ars Technica by Eric Berger - 7/17/2020
The ongoing COVID-19 pandemic is flaring up around several NASA centers.
NASA Administrator Jim Bridenstine said Friday he is "very confident" in a potential November 2021 launch for the large Space Launch System rocket.
While expressing confidence in this date, however, Bridenstine added that there are uncertainties between now and then. One is technical—the core stage of the SLS rocket must undergo a series of tests this summer and autumn before it moves to the launch pad. The second issue is the ongoing COVID-19 pandemic, which is spiking around several NASA centers.
Green Run test
In January, NASA and the contractor for the SLS rocket's core stage, Boeing, moved the vehicle to Stennis Space Center in southern Mississippi. Since then, workers have been putting the stage—which consists of four space shuttle main engines and very large tanks to store liquid hydrogen and liquid oxygen propellants—through a series of tests.
This week, Boeing officials said they expect to conduct the final and most important of those tests in October: lighting all four of the rocket's engines and firing them for about eight minutes to mimic an actual launch.
If this test is successful, the core stage will then be moved by barge to Kennedy Space Center, likely in early 2021. After that point, two side-mounted boosters will be added, along with an upper stage and the Orion spacecraft. This full stack will then undergo further tests before finally launching on an uncrewed test flight. A late 2021 launch date assumes all of these activities go forward as planned, which is far from certain when dealing with a new rocket.
More:
https://arstechnica.com/science/2020/07/nasa-chief-says-hes-very-confident-in-a-2021-launch-date-for-sls-but/
