clans

Space prospecting has been an enticing subject for more than half a century now and continues to capture the imaginations of extremely ambitious engineers and powerful capital allocators alike. It’s also somewhat viable: although most asteroids (and almost all of those that are considered to be “near-Earth”) have ore concentrations lower than those found terrestrially on Earth, there is a class of “metallic” (M-type) asteroids likely rich with platinum group metals (PGMs). In high demand, PGMs like Pd, Os, and Ir are difficult & pollutive to mine and thus are among the most expensive materials known to exist at >$500,000/kg.

Companies like AstroForge have recently raised millions on the business case for returning such metals prospected from asteroids, partly because of the enormous down mass potential (~20-50t) of SpaceX’s Starship. But the asteroid mining field is littered with bad ideas and failed projects. For one, Planetary Resources, a 2010s venture backed by Larry Page, thought it viable to extract volatiles from asteroids and robotically produce chemical fuel for in-space depots. Their money made it as far as a few test launches before running out and their assets acquired by a crypto company. It turns out it’s a bad idea to mine near-Earth asteroids for pretty much anything. Water is mixed in with rock and must be heated >400° C to use. Volatiles are not thermally stable and outgas in the vacuum. Metals are hit and miss. Asteroids are also more like piles of rubble, difficult to land on, and overall very small – so you’d want to land on quite a few. It turns out the moon is much better for mining, but it's still going to be tough.

I wrote a bit on traffic in the US and some more efficient systems after demonstrating the issue with some simple monte carlos.

There are a lot of ways traffic could be better, and I think there is lower hanging fruit than "full self driving"

The ISS (which always has 3+ humans on it) pretty regularly has to maneuver to avoid debris nowadays (NASA is conservative and will do so if a big window has a ~.01% chance of seeing debris). You can count on your hands the number of times a major collision has occurred since the 90s, but that's probably partly because now more than ever we actively track and avoid debris.

Satellites can also be multi-million to multi-billion dollar assets. They're less like cars and more like oil-rigs.

Your math gets you within an order of magnitude or so, check out NASA's work on ORDEM to predict this with Monte Carlos.

Two things: 1) The probability is very sensitive to # of objects and size assumptions. If you decrease the area of the bullets by an order of magnitude, the probability that it you will hit one 10 m^2 satellite in a year goes to 10%+ 2) satellite orbits are not randomly distributed. Within 700-900 km altitude, the probabilities are ~2-3 orders of magnitude higher (1/1000/m^2/y)

https://ntrs.nasa.gov/api/citations/20150003495/downloads/20...

This is a good point, and I definitely did a poor job addressing the fit for the flashiness of the title. The understanding that I have is that the SSN does a pretty poor job cataloguing re-entry phenomena and current models for predicting re-entry are pretty unskilled. The idea for something like this is to simply use existing infrastructure to vastly expand the body of knowledge on re-entry events which will allow for a more complete and robust understanding of what's going on above.

I worked as a researcher on orbital debris during university and now work full time on this and adjacent problems. My full write-up on the approach for using cheap radar data to assess orbital debris is here on my blog.

Are you referring to the IPCC chart in the post? Or another chart? If so, maybe shoot me a link? The chart in the post starts at 1850.

I wrote about the analysis of past models and how they can take advantage of data and markets to be better.