NASA Fuels Artemis 2 Moon Rocket for First Crewed Lunar Flight Since 1972

NASA is preparing to launch Artemis 2, its first astronaut mission to the moon since 1972, with liftoff set for no earlier than April 1. The Artemis 2 Space Launch System rocket first stage is now fully fueled with the liquid hydrogen and liquid oxygen needed for launch today, and the upper stage is fueled with liquid hydrogen, with liquid oxygen loading about 30% complete and rising.

Liftoff remains on track for 6:24 p.m. EDT (2224 GMT). The fueling process, which NASA calls tanking, is continuing with the liquid oxygen needed for liftoff. The core stage of the Space Launch System rocket is nearly fully loaded, while liquid oxygen has not yet been loaded onto the upper stage, called the interim cryogenic propulsion stage, or ICPS for short.

NASA teams have completed the fast fill of the upper stage liquid hydrogen tank on the SLS rocket. Liquid oxygen fast fill continues on the upper stage. On the rocket's core stage, both the liquid oxygen and liquid hydrogen tanks are in replenish mode. Replenish keeps the tank at flight-ready levels by replacing any liquid hydrogen lost to boil-off.

NASA teams have transitioned all cryogenic tanks on the SLS rocket to replenish mode. This includes both liquid hydrogen and liquid oxygen tanks for the core stage and the interim cryogenic propulsion stage. Cryogenic propellants naturally warm and evaporate over time, even in insulated tanks. Replenish counteracts this by continuously adding small amounts of liquid hydrogen and liquid oxygen to maintain proper levels and pressure.

NASA's SLS moon rocket is a towering rocket, the space agency's largest since the Saturn V moon rocket of the Apollo program. It stands 322 feet tall, reaches higher than the Statue of Liberty, and requires 750,000 gallons of propellant to fly. The rocket's core stage will be loaded with more than 700,000 gallons of liquid oxygen and liquid hydrogen during the tanking phase of the countdown.

Artemis 2 will launch four astronauts on a 10-day voyage around the moon. The first phase of the mission will see the crew's Orion spacecraft enter Earth orbit. Once there, Orion will separate from the Space Launch System rocket's upper stage before performing a series of maneuvers in close proximity to the ICPS. These are designed to test Orion's ability to fly close to other spacecraft and hardware such as lunar landers, as future crews will have to do on later Artemis program missions.

From there, Orion will perform a series of engine burns that will place it on a trajectory that loops around the moon, using gravity to send the capsule heading back to Earth. Orion will send the four Artemis 2 astronauts farther from Earth than any humans have ever flown before. On the mission's sixth day, the crew will fly around the far side of the moon at an altitude of 4,000-6,000 miles above the lunar surface.

On day 10, Orion will reenter Earth's atmosphere traveling at about 25,000 miles per hour. The four astronauts will splash down under parachutes in the Pacific Ocean off the coast of San Francisco, where a U.S. Navy ship will recover them.

Key Artemis 2 launch countdown events remaining include the crew weather briefing at T-6 hours, the closeout crew assembling at the pad, the Artemis 2 crew heading to the launch pad at T-4 hours 10 minutes, crew boarding Orion at T-4 hours, crew module hatch closure at T-3 hours 10 minutes, and launch director polling for "go" for launch at T-17 minutes before booster ignition, umbilical separation, and liftoff.