Author Topic: What is used on space solar panels/arrays?  (Read 624 times)

Offline TisforThee

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What is used on space solar panels/arrays?
« on: 02/04/2019 12:11 pm »
Hello,i am working on a space project that provides better resistance aganist small particules in space(rocks,etc.).
An professor we talked with stated that bulletproof glass is used on the solar arrays. If this is true,do we can use polycarbonate fiber(clear) instead of the bulletproof glass?(also polycarbonate fiber is lighter than glass and cheaper)
thanks to anyone responding  :)

Online Hobbes-22

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Re: What is used on space solar panels/arrays?
« Reply #1 on: 02/04/2019 03:47 pm »
That seems improbable. Bulletproof glass is several cm thick, which would make the array prohibitively heavy. Some solar arrays are so thin they can be rolled up.
I'd expect there to be no cover at all.

Offline woods170

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Re: What is used on space solar panels/arrays?
« Reply #2 on: 02/04/2019 07:31 pm »
That seems improbable. Bulletproof glass is several cm thick, which would make the array prohibitively heavy. Some solar arrays are so thin they can be rolled up.
I'd expect there to be no cover at all.

Hobbes-22 is correct. In-space solar arrays do not use bullet resistant glass. Solar arrays generally do not have any special protection against high-velocity MMOD. Evidence of this can be found in the returned solar arrays from the Hubble Space Telescope. In several locations these arrays were punctured by high-velocity MMOD. Nevertheless, the arrays continued to function on-orbit.

Offline whitelancer64

Re: What is used on space solar panels/arrays?
« Reply #3 on: 02/04/2019 08:14 pm »
The solar arrays on the ISS also have several small holes in them. MMOD damage is something that solar panel designers have to keep in mind for space-based applications - mainly by including redundant wiring so damage to a solar cell does not take out the entire array. There's not much else you can do about it.

Also, bullets travel much, much slower than objects in orbit do. Orbital velocity at the altitude of the ISS is about 7.8 km/s. High velocity rifle rounds can be around 1.2 km/s. Subsonic rounds go 400 m/s. Bulletproof glass just isn't designed to handle the energy of objects going at orbital velocity.
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Offline applepyramide

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Re: What is used on space solar panels/arrays?
« Reply #4 on: 02/05/2019 12:27 pm »
Very interesting. Is there any pics of the punctured solar arrays?

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« Last Edit: 02/05/2019 02:53 pm by eeergo »
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Offline SWGlassPit

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Re: What is used on space solar panels/arrays?
« Reply #6 on: 03/12/2019 06:50 pm »
The solar arrays on the ISS also have several small holes in them.

Understatement of the century here.  The solar arrays have thousands of holes.  This is primarily a function of how big they are and how long they've been out there.

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MMOD damage is something that solar panel designers have to keep in mind for space-based applications - mainly by including redundant wiring so damage to a solar cell does not take out the entire array. There's not much else you can do about it.

You also account for the slow degradation that occurs as solar cells get damaged.  Most strikes cause just a tiny, almost imperceptible loss in power production.  Over time, it manifests as a slow decline in available power.

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Also, bullets travel much, much slower than objects in orbit do. Orbital velocity at the altitude of the ISS is about 7.8 km/s. High velocity rifle rounds can be around 1.2 km/s. Subsonic rounds go 400 m/s. Bulletproof glass just isn't designed to handle the energy of objects going at orbital velocity.

In general, you'll do better keeping the solar arrays as thin as possible and letting particles go through.  Glass, when hit by high velocity particles, creates cone-shaped wounds.  A thick coverglass would lead to far more of a solar cell being damaged by a strike than a thin one that just lets the particle through.

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