During the two day ‘wet dress rehearsal’ of the NASA Artemis mission on Monday, the space agency was forced to call off the test, after an issue with a launcher panel.
This is the last major round of testing for the more than $23 billion Space Launch System (SLS) megarocket, before it goes on an uncrewed trip around the moon.
The dress rehearsal tests all aspects of the system, as well as the Orion capsule that will one day take astronauts back to the moon. They also test launch procedures.
The countdown ended early on Monday after engineers had partially loaded liquid oxygen into the SLS core stage tank, while the megarocket stack was on Complex 39B at the NASA Kennedy Space Center in Florida.
A stuck valve, high on the mobile launcher structure that supports the giant rocket, forced the team to scrub the test – after about half the tank had been filled.
Jim Free, NASA Associate Administrator, Exploration Systems, said: ‘Great progress made in yesterday’s wet dress rehearsal attempt, and I’m proud of the team for continuing to learn as we practice the countdown & fueling for the first time.’
During the two day ‘wet dress rehearsal’ of the NASA Artemis mission on Monday, the space agency was forced to call off the test, after an issue with a launcher panel
The stuck valve was 160ft up on the 322ft rocket, attached to the mobile launcher which acts as a gantry and launch platform for SLS.
The problem was in a panel that controls the valve – meaning it couldn’t be opened if there was a problem with fuelling.
This was the second delay in as many days, after initially being given the go-ahead at 06:45 EDT on Sunday, but called off due to a technical glitch stoping the mobile launcher from being pressurised.
Artemis I is scheduled to launch this summer, taking a ‘crew’ of dummies on a trip around the moon and back to Earth – before a crewed flight in 2024.
NASA says that despite calling off the test, it provided the teams a valuable opportunity for training and to make sure loading procedures were accurate.
This was the first time using new systems at NASA’s Kennedy Space Center, and the team were able to monitor the Artemis I core stage as it was exposed to cryogenic liquids and gather data that will inform updates to propellant loading procedures.
‘After troubleshooting a temperature limit issue for the liquid oxygen, which delayed the countdown by several hours, the team successfully developed a new procedure for loading the liquid oxygen and filled the tank to 50 percent,’ a spokesperson said.
Liquid oxygen is an extremely cold, or cryogenic, propellant that is maintained at minus 297 degrees Fahrenheit.
This is the last major round of testing for the more than $23 billion Space Launch System (SLS) megarocket, before it goes on an uncrewed trip around the moon
During chilldown of the lines in preparation for loading the liquid hydrogen, NASA engineers encountered an issue with a panel on the mobile launcher that controls the core stage vent valve.
Given the time to resolve the issue as teams were nearing the end of their shifts, the launch director made the call to stop the test for the day.
Nasa’s Space Launch System: The largest rocket ever made
Space Launch System, or SLS, is a launch vehicle that NASA hopes will take its astronauts back to the moon and beyond.
The rocket will have an initial lift configuration, set to launch in the early-2020’s, followed by an upgraded ‘evolved lift capability’ that can carry heavier payloads.
Space Launch System Initial Lift Capability
– Maiden flight: Mid-2020’s
– Height: 311 feet (98 metres)
– Lift: 70 metric tons
– Weight: 2.5 million kilograms (5.5 million lbs)
Space Launch System Evolved Lift Capability
– Maiden flight: Unknown
– Height: 384 feet (117 metres)
– Lift: 130 metric tons
– Weight: 2.9 million kilograms (6.5 million lbs)
It isn’t clear when NASA will try again, as the team need to investigate the issue, and determine how long it will take to change systems.
The test will be the first full ‘wet dress rehearsal,’ where NASA will conduct a series of final prelaunch tests, including loading the SLS propellant tanks and conducting a launch countdown under similar circumstances to the real launch later in the year.
It provides engineers and officials with a host of information on how the rocket performs, how procedures play out, and informs the decision on when to launch.
The name, wet dress rehearsal, comes from the fact the tests are primarily designed to show that the rocket can be loaded with super-cold liquid propellants.
