NASA plans to make another attempt at launching the Artemis 1 Moon mission on Saturday, September 3rd, after it scrubbed the planned launch on August 29th due to engine problems. The Space Launch System was supposed to go on its first test flight and kickstart the Artemis program that day. However, its ground teams were unable to chill down one of its RS-25 engines that exhibited temperatures higher than the other three. NASA discovered the issue merely a couple of hours before launch and had to scrap the event entirely less than hour before liftoff.
During a press conference about the new target date, SLS program manager John Honeycutt said they believe the problem stemmed from a faulty sensor. The rocket's technical team is still reviewing data and polishing its plan to make sure the launch on Saturday pushes through. Over the next few days, the team will practice propellant loading procedures, which would start the engines' chilldown process 30 to 45 minutes earlier in the countdown in an effort to ensure that they reach temperatures of around minus 420 degrees Fahrenheit.
If the SLS team needs access to the sensor to solve the problem, though, it could delay the Artemis 1 mission by weeks or even months. An SLS launch must meet a number of environmental conditions in order to push through, so NASA can only schedule a mission within specific time windows. Once the current launch availability closes on September 6th, the next earliest possible date for the flight test won't be until September 19th.
The SLS team plans to review data and assess the mission's flight readiness on Thursday. If it decides to proceed with the September 3rd launch, the SLS will be blasting off to space anytime between 2:17 to 4:17 PM EDT, assuming no other issues arise.
