Are extendable solar panels too brittle in atmosphere?

[Bobe]

Obviously solar panels are not meant particularly durable, but I feel like they might be a bit too weak when exposed to a small amount of drag within an atmosphere. I'm referring to their use on rovers, not ships.

Assuming an angle of attack of 90°, an SP-W solar panel breaks apart at roughly 8 m/s on Kerbin, and almost instantly on Eve, maybe about 2 m/s. The atmospheres of Duna and Laythe seems to be low enough that the panels will not break given the top speed of a conventional rover.

Is this realistic (by KSP standards that is)? Does it just mean that extendable solar panels shouldn't be used on rovers on Kerbin or Eve?

The reason I used SP-Ws in the first place was because I couldn't find enough space to attach enough OX-STAT panels. I was originally going for a Curiosity design with twin RTGs on the back, but they shifted the centre of mass too much.

[MaverickSawyer]

Try using Tweakable Everything and disabling sun tracking. I found out that if I enabled sun tracking on the AIES panels (which don't track), they would break at the usual low speeds. However, if Sun Tracking was disabled, they were able to withstand speeds in excess of 40 m/s.

[Capt Snuggler]

would be cool if they had a broken-but-still-functioning state. what if after a medium collision they swap to a "bent/damaged" mesh and cannot track or retract anymore. they would still produce power but not as much.

it would give you a second chance if some minor accident happens.

[Awaras]

Try using Tweakable Everything and disabling sun tracking. I found out that if I enabled sun tracking on the AIES panels (which don't track), they would break at the usual low speeds. However, if Sun Tracking was disabled, they were able to withstand speeds in excess of 40 m/s.

It's because when you disable sun tracking they stay horizontal and (usually) face the air stream edge-on. I've had some solar panels survive for some time during reentry if they happened to be oriented the right way.

[Kasuha]

EVA Kerbals could be able to repair them just like they can repair wheels or landing legs.

[Bobe]

EVA Kerbals could be able to repair them just like they can repair wheels or landing legs.

I'm talking about unmanned rovers.

Even if it were a manned rover and Kerbals could repair panels, what would be the point if it broke every time you accelerated?

[vexx32]

EVA Kerbals could be able to repair them just like they can repair wheels or landing legs.

This, to me at least, never made any sense. Unless you intend to carry spare solar panels as extra mass, there's no way a kerbal could fix a solar panel in that kind of manner. It's not something you can perform a simple patch job on and expect it to still work much the same as before.

[Atoning Unifex]

My solution to this is to simply have a large battery capacity so that it's possible to drive for a decent amount of time before needing to recharge. At this point just stop and open the panels.

[Roxette]

... there's no way a kerbal could fix a solar panel in that kind of manner. It's not something you can perform a simple patch job on and expect it to still work much the same as before.

Ummm, actually... here's a picture of Scott Parazynski, anchored to a foot restraint on the end of Discovery's boom, working to repair a damaged solar array on the International Space Station. The 7-hour, 19-minute spacewalk was performed during the STS-120 mission.

[peadar1987]

Did he use supplies they had on hand though? Or did they have to be sent specially from earth?

[Roxette]

Did he use supplies they had on hand though? Or did they have to be sent specially from earth?

The details are here - it was done with available tools and material. I think duct tape and wire coat hangars should be defined as resources in KSP for this kind of operation

Edited January 25, 2014 by Roxette

[peadar1987]

The details are here - it was done with available tools and material. I think duct tape and wire coat hangars should be defined as resources in KSP for this kind of operation

That is seriously cool!

[peadar1987]

Also, with regard to the OP, "brittle" is not the same as "weak". When something is brittle, it means that it will break without undergoing any plastic (permanent) deformation, so like a cup if you drop it, you'll be able to fit the pieces back together into the same shape as before.

The opposite is ductile, so something that will undergo a lot of plastic deformation before it breaks.

Silicon Carbide is strong but brittle

Some types of glass are weak and brittle

Steel is generally strong and ductile

Chewing gum is weak and ductile

etc.

[vexx32]

Ummm, actually... here's a picture of Scott Parazynski, anchored to a foot restraint on the end of Discovery's boom, working to repair a damaged solar array on the International Space Station. The 7-hour, 19-minute spacewalk was performed during the STS-120 mission.

http://www.nasa.gov/images/content/196046main_image_949_516-387.jpg

I stand corrected. Thanks for that!

However, if the panel shattered, I think it'd be a different story.

[Tw1]

However, if the panel shattered, I think it'd be a different story.

Yes, you'd at least need to collect the shards somehow. But repairing the OX-STAT should be feasible.

[Bobe]

Also, with regard to the OP, "brittle" is not the same as "weak". When something is brittle, it means that it will break without undergoing any plastic (permanent) deformation, so like a cup if you drop it, you'll be able to fit the pieces back together into the same shape as before.

The opposite is ductile, so something that will undergo a lot of plastic deformation before it breaks.

Silicon Carbide is strong but brittle

Some types of glass are weak and brittle

Steel is generally strong and ductile

Chewing gum is weak and ductile

etc.

I know, but in the end I just wanted to get the point across that they break easily.

[Captain Sierra]

My solution to this is to simply have a large battery capacity so that it's possible to drive for a decent amount of time before needing to recharge. At this point just stop and open the panels.

This is usually the best answer, as many batteries can keep you going for a while and then you just stop, open the panels for a few minutes (if I build mine right, less than 45 seconds), close them, and keep going.

[Vahal]

Yes, you'd at least need to collect the shards somehow. But repairing the OX-STAT should be feasible.

Well, turning any stock panel (except Gigantor) into multiple OX-STAT would be nice, it's nothing else than motorised and retractable bunch of OX-STAT. Plus the fact since there isn't a supply system for repair tools you could be able to fix them like you fix tires and legs. All of those operations need -potentially coplicated - stuff to be possible but since in KSP there's no kind of this panels, tires and legs should be seen as same level of fixing after all we just see the panels falling apart not be deformed or blowed into little pieces

[Kennosuke.ken]

Well I just simply knocked over a Gigantor XL solar array with kerbals in space

[Rocket In My Pocket]

4 hours ago, Kennosuke.ken said:

Well I just simply knocked over a Gigantor XL solar array with kerbals in space

Happens to the best of us!

This thread however is very old, and contains outdated info.

As you can see, extendable solar panels are quite sturdy for atmo driving now.

[KSPFanatic102]

Just use KIS & KAS to replace a solar panel with a spare one lol

[Geonovast]

Solar panels are no different than landing struts...