Print This List    Email to a Friend  

Space Shuttle Launch Countdown Clock Explanation  
IDKT 

Tags: launch, countdown, T-minus, time, space, shuttle

T-minus.... The Countdown Clock is one of the most watched timepieces in the world. On this page we explain how to understand the countdown:

	T-43 hours and counting - Start Countdown Clock The countdown gets underway with the traditional call to stations by the NASA Test Director. Mid-deck and flight-deck platforms are removed. Navigational Systems activated and tested.
	T-27 hours & holding Preliminary Flight Deck inspections completed. Complete preparation to load power reactant storage and distribution system and complete flight deck preliminary inspections
	T-27 hours & counting Clear launch pad of all nonessential personnel. Begin operations to load cryogenic reactants into Atlantis's fuel cell storage tanks
	T-19 hours & holding Demating of the Orbiter's mid-body umbilical unit takes place. Final preparations for Shuttle's three main engines begins.
	T-19 hours & counting Begin filling sound suppression systems water tank. Close out the tail service masts on the mobile launcher platform
	T-11 hours & holding Move Rotating Service Structure (RSS) to park position. Activate Orbiter's inertial measurement units. Activate Orbiter's communications systems. Perform ascent switch list
	T-11 hours & counting Activate the Orbiter's fuel cells. Clear the blast danger area of all nonessential personnel. Switch Atlantis's purge air to gaseous nitrogen.
	T-6 hours & holding The Final Inspection Team conducts a detailed analysis of the vehicle as they walk up and down the entire launch tower. Begin loading the external tank with about 500,000 gallons of cryogenic propellants as we begin T-6 and counting.
	T-6 hours & counting
	T-3 hours & holding
	T-3 hours & counting
	T-20 minutes & holding
	T-20 minutes & counting
	T-9 minutes & holding
	T-9 minutes & counting
	T-0 - Liftoff!

Lister: Pratt
Source: NASA.gov

Other lists of interest:

Where Were You? When the Challenger Space Shuttle Exploded IN THE PAST  (0)

1st Teacher in Space (Almost) PEOPLE  (0)

the Names of the Space Shuttle Orbiters INFORMATIVE  (0)

Songs: Time at No. 1 in 1950 IN THE PAST  (0)

Songs: Time at No. 1 in 1951 IN THE PAST  (0)

This list not rated yet – be the first to rate it 

There are no comments for this list. Be the first to post!