Mobile Launcher Platform (MLP)
The Space Shuttle Mobile Launcher Platform (MLP). Each MLP weighs 3,730,000 kg (8,230,000 lb) unloaded and roughly 5,000,000 kg (11,000,000 lb) with an unfueled Shuttle aboard, measures 49 by 41 m (160 by 135 ft), and is 7.6 m (25 ft) high.
The Mobile Launcher Platform was set atop six legs, each 6.7 m (22 ft) tall, when stationary. The Solid Rocket Boosters were mounted on top of the MLP. The External Tank was then lowered between the two boosters and attached to them. After that, the orbiter was lowered into position and attached to the External Tank. The crawler-transporter then carried the combined platform and vehicle to the launch site, and deposited them there together. Once the launch was completed, the crawler-transporter retrieved the empty MLP from the pad to be readied for its next use.