Lightning struck the launch pad of NASA’s giant Artemis 1 moon rocket several times on Saturday (April 2), but the rocket was in good condition when technicians conducted a critical test.
Four lightning strikes struck the area around Launch Pad 39B, where NASA’s Space Launch System (SLS) first megarocket was undergoing a three-day refueling test known as the “wet dress rehearsal” for its Artemis 1 mission to the Moon later this year. The rocket is protected from lightning by three turrets and a catenary structure to deflect blows from the booster to the ground.
The first three lightning strikes were relatively low-power events, NASA officials wrote in an update late Saturday. But the fourth blow, which hit “tower one” of the lightning protection system, was more violent. You can see a clip of the lightning strike from NASA’s live video stream from the refueling test.
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“One of the strikes last night was the strongest we have seen since the new lightning protection system was installed,” wrote Jeremy Parsons, NASA Assistant Manager of Exploration Ground Systems, live-tweeting the test for the agency. “It hit the catenary wire that runs between the 3 towers. The system worked extremely well and kept SLS and Orion safe. I’m glad we’ve improved protection since Shuttle!”
Parsons said NASA improved Pad 39B’s lightning protection system to provide better shielding against strikes and better isolation of electrical current from the launch hardware. Each of its towers is topped with a fiberglass mast and the overhead wires to deflect lightning away from the missile and its service structure. he added.
“The new system also features a suite of sensors, both on the ground and in the mobile launch vehicle, that will help determine the condition of the rocket after a nearby lightning strike, which can prevent delays lasting days,” Parsons wrote in a separate post.
At the time of Saturday’s lightning strikes, the core stage of the Artemis-1 SLS rocket and its Orion spacecraft were powered on, but side-mounted solid rocket boosters and an interim cryogenic propulsion stage were powered down, according to a NASA update.
Early Sunday, NASA’s Artemis 1 launch controllers met to review lightning strike data and wet rehearsal progress, finally giving the go-ahead at 7:20 a.m. EDT (1120 GMT) to begin refueling the Space Start Launch System rocket. Just under five hours later, NASA canceled the refueling test due to a problem with the ground equipment on the rocket’s mobile launch pad.
This weekend’s wet dress rehearsal test began on April 1st and is a full launch countdown practice run for the Artemis 1 mission. During testing, ground crews fill the core stage with 700,000 gallons of super-cold liquid oxygen and liquid hydrogen fuel.
Artemis 1 is NASA’s first SLS mission under the agency’s Artemis program to return astronauts to the moon by around 2025. The Artemis-1 flight will be an unmanned trip around the moon to test the space launch system and its Orion crew capsule, carrying a plethora of experiments and a sensor-covered mannequin.
NASA will announce the results of the Artemis 1 refueling test in a press conference on Monday (April 4) at 11 a.m. EDT (1500 GMT).