NASA engineers finally shut down the huge Space Launch System rocket with fuel on Monday night, passing most of the last crucial test before its inaugural flight. After reviewing the test data, the team will decide the launch date of the world’s most powerful rocket this summer, which is part of the first major mission of the Artemis lunar program.
After launching the fully stacked mega-rocket, with the Orion crew capsule on top, toward the Kennedy Space Center launch pad in Florida, the SLS team began counting back practice called “wet dress rehearsal test”. Although previous attempts in April failed due to problems with faulty valves, hydrogen leaks and launch tower fans, the team has addressed these issues and fully loaded the rocket’s propulsion tanks. They went through almost the entire countdown procedure, stopping at T-29 Seconds at 7:37 p.m. Eastern Time. This may be enough to finish preparing SLS and Orion for launch day.
“It was a long day for the team, but it was a very successful day and it achieved most of the goals we hadn’t completed with the previous wet suit,” said Charlie Blackwell-Thompson, Artemis launch director. , at NASA Press Conference this morning.
Although the team met most of these goals, it did not fully follow the planned script. Launch controllers encountered some technical issues, including a new leak of liquid hydrogen – overcooled to -423 degrees Fahrenheit – on the line connecting to the center stage of the rocket. If this was the launch date, this leak would normally trigger the launch computer to keep the countdown. After failing to stop the flow, the team decided to trick the computer into not seeing the leak warnings so that they could move on with the countdown to practice. They went farther than ever, but did not reach the expected T-9.3 second mark, where, if they had continued, the mid-stage RS-25 engines would have ignited.
The team will now review the data they have collected and, in a few days, make a decision on whether they should pass the countdown test for the fifth time or whether they have enough information to carry out the fundamental Artemis 1. launch in late summer.
The launch of the SLS rocket will be just one part of a set of return-to-the-moon events that will begin this summer. As early as this Saturday, NASA plans to launch Capstone, a small cubed satellite that will travel the orbital path to the Lunar Gateway space station, which is expected to be a staging point for astronauts traveling between the Earth and the Moon.
The next feasible release window for Artemis 1 opens between July 26 and August 10, followed by another release window about two weeks later. This unmanned mission will orbit the Moon as it deploys small spacecraft for side missions and technology demonstrations.
Four other Artemis missions are planned, with more potential in the works. After Artemis 1, the second mission will involve a manned lunar flyby, and if the current schedule is maintained, in 2025, the long-awaited third mission will finally bring NASA astronauts to the surface of the Moon after 50 years since Apollo program. Later Artemis missions will build the Lunar Gateway.
At today’s press conference, team members said they feel safe about rocket systems now that they have reached their most important milestones. “The team showed great discipline, perseverance and strength,” said Mike Sarafin, Artemis Mission Manager. “Artemis 1 paves the way for the Moon and firmly establishes Orion and SLS as our transportation system for the crew and cargo for the Artemis program, and yesterday set us on the path to Artemis 1.”