From LEO to HEO

Fifteen Starship flights to fill up a fuel depot in LEO. 3-4 flights a month. And then you have to keep methane and oxygen cold for months. At 1 Solar luminosity.

A darkhorse alternative has been on various drawingboards for some time, as ToughSF notes: the tether. Looking around, a Tamil, name of Nagaraj Arjun Raja, suggests the Rotating Skyhook.

The idea is to get something to "space" but not yet to orbit. For orbit Raja expects 9.4 kilometers per second δV; BraveAI confirms this figure accounts for the 7.8 km/s orbital velocity needed to maintain orbit, plus 1.5–2.0 km/s lost to atmospheric drag and gravity drag during ascent. I assume Raja assumes this to be launched from Sri Lanka so he's already using the equatorial surface daily velocity.

Raja notes that drag becomes negligible in the short term at 300 km altitude. We don't orbit sats there because sats are supposed to run for the long term. So if Raja's customers can just get something parabolic at apogee 300 km, Raja can catch it before drag and gravity matter. That δV is more like 7.

The skyhook's nexus orbits ~500 km going 7.612 km/s. The tether spins around such that, such that at 200 km below, the velocity is -3 km/s. That leaves 4.612 km/s to pick up the cargo. At the top of the tether, which is 800 km altitude, is +3 km/s. 10.612 km/s around that altitude is a trajectory to almost wherever you want, mate. Cargo will still need to correct that trajectory toward the mission parameter. Although that is Someone Else's Problem; Raja does suggest solutions to that Someone Else in section 7.

This costs up to 4.55 × 10⁷ J per tonne, going back down to Earth; so 4.55 × 10¹⁰ J per kilotonne. Raja believes that can be countered with a honkin' magnet on the nexus, gradually pushing Earth's 25 μT at that altitude. The magnet is in part powered by the current along the tether, presumably conductive along with its other magic properties. That conductive (silver?) wire is not load-bearing; it's just along for the ride. Also various radiators and solar-panels can be attached to the nexus. The more massive the nexus, the less it dips down per cargo load. The skyhook can also catch cargo from outer orbits to bring them down to Earth-capture. That boosts the nexus' orbit for free.

Raja has one more contigency: an ion thruster running 1-5 kW delivering 3000 s of specific-impulse. Of course then you have to deliver ions.

The 200 km of cable can be Zylon worth 7-14 T. "Carbon nanotubes" are also on the table like they always are in articles like this, which would cut down a lot of this mass, if and when we can spin 200 km worth of it (hey at least it's not GEO-length). Likewise I'm not requesting anhydrous silica... yet. Raja is optimistic we can in fact get a good-enough CNT rope in 5-10 years, at the 13.8 GPa which competes with Jensen's anhydrous.

Zylon at this scale would be delivered by the Falcon Heavy. CNT, lighter for the requirements, could go to Rocket Lab. The overall timeframe is maybe 13 years from now.

As for section 7: that is where Raja suggests next-steps. One example is to put more tether-systems in higher orbits to catch and correct those Molniya orbits which the main tether will create. #7.3 handles trash removal. #7.4, most gonzo of all, would pick Mach 10-15 scramjet loads from the 30-50 km upper atmosphere. We would here need to dangle the rope so its velocity is -5 km/s (2.612 km/s in atmo). Drag would start getting serious so this length cannot be permanent. The cable dips down and pulls back I guess.

The War Scroll's Ezekiel

Among the first surviving witnesses to Ezekiel's oracles is 1QM, the "war of the sons of light against the sons of darkness" or War Scroll for short. Ingrid Lilly, who perhaps more than anyone has raised 𝔊967 and parallel Wirceburger Latin to scholarly seriousness, on 2015 presented a paper on how, exactly, 1QM was citing the oracles. I don't know how the paper was received, but she posted her notes. Where the Scroll deals with Gog is column 11, lines 14-16.

(Lilly ignores 4Q491. Phillip Lebsack likewise calls 4Q491 out as a summary, intended for the outer circle of the Yahad. But more to the point 4Q491 and others simply don't cover this column.)

