3 ms·
A recentish one places an estimate at 10B initial costs, and 10B maintenance. 20B is doable by the US alone, yes. Sometimes the truth is stranger than fiction,
by d0lph 8y ago
A recentish one places an estimate at 10B initial costs, and 10B maintenance. 20B is doable by the US alone, yes.
Sometimes the truth is stranger than fiction, it's why you must research. In this case the truth may well be that humans have an easier time making the sun shine less rather than lowering our carbon footprint.
https://en.wikipedia.org/wiki/Space_sunshade https://en.wikipedia.org/wiki/Space_sunshade
- ForHackernews 8y agoEverything I find about this idea looks like pie-in-the-sky speculation and back-of-the-envelope estimates. As far as I can tell, nobody is making serious engineering proposals for this idea. IMHO, you are far too sanguine.
- d0lph 8y agoWhich numbers in particular do you have problems with?
- ForHackernews 8y agoAs a point of reference, the Galileo navigation constellation apparently costs about 10bn (€ not $, but call it even): https://qz.com/1264365/brexit-is-breaking-up-galileo-europes-e10-billion-plan-to-launch-new-satellites/ https://qz.com/1264365/brexit-is-breaking-up-galileo-europes... That system is essentially a modern re-implementation of GPS, a known, proven technology. To suggest that this untested, unproven, highly speculative solar shade project would cost the same is laughable to me. You're also totally discounting the unintended consequences and second-order effects of trying to engineer the climate.
- d0lph 8y agoYour point of reference includes 2 ground control centers, and 30 satellites. To suggest that launching a single satellite would cost the same is to me, laughable. This if anything proves my point, nothing seems insane about launching a lens into space. We have satellites now, this is essentially one with a lens. https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)#System_description https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)... I'm not discounting anything, just assuming scientists and engineers involved have done their job.
- ForHackernews 8y ago> One proposed sunshade would be composed of 16 trillion small disks at the Sun-Earth L1 Lagrangian point, 1.5 million kilometers above Earth. Each disk is proposed to have a 0.6-meter diameter and a thickness of about 5 micrometers. The mass of each disk would be about a gram, adding up to a total of almost 20 million tonnes. > Such a group of sunshades would need to occupy an area of about 3.8 million square kilometers if placed at the L1 point. The deployment of the flyers is an issue that requires new technology. Large railguns or coilguns are proposed to fire a capsule containing a million shades into space every 5 minutes for 10 years using 20 separate launch sites. This is science fiction.
- d0lph 8y agoPerhaps, but that is the 5T one, the "one fresnel lens" option or "one diffraction grating" option are cheaper and seem more feasible. That said, if scientists believe that all they lack is money, who are you to tell them otherwise.
- ForHackernews 8y agoOops: https://www.theatlantic.com/science/archive/2018/08/solar-geo-engineering-cant-save-the-worlds-crops/567017/ https://www.theatlantic.com/science/archive/2018/08/solar-ge... (Not space lenses, but another risky, poorly-understood geo-engineering proposal)
- d0lph 8y agoSeems unrelated, but I'm glad that idea went through scientific review.