After dropping the fully-stacked mega-rocket, with the Orion crew capsule on top, toward the launch site at the Kennedy Space Center in Florida, the SLS team began running a practice countdown called the “liquid test rehearsal test.” While previous efforts in April proved to be due to problems with defective valves, hydrogen leaks and launch tower fans, the team addressed these issues and fully loaded the rocket propulsion tanks. They went through almost the entire countdown process, stopping at the T-29 seconds at 7:37 p.m. Eastern time. That may be enough to complete the SLS and Orion preparation for release day. “It was a tiring day for the team, but it was a very successful day and it achieved most of the goals we had not accomplished with the previous wet dress,” Charlie Blackwell-Thompson, Artemis’s launch director, told NASA at a news conference. this morning. While the team actually achieved most of these goals, it did not exactly follow the planned scenario. Launch controllers encountered some technical problems, including a new leak of liquid hydrogen — supercooled to -423 degrees Fahrenheit — on the line connecting to the rocket core stage. If this was the boot day, such a leak would usually activate the boot computer to keep the countdown. After failing to stop the flow, the team decided to trick the computer into ignoring the leak warnings so that it could count down the practice. They reached it farther than ever, but did not reach the scheduled T-9.3 second mark, where, if they continued, the RS-25 engines in the base stage would start. Now the team will review the data it has collected and, in a few days, decide if it will pass the entire countdown test for the fifth time or if it has enough information to finally move on with the central Artemis 1 released later this summer. The launch of the SLS rocket will be just one part of a series of back-to-the-Moon events that will begin this summer. Just this Saturday, NASA plans to launch Capstone, a tiny cubesat satellite that will travel on the orbital orbit of the Lunar Gateway space station, which is expected to be a stopping point for astronauts traveling between Earth and the Moon. The next possible launch window for Artemis 1 opens between July 26 and August 10, followed by another launch window about two weeks later. This unmanned mission will fly a loop around the moon while deploying small spacecraft for minor missions and technology demonstrations. Four more Artemis missions are scheduled, with more likely to be completed. After Artemis 1, the second mission will include a lunar flight with a crew and if current plans apply, in 2025, the long-awaited third mission will finally bring NASA astronauts back to the surface of the Moon after 50 years of the Apollo program. The next Artemis missions will create the Lunar Gate. At today’s press conference, team members said they felt confident about the missile systems now that they had met the most important milestones. “The team has shown tremendous discipline, perseverance and vigor,” said Mike Sarafin, director of the Artemis mission. “Artemis 1 paves the way for the moon and firmly establishes Orion and SLS as our transport system for the crew and cargo for the Artemis program, and yesterday put us on the road to Artemis 1.”
