Artemis II mission delayed: NASA postpones Moon journey due to rocket fuel leaks
TOI GLOBAL DESK | TOI GLOBAL | Feb 03, 2026, 21:21 IST
NASA has postponed the Artemis II mission due to hydrogen leaks discovered during a pivotal test of the Space Launch System rocket. Originally scheduled for February, the mission's new target launch window is now in March, aiming for a lunar exploration.
NASA has postponed the Artemis II mission, which was scheduled to send four astronauts on a journey around the moon, due to issues encountered during a critical test of its Space Launch System rocket. The mission, initially slated for February, will now aim for March as the earliest possible launch opportunity. This delay allows teams to review data and conduct another "wet dress rehearsal" after engineers detected leaking hydrogen at the base of the rocket during a simulated launch countdown.
The Artemis II mission, intended to be the first crewed flight of NASA's Space Launch System rocket and Orion capsule, was set to launch between Friday and February 11. Mission managers were conducting an elaborate launch day walkthrough, known as a "wet dress rehearsal," at Kennedy Space Center in Florida when the hydrogen leaks were detected. The test was ended with approximately five minutes and 15 seconds remaining in the simulated countdown.
NASA announced the delay shortly after 2 a.m. ET on Tuesday. The space agency will now aim for March, with available launch opportunities from March 6 through March 9, and on March 11, with additional dates in April if needed. This decision comes after a similar issue with hydrogen leaks during the first wet dress rehearsal for the uncrewed Artemis I flight in 2022, which caused a six-month delay.
The wet dress rehearsal is designed to assess the performance and readiness of the rocket by simulating each step of the launch countdown. This involved filling the Space Launch System rocket with over 700,000 gallons of cryogenic propellant. During the fueling process, which began around 12:30 p.m. ET on Monday, mission managers paused twice to investigate leaking hydrogen fuel.
Despite continuing the rehearsal and conducting tests of the Orion spacecraft, the hydrogen leaks reappeared in the final minutes of the simulated countdown. Systems aboard the rocket designed to take over control in the final minutes before liftoff automatically stopped the countdown due to a spike in the liquid hydrogen leak rate.
In addition to the hydrogen leaks, engineers will also investigate several audio issues in communications channels used by ground teams that occurred during the rehearsal. These issues need to be resolved before the mission can proceed.
The four astronauts selected for the Artemis II flight are NASA astronauts Reid Wiseman, Christina Koch, and Victor Glover, along with Canadian astronaut Jeremy Hansen. They had been in quarantine in Houston since January 21 to prevent preflight exposure to germs. However, NASA announced that the astronauts will now be released from quarantine and will not travel to Florida as originally planned.
Instead, the crew will enter quarantine again approximately two weeks before the next targeted launch opportunity. This measure is in place to ensure the crew's health and readiness for the mission.
Artemis II marks a significant step towards NASA's goal of returning astronauts to the lunar surface. It will be the first time the Space Launch System rocket and Orion capsule carry humans into space. The previous Artemis I mission in 2022 successfully completed an uncrewed journey around the moon.
NASA Administrator Bill Nelson stated that safety remains the top priority for the mission. "With more than three years between SLS launches, we fully anticipated encountering challenges," NASA Administrator Bill Nelson wrote in a post on X. "That is precisely why we conduct a wet dress rehearsal," Nelson continued.
"These tests are designed to surface issues before flight and set up launch day with the highest probability of success." The stakes for the Artemis II flight are particularly high, as it represents the first time humans will fly aboard the Space Launch System rocket and Orion capsule. NASA is committed to ensuring the mission's success and the safety of its crew.
"As always, safety remains our top priority, for our astronauts, our workforce, our systems, and the public," Nelson added on X. "NASA will only launch when we believe we are ready to undertake this historic mission."
Officials are expected to discuss the early results from the test in a briefing on Tuesday at 12 p.m. ET. The data gathered from this rehearsal will be crucial in identifying the root causes of the hydrogen leaks and implementing necessary fixes. The successful resolution of these technical challenges is paramount for the safe and successful execution of the Artemis II mission.
The Artemis II mission, intended to be the first crewed flight of NASA's Space Launch System rocket and Orion capsule, was set to launch between Friday and February 11. Mission managers were conducting an elaborate launch day walkthrough, known as a "wet dress rehearsal," at Kennedy Space Center in Florida when the hydrogen leaks were detected. The test was ended with approximately five minutes and 15 seconds remaining in the simulated countdown.
NASA announced the delay shortly after 2 a.m. ET on Tuesday. The space agency will now aim for March, with available launch opportunities from March 6 through March 9, and on March 11, with additional dates in April if needed. This decision comes after a similar issue with hydrogen leaks during the first wet dress rehearsal for the uncrewed Artemis I flight in 2022, which caused a six-month delay.
The wet dress rehearsal is designed to assess the performance and readiness of the rocket by simulating each step of the launch countdown. This involved filling the Space Launch System rocket with over 700,000 gallons of cryogenic propellant. During the fueling process, which began around 12:30 p.m. ET on Monday, mission managers paused twice to investigate leaking hydrogen fuel.
Despite continuing the rehearsal and conducting tests of the Orion spacecraft, the hydrogen leaks reappeared in the final minutes of the simulated countdown. Systems aboard the rocket designed to take over control in the final minutes before liftoff automatically stopped the countdown due to a spike in the liquid hydrogen leak rate.
In addition to the hydrogen leaks, engineers will also investigate several audio issues in communications channels used by ground teams that occurred during the rehearsal. These issues need to be resolved before the mission can proceed.
The four astronauts selected for the Artemis II flight are NASA astronauts Reid Wiseman, Christina Koch, and Victor Glover, along with Canadian astronaut Jeremy Hansen. They had been in quarantine in Houston since January 21 to prevent preflight exposure to germs. However, NASA announced that the astronauts will now be released from quarantine and will not travel to Florida as originally planned.
Instead, the crew will enter quarantine again approximately two weeks before the next targeted launch opportunity. This measure is in place to ensure the crew's health and readiness for the mission.
Artemis II marks a significant step towards NASA's goal of returning astronauts to the lunar surface. It will be the first time the Space Launch System rocket and Orion capsule carry humans into space. The previous Artemis I mission in 2022 successfully completed an uncrewed journey around the moon.
NASA Administrator Bill Nelson stated that safety remains the top priority for the mission. "With more than three years between SLS launches, we fully anticipated encountering challenges," NASA Administrator Bill Nelson wrote in a post on X. "That is precisely why we conduct a wet dress rehearsal," Nelson continued.
"These tests are designed to surface issues before flight and set up launch day with the highest probability of success." The stakes for the Artemis II flight are particularly high, as it represents the first time humans will fly aboard the Space Launch System rocket and Orion capsule. NASA is committed to ensuring the mission's success and the safety of its crew.
"As always, safety remains our top priority, for our astronauts, our workforce, our systems, and the public," Nelson added on X. "NASA will only launch when we believe we are ready to undertake this historic mission."
Officials are expected to discuss the early results from the test in a briefing on Tuesday at 12 p.m. ET. The data gathered from this rehearsal will be crucial in identifying the root causes of the hydrogen leaks and implementing necessary fixes. The successful resolution of these technical challenges is paramount for the safe and successful execution of the Artemis II mission.