As you already probably know the reason it is almost impossible for helicopters to do search and rescue at high altitude like the top of Mount Everest is because the atmosphere is so thin that the blades won’t able to push and therefore lift. Mars’ atmosphere we are told is equivalent to 23 miles altitude here on Earth and yet they claim to have a drone that can fly in that thin atmosphere, don’t you think that by now if such technology really exist every Helicopter would be retrofitted with it for search and rescue at high altitude?