RocketSTEM Issue #13 - September 2016 | Page 78

discovered to their surprise that this lightweight insulating material could indeed puncture a hole in the leading edge of the wing. The tragic loss of the Columbia also led to the realization that a way to inspect and repair damage to the surface of the vehicle, postlaunch, would have to be developed. The huge External Tank, to which the orbiter is affixed, is the last part to be jettisoned after launch and largely burns up over the ocean during re-entry. With the demise of Columbia, a large piece of history had been orphaned and its very existence was hanging in the balance between making history or becoming history. Luckily, someone realized what a treasure and opportunity they had in the one remaining flight-worthy External Tank. About two years ago NASA agreed to gift External Tank #94,  or ET-94 as it is commonly called, to the California Science Center. All the center had to do was arrange transportation. A chain of events and major planning immediately got underway. The tank was huge in size and certainly not flyable by plane as the orbiters had been. Th e move would require careful and special handling all the way. Only a handful of companies were qualified to perform such a move and handle it pretty much “door to door.” Emmert International, a huge engineering and logistics giant with assets located all over the world, had the know-how and experience to fearlessly move almost anything from here to there. Masters of meticulous planning, they arranged everything from pickup of the tank from its home at NASA’s Michoud Assembly Facility near New Orleans, to transfer onto a specially fitted barge and subsequent passage through the Panama Canal (a first for an External Tank). Sounds simple…yet the dimensions of the bulky tank and the distance involved were daunting.  At 154 feet in length, the ET stands at the equivalent of a 15-story building and actually dwarfs the orbiter itself in launch position, where the massive ET looks like a canvas upon which the shuttle has been painted. The orbiter, however, is much heavier than the ET…which was shipped empty, of course, yet still weighed a 65,000 pounds. The tank’s diameter is a slim 27.5 feet…much narrower than the span required by Endeavour to traverse the streets of Los Angeles, significantly reducing the impact on the trees and streets of the metropolitan area…which was minimal by comparison to the Endeavour move. There was, however, a blizzard of permits that had to be sought from the various cities through which the entourage had to pass thorugh during the 16 mile move from the coastline to the museum. There were a number of municipalities and utilities that had to be consulted and carefully coordinated with in order to move signals, signage and electrical wires during the move. Making the 90-degree turns along the route was the major challenge this time. While the wheels on the trailer could be turned 90 degrees, the rig itself could not back up. Each turn had to be precisely engineered and executed in forward motion only.  A lot could have gone wrong – but didn’t – during the 41 day voyage of 4,400 nautical miles journey through the multiple locks and the traffic of the busy Panama Canal. There was a moment of drama that occurred when ET-94 and her tow-barge encountered 76 76 www.RocketSTEM .org