At Cape Canaveral, Florida, the four astronauts assigned to the Artemis II mission have settled into the Orion capsule, poised to embark on humanity’s first lunar journey in over 50 years. Their mission is scheduled for an evening launch.

Stay tuned to ABC News for live coverage of the Artemis II launch.

On Wednesday morning, NASA’s launch team successfully filled the towering 32-story Space Launch System rocket with over 700,000 gallons of fuel. This crucial step prepares the mission for a potential liftoff during a two-hour window starting at 6:24 p.m. EDT at the Kennedy Space Center in Florida.

The crew members, Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen, will be on board for this historic flight. Their path will take them several thousand miles past the moon before making a quick turn back to Earth. This mission is not designed for lunar orbit or moonwalks; instead, it’s a swift round trip lasting under 10 days. NASA anticipates further lunar exploration but plans to conduct a few practice missions first.

Setting Artemis apart from the Apollo missions, which ran from 1968 to 1972, this mission’s crew includes a woman, a person of color, and a Canadian, marking a significant milestone in space exploration diversity.

Artemis II is the opening shot of NASA’s grand plans for a permanent moon base. The space program is aiming for a moon landing near the lunar south pole in 2028.

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What is a countdown hold?

Holds or pauses are built into the countdown ahead of time to provide a buffer to the schedule.

NASA can extend these holds if a problem is detected. This gives the launch team time to investigate the issue and resume counting if it can be fixed in time. NASA can also call an unplanned hold if necessary.

The first planned was set at the 12-hour, 35-minute mark – before fueling – and lasted for two hours and 45 minutes.

The second planned hold occurs at the 40-minute mark and lasts 30 minutes. It’s during this hold that the launch director polls the team to determine whether everyone is “go” or to proceed.

A battery issue crops up

With 52 minutes remaining in the countdown, NASA’s Derrol Nail reported that one of two batteries in the abort system is not displaying the proper temperature.

The launch team is scrambling to determine whether a sensor is at fault or whether the battery itself is faulty. NASA cannot proceed past the six-minute mark unless confident in the batteries’ operation.

How Artemis II astronauts will return to Earth

Like with Apollo, the mission will end with a splashdown homecoming into the Pacific.

Navy recovery ships will be stationed off the coast of San Diego as Orion parachutes into the ocean.

How do Artemis II astronauts get medical care in space?

There’s a medical kit aboard Orion containing basic first-aid items, common medications like antibiotics, and medical devices such as a blood pressure monitor and thermometer.

Astronauts can also have private medical consultations with flight surgeons on the ground via video, similar to a telehealth visit on Earth.

Ahead of launch, the crew was in quarantine to avoid falling ill.

Artemis program started under President Donald Trump’s first term

“President Trump is excited about the next phase with the historic upcoming Artemis II launch,” said White House spokesperson Liz Huston. “This effort will strengthen American leadership in space, usher in scientific discoveries, and serve as the proving ground for missions to Mars.”

Trump is expected to monitor Wednesday’s launch from the White House.

Technical issue resolved

An unspecified issue with the rocket’s flight-termination system, which would send a self-destruct signal to the rocket in case it veered off course and was aiming for a populated area, has been resolved, NASA said.

Spectators cheered when NASA made its announcement.

NASA is probing a technical issue

There is an unspecified issue with the rocket’s flight-termination system, which would send a self-destruct signal to the rocket in case it veered off course and was aiming for a populated area.

“Pretty unique situation here,” NASA commentator Derrol Nail explained.

One of the launch controllers has been called into service to dash over to the adjoining Vehicle Assembly Building to grab space shuttle-era equipment, he said. He stressed that it is not a problem with the rocket itself.

“At this moment the range is no-go, but that is not stopping us from moving forward in the countdown,” Nail reported.

What’s on the menu to the moon?

Forget about puree squeezed from toothpaste-style tubes.

Modern space food is more appetizing and nutritious than the meals that flew to space in the 1960s – though options are still limited.

During the Artemis II mission, astronauts can feast on mac and cheese, tortillas and vegetable quiche. Drinks include coffee, green tea and lemonade, among other beverages.

