Thursday, August 17, 2023

Apophis could be our Venus taxi

On looking up Ben Noo status, which will be granted to us seven weeks from now, I found that the "Osiris" mission is dropping off a package... and will keep on going. To Apophis.

Six years after Osiris slides into our GEO belt, in 2029 Apophis is supposed to run a similar course. This is close enough that Earth's gravity will budge its orbit, too. Currently it's coming out of a near-Venus orbit; after this rock perturbs it, it will shift from near-Earth to 1.38 AU.

I think 1.38 AU is worthless, a road to literally nowhere. But the present orbit is close to a Venus-Earth shuttle, stone-rama if you will. Why not use that?

If we could budge it to aim at Venus directly, I'd suggest mine own 2L4 - which never crosses Earth-Luna proper. Later we might trim off Janhunen-sized bites to be Hop David's Hohmann cyclers; hitting Venus or just SVL3. Otherwise (depending on delta-V) we might consider the slightly-riskier 3-0-2-9. All these require an onboard propulsion-system to jank its orbit once it scrapes by Venus proper; but Venus has, like, its own propellant in its ion-tail and atmosphere.

Why's no-one talking about this? Even Pekka Janhunen just wanted to mine it. Seems a waste to have Apophis shift to a basic Aten ellipse.

JACKHAMMER 9/3: Apophis has 6.1e10 kg mass. Diameter therefore volume seems ill-constrained as of 2018 (pdf) but seems in the mid-300s-meter range; 70% of Bennu's (10/20: the next risk). If a sphere, that is 2.06e7 cubic-meters and 2961 kg/m3 density. Wikipedia, from a 3200 density, assumes volume 1.9e7. To my mind a broken pile of stony rubble should clock in at the lower 2000s.

I suspect that Wikipedia be more right than wrong. Even if I'm right: Apophis is a hard chunk of silicon with insufficient porosity for a colony. Needs work.

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