> NASA's shuttle contractor, Rockwell, built a "main propulsion test article" for the space shuttle in the 1970s, and it underwent more than a dozen test firing

> NASA's shuttle contractor, Rockwell, built a "main propulsion test article" for the space shuttle in the 1970s, and it underwent more than a dozen test firings at Stennis. However, this test campaign ended in January 1981, three months before the first space shuttle launch. In other words, the shuttle test article, with its three main engines, served to uncover any problems before flight. > That will not happen with the SLS test article. NASA is planning the first launch of this rocket, with its core stage, within the next nine months. After this test flight, launching an uncrewed Orion around the Moon, a second flight with astronauts is due to follow in 2023, with potentially a third mission in 2024. The whole point of a test article is to test the system before a high-stakes launch, not afterward.