Mars' radius is 3389.5 km and its present atmo and magnetic-field would certainly allow for 3500 km semimajor, especially given Birch I.3.3-4. Mars' ring at slightly more than half Birch' proposed semimajor requires slightly more than half the mass. Can pull more mass for the tether, too. As with all things Bagestan, I borrow here from Warhammer 40k, in this case the Ring of Iron. I assume the first iteration be equatorial since the Martians want it for the Deimos trade.
Oh right: and because it has to be built in the first place. That'll require Mars' other equator-circling satellite. In all Phobos' 10.6 billion kilotonnes, I am asking the miners to dig out ninety kilotonnes of useful metal. Per 10.1038/s41550-021-01306-2, Phobos and Deimos were once one body from beyond Deimos' orbit; so, I must assume, came that parent's impactor. These two satellites today are rubble-piles not easy to ascertain what elements make up their rubble. Since Birch was writing we've found plenty of superconductors which will be little trouble keeping cool in near-vacuum at 586.2 W/m2 only half the time. Pace the Games Workshop I have no great hopes for iron (nor bismuth). I have higher hopes for rare-earths.
UPDATE 1/6/22: The workers dropping the material between Phobos and ring-altitude can be protected: by still more Phobos ejecta. I don't think we need sweep up much of the junk; it's a layer of redundancy, never unwelcome.
More: spewing out Phobos material and dropping more material to 3500 km semimajor would, by Newton, further help to even up Phobos' eccentricity if not to boost its orbit. And (if equatorial) this solves DuPont and Murphy's question of where to put that ring to protect the atmosphere; it gets the terraforming started. Where the ring doesn't pay for itself over Earth, over Mars the Congressional Republic is going to give serious thought to this idea.
No comments:
Post a Comment