Astronauts use water to rehydrate their meals and a food warmer to heat up their food. Menus are designed to minimize crumbs, which can pose a danger if they clog spacecraft equipment or get into astronauts’ eyes.

Fresh food isn’t an option since the Orion capsule lacks refrigeration.

NASA’s lunar road map after Artemis II

The space agency recently rejiggered its Artemis moon exploration program, modeling it after fast-paced Apollo, which launched moonshots in quick succession in the 1960s and 1970s.

1. Artemis II involves a lunar fly-around by four astronauts.

2. Artemis III focuses on launching a lunar lander into orbit around Earth in 2027 for docking practice by astronauts flying in an Orion capsule.

3. Artemis IV aims to land astronauts on the moon in 2028.

Last month NASA’s new administrator Jared Isaacman laid out a blueprint for a moon base that, along with lunar drones and rovers, is expected to cost $20 billion over the next seven years.

What happens if there’s a solar storm during the moon journey?

Space weather forecasters plan to closely track the sun as the Artemis II crew heads to the moon and back.

In recent months, huge eruptions on the sun’s surface have triggered solar storms that spawned colorful auroras in unexpected places on Earth.

Artemis II astronauts will wear personal dosimeters to monitor radiation levels. If there’s a sudden spike, astronauts can reconfigure the cabin into a shelter by putting barriers to shield themselves from incoming radiation.

Trump sends best wishes to Artemis II crew

President Donald Trump wished them well via social media ahead of the planned launch: “God bless our incredible Astronauts, God bless NASA and God bless the Greatest Nation ever to exist.”

Canadian Space Agency president praises Canadian Hansen

Speaking of Artemis II astronaut – and first-time space flier – Jeremy Hansen, Canadian Space Agency President Lisa Campbell told NASA on Wednesday, “We’re very proud. He’s so ready. He’s been waiting for this his whole life, preparing, training, and he’s a wonderful example of Canada.”

The Apollo generation, in their own words

Charlie Mars, 90, who worked on Apollo’s command and lunar modules: “Because it was the first time, there was an energy. There was a passion that probably is not exactly the same today and hasn’t been for a while.”

JoAnn Morgan, 85, who was the lone female engineer inside launch control during the Apollo 11 landing:

“It will be even greater when they actually have a woman who plants her boots on the moon.”

Charlie Duke, 90, Apollo 16 moonwalker: “If the first ones are successful and we start landing at the south pole, I think millions are going to be watching that. I know I will if I’m still here.”

How space toilets work

Everyone needs to go – even in space.

There were no bathrooms on the Apollo missions. Astronauts urinated into bags and diapers.

A primitive potty was aboard the U.S. space station, Skylab, in the 1970s. The International Space Station now features three bathrooms as the orbiting complex expanded.

The Orion capsule is equipped with a compact lunar loo that was tested on the space station several years ago.

Known as the universal waste management system, the titanium toilet uses air suction instead of water and gravity to remove waste, similar to earlier space commodes. It’s also designed to better accommodate female astronauts.

The system collects urine and solid waste separately – No. 1 is vented into space and No. 2 is stowed for the return trip.

8-year-old designer of ‘Rise’ toy on hand

Lucas Ye’s design for a zero gravity indicator was picked from more than 2,600 submissions to fly to the moon. It also won him a trip to watch the Artemis II launch from Kennedy Space Center.

The 8-year-old from California designed a plush toy called “Rise,” inspired by the iconic Earthrise” photo taken during Apollo 8.

Interviewed by NASA, he said he was, “Really, really, really, really, really, really, really surprised and very happy” to win and be here.

How Artemis II astronauts will stay fit in microgravity

To prevent bone and muscle loss in space, astronauts will keep in shape using a device that acts like a yo-yo.

They can do exercises such as rowing, squats and dead lifts.

Each astronaut will spend about a half hour a day exercising on the device, developed by the Canadian Space Agency.

