A special alert condition aboard USS Voyager, signalled by flashing blue lights, that sends the crew to their stations before the ship lands on a planet's surface.
Blue alert is a ship-wide condition used on USS Voyager for an unusual but not hostile manoeuvre: setting the starship down on a planet. When it is called, blue lights flash through the corridors and the crew report to what the captain calls code blue stations while the landing struts are lowered and the ship enters the atmosphere.
It is first seen in The 37's, when Janeway lands Voyager on a world where humans abducted from Earth in 1937, among them Amelia Earhart, have been found in stasis. The procedure is repeated on later landings, such as the descent to the hostile class Y planet in Demon.
The Intrepid-class design is one of the few Starfleet starships shown to be capable of landing and taking off again, which is why the alert is rarely heard elsewhere.