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.