# Tag Info

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tl;dr: A 5 cm radius plywood surface sphere would be 178 K or -95 °C in LEO if it were in a Sun-synchronous orbit, and 16% colder on average if it had high thermal inertia and was eclipsed half the time. Dissipate 20 W of heat internally though and the surface temperature would rise to 377 K or 104 °C and be about 25 degrees hotter inside. During eclipse ...

5

Typically the outer layer of the spacecraft is chosen for thermal control reasons and for compatibility with UV exposure and atomic oxygen (depending on your altitude). Anodized aluminum or alodined aluminum (chromate conversion coating)1? can be used as outer surfaces but tend to run a bit hot. Kapton as an outer layer has better ratio of emissivity to ...

6

Yes a chemical engineer is a huge asset in space exploration. Anyone who says otherwise doesn't actually know what a chemical engineer learns. Chemical engineers are essentially mechanical engineers with a deep understanding of chemistry (reactions, gases, liquids, solids, energy & mass transfer). For some reason people see the description "chemical ...

2

(Source) Angular dependence Incident angle has significant effect on the response of dielectric stack reflectors, and sail deviations from flatness and spacecraft attitude excursions affect this. Assuming no absorption in the films, what would happen is that the transmitted light would dramatically increase from 1-0.99999=1E-05 to say 1-0.999=1E-03 or 1-0....

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There is a extensive summary report on possible improvements of solar sail materials: "Ultra-Thin Solar Sails for Interstellar Travel - Phase I Final Report" December 1999, Dean Spieth, Dr. Robert Zubrin When reading this report one has to keep in mind that they only look for the properties of the sail itself, not taking into account structural ...

29

A solar sail with an areal density of $1~\mathrm{kg}/\mathrm{km}^2 = 1~\mathrm{mg}/\mathrm{m}^2 =0.001~\mathrm{g}/\mathrm{m}^2$ is impossible by known materials science because graphene has an areal density of $0.77~\mathrm{mg}/\mathrm{m}^2$. Being a single atomic layer of a light atom, graphene is the absolute lower bound for the areal density of pretty ...

-1

In this application, the phenolic resin is pyrolyzed in a non-oxidative environment beforehand and converted into amorphous carbon which can withstand pretty extreme temperatures provided it has a ceramic coating (e.g. SiC, HfC, etc.) for oxidative protection.

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