Standing taller than Big Ben's clock tower at nearly 100m, the rocket and its launch platform weigh about 5,0…

Standing taller than Big Ben's clock tower at nearly 100m, the rocket and its launch platform weigh about 5,000 tonnes. They are being carried by Crawler‑Transporter‑2, a low‑slung, tank‑like vehicle on caterpillar tracks that Nasa built in 1965 to inch Saturn V Moon rockets to the pad. Its maximum speed is about 1mph (1.6km/h), and it crawls even more slowly on bends and up the gentle ramp to the launch pad, so the four‑mile journey can take up to 12 hours. The snail's pace is intentional: as if carrying a precious Ming vase, the slow, gentle motion reduces stresses on the multi‑billion‑dollar rocket and launch tower. The slow speed also gives flight teams the best chance of spotting and stopping any unwelcome movement of what is in effect a mobile skyscraper.