Re: Volatiles to Earth orbit

Ian Malcolm wrote:


The Trojan asteroids at the Jupiter-Sun L4 and L5 points probably have many volatile rich objects as does the outer main belt. With perturbations these could be thrown into the inner solar system and become NEOs

Very good evidence for low density (i.e. volatile rich) asteroids in the Trojans.
http://astro.berkeley.edu/~fmarchis/Science/Asteroids/Patroclus/NATURE04350.pdf

Low density is also part of the evidence for the Martian moons being volatile rich.

However, low density isn't conclusive evidence, as these objects could be "rubble piles" with lots of vacuum pockets.


How much more difficult would it be to recover resources from the trojans rather than the main belt?


Assuming they're the same distance as Jupiter (5.2 A.U.), 5.6 km/sec would send cargo on an earth bound Hohmann from a Trojan.

On arrival, the cargo's moving 8.8 km/sec wrt Earth. However, if you don't mind capturing to a very eccentric orbit (perigee 300 km, apogee 912,000 km), it could take as little as 3.2 km/sec to capture to earth orbit. Some of that might be done with aerobraking, although you'd want to avoid heating volatiles. A total of 12 km/sec


Hmmm. In the outer main belt, there's a healthy population of 3.15 A.U. asteroids. Cargo from these guys would need 5.13 km/sec to head earthward. They arrive traveling 6.9 wrt to earth and it'd take 2km/sec to capture to the same eccentric earth orbit described above. A total of 7.13 km/sec


Insertion and exit delta vee is about 2.65 and 3 km/sec for an Mars to Earth Hohmann. However, the Oberth effect can be exploited at both departure and destination. Cargo from Deimos could be sent earthward and then captured to an eccentric earth orbit for a total of 2.1 km/sec.


I think Kuck's right -- Deimos might be the most accessible source of extraterrestial water. Although there may be some NEOs that beat Deimos.


Hop





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