Asteroid mining: will full asteroid prospecting require sending probes to each asteroid?

Question

It is well known that many characteristics about an asteroid such as orbit, size, rotation and chemical composition can be obtained remotely thanks to passive techniques such as spectrophotometry, radiometry, spectropolarimetry, hyperspectral imaging and thermal modeling or active techniques such as radar measurements.

For the sake of asteroid mining, we are mainly concerned about the internal composition of the asteroids and the content of valuable resources. Are there any asteroids characteristics relevant to asteroid mining that cannot be learned remotely? Said differently, will full asteroid prospecting for the sake of asteroid mining require sending robotic probes to each asteroid?

For instance, it may be expected that the internal composition is heavily correlated with the chemical composition observed in their emission spectra. Is this correct or, if unkown due to lack of datapoints, at least expected to be correct in the academic literature?

Answer 1

It isn't an absolute requirement that a probe would be sent before mining an asteroid, but if a probe isn't sent anyone sending a mining mission is taking a big gamble that it's suitable - if it isn't someone's wasted a whole lot of time and money. We can tell a certain amount from distant observations and make educated guesses as to composition, mass and general shape, you need to get much closer to get the detail needed to increase the chances of success. Is is a solid piece or an accretion of smaller pieces? How is the material you want to mine distributed, and is it accessible? Until you get closer you won't know, so it's likely probes will be sent.

Answer 2

Planetary Resources co. answered this question… at least, on paper.

The Arkyd-something spacecraft would be an Earth-orbit telescope, to winnow down the list of potential targets. The Arkyd-something-else spacecraft (built in series) would then be sent on a flyby or similar mission, which consumes less fuel and therefore money. Fewer such probes would need to be sent due to the telescope dataset, reducing the macro-fuel, macro-money. Eventually there would be Arkyd-something-something spacecraft, to actually “land” (more like docking) on a body and perform in situ measurements, etc. Again, the number of lander spacecraft would fall, given the risk reduction of the prior Arkyds.

This is perfectly in line with precedent- NASA’s macro-program, in line with RKA, etc., has been telescope - flyby - orbiter - lander - sample return. There’s excessive risk in skipping steps; in exchange, schedule is burnt, but we have time to burn for the particular questions being asked. In the case of NEAR Shoemaker, one spacecraft did orbiting and landing, but the landing was “bonus” science, and unplanned and unbudgeted before launch. Nothing to lose.

Asteroid mining per se will likely follow this precedent. The higher masses involved demand more fuel and budget- there’s a reason we don’t do roundtrips when there’s no compulsion to do so. Hence mining operations will be under extreme budgetary pressure, and are looking into not just electric propulsion (per Hayabusa 1/2 and MMX) but sails and siphons to beat Tsiolkovsky’s Law.

Your Answer: No.