A vertical landing of an aircraft is performed using the first battery where the aircraft is unoccupied when the vertical landing is performed, the unoccupied aircraft includes the first battery, and the unoccupied aircraft excludes a second, removable battery. In response to detecting that the second, removable battery is detachably coupled to the aircraft, a power source for the aircraft is switched from the first battery to the second, removable battery. After switching the switch power source, a vertical takeoff of the aircraft is performed using the second, removable battery, wherein the aircraft is occupied when the vertical takeoff is performed.