It’s time for the big test of NASA’s Artemis I lunar mission

As NASA prepares to send humans to the Moon 0:47 (CNN) — NASA’s first mission to the Moon since 1972 is set for its most crucial test to date. The base of the 98-meter-tall Artemis I rocket, which includes NASA’s mega Space Launch System and Orion spacecraft, begins dress rehearsal Friday afternoon at the Kennedy Space Center in Florida. The test is expected to last until Sunday. The results will determine when the uncrewed Artemis I will launch on a mission that goes beyond the Moon and back to Earth. This mission will kick off NASA’s Artemis program, which is expected to return humans to the Moon and deliver the first woman and first person of color to the lunar surface by 2025. The final test simulates each stage of the launch without the rocket leaves the launch pad. This includes powering up the SLS rocket and Orion spacecraft, loading supercold propellant into the rocket’s tanks, going through a full countdown that simulates launch, resetting the countdown clock, and draining the rocket’s tanks. The test began with a call to the stations at 5:00 p.m. ET on Friday and ends on Sunday night with the final countdowns. The station call, which is a check-in with each team associated with a launch, “is a huge milestone because it’s the moment we call our teams, notifying them that dress rehearsal is officially underway,” Charlie said. Blackwell-Thompson, Artemis launch manager for NASA’s Exploration Ground Systems program, during a news conference Tuesday. A live NASA broadcast of Artemis I on the launch pad without audio commentary began Friday at noon ET and will be available throughout the weekend, but don’t expect to see all the drama of an actual launch. Testing includes a countdown The team is targeting a two-hour testing window that opens at 2:40 pm ET on Sunday, barring any delays due to inclement weather or other factors. The countdown will begin on Sunday afternoon after a weather briefing, making sure all teams are ready for a mock launch. Once the rocket has been loaded with more than 3.2 million liters of propellant, the team will go through all the steps towards launch. “Liquid hydrogen has a negative temperature of 268 degrees Celsius, liquid oxygen has a negative temperature of 169 degrees Celsius, so they are very cold substances,” said Tom Whitmeyer, deputy associate administrator for exploration systems development at NASA headquarters, during the press conference. “I used to be involved in this on the shuttle show, and it’s like watching a ballet. You have pressure, volume and temperature. And you’re really working with all those parameters to have a successful tank operation.” The Artemis I rocket can be seen at sunrise on March 21 at the Kennedy Space Center in Florida. Team members will count down to one minute and 30 seconds before the throw and pause to ensure they can hold the throw for three minutes, resume and let the clock tick down to 33 seconds, and then pause the countdown. They will then reset the clock to 10 minutes before launch, count down again and finish in 9.3 seconds, just before power-up and launch occurs. This simulates what is called scrubbing a launch, or aborting a launch attempt, if weather or technical issues prevent a safe takeoff. At the end of the test, the team will drain the propellant from the rocket, just as it would during a real cleanup. Some Steps Will Be Classified Artemis I hit the launch pad on March 18. After this rehearsal, it will return to the Vehicle Assembly Building until it is ready for launch. Updates on the progress of the test will be shared from the Artemis blog and a NASA Twitter account. But no audio or commentary will be provided, and there are no in-person media events surrounding the test. Also, some data will be kept secret due to security concerns. The milestones will be shared on NASA’s site, but details such as specific weather, temperatures and the time it takes to complete certain tasks “are considered important information for other countries,” Whitmeyer said. “So we have to be very careful when we share data, particularly for the first time, you know.” And that’s for a reason. “We’re very, very supersensitive to cryogenic launch vehicles that have the size and capability, which are very similar to ballistic-type capabilities that other countries are very interested in,” Whitmeyer said. “And what they’re specifically looking for is the time stream flow rate, temperatures, anything that helps them or other people to help other people do similar things.” The complex interplay of propellant loading and the sequence of events to avoid stress on the vehicle are the specific types of data that would be of particular interest, he said. Whitmeyer stressed that the agency was being conservative and exercising great caution, “particularly in the environment we find ourselves in today.” Anticipated summer launch The space agency is expected to provide an update on the test results on Monday. Depending on the outcome of the dress rehearsal, the uncrewed mission could launch in June or July. During the flight, the uncrewed Orion spacecraft will launch atop the SLS rocket to reach the Moon and travel thousands of miles beyond it, farther than any spacecraft intended to carry humans has ever traveled. This mission is expected to last a few weeks and will end with Orion’s splashdown in the Pacific Ocean. Artemis I will be the final testing ground for Orion before the spacecraft takes astronauts to the Moon, 1,000 times farther from Earth than the International Space Station. After the uncrewed Artemis I flight, Artemis II will be a manned flyby of the moon, and Artemis III will return astronauts to the lunar surface. The timeline for subsequent mission launches depends on the results of the Artemis I mission. NASA opens capsule with soil samples from the Moon 0:47