adverb on or into (a ship, aircraft, train, or other vehicle)
preposition on or onto (a ship, aircraft, train, or other vehicle)
Aboard is commonly used in the maritime field to refer to being on board a ship or boat.
In aviation, aboard is used to indicate being on board an aircraft.
When referring to space missions, aboard is used to describe being on a spacecraft or space station.
Aboard can be used by writers to describe being on board a ship, plane, or other mode of transportation. It can also be used metaphorically to describe being involved in a project or initiative.
Psychologists may use aboard to describe a patient being on board with a treatment plan or therapy approach. It can also be used to describe being mentally or emotionally present and engaged in a situation.
Pilots use aboard to refer to passengers being on board the aircraft. It can also be used to describe equipment or systems functioning properly and being ready for flight.
Aboard is used by marine biologists to describe being on board a research vessel or boat to study marine life. It can also be used to describe being part of a research expedition or team.