NASA Delays Artemis II Launch to March Amid Recurring Hydrogen Leak Issues
NASA is postponing the launch of Artemis II, the first crewed mission to the Moon in over 50 years, to March as engineers continue to grapple with persistent hydrogen leaks in the Space Launch System (SLS) rocket. The delay follows a fueling test on that revealed the same type of leak that previously hampered the Artemis I test flight in .
The core of the problem lies in the difficulty of containing liquid hydrogen, a crucial component of the SLS rocket’s fuel. Hydrogen, when mixed with air, is highly explosive and its extremely low temperature – minus 423 degrees Fahrenheit (minus 253 degrees Celsius) – presents significant materials challenges for seals and connections. Molecular hydrogen is also the smallest molecule, making it prone to escaping even through minute leak paths.
During the recent fueling test, engineers identified leaks in the connections between the rocket’s core stage and the fueling lines on the launch platform at Kennedy Space Center in Florida. While the test met many planned objectives, NASA determined a second “wet dress rehearsal” – a full practice countdown – is necessary before attempting launch. The next launch opportunities are slated to begin on .
A History of Hydrogen Leaks and a Relaxed Safety Limit
Hydrogen leaks have been a recurring issue for the SLS program. The initial Artemis I mission experienced similar problems, leading to months of delays while engineers revised hydrogen loading procedures. For Artemis II, the same loading procedures were used, but the leak reappeared, indicating a deeper, systemic challenge.
Interestingly, NASA Administrator Jared Isaacman revealed the agency had, in the interim between Artemis I and Artemis II, become more tolerant of a larger hydrogen leak than previously acceptable. John Honeycutt, chair of the Artemis II mission management team, explained that a test campaign was conducted to assess the characteristics of the leak cavity and determine a safe threshold. “They introduced hydrogen to see when you could actually get it to ignite, and at 16 percent, you could not,” Honeycutt stated. This suggests a deliberate, albeit temporary, relaxation of safety margins.
Long-Term Solutions and Program Costs
Isaacman has signaled a shift in approach for Artemis III, which is expected to be at least three years away. He stated that the vehicle will undergo “cryoproofing” – a thorough testing process to ensure the integrity of cryogenic systems – before being transported to the launch pad. The propellant loading interfaces, identified as a source of the leaks, will be redesigned.
The ongoing issues with the SLS rocket are compounded by its substantial cost. NASA’s Inspector General estimates the cost of each SLS rocket to exceed $2 billion. Ground system expenditures at Kennedy Space Center are also significant, with nearly $900 million spent on Artemis ground support infrastructure in alone. A substantial portion of this funding went towards constructing a new launch platform for an upgraded version of the SLS that may never be utilized.
The high cost and slow flight rate of the SLS have drawn criticism from Isaacman, who has emphasized the need for a more efficient and affordable lunar program. The lack of a full-size test model of the SLS core stage further complicates matters, as complete system testing can only occur once the fully assembled rocket is on the launch pad.
Future of Artemis and SLS
Despite the challenges, NASA remains committed to returning to the Moon. Existing legislation mandates the continued use of the SLS rocket through the Artemis V mission. However, Isaacman has indicated that the Artemis architecture will evolve over time, incorporating newer, cheaper, and reusable rockets as industry capabilities mature. This suggests a long-term vision that moves beyond the current reliance on the SLS.
If the March launch window is missed, NASA will be forced to roll the rocket back to the Vehicle Assembly Building to refresh the flight termination system, potentially causing further delays. Isaacman reiterated that the safety of the astronauts remains the highest priority and that NASA will provide updates as preparations for the historic mission progress. “There is still a great deal of work ahead to prepare for this historic mission,” he wrote.
