Days before we enjoyed ‘rockets red glare’ to celebrate America’s Declaration of Independence, NASA and Boeing were already celebrating, having completed the Space Launch System (SLS) core stage critical design review (CDR) well ahead of schedule. It’s an important milestone for several reasons, most immediately because it’s the “go” for full production of the rocket at NASA’s New Orleans facility. Historically, it’s significant because this is the first time since the Apollo program that NASA has reached CDR for a heavy lift rocket. Boeing played a leading role in that event, too. Today’s rocket , the SLS, is the launch vehicle that will send humans farther into the solar system than ever before, including to an asteroid and eventually Mars.  

Representatives from various NASA centers and Boeing – prime contractor for the core stage, including its avionics – met daily for more than a month for the Critical Design Review board at NASA’s Marshall Space Flight Center in Huntsville, Alabama.  

“We are five months ahead of schedule as we progress toward delivering the rocket to the launch pad in Florida for our initial 2017 flight test Exploration Mission-1,” said Boeing vice president and SLS Program Manager Virginia Barnes.  

In the same week, NASA also completed modification of the remaining major SLS contract with Boeing for development of the 200-foot core stage and avionics. The core stage stores cryogenic liquid hydrogen and liquid oxygen that will feed the RS-25 engines at the base of the core stage. Boeing also has also been tasked to study the Exploration Upper Stage, which will be needed to further expand mission range and payload capabilities.  

Boeing is manufacturing components for the core stage, including actual flight hardware, at NASA’s Michoud Assembly Center, while development and integration of flight computers and software continues at Marshall.