In this regard, why do rocket launches have countdowns?
This can be done to investigate a technical process that has gone wrong, or because of marginal weather at the launch pad. Some holds are planned: they are done so the launch-support computers can run automatic checks on the rocket. Under some circumstances, a countdown may be recycled to an earlier time.
Similarly, why do astronauts say minus? The L stands for launch. In the same way, T pronounced T minus, refers to the time remaining on the official countdown clock. The T stands for time. During planned stoppages in the countdown process when the countdown clock is intentionally stopped, the T minus time also stops.
Furthermore, why does NASA use L minus?
"L minus" indicates how far away we are from actual liftoff& doesn't include built-in holds. @T_RexVsLlama They are periods of time in the launch countdown when the countdown clock is halted.
Why can't a shuttle take off before 10 seconds?
At exactly 10 seconds before launch, all the navigation instruments go from a rest position to active, you can see that navigation is tracking, that it knows where it wants to take the shuttle. A few seconds after that, the main engines light. You can't really feel or hear much at that point.
