Crawler-transporters are currently the largest self-powered land vehicles on Earth. These tracked vehicles have been used to transport spacecraft from NASA’s Vehicle Assembly Building (VAB) along the Crawlerway to Launch Complex 39. Designed and built by Marion Power Shovel Company using components designed and built by Rockwell International, each has a mass of 6,000,000-pounds, while boasting eight tracks, two on each corner. It’s controlled from two control cabs located at either end of the vehicle, and travels along the 3.5-mile crawlerway at a maximum speed of 1mph loaded, or 2mph unloaded. Now here’s something you may not know…the average trip time from the VAB along the Crawlerway to Launch Complex 39 is about 5-hours. Click here to view the first image in today’s viral picture gallery. Continue reading for the five most popular viral videos today, including one showing why you should never look directly at the sun with a small telescope.