There is also the 'L' (Local time) clock. There are numerous 'built-in holds', where unscheduled problems can be corrected, and still launch 'on-time'. Is it a convention or something Mathematically, T is time, minus whatever amount of. So in short, T its just a convention, a single letter abbreviated designator for the system clock mostly quoted to stand for Time that a lot of events are synchronised with throughout the duration of the launch. It means that there are 43 hours until the scheduled liftoff according to the countdown clock. What does 't minus 2 days' mean T Minus 2 Days. The 'T' in 'T Minus 43 Hours' means 'Time until launch'. What To Expect During A Space Shuttle Countdown () It could be the start of a particular test in our Orbiter Processing Facility that is independent of the time of day.Īnd I always thought it meant Time not Test. What does the 't' stand for? I joined the space program about 20 years ago and I asked this question of my, of my elders in the program when I did join, and it turns out that T stands for test.

When you are in the firing room on launch day, we hear the terms 't minus' a lot during the countdown. Google thought of a surprising one, for the 'T' issue: Transcript: NASA Launch Director Mike Leinbach on Discovery's Launch and Mission () For example, dialogue heard during the launch of a Delta II rocket carrying the Kepler Space Telescope on March 8, 2009, included: Time: T minus 3 minutes. Is there any web site out there which explains all the terminology which precedes a rocket launch or a space shuttle launch?Ĭan't think of one.

If you subtract the 2 units (again, seconds, minutes, hours, something) from the event time you will get the current time. Usually a time unit is given or indicated, like T minus 2 seconds, or T-00:02:00 (T minus 2 minutes). It means that something will happen in 2 units (seconds, minutes, hours, or other). What does T minus 2 and counting………….means?

What does t minus 3 days mean