NASA’s new megarocket was scheduled to lift off from Florida on Tuesday night for the Artemis 1 mission, a high-stakes event for the space agency, which has struggled for years to launch its flagship lunar return program, AFP reported.

The first flight of the SLS rocket, the world’s most powerful rocket, is scheduled for Wednesday at 1:04 a.m. local time (06:04 GMT), a launch window that could last as long as two hours.

Chances for weather are good, although on Tuesday they dropped slightly from 90% to 80%.

As expected, Charlie Blackwell-Thompson, NASA’s first female launch director, gave the go-ahead Tuesday afternoon for complex refueling operations at the Kennedy Space Center.

2.7 million liters of oxygen and liquid hydrogen will be needed.

Fifty years after the last Apollo mission, this unmanned test flight to fly around the moon without landing should prove the vehicle is safe for future crew.

The same rocket would eventually put the first woman and the first black man on the moon as part of the larger Artemis program.

Despite the night launch on Wednesday, around 100,000 people are expected to watch the show, mostly from the nearby beaches.

“I was too young for the Apollo missions, so I wanted to come and see the next moon launch for myself,” Andrew Trombley, 49, of Cocoa Beach, told AFP.

An engineer had already come from Missouri for the first two attempts. “I can’t wait for her to go,” he said, wearing a Star Wars T-shirt.

“It’s part of America, it’s what America is,” said 59-year-old Florida resident Kerry Warner.

• Why is NASA trying to launch the SLS rocket a colossal waste of money or an audacious space program with which we should be patient?

Delayed releases / 5 years of delays and billions in costs

November 14 was originally scheduled, but Hurricane Nicole made it impossible.

NASA also has two backup dates: November 19 and 25.

Previously scheduled releases in late August and early September were canceled at the last minute due to technical issues.

• ​The Space Launch System: Anatomy of the Rocket That Gets Us Back to the Moon

Then, in late September, the SLS rocket, the most powerful rocket ever built by the US space agency, was returned to a hangar at the Kennedy Space Center to protect it from Hurricane Ian, which devastated parts of Florida.

NASA has reiterated that it will not rush or take risks until everything is in order. The mission is 5 years late and costs several billion dollars.