The 322-foot (98-meter) Artemis I rocket group, including NASA’s massive SLS rocket and Orion spacecraft, will begin rehearsal Friday. The testing is expected to continue through Sunday.
The test 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 loading ultra-cooled propulsion fuel into the missile’s tanks, performing a complete countdown simulating a launch, resetting the countdown clock and depleting the missile tanks. The test will begin calling stations Friday at 5 PM ET and end Sunday evening with the final countdown.
Calling the stations, a check-in with each team associated with the launch, “is a milestone because it’s the time we call our teams to notify them that vampire testing is officially underway.” Charlie Blackwell Thompson, Artemis launch manager for NASA’s Earth Exploration Systems Program, during a press conference Tuesday.
Trial run includes countdown
Once the rocket is loaded with more than 700,000 gallons (3.2 million liters) of propellant, on Sunday teams will go through all the steps toward launch.
“Liquid hydrogen is at minus 450 degrees Fahrenheit (minus 268 degrees Celsius), and liquid oxygen is minus 273 (minus 169 degrees Celsius), so they are very cold materials,” said Tom Whitmaier, NASA associate deputy director of development for Common Exploration Systems. Press Conference.” “I used to get this back in on Shuttle and it’s like watching ballet. You have pressure, volume, and temperature. And you really work on all these parameters 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 9.3 seconds before launch occurs. This simulates what’s called a launch washout, 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
While key milestones will be shared on the NASA website, details such as the exact timings, temperatures, and time taken to complete certain tasks “are considered important information by other countries. And so we have to be very careful when sharing data,” Whitmer said.
This is for a reason.
“We’re really very sensitive to cryogenic launch vehicles of a size and capability that are very similar to the ballistic capabilities that other nations are so interested in,” Whitmaier said. “And what they’re looking for specifically 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 schedule for launching subsequent missions depends on the results of the Artemis I mission.