Astronauts are in the capsule

The four Artemis astronauts have entered the Orion capsule and are in place for humanity’s first trip to the moon in 53 years.

After they arrived at the launch pad, they rode an elevator up to the capsule and signed their names to the so-called white room, where they stage for boarding.

They donned their helmets, made some final adjustments to the suits, and climbed into the capsule. If they take off as planned, they will remain in the capsule – with about as much room as a small camper van – for the next 10 days.

NASA’s liftoff lingo, defined

Watching a rocket launch can be confusing if you’re unfamiliar with the jargon, or specialized language, used by NASA.

Here’s a guide to some key terms:

4. LH2: liquid hydrogen

5. LOX: liquid oxygen

6. Go/no-go: Status check on whether to proceed.

7. Nominal: Everything is going as planned.

8. LAS: The launch abort system is the tower atop the Orion capsule designed to carry the crew to safety during an emergency.

9. Hold: A pause in the countdown clock.

10. Scrub: The launch attempt is canceled for the day. Reasons can include bad weather, technical problems or safety concerns.

Even moon launches are powered by pizza

NASA chief Jared Isaacman has had pizza delivered to the launch team in Cape Canaveral. It’s lunchtime for the team as the opening of the launch window at 6:24 p.m. EDT approaches.

What is the launch abort system on Orion?
It’s an escape system designed to ferry Artemis II astronauts to safety if there’s an emergency on the pad or during initial ascent.

A tower structure mounted on top of Orion can be activated to quickly rip the capsule and astronauts away from the SLS rocket and release it for a parachute splashdown in the ocean, according to Lockheed Martin.

Meet the Artemis II astronauts: Jeremy Hansen

The Canadian fighter pilot and physicist is making his space debut and serving as his country’s first emissary to the moon.

“Maybe I’m naive, but I don’t feel a lot of personal pressure.”

Hansen, 50, grew up on a farm near London, Ontario, before moving to Ingersoll and pursuing a flying career.

He realizes only now how much effort it took to send men to the moon during Apollo.

“When I walk out and I look at the moon now, it looks and feels a little bit farther than it used to be,” he said.

Dangers still loom – something he’s shared with his college-aged son and twin daughters. “The most likely outcome is that we will come back safe. There’s a chance we won’t, and you will be able to move through life even if that happens,” he assured them.

Moon rockets: Space Launch System vs. Saturn V

The SLS rocket stands 322 feet (98 meters), shorter than the Apollo program’s Saturn V rocket. But it’s but more powerful at liftoff thanks to a pair of strap-on boosters.

Atop the rocket is the Orion capsule carrying the Artemis II crew.

The solid rocket boosters are bigger versions of the rocket motors on the space shuttles that carried up most of the parts of the International Space Station, as well as the astronaut construction crews.

The SLS uses the same fuel – liquid hydrogen – as the shuttle did.

Hydrogen leaks repeatedly grounded the shuttles as well as the SLS during testing in 2022 and again earlier this year, bumping Artemis II into April.

Meet the Artemis II astronauts: Christina Koch

The last time Koch blasted into space, she was gone almost a year so she’s not sweating a quick trip to the moon and back.

The 47-year-old electrical engineer from Jacksonville, North Carolina, holds the record for the longest single spaceflight by a woman – 328 days. She took part in the first all-female spacewalk during her lengthy stay at the space station in 2019.

Before she got called up by NASA, Koch spent a year at a South Pole research station. Between that and her space stint, she feels she’s “inoculated” most of her family and friends.

“So far, I haven’t gotten too many nerves from folks. Maybe my dog, but I’ve reassured her that it’s only 10 days. It’s not going to be as long as last time.”

Her and her husband’s rescue pooch is named Sadie Lou.

Meet the Artemis II astronauts: Victor Glover

As one of NASA’s few Black astronauts, Glover sees his presence on the mission as “a force for good.”

The 49-year-old Navy captain and former combat pilot from Pomona, California, makes it a habit to listen to Gil Scott-Heron’s “Whitey on the Moon” and Marvin Gaye’s “Make Me Wanna Holler” from the white-dominated Apollo era.

