Friday, June 03, 2022

Space News!

My notoriously fierce objections to the USA getting involved in Footprint Stunts on the moon are well known. But those objections do not extend to the robotic parts of the program! NASA should very much strive for a leading role in robotic lunar exploration and actual, actual science. For example:

“Over the course of 10 Earth days (one lunar day), Lunar-VISE will explore the summit of one of the Gruithuisen Domes. These domes are suspected to have been formed by a sticky magma rich in silica, similar in composition to granite. On Earth, formations like these need oceans of liquid water and plate tectonics to form, but without these key ingredients on the Moon, lunar scientists have been left to wonder how these domes formed and evolved over time.”

Robotic exploration of lunar polar ice fields? That too! And suspected lava tubes. And "ISRU" methods to extract and use local resources, eventually proving me wrong about the near total lack of anything useful on that dusty, poison plain.

What we do NOT need to do is to race to be the next footprint tourists, and thus not only waste half of NASA's resources, but also humiliate other nations who are eager to send astro/cosmo/taikonauts to that sandbox for photo-ops and for symbolism-drenched national rites of passage. 

Let them have their ‘bar moonzvahs.’ We had ours over half a century ago!

We have other business out there, worthy of grownups.

== More mighty space news! ==

This interview about the possibility of life on Mars - and across the universe on KPBS features cogently formulated questions and a fine job of journalistic editing/splicing efficient- informative answers. Veteran reporter Tom Fudge was even able to mine something useful from my garrulously rambling explanations!


The largest comet nucleus ever seen!newly discovered comet that's on its way in has been estimated at around 140 km or 80 miles wide, that's thousands of times more massive than the pretty consistent average of a few km. (As described with vivid adventure and science in Heart of the Comet!) "It's big and it's blacker than coal," yet already emitting a coma of evaporated volatiles. 

"Comet Bernardinelli-Bernstein follows a 3-million-year-long elliptical orbit, taking it as far from the Sun as roughly half a light-year. The comet is now less than 2 billion miles from the Sun, falling nearly perpendicular to the plane of our solar system. At that distance temperatures are only about minus 348 degrees Fahrenheit. Yet that's warm enough for carbon monoxide to sublimate off the surface to produce the dusty coma."

Our sun in unprecedented detail! These images were taken when Solar Orbiter was at a distance of roughly 75 million kilometers, half way between our world and its parent star, showing the full Sun in unprecedented detail. Amazing how pertinent appear to be every descriptive element in my novel Sundiver!

Odd Radio Circles (ORCs) are space rings so massive that they measure about a million light-years across – 16 times bigger than our Milky Way galaxy. “Astronomers believe it takes the circles 1 billion years to reach their maximum size, and they are so large that the objects have expanded past other galaxies…. Initially, astronomers thought the circles could be galactic shock waves or even the throats of wormholes, among a whole host of ideas.” Only five radio circles have been found in space so far.


ESA’s Gaia telescope has been among the most productive in all science, measuring position and brightness for millions of stars, vastly expanding parallax metrics and now – combined with a Chinese spectrograph – determining something amazing about the age of the Milky Way galaxy. Apparently stars of the ‘thick disk’ component formed very soon after the Big Bang. The thin disc of stars which holds the Sun, was formed during the subsequent, second phase of the galaxy’s formation.  The resulting model of galactic evolution is amazingly detailed. Like the way genetic analysis has let us reconstruct human evolution.

Early life on Earth: Some scientists believe they have found evidence of microbes that were thriving near hydrothermal vents on Earth’s surface just 300m years after the planet formed – the strongest evidence yet that life began far earlier than is widely assumed. And yes, it is a bit of a reach, considering how complex the hematite forms appear. Still, it is amazing what science detectives can reveal.


Does Europa take oxygen (photolytically generated from its surface) and ‘draw it down through the ice roof to the ocean, below? Europa Clipper is the first mission dedicated to Europa. Especially important as we are now pretty sure that almost all of the liquid water in the universe may sit under the ice roofs of Europa-like worlds, vast, numbers of them out there.

 == Space tech ==

Is this for real? Spin launch? The video gives no sign HOW it's done. If you watch not just the video but the clips that play after, there's on glimpse of the hurl cone flung from the end of the rotating arm. One might imagine it being useful for a fixed position area defense system for a high-value base.  The biggest use is likely pop-up replacement of LEO coms and observation CCC assets.  Just being able to do that in a variety of ways could reduce the temptation of rivals to degrade our orbit dependent systems with shotgun pellet denial or EMP.

A University of Georgia team realized that the lesser gravity of Mars means that a lower-quality fuel could nevertheless power rockets into orbit, if it could be made cheaper and easier and store better than methane or hydrogen, and made by a very simple biological ISRU (In Situ Resource Utilization) method relying on cyanobacteria and e.Coli to convert CO2+water+sunlight into LOX and “2,3-butanediol”. A combined process already proved on Earth. A byproduct would be water and oxygen for, well, you know.

Cislunar platforms: Quantum Space announced Feb. 3 it’s starting work on a spacecraft platform that would initially operate at the Earth-moon L-1 Lagrange point and host various payloads. That platform would be serviced by another spacecraft that would deliver and install payloads. The Earth-moon L-1 point, about 60,000 kilometers from the moon in the direction of Earth, offers a “clean sheet” approach compared to working in Earth orbit.

Should we consider a 2-wheel motorcycle for moon astronauts, rather than a 4-wheel buggy?

The Pentagon’s Orbital Prime program is offering seed money to develop technology to gather up the spent rocket parts and dead satellites littering low Earth orbit.

And because the Whole Earth is a planet, after all… John Markoff’s biography of the incredible Stewart Brand. “The definitive biography of iconic serial visionary Stewart Brand, from the Merry Pranksters and the generation-defining Whole Earth Catalog to the marriage of environmental consciousness and hacker capitalism and the rise of a new planetary culture—the story behind so many other stories.”  



Unknown said...

“What we do need to do is to race to be the next footprint tourists…”
should be:
“What we DON’T need to do is to race to be the next footprint tourists…”

locumranch said...

