The SLS Core Stage is ignited and begins on March 18, 2021 with a nominal hot fire test over the entire duration.
Vertical view of the cloud that the SLS Core Stage sends into the sky during the Green Run hot fire test.
On a second attempt, the SLS Core Stage is fired for 8 minutes in the Stennis Space Center in Mississippi.
NASA astronaut Jessica Meir watches as the SLS core phase completes a full 8-minute fire.
It has been a long, difficult, and expensive road for NASA and their rocket space launch system. But on Thursday afternoon, the space agency was able to achieve some success with what appeared to be a nominal ground test fire of the vehicle's core stage.
In brilliant spring sunshine, the four space shuttle main engines that power the rocket came to life on a test rig in Mississippi. Then they burned for 499.6 seconds, depleting the vehicle's supply of liquid oxygen.
About a minute after the test began, the motors began rocking and rolling. This process, known as gimbaling, allows a rocket to change the direction of thrust in flight. This dynamic exercise lasted about 30 seconds and appeared to be nominal.
After the test was over, the engineers in the control room started clapping and cheering. While days of data review are ahead of us, it means NASA, the Space Launch System program, and the core phase prime contractor, Boeing, to pass a full eight-minute test without stopping and in seemingly good condition.
Now NASA will spend some time evaluating the vehicle's performance during the test and its overall health. If all looks good, the core stage could be barge-delivered to the Kennedy Space Center in April, where it will be integrated with the large side-mounted boosters as well as the Orion spacecraft. In the coming weeks, NASA is also expected to set a start date for this Artemis 1 mission to fly an unscrewed Orion around the moon and back. In theory, this could happen in 2021, but a much more likely date is the first quarter of 2022.
Thursday's test came more than 14 months after NASA and Boeing moved the core stage to the test facility at Stennis Space Center, and two months after the first Green Run test was canceled after just 67.1 seconds. The January test was canceled when the pressure levels in the hydraulic system fell below the test parameters.
No such problems occurred on Thursday. Although the cork insulation around one of the motors caught fire and appeared to be burning aggressively before the camera view was cropped, NASA's Green Run manager Bill Wrobel said engineers expected some of it to burn away. The insulation did its job as the sensors under the cork never got above 100 degrees Fahrenheit.
This should not be a problem during an actual start where the vehicle soars to much lower air pressure as the exhaust gas is carried away by the engines.Enlarge /. The cork insulation around one of the rocket's four main engines ignites.
As always, rockets are difficult to design, build, test, and fly, especially large ones like the Space Launch System. And although the design of this vehicle was imposed on NASA by the US Senate in 2010 and the agency spent more than $ 20 billion to get to that point, it is still a huge achievement to complete such a dynamic test after a decade of work .
Ultimately, it remains to be seen what role the SLS vehicle will play in NASA's next chapter in human exploration. It could serve as the backbone for Artemis missions to the moon, or it could be replaced with cheaper commercial rockets that can fly much more frequently.
At least for a day, that's not important at all. Let the engineers do their winning lap.
Listing image by Trevor Mahlmann / Ars Technica