“I listen to those for perspective,” he said. “It captures what we did well, what we did poorly.”

The ability for him now to offer hope to others is “an amazing blessing and a privilege.”

He’s hyper-focused on running “our best race so that we can hand the baton off to the next leg” – a 2027 practice docking mission in orbit around Earth between an Orion crew capsule and one or two lunar landers.

Astronauts head to the launch pad

Wiseman, Glover, Koch and Hansen have left the Neil Armstrong Operations and Checkout Building and are on their way to launch pad 39B.

Waving to family, colleagues and news photographers, the crew boarded the so-called astrovan for the 9-mile ride to the launch pad and their awaiting SLS rocket.

Wait what? What’s the deal with the cards?

Before their highly anticipated walkout, commander Reid Wiseman and his crew played a quick card game with NASA’s chief astronaut Scott Tingle. It’s a preflight tradition since the space shuttle era.

Losing is good: It means the astronaut has gotten rid of all bad luck before launching.

The four thanked the suit techs and posed for photos, keeping a safe distance from many of the bystanders to avoid germs. They then went down the elevator at the Neil Armstrong Operations & Checkout Building and walk out to a barrage of cameras and cheers.

They’ll take a custom-designed astrovan for the ride to the launch pad

House Speaker shares prayer for Artemis’ ‘courageous pioneers’

House Speaker Mike Johnson posted on the social media site X ahead of the planned Artemis II launch.

“Praying for the safety and success of the Artemis II crew and @NASA as they undertake a mission that will carry humanity farther into space than we have gone in over half a century. I had the privilege of hosting these courageous pioneers at the State of the Union earlier this year. Americans are watching proudly as our Golden Age reaches new heights!” Johnson wrote.

Meet the Artemis II astronauts: Reid Wiseman

Wiseman, 50, a retired Navy captain from Baltimore, was serving as NASA’s chief astronaut when asked three years ago to lead humanity’s first lunar trip since 1972.

His wife Carroll’s death from cancer in 2020 gave him pause.

His two teenage daughters, especially the older one, had “zero interest” in him launching again after a 2014 trip to the International Space Station.

“We talked about it and I said, ‘Look, of all the people on planet Earth right now, there are four people that are in a position to go fly around the moon,” he said. “I cannot say no to that opportunity.”

The next day, homemade moon cupcakes awaited him, along with his daughters’ support.

Who are Apollo and Artemis?

Artemis is the twin sister of Apollo in Greek mythology. They are the children of Zeus and Leto. Artemis has long been associated with the moon.

While the Artemis name builds on the Apollo program and pays homage to it, “there is no way we could be that same mission or ever hope to even be,” said NASA astronaut Christina Koch, part of the Artemis II crew.

The Apollo program was all about beating the Russians to the moon and planting the U.S. flag. NASA sent 24 astronauts to the moon between 1968 and 1972, including 12 moonwalkers. Now China is the competition.

NASA is striving for a long-term lunar presence under Artemis, with Mars to follow.

The astronauts are fitted out

The Artemis II astronauts are now in their orange Orion spacesuits that they will wear for launch and reentry. Testing these new suits is one of the main goals of the mission.

The four are expected to emerge for their trip to the pad sometime before 2 p.m.

NASA created bright orange custom spacesuits for launch and reentry. Astronauts will also use them in case of a depressurization or some other emergency.

They can survive up to six days in the suits, inserting a straw into the helmet to sip water or protein shakes and relying on undergarment bags and bladders as a built-in toilet.

Future Artemis crews to the lunar surface will wear white moonwalking suits designed by Axiom Space.

During the Apollo era, astronauts wore the same white bulky spacesuits for launch and return as well as for moonwalks because there wasn’t enough storage on board for different outfits.

An Apollo engineer reflects on moon return

“We should have done Artemis 50 years ago,” said John Tribe, a propulsion engineer during the Apollo era.

The moon rocket is fueled up
The launch team has loaded more than 700,000 gallons of fuel into the 32-story Space Launch System rocket, setting the stage for the Artemis II crew to board.

