Gray mode
Gray mode was an alert status used aboard Federation starships. 

When in gray mode, the starship ran on reserve power, cutting power to non-essential decks and ship systems. It allowed for maximum power conservation, budgeting a starship's energy resources during a time of crisis, while still maintaining an operating status. Gray mode could be invoked during a massive fuel shortage, or when the tactical situation required a reduction in discretionary energy usage.

A number of ship systems were either reduced to a lower operating status, or shut down completely, including:
 The warp core, which was brought to a cold shutdown
 Inertial damping and structural integrity systems, which were operated at minimum output
 Tactical and lateral sensors, which were only used for primary ship functions
 Deflector systems, which were either shut down, or reduced to minimum levels for non-flight operation
 Weapons systems, phasers and photon torpedo launchers, were brought off-line
 Shuttlebay operations were suspended, as the shuttlecraft could provide energy support if necessary
 Life support systems were brought to minimum levels, and shut down on non-essential decks
 Transporter usage was terminated
 Turbolift usage would be suspended at the commanding officer's discretion
 Food replicators were not used, and emergency rations were distributed
 Holodeck or holosuite usage was terminated

The recycling of non-essential items, which could be broken down into raw matter patterns by the replicator, was commonly practiced. Preserving the replicator for usage only during critical situations (such as replicating repair tools, medicine, etc.) could help extend the energy resources of the ship.

In 2269, the  entered gray mode with Hikaru Sulu informing the bridge that the ship had switched to reserve power. ()

Starships were often forced into this condition, due to tactical situations or spatial phenomena, which could also coincide with a red alert. During the year-long temporal conflict with the Krenim Imperium, the  entered a reduced power mode. ()

Gray mode was used aboard the  in 2374 when its supply of deuterium was almost depleted, allowing the ship to conserve its reserves for as long as possible. ()

The following year, Voyager entered gray mode in an attempt to sneak past a Devore sensor array near the Tehara system. ()

Also that year, the Silver Blood Voyager was run in gray mode to conserve energy after the true nature of it and its crew was learned. () 

de:Modus Grau
Alerts