To the moon! NASA launches Artemis 1, the most powerful rocket ever built

The Artemis 1 rocket blasts off from Kennedy Space Center.
The Artemis 1 rocket blasts off from Kennedy Space Center. (Image credit: NASA)

After months of delay, the most powerful space rocket ever built has blasted off from its Florida launchpad, embarking on the first of two test journeys preceding the mission that will return humans to the moon for the first time since 1972.

The $20 billion Artemis 1 rocket — made up of the six-person Orion capsule perched atop the 30-story Space Launch System (SLS) 'mega moon rocket' — fired 8.8 million pounds (3.9 million kilograms) of thrust to lift off at 1:47 a.m. ET Wednesday (Nov. 16) from Launch Pad 39B at NASA's Kennedy Space Center in Florida, embarking on a 30 day, 1.3 million mile (2.1 million kilometers) maiden voyage to the moon and back.

This flight is the first of three missions that will be vital testbeds for the hardware, software and ground systems intended to one day establish a base on the moon and transport the first humans to Mars. This first test flight — part of the Artemis program, named after the twin sister of the ancient Greek god Apollo — will be followed by Artemis 2 and Artemis 3 in 2024 and 2025/2026, respectively. Artemis 2 will make the same journey as Artemis 1, but with a four-person human crew, and Artemis 3 will send the first woman and the first person of color to land on the moon's surface, at the south pole. 

Related: Lightning strikes Artemis I mission's 'Mega Moon rocket' launch pad during tests

"We are going," NASA wrote on Twitter following the launch. "For the first time, the NASA SLS rocket and NASA Orion fly together. Artemis 1 begins a new chapter in human lunar exploration."

Two minutes and 12 seconds after liftoff, Artemis 1's two side-mounted solid rocket boosters separated to splash down in the Atlantic Ocean. Then, roughly six minutes later, the SLS's core engines shut off and the rocket's two stages split, leaving Orion and the SLS upper stage to make a short orbit of Earth, which it followed with a 22-second engine burn to move the rocket farther from our planet. Finally, the upper stage's first burn was followed by an even longer, 18-minute, trans-lunar injection burn that ramped up Orion's speed from 17,500 mph (28,164 km/h) to 22,600 mph (36,371 km/h), launching the capsule away from Earth's gravity and sending it on its journey towards the moon.

This was NASA’s fourth attempt to launch the rocket. The first two attempts were scrubbed because of technical problems, including a hydrogen leak and a suspected faulty temperature sensor inside one of the rocket's core stage engines. The third launch was canceled when Hurricane Ian slammed into Florida in late September, forcing NASA to move the rocket back to the safety of its hangar. This week’s launch was also delayed by two days due to 100 mph (161 km/h) gales from Hurricane Nicole; the rocket remained on the launchpad during the storm and escaped with only superficial damage. 

This morning's launch also had its fair share of technical hitches. A hydrogen fuel line leak and a faulty internet connection that knocked out a key radar system left engineers scrambling to fix the problems before the closing of the two hour launch window, leading to a forty minute delay before the engines were ignited. Thankfully, both problems were minor and promptly fixed, according to NASA.

Orion will make two fly-bys of the moon at an altitude of 62 miles (100 km) above the lunar surface, zipping as far out as 40,000 miles (64,000 km) beyond the moon before returning to Earth

Stowed aboard Orion are three mannequins that NASA will use to test for radiation and heat levels during the flight. A Snoopy soft toy is also along for the ride, floating about the capsule as a zero gravity indicator.

When Orion comes back, it will return hotter and faster than any space vehicle ever has, heating up to 5,000 degrees Fahrenheit (2,800 degrees Celsius) as it enters Earth's atmosphere at 32 times the speed of sound. This will put the capsule's ablative heat shield to the test, which, alongside the craft's parachute, will use air friction to slow Orion down to just 20 mph (32.2 km/h), after which it should plop down safely and ready for retrieval in the Pacific Ocean, off the coast of Baja California, Mexico.

NASA is conducting additional experiments alongside the main mission. The SLS's discarded upper stage is carrying 10 CubeSats (a class of miniature satellites) which will deploy just a few hours after the launch. Of these 10, four are dedicated to studying the moon, including one which will search for water ice on the lunar surface; three will study space weather and the effects of radiation on yeast DNA; two will perform crucial tests of deep-space communication technology and plasma thrusters; and one will unfurl a small solar sail in an attempt to fly by a small near-Earth asteroid

As for the SLS itself, not everything on it is completely new. The rocket's core stage uses four liquid hydrogen and liquid oxygen RS-25 engines from the space shuttle era, and two five-stage solid rocket boosters that are improved versions of NASA's previous space shuttle boosters. 

NASA is banking on a successful mission for Artemis 1, which has come under scrutiny for a price tag that ballooned to eye-watering levels. Having thus far cost more than $40 billion to develop, the program is projected to knock U.S. taxpayers back by $93 billion by the end of 2025, according to the office of NASA Inspector General Paul Martin, the space agency's internal auditor.

"Given our estimate of a $4.1 billion per-launch cost of the SLS/Orion system for at least the first four Artemis missions, NASA must accelerate its efforts to identify ways to make its Artemis-related programs more affordable," Martin said at a March 1 testimony before the House Subcommittee on Space and Aeronautics. "Otherwise, relying on such an expensive single-use, heavy-lift rocket system will, in our judgment, inhibit if not derail NASA's ability to sustain its long-term human exploration goals of the moon and Mars."

However, despite the expense, NASA insists that the program is worth it; saying that the Artemis project not only drives technological innovation but will be a crucial next step in the story of human exploration.

"This time we're going not just to touch down [on the moon] and leave after a few hours or a few days — we're going back to learn, to live, to work, to explore, to determine is there water; therefore on the [moon's] south pole that would mean we have rocket fuel, we have a gas station up there," NASA administrator Bill Nelson told BBC Radio 4. "This time we're going to learn how to live in that hostile environment for long periods of time, all with the purpose that we're going to Mars."

Ben Turner
Staff Writer

Ben Turner is a U.K. based staff writer at Live Science. He covers physics and astronomy, among other topics like tech and climate change. He graduated from University College London with a degree in particle physics before training as a journalist. When he's not writing, Ben enjoys reading literature, playing the guitar and embarrassing himself with chess.