Any obscure pedants out there who might ‘get' why - if I were invited to contribute a story to “New Tales From The White Hart” - I might offer one called “The PlanetAgent”? Obscure!

I'll take bad puns for $200, Alex:

I suspect another rant about the evils of feudalism & aristocracy with the story title being dyslexic wordplay for Plantagenet. I also wager a plot twist that features the Kentucky Rifle as a 'firearm for freedom',

Unfortunately, the majority of post-post comments indicate a preponderance of pacifists, magical thinkers and irrational optimists but damn few readers left who are familiar with works of Heinlein, Van Vogt, Leinster or Paine.

The Star_Trek future of brotherhood, comfort, peace & plenty that they imagine is more likely to give way to one filled with useless & desperate people who console themselves with drugs, gaming and self-annihilation, as predicted by Yuval Harari.

Did I say 'likely to give way to' and 'predicted' ?

I apologize for such horrendous misinformation because, most assuredly, this is NOT the future but the world we currently inhabit -- drugs, gaming & self-annihilation -- and this leaves us with a paucity of immediate options:

Either (1) we avail ourselves with 'all the advantages of modern design' and allow ourselves to be carried along the corridor on a conveyor belt in extreme comfort and past murals depicting Mediterranean scenes as in Monty Python's Architects Sketch, or (2) we arm ourselves to the teeth and obliterate all those who would declare 85% of humanity 'non-essential' as our own ruling class just did during the recent Covid Pandemic.

Human technology is truly a wonder to behold and, like Dr. Brin, I want more of it, BUT we cannot allow technology -- and, its bastard child 'efficiency' -- to be weaponized against the majority of humanity.

Like Procrustes, we shall all be found wanting when we are measured as we have measured others.


David Brin said...

Talk about variable! When he takes his vitamins, I sometimes get halfway into a locum posting without having noted who did it, thinking "huh, interesting"... till inevitably he tips over into one delerium or another, alas. In this case, even knowing he's nuts, I found it all worth a scan. Go figure.

David Brin said...

And yes, he got the 'plantagenet' cue that I bet no one else did. And that I forgot. Again, go figure.

Alfred Differ said...

The Star_Trek future of brotherhood, comfort, peace & plenty...

...was assumed to have followed WWIII where humanity tried to extinguish itself in nuclear fire.

No doubt without that calamity it sounds implausible. Sounds.

I suspect it or something like it is in reach, though. We might not have the trauma related to altering our own genetics that TOS also assumed, but old-fashioned wariness would likely be there.

It's not like TOS portrayed perfection back home, though. Some of those plots implied unpleasantries. It was TNG that went toward utopia-at-home.

Alfred Differ said...


Yah, but 50 years before that... some of the folks who currently identify with the GOP were under the Democrat's umbrella and... well...

People think we are a two party system. We aren't really. It's just that we do a lot of our bargaining before the elections. Factions move around. Dixiecrats picked up and moved in the 70's. Progressives shifted away from the GOP around the same time. State parties under the same umbrella are NOT necessarily in agreement either.

Our factions are very real and the governing alliances they form are not static. If we had stronger bonds between them, the Democrats would govern at the national level much more often than they have in the last generation.

Alfred Differ said...

That spin launch system would play havoc with pressure gradients in liquid fueled rockets. For solid boosters I can see it being tried, but for liquid fueled system... you'll need specialized rocket engines that would be challenging to test. How exactly would one construct the test stand, hmm?

They leave the impression the engine is supposed to ignite shortly after release. Liquid fuels would be sloshing right about then. Ugh. I'm not sure testing could reliably report success even if one of them lit successfully. So... try it lots of times and don't sweat fluid dynamics? Sounds like a recipe for failed starts and RUD's.

So... solids.

Larry Hart said...

Alfred Differ:

It's not like TOS portrayed perfection back home, though. Some of those plots implied unpleasantries

TOS did its best not to show much of anything about earth of its time. The only visits to earth were time-travel stories to the present day or further back.

There wasn't even all that much about Federation culture itself. It was more tightly focused on the adventures of the crew of the starship Enterprise. Much as the early episodes of The West Wing were about the trials and tribulations of the White House staff rather than the president himself.*

It's the fanfic that grafted a whole connective tissue of details onto the series which later became accepted canon. Why, for example, does everybody know that Kirk's middle name is Tiberius and Sulu's first name is Hikaru, when neither was mentioned in TOS?

* Martin Sheen only had a walk-on role at the end of the series pilot.

Larry Hart said...

Alfred Differ:

People think we are a two party system. We aren't really. It's just that we do a lot of our bargaining before the elections. Factions move around. Dixiecrats picked up and moved in the 70's. Progressives shifted away from the GOP around the same time.

The problem today is that liberals--especially the further left ones--seem to have forgotten this, while the right-wing has not. We keep eating our own because they haven't delivered us our pony yet, while the other side knows what they're after and keeps their eye on the prize.

State parties under the same umbrella are NOT necessarily in agreement either.

There are legitimate complaints about corruption among Illinois Democrats which bear very little resemblance to national politics. And to be fair, for four years (2015-2018), we had a Republican governor, Bruce Rauner, who probably never mentioned Donald Trump's name and kept his distance from the national craziness as much as possible.

Tangentially, too bad hardly anyone else "here" is in range of local tv ads for Republican primary candidates. The monkey-shit they're hurling at each other is hilarious, especially when the pro- and anti- ads for the same candidate run in succession. There's an ad "against" Darren Bailey paid for by the Democratic committee which I swear is actually intended to make Republicans vote for the guy instead of one of the opponents ("Tell Darren Bailey he's too conservative for Illinois!"). And another anti-Richard Irvin ad seems designed to trick Democrats into supporting him ("He called President Trump [sic] an 'idiot', and he supports Black Lives Matter!").

DP said...

