The last External Tank from the Space Shuttle program has been slowly making its way from Michoud Assembly Facility (MAF) in New Orleans, Louisiana to its final home at the California Science Center in Los Angeles, California. The trip by ocean-going barge left April 12, took it down to Panama, crossed over via the Panama Canal, and then up the Pacific Coast. It isn’t the first ET to do this; another ET took this route back in the early 80s when NASA was preparing for west coast Shuttle launches from Vandenberg AFB; an ET was delivered to VAFB to be stacked along with two SRBs and the prototype shuttle Enterprise for fit checks. After the Challenger accident, west coast Shuttle preparations ended, and that ET when back through the Panama Canal and around to Florida, where it eventually flew to space.
This ET, of course, never went to space. ET-94 was one of a set of three Lightweight Tanks built after production of the Super Lightweight Tank began, ordered for use on non-ISS science missions. Why continue to build Lightweight Tanks at all? It had to do with logistics mainly, and would have been a cost saving decision. Ultimately, however, only two of the “deferred build” Lightweight Tanks were ever built. After ET-94 was completed, ET-93, the first of the deferred build LWTs, was stacked and went to space on STS-107, the fateful final flight of Columbia. With Columbia and her science-only missions gone, there was no reason to build the third LWT — and as foam shed from the ET was quickly identified as the root cause of the Columbia accident, ET-94 immediately became the target of intense scrutiny. Large sections of foam were removed from it for testing, to determine whether a design flaw was behind the accident. These sections were never replaced, as ET-94 was too heavy to support ISS missions, and it was removed from flight status and kept essentially as a spare.
The final SLWT flew on STS-135, the final flight of the Space Shuttle program, leaving ET-94 as the only flight ET left in existence. (All the tanks that flew were destroyed, as it is by design an expendable component.) So with the Shuttle program over, and hardware gradually filtering out into museums around the country, this one needed a home. The California Science Center came up with what may be the perfect proposal — when they proposed taking Endeavour, they also proposed taking ET-94, and building a set of high fidelity mock SRBs and actually stacking the whole thing together as if it were a real Shuttle stack, ready to launch. The upshot is that all three Orbiters will be displayed in different configurations: Endeavour ready to launch, Atlantis as if in flight, with payload bay open, and Discovery on her landing gear, as if just returned from space. (Enterprise, the flight prototype, is also displayed on her landing gear.)
So, once CSC was ready to receive, preparations were made for ET-94 to leave the MAF, and it’s been slowly motoring its way around. This week, as it headed up the Mexican coast, they had an extra surprise: a fishing boat sunk off the coast of Mexico, leaving its crew of four stranded in a lifeboat. The tugboat Shannon Dann was able to retrieve the crew, and brought them along. Yesterday, they arrived with the ET in San Diego, to go through US Customs. The rescued fishermen got off there, and the Shannon Dann resumed her journey north towards Los Angeles, and are expected to arrive at Marina del Ray on Wednesday. There will be a parade next Saturday through the streets of Los Angeles, following the ET to CSC much as they did with Endeavour a few years ago.
Here, ET-94 passes through the Gatun locks in the Panama Canal (thankfully, sped up — locks are not particularly speedy):
And here’s from the Centennial Bridge to the Pedro Miguel lock: