In reply to Andrew Meulenberg's message of Mon, 19 Dec 2022 20:26:52 -0600: Hi Andrew,
Thanks for the info. It's nice to have comment from an "insider". :) >Robin, > >The whole deal is a set of tradeoffs that depends on the environment to be >encountered. At some altitudes, the Van Allen Belts have too much >penetrating radiation to allow solar cells to be used for long-term >missions. > >Addition of coverslides makes the solarcell assembly vulnerable to solar >ultra-violet radiation. It is necessary to use high-purity fused silica for >the coverslides to prevent themselves from being damaged by the UV. But >these coverslides allow the UV to damage the adhesive that holds them to >the solar cells. Thus, it is necessary to put a UV filter on these >coverslides. The UV filters can be damaged by the trapped-proton >environment if there is a manufacturing error. Cerium-doped microsheet >(CMS) is generally used for coverslides because it does not transmit the UV >that can damage the special adhesives (flexible conformal coatings) that >can function through the thermal excursions experienced when the spacecraft >enters and exits the Earth's shadow. However, the CMS cutting out the >damaging UV also lowers the starting efficiency of the solar arrays that >can derive energy from the UV. > >It is a tradeoff that must even recognize the possibility of solar flares >that, when extreme and aimed at the earth, can cause more damage (in days) >than all of the other sources of degradation over the rest of the mission. >The tradeoff is further complicated by the variety of cells and materials >(filters and coverslides) available. There is also the mission variables >that are sometimes of greatest concern. Sometimes it is more important to >have max power at the beginning of a mission; sometimes at the end. > >It was a portion of my job for nearly 30 years. > >Andrew [snip] Cloud storage:- Unsafe, Slow, Expensive ...pick any three.