Our divisions go back to the founding of the country, with different social groups with different beliefs and values founded 10 of the 11 "nations of North America:

On the Left:

Yankeedom (utopian Puritans)
New Netherlands (Mercantile Dutch)
El Norte (Hispanics)
Left Coast (New Englanders)

On the Right:

Midlands (Quakers)
Greater Appalachia (warlike Scotch-Irish)
Tidewater (English aristos)
Deep South (English salvers from Barbados)
Far West (disenfranchised Confederates)
New France (Louisiana, not Quebec)

David Brin said...

DP your genealogy is too complicated. There is America... the Union side of our 250 year ongoing civil war between cojoined twins... and the romantic/gray/red anti-modernity, anti-urban, anti-nerd or fact, hysteria-driven, oligarch-lackey Confederacy.

LH, my poster child typifying what is wrong with the US left is Seth Meyer. I am almost sick of him. He blames Biden for every failure to deliver ponies, when it is the Left who betrys the coalition at every turn. JB would poll above 50% if flouncing-preening sanctimony junkies like Meyer didn't play to the same old sick Nader/Jillstein purity narrative.

Jon S. said...

Another problem, in my experience, is that so many on the left think all they have to do is elect their preferred president and everything will be gravy - as if Bernie, had he been elected in 2016, would have gotten anywhere against McConnell and his minions (it's not a party, it's a cult). They fail to grasp how the far right took over the party, and much of the country, by putting their people in at all levels, from alderman and county sheriff up to the House and Senate. Getting Donnie in was just the rotting cherry on their shit sundae.

Similarly, the left has to vote their people in everywhere. You start building a skyscraper at the foundation, not the spire. And I'm going to keep riding this hobbyhorse until either people listen, or I'm locked up for being a liberal thought-criminal.

Alfred Differ said...

I think the article DP points to has a fair way to 'decompose the social vector' that makes up the US, but I don't think they fall neatly into left/right categories.

For example, there is a difference between Scots-Irish who came over from the period when Scotland was consumed into Great Britain and those who came over later as a result of disenfranchisement, famine, or just seeking work. There's a lot of variety due to the long integration time for immigrants from that group.

There is also a lot of variation among the English who came over due to their civil war in the 17th century. Colonial governance by one faction or another has a lot to say in the founding culture of a State in the early US.

We can argue we are conjoined twins, but I think the better analogy is as a fractured family of a dozen siblings. The 'twins' are the meta-stable factions those siblings form.

David Brin said...

Jon S.... it's worse. They enjoy pissing on allies far more than working in a coalition to defeat real foes.

Alfred Differ said...

...pissing on allies...

Reminds me of some libertarians I know. 8)

The disease should have a name...

gerold said...

I'm not convinced a permanent human-habited lunar base is just a "bar moonzvah." The south pole has areas with nearly constant solar radiation in close proximity to sizable surface ice deposits in permanent shadow. Seems like a nice neighborhood to plant the flag. And how does that "humiliate" other nations? Make it a transnational effort, where every nation is welcome to contribute. Instead of wasting their efforts on some PR stunt they could do something real. A moonbase would be a great place to leave petty nationalism behind.

Maybe a prerequisite for a manned station would be a way to make mooncrete on site using local materials and a manufacturing system for PV cells. And growing food. Food, shelter and power. A human could live on that.

Larry Hart said...

On Hollywood liberalism...

SOME IDEAS IN AMERICAN LIFE are so widely held and frequently invoked that it can seem like bad manners or outright delusion to suggest that they might not be true. There is a class of facts — it would be more accurate to call them myths or shibboleths — that everybody knows and nobody entirely believes. The Supreme Court is above politics. Rock ’n’ roll will never die. Hollywood is liberal.
Maybe it’s folly — or bias — to raise an eyebrow at such partisan political rhetoric, or to challenge the emotions and assumptions that underlie it. And perhaps a defense of Hollywood against the charge of leftist propagandizing will seem, well, defensive. But the argument I want to make doesn’t really concern the sociology of the business. I’ll stipulate that the people who make movies may skew progressive in their beliefs, commitments and voting patterns. The movies themselves tell another story.

MANY DIFFERENT STORIES, OF COURSE. About the grit and glory of the American military; about the heroic, essential work of law enforcement; about the centrality of revenge to any serious conception of justice; about the superiority of common sense over credentialed expertise; about the lessons ordinary small-town folks can teach fancy city slickers; about individual striving as the answer to most social problems; about the need for heroes.

DP said...

Alfred, the categories have changed over time.

For example, the people of Greater Appalachia have one enduring characteristic: they don't like to be told what to do by anyone in authority.

During the ACW, that meant rich Southern plantation owners. So the Appalachians sided with the Union and formed West Virginia, and nearly formed the state of East Tennessee.

Today it means liberal bureaucrats and environmentalists so they have joined with the Deep South.

Larry Hart said...


For example, the people of Greater Appalachia have one enduring characteristic: they don't like to be told what to do by anyone in authority.

Isn't it a little more nuanced than that? I can't speak for Appalachia in particular, but right-wingers in general seem to be less about standing up to authority than they are about the freedom to choose their authority figure, and once having chosen, to follow him unquestioningly.

They certainly didn't object to being told what to do by Donald Trump when he was sitting in the Oval Office. Heck, when speaking about other individuals, especially ones whose Trump-friendliness had changed with time (James Comey, Lindsey Graham, Bill Barr, etc), Trump literally had to tell them whether to cheer or boo before the audience knew how to react. And the courts are now full of cases involving January 6 insurrectionists claiming that the only reason they stormed the Capitol was because their president told them to.

They don't dislike being told what to do. They dislike being told that they are wrong about something. They'll obey to the death a leader who tells them they are right about everything.

GMT -5 8032 said...

I am interested in the amount of radiation near gas giants. A few years ago, I remember reading about how the Juno satellite would be exposed to amazing amounts of radiation as it orbited Jupiter. I've read a little about the reasons for these radiation levels. I wonder how these levels compare with the radiation levels around the other gas giants in our solar system.

