Vague recollections from pop-sci books or articles in my teens, which were in another century, so no guarantees for anything.
But OK, so add an emergency battery. Or a parachute, if that's lighter. (OK, more liable to wind drift -- but OTOH, a big signal flag to find it by.)
But OK, so add an emergency battery. Or a parachute, if that's lighter. (OK, more liable to wind drift -- but OTOH, a big signal flag to find it by.)