Artemis 2 Live Updates: Countdown to the Moon 🔴

About 25 hours after launch, Orion’s main engine will perform a translunar injection burn to set course toward the Moon. Just before the crew goes to sleep on the fifth day of flight, Orion will enter the lunar sphere of influence. As the force of the Moon’s gravity becomes stronger than Earth’s, the spacecraft will be naturally pulled toward the Moon.

On the sixth day of flight, the lunar flyby will begin. As Orion zooms over the lunar far side, the Artemis 2 astronauts will observe parts of the surface humans have never laid eyes on. The information they gather will greatly enhance lunar science, helping researchers on Earth better understand our closest celestial neighbor.

The next day, Orion will exit the lunar sphere of influence and embark on a free-return trajectory back to Earth. On the tenth day of flight, the crew capsule will separate from the service module and reenter Earth’s atmosphere at 24,700 miles per hour (39,750 kilometers per hour). The capsule will splash down off the coast of San Diego, California, bringing an end to the mission.

At 11:09 a.m. ET, the launch team initiated the liquid hydrogen topping phase for the SLS rocket’s upper stage, or ICPS. This step takes place after chilldown and vent-and-relief checks are complete to ensure the LH2 tank reaches full capacity. With topping complete, the team transitioned to replenish mode at 11:15 a.m.

That cute little plushie Artemis 2 commander Reid Wiseman is holding is actually the fifth member of the crew. Called “Rise,” the toy was designed by Lucas Ye, a second-grader from Mountain View, California. Ye’s design was inspired by the iconic Earthrise photo from the Apollo 8 mission.

Rise will serve as the mission’s zero gravity indicator—a small plush object that rides with a crew to visually indicate when they are in the microgravity environment of space.

The Artemis II zero gravity indicator “Rise” was having a main character moment as the Artemis II astronauts flew to @NASAKennedy today to prepare for launch. pic.twitter.com/VlTx6OhovG

— NASA Artemis (@NASAArtemis) March 27, 2026

At 10:24 a.m. ET, the launch team began liquid hydrogen topping for the SLS rocket’s core stage. This process involves adding small amounts of LH2 to the fuel tanks after fast fill is complete to ensure they remain at full capacity ahead of launch.

That’s because the super-cold propellant naturally boils off, according to NASA. This step will maintain the precise fuel levels needed for launch while keeping the system thermally stable.

At 10:35 a.m., the team entered the “replenish” phase for SLS core stage LH2 tanking. This continuous, low-rate flow of LH2 into the tanks keeps them topped off and thermally stable as the cryogenic propellant boils off. It is the final step in the fueling process.

Spaceflight is hard, and no mission has higher stakes than a crewed deep-space flight. Of course, NASA would not be pursuing a launch attempt today without strong confidence in the mission and crew safety, but no spaceflight is risk-free, and the agency can’t predict every anomaly.

Some of the worst-case scenarios that could arise over the course of Artemis 2 include an orbital injection error, a failed translunar injection, an Orion service module systems failure, a heat shield malfunctions, or a bout of violent solar weather. These issues could prevent the mission from achieving its key objectives, or worse—endanger the crew. You can learn more about the risks associated with Artemis 2 here.

NASA’s super heavy-lift rocket is currently the only launch vehicle capable of sending the agency’s Orion spacecraft, four astronauts, and large cargo to the Moon on a single launch. It’s made up of two main components: a core stage and an upper stage.

The core stage stands more than 212 feet (65 meters) tall and stores 733,000 gallons (2,774,707 liters) of cryogenic propellant to power its four RS-25 engines. At T-0, the core stage’s solid rocket boosters will produce 8.8 million pounds (4 million kilograms) of thrust to blast off.

The upper stage, or interim cryogenic propulsion stage (ICPS), has one Rl10 engine that generates nearly 25,000 pounds (11,000) kilograms of thrust. After launch, this stage will separate from the rest of the rocket with Orion to adjust the spacecraft’s orbit in preparation for translunar injection.

At 9:52 a.m. ET, the launch team transitioned to the fast fill of liquid hydrogen for the SLS rocket’s interim cryogenic propulsion stage (ICPS). With the chilldown phase complete, engineers are rapidly loading super-cold LH2 into the upper stage tanks to ensure they are fully fueled and ready to go for launch.

At 9:36 a.m. ET, the launch team began the liquid hydrogen chilldown for the the SLS rocket’s upper stage, also known as the interim cryogenic propulsion stage (ICPS).

This process gradually cools the ICPS fuel lines and hardware to cryogenic temperatures using super-cold LH2, according to NASA. Like the slow-fill phase earlier this morning, this process is essential to preventing thermal shock and ensuring the stage is properly conditioned for full propellant loading later today.

The ICPS has a critical role to play in Artemis 2. Shortly after launch, Orion and ICPS will separate from the rest of SLS. ICPS will then perform an initial burn to maintain Orion’s trajectory.

About 49 minutes into the flight, the ICPS will fire its engine again to raise the perigee—the lowest point of Orion’s orbit—to an altitude of 100 miles (161 kilometers) above Earth. It will then fire a third time to raise Orion into a high-Earth orbit. This will set the spacecraft up for the translunar injection that will put it on the path to the Moon.

Artemis 2 commander Reid Wiseman, pilot Victor Glover, and mission specialists Christina Koch and Jeremy Hansen officially began their launch day with a scheduled wake-up call at 9:25 a.m. ET.

This is a historic crew. Glover will be the first person of color to visit the lunar environment, Koch the first woman, and Hansen the first Canadian—and first non-American—to make the journey. These firsts signal that NASA has truly entered a new era of human spaceflight—one that is far more diverse than the Apollo era.

At 9:04 a.m. ET, the launch team transitioned to the fast fill of liquid hydrogen into the SLS core stage.

With the slow fill phase complete, this phase will rapidly load cryogenic LH2 into the rocket’s massive tanks, bringing them closer to full capacity, according to NASA. Because the hardware has now been thermally conditioned, teams can safely increase the fueling rate.

Liquid hydrogen is a tricky fuel to work with, which is a large part of why the SLS has experienced so many hydrogen leaks in the past. As the smallest molecule—consisting of two bonded hydrogen atoms—LH2 can escape through minuscule gaps in seals and joints. The extremely cold temperature of the fuel, which is -423 degrees Fahrenheit (-253 degrees Celsius), can also cause these hardware elements to become brittle and crack.

Today is a very exciting day. In a matter of hours, humanity’s decades-long hiatus from crewed lunar spaceflight may finally come to an end. Here’s where Artemis 2 countdown proceedings currently stand.

Artemis Launch Director Charlie Blackwell-Thompson gave the official “go” for tanking at 7:33 a.m. ET. At 8:35 a.m., the launch team initiated the slow fill of liquid hydrogen (LH2) and liquid oxygen (LOX) into the SLS core stage. According to NASA, this phase introduces the super-cold propellants at a controlled rate to allow the rocket’s plumbing and tanks to gradually adjust to cryogenic temperatures. This minimizes stress on hardware and prepares the rocket for faster fueling later today.

Essentially, ground teams are setting the stage for full tanking operations. Tanking will be the most challenging part of today’s launch preparations, and SLS is known to act up during this process. Back in February, hydrogen leaks derailed the first Artemis 2 wet dress rehearsal. Here’s hoping tanking goes smoothly today.