This would have a big impact on efforts for manned exploration of the outer planets. Looking at fiction, what really would have happened to the Discovery 1 and the Leonov if they had orbited Jupiter as described in Clarke's novels 2001 and 2010? Or, looking at Niven and Pournelle's THE MOTE IN GOD'S EYE, how much radiation would the MacArthur and the Lenin have endured if they had transited the radiation belt of a Jupiter like planet in order to scoop hydrogen from the atmosphere?

scidata said...

Pop quiz: who coined the term "gas giants"?

Jon S. said...

Pop quiz: who coined the term "gas giants"?

Took literally half a second on Google, but the answer is fascinating. Won't spoil it here, though. :)

I just want to know who decided the outer planets of our system are called "ice giants" when the volatiles are in fact boiling down there? Why not "steam giants"? (Try to Google that and all I get are results about Norse beliefs.)

Larry Hart said...

Jon S:

I just want to know who decided the outer planets of our system are called "ice giants" when the volatiles are in fact boiling down there? Why not "steam giants"? (Try to Google that and all I get are results about Norse beliefs.)

For Norse beliefs, try "frost giants"

Der Oger said...

Or, looking at Niven and Pournelle's THE MOTE IN GOD'S EYE, how much radiation would the MacArthur and the Lenin have endured if they had transited the radiation belt of a Jupiter like planet in order to scoop hydrogen from the atmosphere?

When I looked at the scooping hydrogen problem for the Traveller and Stars Without Number games(which do not present space magic solutions to this problem), I guessed that possibly the magnetic fields of a gas giant bend the radiation probably in a fashion that it could be relatively safe to use the polar regions for refueling. That, in turn, had other in-game implications.

But I have yet to hear how the resident astrophysicists would solve the radiation problem when colonizing Jupiters Moons or travelling through that area.

duncan cairncross said...

Re - Mote in Gods Eye

Niven's ships were well enough "shielded" to dip into the Photosphere of a Red Giant

I don't think the radiation belt of a Jovian planet would have been an issue

Jon S. said...

No, what I meant was, when I try Googling "ice giants" I mostly get info about frost giants.I just want to know who decided that Uranus and Neptune were ICE giants, not STEAM giants.

Peter Andersson said...

Moon Motorcycles!

I guess that means the next "Fast and Furious" movie really will be set in space! :-)

gerold said...

Jon S: ice giants may be hot hearted but cold skinned. No one wants to visit the heart of an ice giant. Diamonds melt down there.

DP said...

Gas giants aren't nearly big enough.

You all need to check out Brown Dwarfs floating in space between the stars that generate enough infrared to support life on their exomoons but are too small to ignite as a star..

Dr. Brin, two questions:

1. Have we determined yet the ratio between BDs and normal stars?

2. Can't we come up with a better name, something cooler like "Dark Stars".

scidata said...

So, Jon S. was too polite to directly answer the quiz (gas giants), it was James Blish.

If hope had a soundtrack, it might be "Peace Train" by Yusuf Islam (Cat Stevens), covered by a Southern country band:

Their nifty video montages are done by Terry Heinlein. That led me on one of those chain of links searches that included James Blish. (no connection between Terry and Robert Heinlein was found, but it's such a unique surname I had to look).

David Brin said...

Gerold said: “I’m not convinced a permanent human-habited lunar base is just a "bar moonzvah." The south pole has areas with nearly constant solar radiation in close proximity to sizable surface ice deposits in permanent shadow. Seems like a nice neighborhood to plant the flag. And how does that "humiliate" other nations? Make it a transnational effort, where every nation is welcome to contribute. Instead of wasting their efforts on some PR stunt they could do something real. A moonbase would be a great place to leave petty nationalism behind.

Except the number of conflations there is appalling.

Artemis is a stunt. It has nothing at all to do with a "permanent moon base." which I'd love to live to see. Which might become a practical LONG range goal if Elon's full stack actually works and can be refueled, as advertised.

At NIAC we have funded the first projects on sun+shadow energy tranfer methods, NONE of which require human presence, which distracts from efficiency by 1000 fold.

"And how does that "humiliate" other nations?' CRAP you are serious? That is the top attraction of Artemis to the MAGAsSteal from China their moment.

" Make it a transnational effort, where every nation is welcome to contribute."

Yep,. that is where it will go. And we will thus be required to hand over every pertinent tech to ouf 'partners.' That is the plan, all along.

Der Oger said...

Maybe ... the moon as a safeguard against extinction-level events?

Think of building thousands of emergency shelters in advance to evacuate people to it ...

... or just lunar palace hideouts where future Jeffs and Elons can ride out the apocalypse below and spend their wealth on truly decadent megaprojects?

... or a strategic asset that could deny other nations or rival corporations access to deeper space?

Alfred Differ said...

Jon S,

Sorry. I don't know who is responsible for the naming distinction between gas and ice giants. It makes sense to astronomers, though. Gas giants in our solar system are radiating more energy (mostly IR) than they are receiving from the Sun as they are still in the process of differentiating inside. Ice giants aren't so much... because they've cooled in that respect. That doesn't mean they are cold inside, but they've sorted things out down there.

That's the way I interpret their naming intent anyway.

[Earth has settled that way too, but U-238 is radioactive.]

David Brin said...

Der Oger. No matter how horrible an event strikes Earth... nuclear war or asteroids or whatever... Earth will remain VASTLY more habitable by technological humans than any other place in the solar system. A habitat 1000 feet under the sea is more habitable for more people at less expense with more resources at-hand than anything we could build on the Moon.

Perhaps that will change, with truly advanced ISRU and robotics... over long time scales. But for the foreseeable future, that liferaft thing is just not a plausible reason to do space. We have other reasons. Sufficient ones.

gerold said...

D Brin: I wasn't referencing Artemis - to tell you the truth I don't even know what that is - but rather a long term human moon base with on-site manufacturing capability to produce food, water, energy and rocket fuel.

As far as "humiliating" other nations; huh? You're worried about humiliating others if the US goes it alone, and worried about technology transfer if we cooperate? Maybe we should just stay home and keep the shutters down then.

duncan cairncross said...

