NASA is investigating the idea of aircraft with a single pilot ("Single Pilot Operations,” or SPO), rather than the two in use today. The key is that a second officer is present as well—on the ground, The ground officer is monitoring 12 planes at once.
[...] a specialized two-position ground control station where the operator when sitting in the right seat fills the role of “super dispatcher” for as many as 12 single-pilot airliners in cruise flight. If one of the 12 aircraft enters an “off-nominal” state due to an issue or anomaly, the ground station operator moves to the left seat and becomes a ground-based first officer dedicated to that aircraft.
If there’s a really big problem, the ground officer can take control of the plane remotely.
In a contingency, which has to be triggered by the captain, the super dispatcher transitions into dedicated support mode as a first officer in the left seat of the ground station; the pilot and first officer then conduct a briefing over an open microphone loop to assign duties, including who will fly the aircraft (the first officer flies via inputs to the autoflight system in the mode control panel representation in the ground control station).