NASA aborted a practice countdown for its new mega rocket, the Space Launch System, on Sunday morning. Returning astronauts to the moon is a key component of upcoming missions, and the agency said there was a problem with the mobile launch tower.
NASA will try again on Monday.
The 322-foot rocket and its Orion capsule are critical components for Artemis, NASA’s lunar landing program. The system, which can get astronauts into lunar orbit but relies on other components to land them on the lunar surface, is billions of dollars over budget and years behind schedule.
The weekend’s exercise, which NASA is calling a wet dress rehearsal, is the final major test before the rocket launch on its first unmanned test flight, which could take place as early as this summer. By simulating a countdown without the excitement of engines firing and a rocket rising into space, NASA hoped to fix glitches with equipment and procedures.
The rehearsal, which began Friday night, was “wet” because it was supposed to involve pumping more than 700,000 gallons of liquid oxygen and liquid hydrogen into the massive rocket’s fuel tanks.
Heavy thunderstorms swept across the launch site on Saturday afternoon four lightning strikes Protective towers around rocket and launcher. Preparatory work on the launch vehicle had to be halted during the storm, but after reviewing the data, NASA said no damage had occurred and the countdown could continue.
On Sunday, the dress rehearsal was more than three hours behind schedule. Then the stop came just before the fuels were supposed to start flowing. NASA said the problem was found in the mobile launch vehicle, or moving turret, with numerous systems used to control the rocket on the ground before it lifts off. Fans that create positive air pressure in closed areas of the mobile launcher were not working. The positive pressure is needed to prevent the build up of hazardous gases, including those that could potentially ignite.
The fan has been running since the mobile launch vehicle was brought to the launch site last month and continued to run during Saturday’s thunderstorm, Charlie Blackwell-Thompson, the launch director, said during a news conference Sunday night.
To load propellants, the fan is switched to another mode where it can inject more air. The fan ran in this mode for several hours before the problem started.
“We don’t think it’s related to the lightning,” Ms Blackwell-Thompson said.
Then a backup fan also failed, apparently for some other reason, causing the countdown to stop.
“We decided we really wanted to understand that as it was the first time the vehicle had been loaded,” said Ms. Blackwell-Thompson. “And we make the decision to stay downstairs.”
On Monday, fuel loading is scheduled to begin at 7 a.m. Eastern Time and the exercise is scheduled to end in the afternoon. If the dress rehearsal continues to falter, another attempt may be possible on Tuesday.
The first test flight of the Artemis 1 space launch system could take place this summer when the Orion capsule flies around the moon and back to Earth with astronauts on board. The second Artemis flight, scheduled for 2024, would have astronauts on board for the same journey. Artemis 3 is said to be the first moon landing by astronauts since 1972. NASA has proposed a date for this manned voyage in 2025, but further postponements could be forthcoming.