An away mission was a mission during which an away team; such as a landing party or boarding party performed tasks in locations outside of their starship or starbase. This included missions on planetary surfaces and other starships. Away missions ranged from exploration or first contact to combat. The majority of these missions were launched using a ship's transporter to send the crew to their destination. When use of the transporter was dangerous or impossible, shuttlecraft were used.
Starfleet had several regulations and guidelines concerning away missions. While during the 23rd century, it was commonplace for a ship's captain to lead away missions; in the 24th century, this was discouraged in favor of having the first officer lead the away team. This new regulation did not prevent captains from joining all away team missions, however. For example, Captain Kathryn Janeway was part of the team that stole a transwarp coil from a Borg sphere and led the rescue mission into the heart of Borg territory, personally rescuing Seven of Nine. (VOY: "Dark Frontier") Several years later, Captain Jean-Luc Picard insisted on joining the away team which found B-4, as he was "itching to try out the Argo." (Star Trek Nemesis)