About the only thing that could make the Earth less inhabitable than the rest of the solar system would be an intelligent and implacable enemy - some sort of alien or AI

And its difficult to imagine anything intelligent enough to make earth uninhabitable that was also not intelligent enough to chase us anywhere in the solar system

joepublic said...

A two part critique of the Spinlaunch project can be found by the Youtuber Thunderf00t, here:
and his follow-up here:

Alfred Differ said...


The point about humiliation is this. The US should want other players up there.* Whatever moves them to do it should be tolerated by us as much as we can because there is a long-term benefit for those of us in the US. Larger markets more often than not serve our vision for humanity.

If nation X decides they want to join the adult's table by showing they can get to the Moon and do something useful, we should cheer them on. We should also be very curious how they do it. 8)

* The US military is not excited about others being up there too. It's going to happen, though, and they know it. They already have plans for maintaining our superiority that involve spending lots developing leads and staying ahead. Keeping others back is only part of that strategy and they know it won't work forever.

kvs said...

According to Wikipedia, Jupiter and Saturn are mostly hydrogen and helium while Neptune and Uranus have a lot of other elements as well (oxygen, etc.). Since a lot of the compounds (water, ammonia, etc.) are called "ices" by the planetary scientists (skipping over details...) they are called "ice giants"

One cool think that Wikipedia claims is that the terms "gas giant" and "ice giant" were both coined by science fiction writer and then adopted by the scientific community.

GMT -5 8032 said...

Just be careful if you write about degenerative brown dwarfs. That sounds like something out of GAME OF THRONES and could get you in trouble in some areas.

scidata said...

Admiral Linda L. Fagan (Coastguard) has been installed as the first woman service chief. Clever move.

Alfred Differ said...

Heh. Ices. Just like everything heavier than helium is a metal to cosmologists. 8)

White dwarfs are the degenerate ones. 8)

Der Oger said...

I know, it is far away in the future, but:
Wouldn't be the moon an ideal industrial hub for starship construction and launches?

Less energy needed to send a craft from there to Mars and other sites than launching it from earth; also, maybe, only a fraction of energy is needed to move heavy parts around?
Or asked the other way round:
Wouldn't the moon allow for more energy-efficient engineering & construction (once all parts are in place, of course)?

David Brin said...

gerold, the TOPIC was Artemis because that is the insanely unproductive stunt that Trump imposed on us and on NASA, to drain away resources from more advanced things we might be doing, in order to basically repeat Apollo. For you to raise some distant notion of moon cities , when the topic was Artemis... THAT is the non sequitur, here.

Racing to re-stage Apollo, just a year or two before the Chinese try their own symbolic rite of dusty footprints is the very essense of attempted humiliation. Utterly unnecessary when we could instead sell them components and services and pat them on the back.

Joint mission is even worse. We have OTHER things to do out there! Please re-read your note, above. It bears no relation to anything at hand. Especially suggesting I want to sit on our hands.

We have OTHER things to do out there!

Unknown said...

Unless you are building aluminum starships, not sure ON the moon is the right place. Maybe put a fabrication plant in orbit around the moon, or at a Lagrange point, using asteroid-refined metals? Taking stuff down just to bring it back up seems like a waste.


P.S. In a nice Trek bow to realism, the only Federation starships I ever saw being assembled (not counting one stupid remake movie) were at orbital stations.

P.P.S. Making Earth uninhabitable...does grey goo count?

Alfred Differ said...

Industrial centers are likely to be mostly unmanned out there. Human-tended mostly. We are already heading that way on Earth, so I expect more of the same. Big fab machines.

People collect at transportation hubs to trade. That's where the cities will be. Easy places to get to and from. Low delta-vee and frequent orbit change opportunities. Time is money. People might reside on the lunar surface eventually, but not until the obvious hub sites have traffic (commodities, goods, and services) to justify other people further out along the economic tree.

What people will do is poke around in places. They might send machines or go themselves. Probably both. Exploration isn't colonization, though. It sure isn't industrialization either.

Where will those transportation hubs be? Most likely at the Earth-Sun L1 & L2 regions AND the Earth-Moon L1 & L2 regions. That's just orbital dynamics.

duncan cairncross said...


Other likely location - Mars orbit
You have materials available - Deimos escape velocity 20 km/HOUR
And Mars is a useful place to do an aerocapture maneuver to save fuel when arriving

Alfred Differ said...


Eventually. Deimos and Phobos are the likely first targets for materials. Still... markets emerge at transport hubs. Lagrange points are wonderfully chaotic nudge points with large volumes around them that are meta-stable.

Lots of classic examples people can draw upon all across the world. European 'civilization' returned after Rome's collapse first at the transport hubs. Those hubs moved as trade loci were added and subtracted, but the rule still applied.

In the US, Chicago exists because it is a sensible trade hub for interior routes. Cities along the various rivers feeding out the Mississippi exist because they made sense as places to concentrate capital for interior trade.

No matter where one imagines humans might go in the solar system, it's worth asking whether trade will concentrate there. Lots of stories have people living in the asteroid belt with Ceres as a major stage. Does it make sense to concentrate capital and goods there? If it does, it will happen. If not, it won't unless some "King" decides to erect his castle in an analogous swamp... aka St Petersburg.

David Brin said...

Now that we know the Martian surface has exploitable near-surface colatiles (water ice) the biggest game changer would be if Phobos does, as well. 2:1 odds against, alas. But if so, then ISRU robots could have full tanks ready before humans even head forth from Earth orbit for Mars. Both economics and safety improve by order of magnitude.

scidata said...

Water ice must emit some sort of IR signature as Phobos orbits in and out of sunlight. The JWST could pick that up in its sleep.

Jon S. said...

And sometimes those loci exist as fossil remnants of late technologies. The USAF located HQ SAC at Offutt AFB south of Omaha, NE, because it was a locus of telegraph and telephone trunk lines, first installed when Omaha was the transshipment nexus for livestock. The nexus moved to Chicago, but the telegraph lines weren't things that could just be picked up and moved, and the long-distance telephone lines followed the old train routes at first. When the Air Force was established in 1947, it made perfect sense for the Strategic Air Command to be located in a place where there was lots of existing long-distance communication infrastructure.

