NASA has had to scrub the wet dress rehearsal of its mega moon rocket, the Space Launch System (SLS). The test, which had been planned to run this weekend and involves filling the rocket with fuel and counting down as if for a launch, was called off on Sunday, April 3.
“Teams have decided to scrub tanking operations for the wet dress rehearsal due to loss of ability to pressurize the mobile launcher,” NASA wrote in a brief update. “The fans are needed to provide positive pressure to the enclosed areas within the mobile launcher and keep out hazardous gases. Technicians are unable to safely proceed with loading the propellants into the rocket’s core stage and interim cryogenic propulsion stage without this capability.”
Engineers have investigated the problem and determined that the fan problem is the only issue, according to space.com. Everything else is checking out as expected, so the team will move quickly to fuel the rocket once again tomorrow, Monday, April 4.
The test this weekend had been already running behind schedule due to delays caused by the weather. Earlier in the day, NASA announced that there had been four lightning strikes that hit the launch pad’s lighting towers. The agency confirmed that “the first three were low-intensity strikes to tower two and are continuing to review data from the fourth strike, which was higher in intensity to tower one.” Both the SLS rocket core stage and the Orion spacecraft were powered up at the time, but there was no concern about damage to these, and the lightning towers are designed to channel away lightning strikes in just this situation. The fan issue is not thought to be related to the lightning strikes.