NASA and lead contractor Boeing have confirmed that four-fifths of the first massive SLS core stage has been assembled.

At 58 meters (190 feet) tall, the SLS core stage in its current configuration is the largest rocket stage the agency has built since the Saturn V. Once complete, the five-segment stage will be powered by four RS-25 engines and stand at 64 meters tall (212).

“Building and assembling this massive integrated propulsion and avionics stage for the world’s most powerful rocket, the only launch vehicle that can return astronauts to the Moon, is an engineering feat,” said Julie Bassler, SLS stages manager. “To manufacture the Space Launch System, we are working with more than 1,000 companies across the country. It’s truly America’s rocket.”

Notwithstanding Bassler’s patriotism, the immensely complicated SLS supply chain is likely one of the causes of the program’s massive delays and cost overruns.

In 2014, NASA announced that the SLS would be launched on its maiden mission in November 2018. As the date approached and the rocket wasn’t close to being launch-ready, the date was moved out to 2019. In November 2017, less than a year after the last revised launch date was announced, officials confirmed that the maiden flight would slip another year to June 2020.

The program cost overruns have not fared much better. In October 2018, the agency’s Office of Inspector General (OIG) released a report titled NASA’s Management of the Space Launch System Stages Contract. The report stated that “At its current rate, we project that Boeing will expend at least $8.9 billion through 2021 — double the amount initially planned.”

Boeing’s management of the rocket’s development was identified as being a major contributor to the program’s difficulties. “Cost increases and schedule delays of Core Stage development can be traced largely to management, technical, and infrastructure issues driven by Boeing’s poor performance.”

In order to stand any chance of making the June 2020 launch date, NASA has revealed that it is exploring the option of ditching the rocket’s “Green Run” test. The test is essentially a long static fire test of the core stage without the side boosters for a period of 8 minutes. It is essentially a stress test of every component of the rocket in launch conditions. The test alone accounts for several months of work and that’s if all goes well. If an issue is discovered during testing, the rocket’s development could be set back months or even years.

Despite the setbacks, the SLS rocket remains a major element in NASA’s ambitious goal of returning to the Moon by 2024. Its development, as a result, could very well receive the additional funding and support the agency and its many contractors need to complete it in time to launch American astronauts to the Moon.





