The crawler’s eight tracks each comprise 57 individual shoes – every one of which weighs nearly a tonne. Image Credit: NASA
They say a week is a long time in politics, but 50 years is practically an eternity when it comes to spaceship construction and space exploration.
Yet remarkably, that’s how long NASA’s crawler-transporters have been ferrying spacecraft to the launchpad at Kennedy Space Center.
The two crawler-transporters that carried Saturn rockets to the launchpad for the Apollo missions and ferried space shuttles on the first stage of over 130 flights will, incredibly, be the same vehicles that carry NASA’s new Orion craft to the blast-off zone as manned spaceflights from Kennedy Space Center recommence.
The vehicular veterans are currently in the process of being modified to accommodate Orion’s Space Launch System as well as commercial spacecraft, but that didn’t stop NASA taking them for a birthday run-out earlier this week, which you can see in the video below.
‘Run-out’ might not be quite the appropriate word – the crawler-transporters have a top speed of around 3.2km/h, and that’s when unencumbered.
Loaded with their multimillion dollar cargo, that figure slows to 1.6km/h.
Then again that’s hardly surprising, when each transporter weighs a staggering 2,721,000kg.
Each transporter measures 40m long by 34m wide, with the central platform that actually carries the spacecraft measuring 27.4m x 27.4m.
The cargo-less crawler stands 6.1m high and moves on eight tracks, two on each corner, each of which is made up 57 ‘shoes’ measuring 2.3m x 0.45m (7.5ft x 1.5ft) and weighing 952kg.
Built by Ohio’s Marion Shovel Company – which drew on its experience of making heavy-lifting gear for the mining industry – the crawler-transporters were, at the time they were completed, the largest self-powered vehicles on the planet.
Even more impressively, they still are: bigger land vehicles do now exist but they require an external power source, whereas the crawler-transporters are powered by their own traction motors and diesel-powered AC and DC electrical generators.
They won’t win any awards for environmental friendliness when it comes to fuel consumption, though, guzzling 125.7 gallons of diesel for every mile they travel.
And they’ve burned up quite a few miles over the course of their half-century-long careers, with the odometer on CT-1 currently reading 3,154km and CT-2’s indicating a total of 3,552km travelled to date.
The two crawler-transporters have, as you’d expect, been upgraded a number of times over the years, notably with new shoes in 2004 and new generators in 2012, among numerous other incremental improvements that have seen the crawlers’ load capacity increase from 5.4 million to 8.2 million kg.
That boost comes just in time to ensure the crawlers are ready for their next mission-critical tasks… and for another 50 years’ service.