Lightning struck the launch pad home of NASA's giant Artemis 1 moon rocket several times on Saturday (April 2), but the rocket was in good health as technicians worked through a critical test.
Four lightning strikes hit the area around Launch Pad 39B, where NASA's first Space Launch System (SLS) megarocket was undergoing a three-day fueling test known as a "wet dress rehearsal" for its Artemis 1 mission to the moon later this year. The rocket is protected from lightning by three towers and a catenary wire structure to divert strikes to the ground away from the booster.
The first three lightning strikes were relatively low-power events, NASA officials wrote in an update late Saturday. But the fourth strike, which hit "tower one" of the lightning protection system, was more powerful. You can see a clip of the lightning strike from NASA's live video stream of the fueling test.
"1 of the strikes last night was the strongest we have seen since we installed the new lightning protection system," wrote Jeremy Parsons, NASA's deputy manager of the Exploration Ground Systems, who is live tweeting the test for the agency. "It hit the catenary wire that runs between the 3 towers. System performed extremely well & kept SLS and Orion safe. Glad we enhanced protection since Shuttle!"
Parsons said NASA upgraded Pad 39B's lightning protection system to include better shielding against strikes and better separate electrical current from launch hardware. Each of its towers is topped with a fiberglass mast and the catenary wires to divert lightning away from the rocket and its service structure, he added.
"The new system also has an array of sensors, both on the ground and the mobile launcher, will help determine the rocket's condition after a nearby lightning strike, which can prevent days of delays," Parsons wrote in a separate post.
At the time of the lightning strikes on Saturday, the Artemis 1 SLS rocket's core stage and its Orion spacecraft were powered up, but the rocket's side-mounted solid rocket boosters and an interim cryogenic propulsion stage were off, according to a NASA update.
Early Sunday, NASA Artemis 1 launch controllers met to review data from the lightning strikes and the progress of the wet dress rehearsal, ultimately giving the "go" to begin fueling the Space Launch System rocket at 7:20 a.m. EDT (1120 GMT). Just under five hours later, NASA called off the fueling test due to a problem with ground equipment on the rocket's mobile launch platform.
This weekend's wet dress rehearsal test began April 1 and is a full launch countdown practice run for the Artemis 1 mission. During the test, ground crews will fill the core stage with 700,000 gallons of super-cold liquid oxygen and liquid hydrogen propellant.
Artemis 1 is NASA's first SLS mission under the agency's Artemis program to return astronauts to the moon by 2025 or so. The Artemis 1 flight will be an uncrewed trip around the moon to test the Space Launch System and its Orion crew capsule, which is carrying a bevy of experiments and a mannequin covered with sensors.
NASA will provide an update on the results of the Artemis 1 fueling test in a press conference on Monday (April 4) at 11 a.m. EDT (1500 GMT).