NASA officials avoided giving clear numerical risk estimates for the upcoming Artemis II mission, the first crewed flight toward the Moon in more than 50 years. During a press conference at Kennedy Space Center, agency leaders emphasised that while risk assessments exist, the numbers may not fully represent the uncertainties involved in such a unique mission.
Artemis II will send four astronauts on a nine-day journey around the Moon before returning to Earth. The spacecraft will travel far beyond the distance reached by astronauts aboard the International Space Station, making it the first human mission to the Moon’s vicinity since the Apollo era ended in 1972.
However, the mission will rely on the Space Launch System rocket and Orion spacecraft flying together for only the second time, leaving engineers with limited real flight data to evaluate potential hazards.
NASA cautious about publishing risk numbers
NASA officials confirmed that the agency has completed a probabilistic risk assessment for Artemis II but chose not to publicly release the final figures.
Lori Glaze, NASA’s acting associate administrator for exploration system development, questioned how meaningful such numbers can be when there is only one previous flight to analyse.
She said risk models can compare systems relative to each other, but they may give a false impression of certainty when the available data is extremely limited. Artemis I, an uncrewed demonstration mission in 2022, remains the only full-scale test of the SLS rocket and Orion spacecraft combination.
Despite these uncertainties, NASA leadership approved continued preparations after a flight readiness review held in Florida. The mission is now scheduled to launch no earlier than April 1.
Glaze described Artemis II as a test flight that inevitably carries risk but said the team believes the hardware and workforce are ready.
Technical challenges and launch preparations
NASA originally targeted February for the launch but postponed the attempt after engineers discovered a leaking hydrogen seal in the rocket’s fuelling line. Another problem involving helium loading in the rocket’s upper stage forced teams to roll the vehicle back to its assembly building for repairs.
Engineers have since replaced the seals and completed a successful countdown rehearsal showing the new components remain leak-tight.
Mission managers decided not to conduct another full fuelling test before launch. Instead, the next time the rocket is fuelled will be during the actual launch attempt.
NASA currently has six potential launch opportunities in early April. If those windows are missed, the agency would have to wait until later in the month for another chance.
Understanding the true risk of a Moon mission
John Honeycutt, chair of the Artemis II mission management team, acknowledged that calculating an exact probability of failure is extremely difficult.
NASA aims to reduce the risk of mission failure below roughly 1 in 50 for future Artemis flights. However, Honeycutt suggested the Artemis II mission likely carries a higher level of uncertainty due to the limited flight history of the rocket and spacecraft.
He explained that risk models depend on many assumptions about how different systems might fail and how those failures could cascade. Past disasters have shown that statistical models can overlook unexpected combinations of events.
The space shuttle Columbia accident in 2003 illustrates this challenge. Engineers would have needed to calculate not only the probability of foam falling from the shuttle’s fuel tank but also every possible way such debris could damage the spacecraft.
Astronauts prepare for the dangers
Despite the uncertainties, the Artemis II crew says they understand and accept the risks.
Mission commander Reid Wiseman described how he spoke openly with his family about the dangers of spaceflight, including explaining legal documents and contingency plans in case something went wrong.
The mission will push the spacecraft to extreme conditions, including speeds approaching Mach 39 during Earth reentry and distances up to roughly 250,000 miles from Earth.
Even with the unknowns, Wiseman said he feels completely committed to the mission and confident in the Orion spacecraft.
NASA officials say their primary goal remains ensuring the crew returns safely. Honeycutt summed up the priority simply: bring the astronauts home safely after completing the historic lunar test flight.