Mostly ll. 14-15 parallels Ezekiel 36:23. The narrator (the people) is addressing an Entity. This One is to make a name through the ensuing wars; to show Thyself great and holy among what's left of the nations (okay; goys) that they know. What they will know is not preserved (Ezekiel would have it I am YHWH). What is preserved shows (already!) an identification with the object of supplication, with Hash-Shem. But wait! - there's more! Line 16 immediately refers to the judgements against Gog.

1QM col. 11 skips over the whole chapter 37 about those dry bones. Lilly here points out that so does P967. For the Greek (and Latin), the bone chapter comes after the Gog oracle to introduce that great new Temple to come.

Texas doesn't need our Ogallala

I'm keeping tabs on the water we ain't got in the Rockies' foothills. Estes Park and the Thompson down to Loveland and Greeley drink it from Grand Lake, whether or not they should (the Colorado watershed thinks we shouldn't). Much of the Platte basin / watershed is instead pulled up from the Ogallala (map). That sunless freshwater sea is running dangerously low.

Hydraulic fracking involves hydro, sure; but that imported water goes even further down than the aquifer. More on that, anon...

Townhall, of all places, is ringing the alarm. This may represent that intersection between farmers and conservatives. Flanakin has an aside on the desal which Corpus Christi isn't doing. That on its face is a Texas problem downstream of us - so, I'll try mainlining Flanakin's aside.

Five years back I'd pondered drilling into the aquifer to channel the north, with more water; to the south, with more sunlight. Mind: my side of the Front Range will suffer even more. Such puts more pressure on the Thompson therefore on the Colorado. It also gives south-coastal cities like Corpus an excuse not to do infrastructure (Jevons' Paradox again).

Flanakin is mainly summarising Scott Tinker and Andrew Coppin. Tinker is focusing on the Permian - the Texas side. Flanakin doesn't say, but drillers know: the oil in the Permian comes with water of its own, beneath the Ogallala. Problem: that fossil water is in-situ with the... fossils. Which were ocean fossils. So it's all seawater - saltwater. Tinker believes that the wastewater could be desalinated and sent to the farmers. The Permian farmers, then, won't need the aquifer.

Luckily energy is cheap out there on the Permian, like it used to be along the Columbia River. I just mentioned the south gets more sun. And they're using it!

Meanwhile aquifers and the deeper salt seas might consider monitoring the stale air.

Beryllium everything

As Elon Musk loves stainless steel, and Jensen adores anhydrous glass; in the 1950s Isaac Asimov had a crush on beryllium. He thought in 1953 the asteroids would host a beryllium economy. The only catch was that the dust is toxic inducing the condition berylliosis. Asimov had to address this in another story the following year, "Sucker Bait".

As to, why the fourth element: the Young modulus against density. Such has kind of been a thing around these here parts. This is why anhydrous glass elsewhere - one reason. For smaller chassis-es Delta prefers this to titanium. I mean, why not, for unmanned craft; frankly all metals will get our monkeys nuked outside our magnetic shield.

Beryllium also promises heat capacity. After storing the heat, a sat can expel the heat for short bursts of high I_sp. No nukes! (Just the, uh, beryllium.) Also no radiators, since this whole setup is the radiator.

This would seem excellent for station-keeping an unmanned sat. Assuming you couldn't use a sail and the sat didn't need to be cooled unreasonably low. Lunar-orbital course-corrections? Solar flybys with Oberth?

Now: I've had trouble lately with Google AI. Lately it has hallucinated D&D modules HWA4-7 which never existed (nor should they). Here, take the following with grains of the sodium chloride.

Beryllium is Toray-esque brittle under 300° C (2-4% elasticity) but above that gets more "ductile". Melts at 1284°. Compare silica 1713°. I think the deal with "heat capacity" is that the metal will take a long ass time to push over that limit before it finally gives up and melts.

As far as, where to mine it: I think Asimov was under the (correct) impression that it would accumulate in the asteroids. For the smaller C types it does not concentrate in veins; but the larger ones might differentiate. Asimov didn't know, so projected the beryllium mines for Pallas. Ceres too, I'd recalled; maybe in the first edition of his book, which he subsequently quietly edited out.

