Why isn't NASA having a ground-based solar panel to charge the Li-ion batteries on board the JPL Mars Helicopter?

They say that it is going to take a day for the current on-board Solar Panels to charge the batteries. So why not have larger ones on the ground, which could charge it faster?

Is it because it isn't needed for this project since it's just a technology demonstrator and not specifically for science missions. So they don't want to add more payload because it will increase complexity in deployment etc. And that they might have it for future missions which will be specifically for collecting scientific data? Or is it something else?

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    $\begingroup$ If a ground-based solar panel is used to charge the Li-ion batteries of the Helicopter, the Heli has to return each time precisely to the panels and dock to the charger. If the Heli fails to return only one time, it is lost. A Heli with own solar cells is much more flexible and may access a larger area and longer distances using small increments. $\endgroup$ – Uwe Aug 22 '19 at 9:19
  • $\begingroup$ @asdfex That specifically relates to reusing the rover power supply, as opposed to any form of ground based recharging. I think this is interesting distinction (for example wisdom for that question is in-part about protecting the rover). $\endgroup$ – ANone Aug 22 '19 at 9:46

Rate of charge isn't really an issue. The harm in leaving the helicopter parked for days or even weeks is not that great, so the solar panels can be quite small/low mass as high powers are not needed. On the other hand to have accurate enough piloting and mating hardware etc need to perform a coupling is likely heavier.

There are also downsides of your proposed design (As Uwe points out):

  • Range is very limited hence being forced to return to a single site each time would be a major limitation.

  • It's error prone. One failed dock, snagged cable, you-name-it and game-over.


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