Photo: Kip Boquet, left, and Nick Acosta Mora, Boeing technicians, drill holes in an intertank section that connects the Space Launch System’s fuel tanks. DECEMBER 2016 | 21 tool, which stands 170 feet (50 meters) tall and weighs 1,650 tons (1,500 metric tons), but also a fuel tank at the same time. “It’s incredibly satisfying to see this come together in the factory,” said Steve Ernst, Boeing propellant tank team lead for the Space Launch System. “They’re changing the approach to space travel.” The size of Boeing’s liquid hydrogen tank, which consists of five barrels and two domes, made it necessary to introduce heavier equipment and switch from horizontal to vertical welding, said Will Walsten, Fabrication specialist. “Welding a vertical stack had never been done before,” Walsten said. “We never had a welding tool this big, either.” Space Launch System fuel tanks will feed 733,000 gallons (2.7 million liters) of cryogenic propellant to the RS-25 engines at liftoff. The process is similar to draining a family-sized swimming pool every 60 seconds, according to NASA. Boeing’s non-reusable core stage will separate and drop into ocean waters within minutes after sending the rocket through Earth’s strong gravitational pull, the most difficult part of the journey, and into lunar orbit. The Space Launch System will reach a speed of Mach 23, or 23 times the speed of sound, traveling faster than 17,000 mph (27,300 kilometers per hour)—generating 20 percent more power than the Saturn V rocket that carried astronaut Neil Armstrong to the moon. “Our team has been working with experts from across Boeing, and with NASA, to deliver the affordable, reliable, evolvable rocket America needs for deep space travel,” said John Shannon, Space Launch System vice president and program manager. “We’re building flight hardware now, getting ready for first flight, and working on additional capabilities for Mars missions. It’s an exciting time to be in the space industry.” In the Michoud high bay, a crane lifts the completed liquid hydrogen tank off the welding tool and onto a horizontal cradle. The tank is moved, in order, to an area where it is washed, another location where it is pressure-tested on hydraulic jacks and yet another where a protective thermal spray is applied to the exterior surface. The Space Launch System’s first liquid hydrogen tank was completed this summer and soon will be barged upriver to Marshall Space Flight Center, in Huntsville, Ala., for structural load testing. Michoud now is manufacturing a second tank geared for spaceflight, one that will be attached to the smaller liquid oxygen tank, the RS-25 engines, and a huge network of lines that connect to fuel, avionics and other electronics before this section of the spacecraft is moved by barge to NASA’s Stennis Space Center, in Bay St. Louis, Miss., for an engine test firing. For the unmanned test flight in two years, Space Launch System sections will be stacked into a final configuration inside the Vertical Assembly Building at Kennedy Space Center, in Florida. A team is erecting a 20-section platform for that purpose. The spacecraft will lift off from Launch Complex 39, Pad B, which previously served as the starting point for Apollo and space shuttle trips into orbit, among more than 50 other launches. A new 355-foot (108-meter) mobile launcher will position the Space Launch System on the pad, which is being refurbished. “I plan on seeing the first one go up—and many more from that time on,” said Leo Williams, Boeing’s Vertical Assembly Center weld manager at Michoud. “Everything’s a challenge when you have something new and it has never been done before. But this is something that can be done.” To reach Mars, NASA astronauts will need eight months to travel
Frontiers December 2016 Issue
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