NASA is another small step closer to sending astronauts on a journey to Mars, as the first two segments of the Orion spacecraft's crew ...
NASA is another small step closer to sending astronauts on a journey to Mars, as the first two segments of the Orion spacecraft's crew module were welded together.
On Saturday, Lockheed Martin and NASA engineers at the NASA's Michoud Assembly Facility in New Orleans welded together spacecraft's tunnel and forward bulkhead of the Orion crew module that will fly atop NASA's Space Launch System (SLS) rocket on a mission beyond the far side of the moon.
The tunnel is the passageway astronauts crawl in and out of when Orion is docked with another vehicle. The forward bulkhead, located at the top of the crew module, must handle extreme loads during re-entry because that is where the parachutes are connected when they deploy.
The primary structure of Orion's crew module is made of seven large aluminum pieces that must be welded together in detailed fashion. The first weld connects the tunnel to the forward bulkhead, which is at the top of the spacecraft and houses many of Orion's critical systems, such as the parachutes that deploy during reentry. Orion's tunnel, with a docking hatch, will allow crews to move between the crew module and other spacecraft.
The next mission designated Exploration Mission-1, will last more than 20 days and will certify the design and safety of Orion and SLS for human-rated exploration missions. The first prototype of Orion have successfully carried out the Exploration Flight Test-1 in December 2014.
Engineers have undertaken a meticulous process to prepare for welding. They have cleaned the segments, coated them with a protective chemical and primed them. They then outfitted each element with strain gauges and wiring to monitor the metal during the fabrication process.
Prior to beginning work on the pieces destined for space, technicians practiced their process, refined their techniques and ensured proper tooling configurations by welding together a pathfinder, a full-scale version of the current spacecraft design.
Through collaborations across design and manufacturing, teams have been able to reduce the number of welds for the crew module by more than half since the first test version of Orion's primary structure was constructed and flown on the Exploration Flight Test-1 last December.
The Exploration Mission-1 structure will include just seven main welds, plus several smaller welds for start and stop holes left by welding tools. Fewer welds will result in a lighter spacecraft.
"After going through the manufacturing process for the Exploration Flight Test-1 vehicle, we determined we could reduce the vehicle's weight if we lessened the number of pieces being welded together since those welded areas weigh more," said Mike Hawes, Lockheed Martin Orion vice president and program manager.
"So for this next spacecraft, seven bigger pieces are coming together, instead of the eighteen for EFT-1, which makes the welding process a little more challenging than before."
In order to certify the new welding process, the team at Michoud Assembly Facility welded a pathfinder vehicle to verify the design changes and welding changes would perform as expected.
In early 2016, once the pieces that make up the crew module's pressure vessel are welded together, it will be shipped to the Operations and Checkout Facility at NASA's Kennedy Space Center in Florida.
There it will undergo final assembly, integration and testing in order to prepare for Exploration Mission-1 when Orion is launched atop NASA's Space Launch System (SLS) for the first time.
The test flight will send Orion into lunar distant retrograde orbit—a wide orbit around the moon that is farther from Earth than any human-rated spacecraft has ever traveled.