Beryllium happens to be lithophilic. That means it should be gathered from regolith in subplanetary crusts. Our own Moon is that; also Vesta. If we were looking for siderophiles like tungsten we'd get that from Psyche or scout out craters.

Leadup to Boomer Day

As Murrka prepares to celebrate 250 years since perhaps the second-worst founding document in world history, the Dickinson-Barclay documents are up. The William and Mary Quarterly is examining them.

John Dickinson sent these to David Barclay Jr in London, the latter being perhaps best known for Barclay's Bank. John Dickinson was trying to alert Parliament - through London finance! - that New England's problems were serious.

From New England, we know better Hutchinson's Strictures (pdf). By then - 1776 - the disease had already spread as far south as Virginia and parts of the Carolinas. It could perhaps have been stanched at least before New York City and Long Island.

When the cable is disconnected

Suppose there's a problem somewhere around L1. If there's a space station, it cuts its losses likely starting with the counterweight, dominated by rope. The elastic cables fall. Let's look at Sinus Medii's side first.

Up to 60 Mm of Kevlar or Dyneema collapses upon the base. Coil it, box it, unscroll it - what is the base supposed to do with all this?

Also involved: potential-energy, by the integral mg(h)dh. The base must prepare for terajoules. The drop of this cable is a force, perhaps accelerating as more falls; like a slow motion explosion, more Chernobyl than Nagasaki. Loonies can harness this, but maybe not by design.

Under that; I want some structure as can funnel the thousands of m³ to some convenient depository away from useful work. We need to place it somehow/-where so we don't knot it and doesn't get METEORED. The depo would be large and/or deep: a fair purpose for a kilotower. Assume the depo is dustfree anyway. (If we're banning lander-rockets, that should help.)

Redirect poast

I've been up to stuff, but not so much stuff for the blog, so... I'll do what I used to do and point y'all to 1d6chan. Which was 1d4chan back when.

Over there I've an interest in the deep archaeology of the D&D genre. A (grade-four) classmate, name of Silas, gave me the Mentzer Basic set for my tenth birthday. My parents got me more material the following Christmas, including the Moldvay Basic and the Marsh Expert sets. Over the next year we'd acquired still more (I say we because my little bro got Descent into the Depths, "official module of GenCon XI" - used). I certainly had the Companion Set in fifth grade. Also some AD&D but maybe I wasn't then ready for it - I'll get to this.

These days I've been pondering the stuff which TSR did not publish, in either line. But still important stuff.

Take Paul Jaquays' The Caverns of Thracia. This has turned out a bigger deal than I'd thought. I mean, I already knew that his M5 module added the fourth dimension to that Moldvay-Cook Known World we now call Mystara. Much more so - I propose - than Niles could manage with Alphatia. Here, we see how it was that the TSR writers had to sit up and pay attention to Jaquays such that M5 could happen.

(Where debased mages make themselves into liches in their elder life; it seems that, today, roleplayers become ... Jaquays. We didn't have JK Rowling to warn us, back then. But! back to the main post :-)

Another module I've covered is that module which laid out what was played at GenCon X, in 1977. I shan't name it; roll your cursor over that link. This wasn't as memorable except inasmuch as it might represent the last ten-level dungeon in the lore.

Among the supplements I'd got as a fourth-grader was the Monster and Treasure Assortment. This came out before the Palace of the Silver Princess. This came out before the G1-2-3 and the aforementioned D1-2 bundles. I remember thinking at the time - what the hell is a "Type III Demon"? Marsh's Expert Set didn't tell me. Why would we care to dig into a ninth or tenth level? Marsh was pointing me to wilderness adventure! (And the Companion Set was talking about ruling counties and leading armies.)

I think that, over the 1970s, which may not be appreciated by younger GenX as got to the hobby through Mentzer, the hobby was dominated by the deeper dungeon delve. Computer gamers see aspects of this in Nethack and Rogue. The "Roguelike" take on dungeons kept this up even after Lakofka's failure in GenCon XII which, those players complained, was a step back from the Depths in GenCon XI. I don't know that software gamers got a good Underdark until Ultima V in, what, 1988.