No seriously, the radio is not connected to the computer system, the comptuer system is extremely conservative by many standard and is not connected to the in flight wifi. You cannot have an air-gap attack without a microphone or similar device.
The gao report is a complete nonsense and was laughed out by all technical people involved in the computer system of airplane or in flight entertainment.
"So, Mr cyber Expert and Pilot, other than saying "nuh uh", do you have anything to suggest there is no chance of this?"
Aside complete network separation and absence of microphone ? Really guys sometimes there is absolutely NOTHING about threat reports.
NASA, JAXA and similar outfit drool at the perspective to have a long term project where they need to send a lot of cargo up, means a lot of contract and assured budget.
Those folk tells the space solar collector are possible and desirable.
The folk at energy production on the other hand use a calculator for cost of setting up, maintaining compared to generated energy and they usually view that as possible but not profitable compared to a similarly sized (in megawatt) installation on earth with physical batteries.
Sorry I i trust far more than who are involved i energy generation, than those involved into profiting by cargoeing the stuff.
For God's sake, stop researching for a while and begin to think!