NASA detected new fuel leaks on the Artemis rocket during a fuel test on Wednesday (21). They would have been reduced to a minimum – but that could mean that the launch to the Moon, scheduled for Tuesday (27), is postponed again.
It is the third time that the space agency detects problems in the SLS (Space Launch System, the most powerful rocket ever built by NASA). This hydrogen leak was similar to what prevented the last launch attempt on September 3; in the first, on August 29, there were failures in one of the four engines.
The long supply test, which lasted from early morning until late in the day, had its ups and downs. At around 5:30 pm, NASA declared that “all objectives of the cryogenic demonstration of Artemis 1 have been met.” “After finding a hydrogen leak early in the loading process, engineers were able to resolve the issue and proceed with planned activities.”
On Sunday, a team from the agency will meet to decide whether the rocket will actually launch on Monday. If not – which is very likely –, the next date considered is October 3. Another concern, which has been monitored, is the arrival of Hurricane Fiona in the United States.
After the last failed launch attempt, some parts and valves were replaced. So NASA basically spent yesterday closely monitoring the SLS, which is positioned on the launch pad at Kennedy Space Center off the coast of Florida, to see if the problem had been fixed.
The rocket’s main stage was filled very slowly, with 3.3 million liters of supercold liquid hydrogen. A leak, at a rate of 7%, stopped the process, but it was circumvented in a matter of hours and the test can be completed, with the bleeding of the engines (which reduces their temperature). There were also pressurization and calibration tests, simulating the conditions experienced shortly before launch.
Why so much leakage?
According to NASA, the insertion of fuel — a mixture of liquid hydrogen and oxygen — can cause damage to the tank, due to sudden changes in temperature and pressure. To get around this risk, he tried a “gentle and gentler” filling process during yesterday’s simulation, slowly inserting them through a pipe at very low temperature. That’s why the test lasted so many hours.
This time, the leak occurred in the “quick-disconnect umbilical cord”, a 20 centimeter area connecting the supply system to the rocket, which had recently been repaired. The team then stopped the flow of hydrogen and decided to heat the line, increasing the pressure, to see if the leak would “heal” on its own when the process resumed.
The space agency says the procedure worked. But the leak was not contained—it was reduced to a manageable margin, below the threshold of concern. Remembering that a large escape of pressurized gas can be fatal for the mission, since hydrogen in contact with air is very flammable.
After the critical test, which was broadcast live on NASA channels, Charlie Blackwell-Thompson, the mission’s launch director, said she was “extremely encouraged” by the results, but that the team still needed to evaluate the data before deciding on the launch. Thus, there is a possibility of a further postponement.
The Artemis program
Artemis 1 is the first in a series of ambitious missions that aim to take humans back to the Moon — and eventually to Mars. This voyage will not have people on board yet; it will be a big test “worth” of the entire system, including the largest and most powerful rocket in NASA’s history, the SLS, and the new Orion capsule – where the crew will be in the future.
The voyage is expected to last 42 days, a trial by fire (at times literally) for the ship’s operation and components, such as solar panels and heat shields, until it lands in the Pacific Ocean. Can it withstand the heat, high speed and radiation of space? Thus, its ability to reach our satellite and return to Earth safely for future crew members will be tested.
If all goes well, in 2024, the journey will be repeated with four astronauts on board. They will “just” make a ten-day flyby, circling to the far side of the Moon, about 400,000 kilometers from Earth (the farthest into deep space any human has ever been).
In 2025, finally, the goal is to “alunise” (land on the Moon) and disembark the crew at the South Pole, a different and more challenging location than the ones visited during the Apollo program. No person, not even a robotic mission, has ever landed there.
After 2034, if successful and with funding, the next stage of the Artemis program is to install the “Lunar Gateway”, which would orbit our satellite and serve as a mission support point (a miniature Space Station). In partnership with other agencies, private companies, NASA also intends to establish a permanent base on the ground.
The goal is for the entire structure and experience to also allow manned trips to Mars, initially planned for the late 2030s. Our satellite would serve as a stopover and refueling point on this long journey.
The first time that man was on the Moon was in 1969, in the famous Apollo 11, by Neil Armstrong and Buzz Aldrin. Twelve different people have walked the lunar soil until Apollo 17, the last manned mission, in 1972.