Today the cattle yards of Omaha are a shadow of their original glory, the telegraph is all but obsolete, and telephone landlines appear poised to follow, but the joint US Strategic Command (USSTRATCOM) is still sitting in a reinforced-concrete-lined hole that's proof against the biggest bombs in use at the end of the Second World War.

David Brin said...

"Water ice must emit some sort of IR signature as Phobos orbits in and out of sunlight. The JWST could pick that up in its sleep."

Not really, if it's buried pretty deep, with the outer layers baked by a billion years of sunlight. That's just my doctoral dissertation, BTW...

scidata said...

Dr. Brin: doctoral dissertation

Heh. Well if I was on the thesis committee, I'd ask, "Have you considered a large impact fissure that might partly reveal the interior?"

Can you believe my cheekiness? It took me a year to work up the courage to post in CB, now I'm a smart-ass :)

David Brin said...

scidata UR gr8. And show me the impact. These are long time frames.

Paradoctor said...

If you're going to put a base on the Moon, then I say that the cheapest, safest, and most effective way is to put telepresence robots there, and operate them from Earth. The best space-suit is a telepresence waldo.

It's true that the 2.5 second light round-trip time makes the waldo not quite you-are-there; more like you-are-riding-a-stupid-mule; but that can be coped with. Maybe onboard AI can do some of the realtime responses. Through it you can see in IR, in UV, and spectroscopically; and you will never suffer from vacuum or radiation or low-gee. Or isolation from Earth. Or freeze-dried food. Also, it's expendable, and you aren't.

If they ever invent the 'ansible' - that is, FTL signalling - then ansible waldoes would outperform the Enterprise. Who needs life support?

duncan cairncross said...

Paradoctor - that time gap is the best reason for an AI

It would not have to be a very powerful AI as it would be being led by the human -

scidata said...

Re: ansible waldoes
That's what the Turing Test is all about. A sufficiently advanced ghost in a machine is equivalent to human intelligence. However, it's not romanticism to point out that that's only hypothesis, not proven fact. Piers Anthony delved into this in "Macroscope", as have many others ("The Fly", "Transcendence", even "2001"). I call it 'secret sauce', others go full wingnut (eg Francis Collins). A poetic way of putting it:
"A totally unmystical world would be a world totally blind and insane." - Aldous Huxley

Alfred Differ said...


Anything you put in the Easy-Bake oven for 3 billion years is going to have a brick-hard exterior. The Sun isn't as bright out there, but UV still breaks up molecules.

I think the only plausible debate regarding Phobos volatiles is whether it's worth drilling to get them or lifting them from Mars. My suspicion is the drill is cheaper, but if crazy tourists are going to-and-fro... who knows?

And yah... comet nuclei that haven't been in the oven as long are more interesting. If... they have reasonable orbits.


There is an old debate among space advocates about how things will unfold. At times it's more like a war of religion. If I have to pick a side (I'd rather not), I usually argue that we will make some use of the Moon mostly from orbit and then move on to NEO's. I'm only interested in economic development when I pick a side, though.

Scientists will go where their interests lead. They don't have budgets large enough to make a dent in what the engineers need to know and economic development is mostly about engineering and finance.

duncan cairncross said...

How nessesary are they?
With abundant energy from the sun we may not need "volatiles" - instead we should be able to break down the solid "rock" - rock has lots of oxygen - and some rocks have hydrogen

Something common and on the surface may be a better source of the elements we need than drilling for "volatiles"

We have a tendency to think in terms of compounds rather than elements - which is a reflection of the way to do things on a planets surface with lots of compounds and a dire shortage of energy

gerold said...

I'm certainly not convinced that a moon base is necessary or advisable. The arguments in favor of orbital platforms are strong. Whether a human presence makes sense is also debatable. Life support is heavy/expensive. A big part of that tradeoff is the pace of robotic and AI tech. Right now people still have a big advantage when it comes to intelligence and flexibility. How long will that last? 20 years? 40? Do we want to wait for them to catch up?

One advantage of a moon base is ready access to matter and energy. The South Lunar Pole has areas with near constant sunlight and (potentially) large deposits of surface ice in perpetual shadow craters. This could eliminate a major drawback: the lunar gravity well. Water makes good rocket fuel if you have enough energy. If we can make solar panels/film on site, huge amounts of energy could be made available. With energy all things are possible.

If we want/need to have people in space, the moon has a couple more advantages: shielding from radiation and gravity. I don't know if 1/6 g is enough to prevent the kind of physiological degradation we get in zero g, but that would be very helpful.

One other "resource" we get off-planet is never discussed: near zero ambient temperature. Seems like this could be very useful for electronics. Quantum computing might be more practical, and free superconductivity might have all kinds of advantages.

I know if I was a transcendent AI I'd want to live in the cold. Hard to think straight at 300 K ambient.

gerold said...

Duncan: breaking down mineral oxides takes a lot of energy but a solar smelter in zero-g might be a good way to get high enough temperatures to volatilize minerals. Moon dust has a lot of oxygen, silicon, aluminum, iron, magnesium and titanium; blast it with enough concentrated solar radiation and it'll fractionate into constituent elements. I'm not sure how to process it afterwards however; zero-g is nice because you don't need a crucible for containment, but what do you do with a blob of super-hot molten or gaseous matter? Gravity is nice for fractional distillation and cracking, but if some smart space manufacturing engineers can figure out a way to process hot elemental matter out in the vacuum things could get interesting.

Alfred Differ said...


Volatiles are critical.

Put your engineer hat on a bit and consider answers to the following questions.

1. What fraction of car users make their own cars for personal use?
2. What fraction make some part of their car that is critical to its function as part of their maintenance of the vehicle?
3. What fraction refine their own fuel for use in their car? (May include biodiesel.)

I suspect those fractions aren't zero, but pretty damn close. The last one is probably largest, but not huge.

