves (other commenter), I live more than 50 miles from the nearest plausible target, and around 150 miles from the nearest *likely* target. A 300kt air burst over either one would be beyond blast wave from my house. Of course, they might miss, but so what? I’ll be 76in a few weeks. I’ll be in Elysium before I know it
Fact is that I know about all this stuff and have written extensively about it. I guess since I’m not a PhD, knowledge, etc., doesn’t count.
Inventors make something happen
Professors figure out why it happens
Then engineers figure out how to make a lot of things happen, affordably.
And the current-day automobile industry doesn’t have engineers anymore. At least cars are no longer affordable?
Elon Musk makes things happen. All our engineers belong to him. Professors want him dead.
Mike Griffin has 5 PhDs all by himself. He designed Ares 1, which would have pogoed astronauts to death.
The lengths some people would go to to avoid flying Delta IV airlines…
My favorite part of Ares 1 was the upward firing rockets.
My favorite part of Ares 1 was the upward firing rockets.
One term you’d never hear on the unified comm link during ascent: “…FTS is safe’d…”
That’s a joke, correct?
The thing with a PhD is that one is quite enough. You have demonstrated your ability to research a topic and solve a problem in it. Don’t get more than one PhD to show you are some kind of braniac. Go forth and teach yourself the methods to research the next topic and solve a problem in it.
Sadly, no. He really has 5 PhDs.
Depends on who is paying for it.