How do you get a fully stacked rocket from the assembly building to the launch pad? Companies have various methods which work for various loads. But what if your rocket is a Saturn V, Space Shuttle, or the new NASA Space Launch System (SLS)?
Two crawler-transporters were designed and built in 1965 by Marion Power Shovel Company at a cost of US$14 million (US$128.5 million in 2022) each. Upon its construction, the crawler-transporter became the largest self-powered land vehicle in the world. While other vehicles are now significantly larger, they are powered by external sources.
Early in 2016, NASA finished upgrading crawler-transporter 2 (CT-2) to a “Super Crawler” for use in the Artemis program. The increase to its lifting capacity was from 5,400 to 8,200 tons (12 to 18 million pounds).
NASA performed a rollout of the Artemis 1 Space Launch System and Orion on March 17, 2022 for the first Wet Dress Rehearsal, and the rollout for launch, which is scheduled for a launch attempt on August 29, 2022 at 08:33 EDT. The rollout for the WDR, marked the first time one of the crawler transporters rolled a launch vehicle to the launch pad since Space Shuttle STS-135.
The crawler-transporter has a mass of 2,721 tons (6 million pounds; 2,999 short tons) and has eight tracks, two on each corner. Each track has 57 shoes, and each shoe weighs 900 kg (1,984 lb). The vehicle measures 40 by 35 meters (131 by 114 ft).
The vehicle gets 34 feet to the gallon of diesel fuel.
The height from ground level to the platform is adjustable from 6.1 to 7.9 m (20 to 26 ft), and each side can be raised and lowered independently of the other. The crawler uses a laser guidance system and a leveling system to keep the Mobile Launcher Platform level within 10 minutes of arc (0.16 degrees; about 30 cm (1 ft) at the top of the Saturn V), while moving up the 5 percent grade to the launch site.
As part of NASA Social, Adafruit Engineer Anne Barela toured Kennedy Space Center, was in briefings with senior staff, and received tours of the facilities. This included CT-2 which took Artemis I to the pad. Here are her impressions:
Each Crawlerway is 2 m (7 ft) deep and covered with Alabama and Tennessee river rock for its low friction properties to reduce the possibility of sparks.
The machine is massive – and to carry the combined weight of the Mobile Launcher and Artemis, it needs to be beefy. It was amazing to be able to be this close and to examine this amazing machine.