Rain is coming but it’s not a threat

The wind is picking up at Cape Canaveral, more clouds are appearing and rain is expected in about two hours. But there is no lightning threat, NASA says, and there’s still an 80% chance the weather will be good enough to launch.

What’s the difference between L-minus and T-minus?
L-minus tracks the overall time to liftoff, counting down the days, hours and minutes away before the planned blastoff. It doesn’t include built-in holds, or pauses – that’s T-minus time.

The T-minus countdown in the final 10 minutes is where nerves tense up and hearts start pounding. Automated software kicks off a series of highly choreographed milestones. During this period, the clock can be stopped if a problem is spotted and restarted if it’s fixed in time.

T-0 is the moment of liftoff – zero – when the boosters ignite and the rocket begins its journey.

How launch windows work

NASA has a narrow time frame each month to fly to the moon.

The Earth and moon must be aligned just so to achieve the proper trajectory for the mission. In any given month, there’s only about a week when Artemis II astronauts can lift off.

The Orion capsule needs to get a check of its life-support and other systems in near-Earth orbit. If that goes well, Orion will fire its main engine to hurtle toward the moon, taking advantage of the moon and Earth’s gravity to get there and back in a slingshot maneuver that requires little if any fuel.

Orion also needs sunlight for power and can’t be in darkness for more than 90 minutes at a time. Plus NASA wants to minimize heating during reentry at flight’s end.

The latest launch window runs through April 6. The next opportunity opens on April 30.

Hydrogen is on board

The hydrogen tank of the rocket’s core stage is 100% filled. NASA said no significant leaks have been observed so far in fueling. It was hydrogen leaks that prevented the rocket from flying in February.

Time to wake up and go to the moon

The alarm clocks just went off in Kennedy Space Center’s crew quarters.

That means it’s rise and shine for the three Americans and one Canadian who are about to become the first lunar visitors in more than 53 years.

They have a long day ahead of them, whether they launch or not.

After breakfast, they’ll start suiting up. NASA’s launch window opens at 6:24 p.m. and lasts a full two hours.

NASA controllers wear green for go

Launch director Charlie Blackwell-Thompson is wearing green as are many of the controllers alongside her in the firing room.

Green represents “go” for NASA, a color symbolizing good luck.

The team is monitoring the fueling of the 322-foot moon rocket, set to blast off Wednesday evening.

Moon mascot, unveiled

A plush toy named Rise will ride with the Artemis II astronauts around the moon, carrying the names of more than 5.6 million people.

Rise is what’s known as a zero gravity indicator, which gives the astronauts a visual cue of when they reach space.

The design was inspired by the iconic “Earthrise” photo during Apollo 8, showing the planet as a shadowed blue marble from space in 1968.

Rise was selected from more than 2,600 contest submissions. It was designed by Lucas Ye of California.

Commander Reid Wiseman and his crew tucked a small memory card into Rise before the toy was loaded into the Orion capsule. The card bears the names of all those who signed up with NASA to vicariously tag along on the nearly 10-day journey.

“Zipping that little pocket on the bottom of Rise was kind of the moment that put it all together for me,” Wiseman said. “We are going for all and by all. It’s time to fly.”

Rocket fueling is underway for NASA’s Artemis II moon launch

NASA is fueling the new rocket that will send four astronauts to the moon.

Launch teams have begun pumping more than 700,000 gallons (2.6 million liters) of liquid hydrogen and liquid oxygen into the Space Launch System rocket at Kennedy Space Center in Florida.

It’s the latest milestone in the two-day countdown that kicked off on Monday when launch controllers reported to duty.

It will take at least four hours to fully load the rocket before astronauts climb aboard for humanity’s first flight to the moon since Apollo 17 in 1972.

The two-hour launch window opens at 6:24 p.m. EDT.

The Artemis II crew is historic for NASA’s moon missions

The Americans who blazed the trail to the moon more than half a century ago were white men chosen for their military test pilot experience.

The Artemis II crew includes a woman, a person of color and a Canadian, products of a more diversified astronaut corps.