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>absorbent or light diffusing material should be mandatory Absorbency is bad because it causes overheating and IR astronomy pollution. Diffusion is bad because
by schiffern 4y ago
>absorbent or light diffusing material should be mandatory
Absorbency is bad because it causes overheating and IR astronomy pollution. Diffusion is bad because it reflects light toward Earth.
Specular surfaces (mirrors) can reflect light entirely into space and away from observers on the ground.
This explains why SpaceX created their own radio-transparent, space-rated mirror. They are offering it—at cost—for use by other satellite manufacturers.
https://www.teslarati.com/spacex-shares-how-its-making-starlink-satellite-less-bright/ https://www.teslarati.com/spacex-shares-how-its-making-starl...
https://planet4589.org/astro/starsim/2022-05-07_SpaceX_Sustainability_for_FAS_V3.pdf https://planet4589.org/astro/starsim/2022-05-07_SpaceX_Susta...
- tullianus 4y agoThe effect of downward-pointing black coatings on LEO satellites is higher spacecraft temperatures, but the cost of those higher temperatures is on spacecraft design/use, not on IR astronomy. Starlink satellites run screamingly hot even without the dark coatings; if they're a problem for IR telescopes, then that should already be a problem. A few extra degrees shouldn't break the budget.