NASA Administrator Charles Bolden Monday visited the agency's Michoud Assembly Facility in New Orleans to see the progress being made on the Space Launch System (SLS), the most powerful rocket ever built that will take American astronauts into deep space, first to an asteroid beyond the Moon and eventually on to Mars.

Bolden, who was joined by Sen. David Vitter of Louisiana, toured construction of Michoud's advanced welding facility, the Vertical Assembly Center. There, 27.5-foot diameter cylinders, domes, rings and other elements will be brought together to form the fuel tanks and core stage of SLS, which is targeted for its first flight test in 2017. When completed in March, the Vertical Assembly Center will be home to one of the largest welding tools of its kind.

Three of four major robotic welding tools already are installed at Michoud, where SLS's core stage prime contractor, the Boeing Co. of Chicago, is leading a team producing test articles for the rocket. Michoud's advanced manufacturing facilities and workforce also built Orion's structure for its prime contractor, Lockheed Martin Corp. of Bethesda, Md.

"American astronauts are living and working in space aboard the International Space Station, preparing for deeper space exploration and the SLS is the rocket that will take them there," Bolden said during the tour.

"We're making tremendous progress on SLS, and I salute the team at Michoud for making sure the United States continues to lead the world in exploration."

Bolden also took time during his tour to place a call to the International Space Station mission control at NASA's Johnson Space Center. He congratulated the flight team there, the International Space Station (ISS) crew and the Orbital Sciences team in Dulles, Va., on the successful installation of Orbital's Cygnus cargo spacecraft to the station Sunday.

"The United States no longer has to rely on others to get cargo and science experiments to the International Space Station," said Bolden following the call.

"Thanks to the bold commercial space plan we've been pursuing, we now have two American companies to resupply station, launching once again from U.S. soil. My hat's off to the Orbital and NASA teams who worked so hard over the weekend to successfully capture and berth the Cygnus spacecraft to the ISS."

For more than 50 years, Michoud has built large-scale space systems for NASA, including stages of the Saturn V moon rockets and external tanks for the space shuttles. Michoud has more than 43 acres of advanced manufacturing space under one roof.

"The Space Launch System is becoming a reality thanks to the unique workforce and tools at Michoud and NASA facilities across the country," said SLS Program Manager Todd May, who joined Bolden on the tour. "We're on schedule and looking forward to SLS's first launch."

During his visit, Bolden, a former astronaut, donned part of a spacesuit to make a plaster cast of his boot print to commemorate Michoud's historic role in space exploration. Bolden traveled to orbit four times aboard space shuttles between 1986 and 1994, commanding two of the missions and piloting two others. His flights included deployment of NASA's Hubble Space Telescope and the first joint U.S.-Russian shuttle mission, which featured a cosmonaut as a member of his crew.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the SLS Program and the Michoud Assembly Facility.