A 322-foot (98 m) stack of Artemis I rockets, including NASA’s massive Space Launch System and Orion spacecraft, began rehearsal Friday afternoon at the Kennedy Space Center in Florida. The testing is expected to continue through Sunday.
The results will determine when the unmanned Artemis I will set out on a mission beyond the moon and back to Earth. This mission will launch NASA’s Artemis program, which is expected to return humans to the moon and land the first woman and first people of color on the moon by 2025.
The rehearsal simulates each stage of the launch without the missile actually exiting the launch pad. This includes powering up the SLS rocket and Orion spacecraft, loading ultra-cooled propellant into the rocket’s tanks, performing a full launch simulation countdown, resetting the countdown clock, and drying the rocket tanks. The test began calling stations at 5 p.m. ET on Friday and will end Sunday evening with the final countdown.
The station call, which is a check-in with every team associated with the launch, “is a huge milestone because it’s the time we call our teams, tell them that wetsuit training testing is officially underway,” said Charlie Blackwell Thompson, Artemis launch manager for NASA’s Earth Exploration Systems Program. , during a press conference on Tuesday.
Trial run includes countdown
Once the rocket is loaded with more than 700,000 gallons (3.2 million liters) of propellant—”wet” at rehearsal—the team will go through all the steps toward launch.
“Some venting may be seen during venting,” according to the agency, but this is related to what is visible on the launch pad.
“Liquid hydrogen is at minus 450 degrees Fahrenheit (minus 268 degrees Celsius), and liquid oxygen is negative 273 (minus 169 degrees Celsius), so it’s very cold materials,” Tom Whitmaier, associate deputy director of exploration systems development at NASA Headquarters, said during the conference. Journalist.” “I used to do this again on the shuttle program, and it was like watching a ballet. You have pressure, volume, and temperature. And you really work on all these parameters in order to have a successful tank operation.”
Team members will count down the 1 minute 30 seconds before launch and pause to make sure they can keep running for three minutes, resume running the clock and let it go down to 33 seconds, then pause the countdown.
Then, they’ll reset the clock to 10 minutes before launch, countdown again and finish in 9.3 seconds, just before ignition and triggering occur. This simulates what’s called a launch purification, or aborted launch attempt, if weather or technical issues would prevent a safe takeoff.
At the end of the test, the team will drain the rocket’s propellant, just as it would during a real cleanup.
Some steps will be classified
Milestones will be shared on NASA’s website, but details such as the exact timings, temperatures, and time taken to accomplish certain tasks “are considered important information by other nations,” Whitmer said. “And so we have to be very careful when sharing data, especially for the first time, you know.”
This is for a reason.
“We’re really, really, really sensitive to cryogenic launch vehicles of a size and capacity, which are very similar to the ballistic capabilities that other nations are so interested in,” Whitmer said. “And what they’re specifically looking for are timing sequence flow rates, temperatures, and anything that would help them or other people most likely to help others do similar things.”
He said the complex interaction between the loading fuel and the sequence of events to prevent stress on the vehicle are the specific types of data that will be of particular interest.
Whitmer stressed that the agency has been conservative and exercised a great deal of caution, “particularly in the environment we are in these days.”
Anticipating the summer launch
The space agency is expected to provide an update on test results on Monday.
Depending on the outcome of the rehearsal, the unmanned mission could begin in June or July.
During the flight, the unmanned Orion spacecraft will blast above an SLS rocket to reach the moon and travel thousands of miles behind it — farther than any spacecraft intended to carry humans has traveled. This mission is expected to last a few weeks and will end with Orion spray in the Pacific Ocean.
Artemis I will be Orion’s final testing ground before the spacecraft carries astronauts to the Moon, 1,000 times more Earth-bound than the International Space Station site.
After the uncrewed Artemis I flight, Artemis II will be a lunar flight, and Artemis III will return astronauts to the lunar surface. The launch schedule for subsequent missions depends on the results of the Artemis I mission.