Why do countdowns in space missions?

giphy.com

An English term for this is the use of countdown. A satellite is set at a time before launch, and many processes have to be completed within that time. This is where the countdown starts.

Straightforward counting shows real-time. While speaking the reverse number, the remaining seconds are detected. In fact, after the flight, the watches start counting straight. Some functions of the rocket and its associated system are fixed at predetermined times. The test succeeds as they are completed.

Countdown starts

10–9–8– …… 4–3–2–1–0–1–2–3–4… ..8–9–10

There is usually a number of seconds. Just tucking in does not know how many seconds are left.

The countdown starts 72 to 96 hours before the satellite launch. During this time some pre-flight procedures are completed. Part of connecting the satellite with the rocket, refueling, and testing auxiliary equipment. The flight program runs smoothly with the help of this checklist.