As of January 2022, 98 States have ratified the Rescue Agreement, 23 have signed, and three international intergovernmental organizations (the European Space Agency, the Intersputnik International Organization of Space Communications, and the European Organisation for the Exploitation of Meteorological Satellites) have declared their acceptance of the rights and obligations conferred by the agreement.
[1] The Rescue Agreement requires that any state party that becomes aware that the personnel of a spacecraft are in distress must notify the launching authority and the Secretary General of the United Nations.
If the distress occurs in an area that is beyond the territory of any nation, then any state party that is in a position to do so shall, if necessary, extend assistance in the search and rescue operation.
However, this phrase again leaves uncertain whether someone simply along for the ride—such as a tourist on a Virgin Galactic flight—would be considered part of the "personnel of a spacecraft".
For example, Mir and later the International Space Station have each maintained docked Russian Soyuz spacecraft to be used as an escape mechanism in the event of an in-orbit emergency; in certain scenarios this vessel might also be able to assist in a rescue.