In 2014, NASA made history with the successful test flight of the new Orion spacecraft being developed to eventually take a four man crew all the way to Mars. Orion will be the first spacecraft capable of carrying humans (the test flight was unmanned) to venture into deep space since the Apollo missions over 40 years ago. Orion is also the first fully friction-stir welded vehicle to successful fly in outer space.
On May 7th, Orion’s manufacturer, Lockheed Martin, began welding on the Orion’s crew module pathfinder at NASA’s Michoud Assembly Facility in New Orleans.
A pathfinder is a full-scale working model of the craft. It is used to test the manufacturing processes and procedures that will be used on the final product. The pathfinder helps improve design and performance without putting lives at risk during testing in space. For example, to reduce mass and manufacturing time, engineers have worked to decrease the number of welds required to build the crew module. The 33 weld operations required to construct the first module had been reduced to 19 by the time of the 2014 test flight. Further modifications have brought the number of welds down to 15.
These welds are created with a next generation friction stir weld process, capable of producing welds with the strength and quality necessary to guarantee structural integrity in the harsh environment of space.
Unlike arc welding, friction-stir welding doesn’t involve molten metal; at least not in the traditional sense. In the FSW process a rapidly spinning nib called a probe is plunged into the joint between two clamped pieces of metal. The frictional heat generated by the spinning probe softens the metal and causes it to flow. Coalescence is achieved when the softened metal behind the moving probe solidifies into a single product.
Friction-stir welding works particularly well with the ultra-light aluminum-lithium alloy used to build much of the Orion spacecraft. The process also allows for superior weld strength without the need for post-weld heat treatment, making it ideal for the rugged demands of space travel. And the Orion’s demands are more than rugged, as NASA plans to use the vehicle to explore some of the most extreme conditions known to man.
Friction stir welding will also be used to construct the rocket that will carry the Orion spacecraft into space. Touted by NASA as a, “safe, affordable and sustainable means of reaching beyond our current limits,” the new Space Launch System will be the most powerful launch vehicle ever built.
The Orion pathfinder is expected to be complete and outfitted for engineering demonstrations by late summer. Welding on the manned Orion spacecraft is expected to begin in late July.
If you want to know more about friction-stir welding and other exciting developments in the welding industry, as well as how to put yourself on the path to participating in these developments, visit us at AWS Learning, where you can find online courses, virtual conferences and other digital tools to help you expand your welding career.
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