Alligators & Rocketships

Vehicle Assembly Building & Solid Rocket Boosters

Mobile Launcher Platform on Crawler	The orbiter, solid rocket boosters, and external tank are built-up on top of a huge deck known as the Mobile Launcher Platform. To begin putting the Shuttle elements together, one of two Crawler Transporters must first move one of the three Mobile Launcher Platforms into the Vehicle Assembly Building. The crawler is one of the world’s largest moving land vehicles, weighing more than 3000 tons. It has a maximum loaded cruising speed of one mile per hour and consumes approximately 150 gallons of diesel fuel per mile.	Crawler Transporter
Once the Mobile Launcher Platform is inside the VAB, special crews begin building the two Solid Rocket Boosters (SRBs). The boosters consist of the aft skirt (the flared bottom section) containing hydraulic components capable of pointing the exhaust nozzle and the four main solid rocket propellant segments. The forward segment contains some of the 'brains' of the booster, and the nose cap contains a drogue chute and three main chutes, weighing just over one ton each. Once built, the SRBs are ready for the huge external tank, which is then lowered into place and structurally mated to the SRBs at four attach points.		Solid Rocket Boosters
Orbiter Lowered into Position	It is then lowered into position and bolted to the external tank in three places using explosive bolts for release during launch. Similar bolts are used to attach the stack to the Mobile Launcher Platform. Once mated, the orbiter will spend approximately one week in the VAB undergoing extensive integrated interface testing.
Firing Room	Wherever the orbiter is located, all testing of its vital systems through the actual launch itself, are monitored and controlled from one of four firing rooms in what is known as the Launch Control Center. Once interface testing is complete, the Shuttle system is then rolled out of the VAB to one of two launch pads atop the crawler transporter. This takes about six to eight hours in the LC39 area. The distance covered from the VAB is about 3.5 miles to pad A, and 4.25 miles to pad B.	Shuttle Stack on Crawler