Now shift your attention to what your life might be like on the Moon… or anywhere else out there. Are you really going to make your own oxygen? Manufacture your own water? Craft every other detail you need to keep alive and functional? Nah. You will want to buy it.

If you make it all yourself, you are a one person market. We call such people HG nomads. If people in your colony make it all themselves, you live in a commune or tiny ordered community. Neither of these options are going to leave you with enough time to teach your kids the technology skills they'll need to keep doing it. Go down this path and your fellows will retreat into the kind of poverty humanity faced for most of our existence as HG nomads.

Nah. You'll buy your oxygen if you can. You'll have water shipped to you if you can. You'll buy your tech from elsewhere if you can. Pulling that off means you have to have something to sell. Fortunately, there is something up there that is worth a frickin' fortune to people who want to make money doing ANYTHING else. Fuels, oxidizers, and all the other things 'life' needs. Whether people are up there in large numbers depends on all three, but it starts with fuels and oxidizers. Those start with volatiles.

Trade requires moving stuff from here to there. Movement requires delta-vee which requires fuels and oxidizers. (aka volatiles)

Ignore the gold and platinum. Stick to the lower atomic numbers and the molecules they make.

Think like a mining engineer.

David Brin said...

Gerold points out correctly that tightly bound oxides are a bitch to break up. That's almost every 'resource' on Luna.

duncan cairncross said...

Hi Alfred its the ones that "make" and sell the volatiles that will use locations with low delta V requirements

Energy costs in free space should be incredibly low
Energy costs when you are down a hole will be high as your mirrors will need to strong to resist gravity and atmosphere and your power source will move across the sky and hide half the time

So volatiles that are down a hole will need to compete with volatiles made from the nasty oxides with cheap energy

gerold said...

Alfred: being an HG nomad on the moon isn't very practical. But because of the cost of escaping the earth's gravity well we need to source locally as much as possible. Lift the manufacturing tools but obtain raw materials outside earth.

The moon has lots of local material and it's close to earth. Asteroids are great but they're a long ways off. Travel time and reaction mass required to get there, synch velocity, gather the materials and then get to where it can be processed are all costs.

The moon also has a gravity well and that makes it costly to get off. But depending on how much surface ice is available in the perpetual shadow craters, oxygen and hydrogen - rocket fuel - may not be a limiting factor. If ice is not abundant, then maybe rail gun propulsion - that's how Heinlein got heavy stuff off the moon in Harsh Mistress - is the way to go. Solar energy converted to electrical power could make that work if we can cover the South Polar peaks with solar cells. Need to be able to make them on site of course.

I've always pictured a solar smelter floating at a Lagrange point. That way you can get 24 hour continuous insolation and go as hot as needed. But maybe the earth-moon L1 point could be the site of focusing mirrors with a "crucible" on the lunar surface (?)

I love the solar smelter idea but the engineering would be tricky.

Alfred Differ said...


Energy costs in free space should be incredibly low.


Because sunlight is plentiful, right?
Try moving further out in the solar system where most of the easier resources are found.

Papa Sol kinda arranged this and he's had a few billion years to set up the game for us. Where sunlight is most plentiful, everything has been thoroughly baked. The easy stuff to get has already been chased out of the solar system baked away and dispersed as ions.

In case it isn't clear, I'm saying energy will be cheapest where it is least useful. Working out further from the sun will require structures that have to be maintained. They won't be cheap because it takes energy to make them in the first place.

"Costs should be incredibly low" always provokes skepticism in me. I hope you are right, but my gambling instinct says to bet against you.

As for volatiles in a hole… I agree up until someone uses some of them for heat transfer. If the hole is baked hard enough, it is a pipe once you drill it out.

For Belt operations, I'll go on record as saying y'all are going to need nuclear energy. Slow fission to provide heat for industrial purposes. It's a damn long way out there.


being an HG nomad on the moon isn't very practical

I'd argue it is one step short of dying. If it doesn't happen to the fool trying, it will get their kids. I'd say this about most of space too, but especially Luna's surface.

…because of the cost of…

Yes, but…

This is exactly the problem markets solve for us. We often dislike the solutions, but it works. If someone is willing to pay $X for commodity Y at location L on calendar day T, they offer their end of a futures contract. If $X is high enough, someone buys into their end of the contract and the game is underway.

Those contracts can't be written at the moment because $X must account for the fact that engineers don't know how to do a lot of what's needed up there.

Yet… there are launch companies building rockets and promising to fly object Y from pad P on roughly calendar day T. THAT engineering knowledge is advancing fast. Some of them are getting pretty good* at delivery Y to a relatively exact location L (defined by orbit parameters)… so what do WE want to put up there? What can WE do that advances the engineers so we get a little closer every day to those commodities futures contracts?

* WE can put things in sun-sync orbit on a regular basis now with a ride on scheduled, dedicated buses operated by SpaceX. What do WE want to do?

duncan cairncross said...

Re cost of solar in the outer system

All you need is mirrors - if the sun is 10 times as far away then a mirror ten times as large (100 times area) -

Mirrors should be dirt cheap - the only "load" is sunlight
spinning disc maybe?
Half a huge soap bubble balloon?
The technologies that are being developed for solar sails would work - only no need for super duper light - just light would do

the expensive bit is at the focus - turning sunlight into whatever - and that stays the same cost no matter how far out you go

Going further out increases the cost of the supercheap bit

john fremont said...

That's the same reasons Cheyenne Mountain outside of Colorado Springs was chosen. The old Ent Air Force Base was at the locus of telephone and telegraph lines as the Springs was another major stop for cattle drives on the way to Denver. Also the location of Ent was also good for radio repeaters. Relocate the base into a nearby block of granite to protect it from nuclear attack. Now of course most of the old Air Force bases in Colorado have been reassigned to Space Force

Alfred Differ said...


The load isn't just sunlight. There are a number of perturbing forces.

I used to play with solar sail designs years ago (how I met our host) which also have the complicating need to unfold if launched from Earth. You can avoid unfolding, but you can't avoid gravitational perturbations and solar wind.

