Last Flight-Qualified Space Shuttle External Tank Sets Sail for California

NASA Shuttle External Tank
NASA’s last remaining flight-qualified space shuttle external tank departs the port at the space agency’s Michoud Assembly Facility in New Orleans on Tuesday, April 12, 2016. (Image credit:

NEW ORLEANS — NASA’s last-existing, built-for-flight space shuttle external tank was launched Tuesday (April 12) on a 40-day sea voyage from New Orleans to Los Angeles, 35 years to the day after the first such tank fueled the maiden flight of the iconic winged spacecraft.

Secured atop an open-air, flatbed barge, the 154-foot-long (47 meters) orange-brown tank left the dock at NASA's Michoud Assembly Facilityin Louisiana, beginning its journey to the California Science Center for display with the retired space shuttle Endeavour. The exhibit, slated to open in 2019, will be the only place to see a fully authentic space shuttle in a launch pad-like configuration.

"Today is a milestone in history for Michoud and also for the space shuttle program. We bid farewell to NASA's last flight-certified external tank," said Bobby Watkins, director of the Michoud Assembly Facility. "It's hard to say goodbye, but we know it is receiving the proper recognition by going to the California Science Center." [NASA's Space Shuttle Program In Pictures: A Tribute ]

Over the course of the 30-year space shuttle program, the Michoud facility produced a total of 139 external tanks — three test articles and 136 intended for flight. Of the latter, all but one was used to launch the shuttle's 135 missions, the first of which lifted off on April 12, 1981 and the last of which landed on July 21, 2011.

The backbone of the shuttle stack, the external tank was the only major part of the space transportation system that was not recovered and reused. The tank fed the orbiter's three main engines with liquid oxygen and liquid hydrogen for the first eight minutes of flight and then was jettisoned to fall back into the Earth's atmosphere to be destroyed.

Built in 2001, tank no. 94 (ET-94) would have likely helped launch a science-dedicated mission were it not the for the loss of the orbiter Columbia two years later. The sister tank to ET-93 that was used to launch the fallen shuttle, ET-94 was instead used as a test article to validate modifications to return the shuttles to flight.

"Even though it never flew — it was almost there — it was significant to be here when it helped us go through return to flight after Columbia. There were a lot of things linked to ET-94 that were donated to make sure we could make the next flight safe," said Jody Singer, the deputy director of NASA's Marshall Space Flight Center. "So when you think about it, it is really appropriate for ET-94 to be the one that is put on center stage now. It is time for it to have its day and be displayed."

NASA and California Science Center officials present a signed title transfer document for the last space shuttle external tank, ET-94, during a ceremony at the Michoud Assembly Facility on Tuesday, April 12, 2016. Pictured from left to right: Bobby Watkins, Michoud Assembly Facility director; Parker Counts, NASA’s project manager for the external tank from 1992-1999; Jody Singer, Marshall Space Flight Center deputy director; Jeffrey Rudolph, California Science Center president; Jeanette Epps, NASA astronaut; Steve Cash, former space shuttle propulsion office manager; and Dennis Jenkins, project director for Endeavour's display at the California Science Center. (Image credit:

In 2015, NASA agreed to donate the tank to the California Science Center for its display with Endeavour.

On Tuesday, prior to the tank leaving the dock, NASA and Science Center leaders signed a document ceremoniously transferring the title to ET-94 to the Los Angeles museum.

Led by the tugboat "Miss Gloria," ET-94 sailed away from Michoud atop the barge "Gulfmaster I" at 2:15 p.m. CDT (1915 GMT) for the first leg of its trip, a journey along the Intracoastal Waterway to Gulfport, Mississippi. There, the local tug will be changed out for an ocean-going boat, the "Shannon Dann," which will transport the tank-laden barge on a 10-day voyage to the Panama Canal.

The tank's transit from the Atlantic to Pacific Ocean could take as much as a week depending on the ship traffic at the canal. Once through, it is expected the barge will need another 17 to 20 days to reach Marina del Rey, following a brief stop in San Diego, California.

The California Science Center will welcome ET-94 ashore by hosting its annual Discovery Ball at the marina on May 20. As the party wraps up around midnight, the tank, riding atop three wheeled dollies and towed by a custom Mack truck, will embark on a 13- to 18-hour road trip through the streets of Los Angeles to its new home.

At the Science Center, ET-94 will first undergo repairs and have its feedlines and other original hardware re-installed prior to being mated to Endeavour.

"We pledge to not only take good care of it, but use it to inspire the next generation of scientists and engineers for many years," said Jeff Rudolph, president of the California Science Center. "I hope that you will follow ET-94's journey over the next six weeks. We're calling it 'ET Comes Home' because it's coming to its new home."

See the official mission patch designed for ET-94’s voyage to California at collectSPACE.

Follow on Facebook and on Twitter at @collectSPACE. Copyright 2016 All rights reserved.

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Robert Z. Pearlman Editor, Contributor

Robert Pearlman is a space historian, journalist and the founder and editor of, an online publication and community devoted to space history with a particular focus on how and where space exploration intersects with pop culture. Pearlman is also a contributing writer for and co-author of "Space Stations: The Art, Science, and Reality of Working in Space” published by Smithsonian Books in 2018. He previously developed online content for the National Space Society and Apollo 11 moonwalker Buzz Aldrin, helped establish the space tourism company Space Adventures and currently serves on the History Committee of the American Astronautical Society, the advisory committee for The Mars Generation and leadership board of For All Moonkind. In 2009, he was inducted into the U.S. Space Camp Hall of Fame in Huntsville, Alabama. In 2021, he was honored by the American Astronautical Society with the Ordway Award for Sustained Excellence in Spaceflight History.