Diff for "OffEarth"

Off Earth

Erika Nesvold 2023 Beav. Lib 629.442 NES

Preface

• vii "We'll worry about that later" is not something I ever expected to hear from a leader in the space industry."

  • Ms. Nesvold: please learn about how people actually make stuff and solve problem. Your linkedin CV shows zero business or engineering experience.

  • That's peachy keen for an exoplanet astrophysicist, but your business/engineering skills may be quite a bit less than my astrophysics and exoplanet skills (8 shelf feet of outdated graduate level texts).

• vii "now defunct" ... Perhaps Deep Space Industries CEO (2012-2017) Daniel Faber. I'm skeptical of Faber as a self-appointed "leader", and it is unlikely that he has ever had enough resources or funding to worry about many things now, especially in response to an out-of-the-blue question from an unknown conference attendee. OF COURSE this is a topic that should be addressed long before design and deployment, but NOT long before a lunar mining startup struggles to learn whether lunar mining makes sense to study.

  • IMHO, I don't think lunar mining makes any sense at all, not even for filling sandbags (which the sharp dust would abrade to shreds). Lunar crust is oxide minerals; reducing it to elemental Silicon, Aluminum, and Iron requires electricity and carbon electrodes. Practically zero carbon on the Moon. Photovoltaic electricity? Not with a two week night.
  • Besides those drawbacks, the Moon is covered with highly abrasive glass fragment dust, which ruins optics and would rip holes in sandbags. The dust is launched upwards by solar UV, perhaps many kilometers, to settle on upward facing surfaces; this has rendered the Apollo retroreflectors almost useless. It would be far worse for efficient PV illumination.
  • The Moon is a slagheap. We are very lucky the the Tethys impact stripped that slag off the Earth.
  • Lunar escape velocity is 2380 meters per second. Less than Earth, but more delta V than delivering materials from Near Earth Asteroids (a threat worth eliminating) or even Deimos, orbiting distant Mars.

  • Therefore, if you want Mr. Faber to think about these things, help him think about them. If his plans remain poorly thought out, inform his investors, and help them find better investment opportunities.

  • For example, Deimos may also be useless slag, but its tiny escape velocity will not trap abrasive impact bubble dust. Deimos may be cold enough to trap water ice beneath the surface. Will extraction ruin Deimos forever? Deimos is 1.5e15 kg; if extracted rationally and prudently (say 1500 tonnes per year), Deimos will last a billion years.
  • We can combine that soda-straw extraction "pipeline" with extensive sample collecting and scientific evaluation - better to pay for Deimos science with judicious Deimos extraction, rather than launching Earth materials through a Tsiolkovsky-equation-narrowed carbon-fueled production pipeline from Earth.
  • Sure, Deimos is "years away", but after a delivery "pipeline" is filled (filling may take 20 Earth years), it will be a reliable pipeline. Yes, this is an annoying delay, but annoying is better than absurd and fruitless haste.