It only looks like empty space out there. The fact is the Earth orbits the sun through the top of the Sun's gusty atmosphere. Build your mirrors and you'll notice. [The wind gusts and the objects being orbited aren't spheres.]

You need structure and attitude control for the mirrors. Put your engineering hat on and break out the CAD and FEM tools. It's not as simple as you think.

scidata said...

If only there was some way to gather solar energy where it's abundant then transport it out to where it's needed. Some sort of electricity storage device.

David Brin said...

Gerold, alas, you know some things... not others. Asteroids - even 'near-Earth" NEOS - take more TIME to get to than lunar surface. Hence Luna is better for living people. That plus shelter and gravity for bones and swimming pools.

So Luna WILL likely see settlemens, even cities. And no way that is a reasonable near or medium goal.

Asteroids have vastly more useful stuff. Except for water ice, Luna has none. Near term oxides refining is as mythical as 'Helium Three."

NEOs are MUCH less energy costly to get to and back. For robots it is a no brainer.

For now, Luna is for tourists. Period. And we should let the eager tourists rush for their photo shoots, like we did 55 years ago.

David Brin said...

Developing very large mirrors and sails and solar concentrators for asteroid refining are all projects we have funded (some continuing) at NASA's Innovative & Advanced Concepts program - (NIAC) .

Alfred Differ said...


That's were the nukes come in. Not stored solar energy, but high energy density anyway. We'll need that tech to bootstrap toward the vision Duncan describes.

A.F. Rey said...

Sticking a little politics into the conversation, the Democrats in Laura Boebert's district seem to be taking your advice and voting in the Republican primary.

They aren't registering as Republicans, though, but as Independents, which allows them to vote in whichever primary they prefer. But you can't imagine them changing party affiliation just to continue voting Democrat. ;)

The only problem is there are not enough of them. Only about 3700 have changed affiliation, and Boebert won by about 10,000 votes. But it may be enough to tip the balance come June 28. :)

duncan cairncross said...

A.F.Rey - which way would a democrat vote?

If they have Boebert as the GOP candidate then there is a greater chance of the GOP losing

On the other hand if Boebert wins its worse than a sensible Republican

There is no "correct choice" - only guestimates

duncan cairncross said...


The stresses on a mirror would only become significant at the kilometer size range

And a square km of mirror would be focusing a Gigawatt of power - even out at Jupiter that would be 40 Megawatts

A soap bubble would do for the mirror - a 1 km square mirror could need a frame of 1 cm angle aluminium ??

Tradeoffs - the lighter the frame the greater the number of position control modules

But the cost of the mirror, frame and position control modules would be a rounding error compared to the cost of the energy receiver at the focus

Alfred Differ said...

Projects funded like that through NIAC are part of why I'm not more negative about NASA in the modern age. I've never been inclined to fault everyone in the agency for the fact I cannot buy a tourist ticket to Luna just yet, but I admit I've come pretty close at times.

One of my attitude drivers stems from an event in the mid-90's. I was chasing after solar sail documentation and asked the JPL archives for copies of Halley Rendezvous reports. Apparently I was the first civilian to do so after the Cold War was over, because I triggered a declassification process. I wasn't in a rush and received a box of stuff several months later. I was a happy pig in the mud until I noticed some of the reports never got written. I asked about them and the archive people said they never received them. The report references documents from various contractors… who didn't finish before the money ran out.

I learned from friends that this wasn't unusual. The political purpose having been met (keep staff employed) no one cared much about the final project artifacts. That struck me as fraud and still does, but it technically isn't if the government funding source doesn't care either. A wink and a nod makes it clear what is actually being purchased… and it wasn't results.


I wound up working on some software to simulate sails out there that tried to represent perturbations correctly. There were a number of code blocks owned by research teams that approximated possible missions, but nothing I could get my hands on treated the problem properly. One included sunlight forces, but ignored spherical harmonics. Another looked at several perturbations, but only over long time integrations. It was frustrating because I wanted to search for commercially feasible flight profiles to and from promising targets. I got part way into it and discovered the usual hindrance. No one had computers fast enough to do what I imagined except the big guys. Solar sail research was not done by the big guys. No one funded it much back then.

I suspect we CAN do these things today. Every so often I get tempted to revive that work on my own dime.


I sincerely hope NIAC demands all final reports be completed. You never know when Joe Citizen Engineer will develop an itch and want to see what his money is doing… then leverage the work to avoid re-inventing what's already been done.

Alfred Differ said...


Your back-of-the-envelope calculations don't convince me. I can do them too… and have for solar sail ideas.

1. It's not empty out there. (We really ARE inside the Sun.)

2. The sun emits a fair amount of UV and soft x-rays impacting the fragility of your structures.

3. The sun emits a very gusty particle flux further impacting your structures and their control systems.

On Earth, much of the surface is hostile to human life. We manage because the air is breathable and we have enough tech to buy time in those places learning how to make things that reduce 'hostile' to 'manageable.' Over the last few millennia, we've been converting 'hostile' to 'manageable' as well.

In space, only a few places are hostile. The rest are incredibly toxic.

It's mostly in the toxic places where your engineering assumptions will be tested.


I don't want to sound like a nay-sayer with all this. We CAN build large structures out there and will learn how to do it. All I'm arguing against is that they'll be the cheap option. If I had to gamble my own money, I'd bet on nuclear being the cheapest once you get out past NEO's. Near Earth, I'd argue for PV's running equipment and small mirrors to bake things but not smelt. Sintering* of lunar regolith should be possible on Luna, but metal reduction is something I'd bet against for the foreseeable future.

* Sintering is important if you want to beat the dust problem. Tourists will quickly lose interest in Luna when they realize how nasty the dust is. Sharp, tiny fragments. Worse than hostile.

David Brin said...



David Brin said...

Alfred etc the answer is that Space ... is.... hard! It was easier to change ancient crimes of prejudice than it was to make wheel stations spinning to Strauss waltzes.