Human spaceflight (also referred to as manned spaceflight or crewed spaceflight) is spaceflight with a crew or passengers aboard a spacecraft, the spacecraft being operated directly by the onboard human crew. Spacecraft can also be remotely operated from ground stations on Earth, or autonomously, without any direct human involvement. People trained for spaceflight are called astronauts, cosmonauts, or taikonauts; and non-professionals are referred to as spaceflight participants.