ST

ST, St, St. or st may refer to:

Academia

Business and Organization

Countdown

A countdown is a sequence of backward counting to indicate the time remaining before an event is scheduled to occur. NASA commonly employs the term "T-minus" during the preparation for and anticipation of a rocket launch, and even "E-minus" for events that involve spacecraft that are already in space, where the "T" could stand for "Test" or "Time", and the "E" stands for "Encounter", as with a comet or some other space object. Other events for which countdowns are commonly used include the detonation of an explosive, the start of a race, the start of the New Year, or any anxiously anticipated event. An early use of a countdown once signaled the start of a Cambridge University rowing race. The first known association with rockets was in the 1929 German science fiction movie Die Frau im Mond (English: Woman in the Moon) written by Thea von Harbou and directed by Fritz Lang in an attempt to increase the drama of the launch sequence of the story's lunar-bound rocket.

Rocketry

A countdown is a carefully devised set of procedures ending with the ignition of a rocket's engine. Depending on the type of vehicle used, countdowns can start from 72 to 96 hours before launch time.