Roads made of river rocks allow NASA’s gigantic crawler-transporter to carry the SLS rocket to its launchpad and back. 🚀

River rocks are mostly quartz, round and 3-4“ in diameter, important features for high weight tolerances. They act as ball bearings that allow the crawler to turn with minimal issues. When the weight of the crawler rolls over the rocks, they absorb energy from compaction, helping to reduce the vibration on the surface that could cause damage to any flight hardware being transported.

NASA’s four-wheeled, flat-topped, metal Crawler-Transporter 2 on the move, as seen from the front. Its wheels are larger than the size of an entire truck.

For Day 16 of the Photoblogging Challenge.

Image: Leif Heimbold / NASA