NASA has begun the process of constructing a mock-up of the vast core section of its planned Space Launch System (SLS) rocket. The simulated core will serve as a practice tool for NASA prior to the 2018 launch of the SLS, which the agency hopes will move mankind one step closer to undertaking a manned mission to Mars.

The SLS, to be launched in 2018, will be the first of three generations of the next-generation launch system planned for operational service. However all three iterations will use the same core structure.

The test core will measure 213 ft (65 m) in length, boasting the same proportions as a mission-ready Block 1 core stage, and will be used to trial the logistical side of launching what will be the most powerful rocket ever constructed. It will mimic the fuselage of the core segment, as well as the shape of the four RS-25 liquid fuel engines housed at the bottom of the main stage segment.

"We don't want the first time we transport the core stage to be with flight hardware," states Shane Carpenter, lead engineer for the project at NASA's Marshall Space Flight Center. "That's why having a pathfinder is critical to the program."

As well as allowing NASA to hone the transportation aspect of launching the SLS, the 230,000-lb (104,326-kg) steel mock-up will provide an opportunity for the agency to simulate final assembly of the core and a lift-off scenario.

The fabrication of the test stage will be relatively cheap, as it will lack the costly propulsion and avionics hardware to be integrated with a completed rocket. In reality, it'll be little more than a shell.

Once completed, the core will be moved to the Michoud Assembly Facility in New Orleans. The complex is currently playing host to the construction of the actual SLS core to be used as part of Exploration Mission 1, which will put NASA's next generation Orion spacecraft through its paces on the far side of the Moon.

In order to prepare for the arrival of the mock SLS, NASA has been forced to undergo a comprehensive overhaul of a selection of its launch infrastructure. One of the planned modifications includes enlarging the agency's Pegasus barge, which will be responsible for transporting the core stage of the leviathan rocket from the production facility part of the way to its launch site, from 260 ft (79 m) to 310 ft (94 m).

In order to ensure that the trip is as smooth as possible for the flight ready hardware, the test article will be loaded onto the Pegasus barge and transported to Stennis Space Center, Mississippi, and then on to the Kennedy Space Flight Center, Florida, in order to test upgrades made to the Vehicle Assembly Building.

The SLS core simulator is expected to be completed and ready for testing in 2017.

Source: NASA