‘The wet dress rehearsal will be the final major test for the Artemis I mission and will ensure the rocket, spacecraft, ground equipment and launch team are “go” for launch,’ NASA explained.
Atop the massive Space Launch System rocket is the Orion capsule, which will take the first woman and first person of colour to the moon some time after 2025.
NASA expects the official Artemis I launch, the first involving SLS and Orion, to happen anytime from the end of May to mid-July – depending on the rehearsal.
‘We continue to evaluate the May window, but we’re also recognising that there’s a lot of work in front of us,’ said Tom Whitmeyer, NASA Deputy Associate Administrator, with responsibility for exploration systems development.
That work includes analysing the data from the wet dress rehearsal.
‘During the test at the launch pad, engineers will be on duty in the Launch Control Center and in other stations where they will work during the Artemis I launch,’ NASA explained in a blog post about the wet dress rehearsal.
Space Launch System, or SLS, is a launch vehicle that NASA hopes will take its astronauts back to the moon and beyond
NASA expects the official Artemis I launch, the first involving SLS and Orion, to happen anytime from the end of May to mid-July – depending on the rehearsal
‘They will capture as much data as possible on the performance of all the systems that are part of SLS and the Orion spacecraft as well as the Kennedy ground systems.’
After the wet dress rehearsal, the combination of Orion and SLS will stay on Pad 39B for about a month, before rolling back into the hanger for more analysis.
While it is the first mission for the massive Space Launch System rocket engine, it will be the second for the Orion capsule, which was involved in a test flight in December 2014, going to space on a ULA Delta IV Heavy.
When it launches, Orion won’t have any crew on board, despite being able to hold up to four astronauts. Instead, it will carry dummies to the moon and back.
These are designed to replicate human weight and give scientists and engineers and insight into flight performance, without putting humans at risk.
The Artemis I mission will see the Orion spacecraft, the SLS and the ground systems at Kennedy combine to launch the Orion 280,000 miles past Earth around the moon over the course of a three-week mission.
If Artemis I is a success, then NASA will send Artemis II on a trip around the moon, this time with a human crew on board.
The Artemis II mission plans to send four astronauts in the first crewed Orion capsule into a lunar flyby for a maximum of 21 days.
NASA will land the first woman and first person of color on the moon in 2025 as part of the Artemis mission
Artemis was the twin sister of Apollo and goddess of the moon in Greek mythology.
NASA has chosen her to personify its path back to the moon, which will see astronauts return to the lunar surface by 2025 – including the first woman and the next man.
Artemis 1, formerly Exploration Mission-1, is the first in a series of increasingly complex missions that will enable human exploration to the moon and Mars.
Artemis 1 will be the first integrated flight test of NASA’s deep space exploration system: the Orion spacecraft, Space Launch System (SLS) rocket and the ground systems at Kennedy Space Center in Cape Canaveral, Florida.
Artemis 1 will be an uncrewed flight that will provide a foundation for human deep space exploration, and demonstrate our commitment and capability to extend human existence to the moon and beyond.
During this flight, the spacecraft will launch on the most powerful rocket in the world and fly farther than any spacecraft built for humans has ever flown.
It will travel 280,000 miles (450,600 km) from Earth, thousands of miles beyond the moon over the course of about a three-week mission.
Artemis 1, formerly Exploration Mission-1, is the first in a series of increasingly complex missions that will enable human exploration to the moon and Mars. This graphic explains the various stages of the mission
Orion will stay in space longer than any ship for astronauts has done without docking to a space station and return home faster and hotter than ever before.
With this first exploration mission, NASA is leading the next steps of human exploration into deep space where astronauts will build and begin testing the systems near the moon needed for lunar surface missions and exploration to other destinations farther from Earth, including Mars.
The will take crew on a different trajectory and test Orion’s critical systems with humans aboard.
Together, Orion, SLS and the ground systems at Kennedy will be able to meet the most challenging crew and cargo mission needs in deep space.
Eventually NASA seeks to establish a sustainable human presence on the moon by 2028 as a result of the Artemis mission.
The space agency hopes this colony will uncover new scientific discoveries, demonstrate new technological advancements and lay the foundation for private companies to build a lunar economy.