Alligators & Rocketships

Launch & Recovery

Main Engines Firing	Seven seconds prior to lift-off, the three main engines are started almost simultaneously -- taking about three seconds for each engine to gain full thrust. By use of a very powerful pyrogen motor at the top of each of the solid rocket boosters, they go from zero to 2.9 million pounds of thrust in less than half a second. At this point, we have lift-off. During thrust build-up and initial ascent, 300,000 gallons of water are used to cool the pad surface and to suppress the intense sound waves generated during launch which could damage or even knock off some of the orbiter’s protective tiles. Once the Shuttle clears the pad surface, all ground control of Shuttle systems is taken over by Johnson Space Center in Houston, Texas. At T-0 the Shuttle is burning fuel at a rate of 21,500 pounds per second!	Shuttle Lift-off Shuttle After Launch
SRB Separation	After launch, the Shuttle has rotated 90 degrees and has begun to head east or northeast. One hundred seconds into the flight, the whole stack weighs less than half of what it did at launch. Approximately two minutes into ascent, the orbiter is 24 miles high and traveling at Mach 4 when the SRBs have depleted their propellant.
SRB With Parachute	The SRBs are then jettisoned and at the proper altitude, a small drogue chute is deployed to slow their descent. Then, three main chutes are deployed to ensure a safe splashdown about 140 miles out into the Atlantic. Once down, two NASA recovery ships are waiting to recover the boosters which will later be taken apart, cleaned, and repacked with propellant for a future flight.	SRB Recovery Ships
External Tank Separation	At this point, the orbiter is in a semi-elliptical orbit. The Orbital Maneuvering and Reaction Control systems' thrusters are then used to refine the orbit and maneuver the Shuttle in space. Typical orbits are around 165 miles above the earth. However, some missions have flown as low as 129 miles and others nearly 360 miles above the earth. Once in space, one of the first tasks is to open the payload bay doors. The inside face of the payload bay doors are actually big radiators and must be opened to help cool the orbiter's electronics.	Shuttle In Orbit In Orbit With Payload Doors Open