Re: if it can't regain a GPS signa
"it still needs GPS for guidance. If it loses that, as the article says, it will enter a failsafe mode and either return to the operator or slowly/safely descend after a period of time if it can't regain a GPS signal."
When there is no GPS (which, as others have noted, is eminently jammable):
How does it know which way to go to return to the operator?
How does it know which way is down, and how slowly it is descending?