Artemis 1: Going back to the moon – Space.com

The Artemis 1 mission will soon let human voice bellow from the lunar surface.

2022 marks half a century since the Apollo astronaut Eugene Cernan left the last footprints on the moon in 1972 and a lot has changed since then.

That year the first scientific hand-held calculator was released; today we carry more computing power in our pocket than that which safely guided the Apollo astronauts to the moon and back.

Related: Every mission to the moon

Now, at long last, humanity is about to leave Low Earth Orbit (LEO) again. Only two dozen astronauts have achieved that feat so far, all of them white men. Soon the first female astronaut and astronaut of color will join the lauded lists of moonwalkers. It's all thanks to the Artemis program NASA's plan to explore more of the lunar surface than ever before.By 2025 we could see astronauts walk in the lunar dust once more, with the upgrade from grainy black and white video footage that half a century of technological progress will bring. A whole new generation could see themselves as budding space travelers, inspired to dream big.

But pulling this off requires an entirely new launch system and a bit of practice first.

March 2022 will see the launch of Artemis 1 an uncrewed test flight. It will be the maiden use of NASA'sSpace Launch System(SLS). It's a rocket that will send the new Orion Multi-Purpose Crew Vehicle(MPCV) on a 236,000-mile-long (380,000-kilometre-long) journey to the moon. If all goes to plan then it will be followed by a crewed mission Artemis 2 in 2024. It will test everything out in Earth orbit, then it's full steam ahead for the history-making Artemis-3 crew to land on the lunar south pole and spend a week there in 2025.

Even without a crew, Artemis 1 will be a record-breaker. According to NASA, "Orion will stay in space longer than any ship for astronauts has done without docking to a space station and return home faster and hotter than ever before." But first it has to leave the Earth.

Two huge boosters and a core stage filled with 733,000 gallons (3,332 liters) of propellant will power the rocket through Earth's atmosphere. Once in space, the boosters will be jettisoned and the core stage will separate from the Orion spacecraft atop it. Orion will then orbit the planet while it deploys its solar panels. Finally, the Interim Cryogenic Propulsion Stage (ICPS) will fire to eject Orion from orbit and send it on its way towards the moon.

Stacking the rocket

Before it can launch, the parts of the rocket and spacecraft are joined together.

Once the ICPS has been discarded it has another job: to deploy a series of tiny satellites that have hitch-hiked along for the ride. They include BioSentinel, a mission that will carry yeast samples beyond LEO. The idea is to study radiation levels and their effect on living organisms, which will provide key insights in keeping astronauts safe when they fly on Artemis 3.

After separation with the ICPS, Orion will be propelled and powered by the European Service Module built by the European Space Agency. "The Service Module will also provide consumables for future crew, including water and oxygen," says Phillippe Berthe, ESA's Project Coordination Manager for the module.

Artemis 1 may not have a human crew on board, but the Commander's seat will be occupied by a mannequin dressed in the Orion Crew Survival System a special suit designed to help protect against radiation. Two radiation sensors will monitor radiation levels.

The mannequin will be strapped in, but the weightless environment also needs testing. So NASA is flying a "zero gravity indicator" in the form of a Snoopy cuddly toy dressed in an iconic orange NASA jumpsuit. The comic strip character has a long association with lunar exploration the crew of Apollo 10 used it as nickname for their lunar module.

So how does the new Service Module compare to the lunar modules that sent Apollo astronauts to the moon? "The propulsion is largely the same, it is very comparable to the Apollo era," says Berthe. Yet half a century of technological progress has brought other strides forward. There have been vast improvements in solar cells, Berthe says. So that's where the spacecraft will derive most of its power.

"Computing power is another major improvement," says Berthe. The Apollo astronauts famously flew to the moon with less computing power than found in an iPhone. That meant a lot of manual tasks for the crew. This time around, the spacecraft's powerful computers can do most of the heavy lifting. "We can program much more complex operations now. The crew don't need to intervene directly in every nitty-gritty detail," Berthe says.

Artemis 1 will be gone for between 26 and 42 days. It'll take 1-2 weeks to get to the moon, where it will swoop down close to the lunar surface and use the gravitational kick it receives to enter a so-called "distant retrograde orbit". Retrograde means that it will orbit the moon in the opposite direction to that in which the moon spins. It will stay in that orbit for between 6 and 19 days. Then it will swing back down towards the moon for another kick to help power its 9 to 19 day journey back to the Earth.

Artemis 1 will be gone for between 26 and 42 days. It'll take 1-2 weeks to get to the moon, where it will swoop down close to the lunar surface and use the gravitational kick it receives to enter a so-called "distant retrograde orbit". Retrograde means that it will orbit the Moon in the opposite direction to that in which the moon spins. It will stay in that orbit for between 6 and 19 days. Then it will swing back down towards the Moon for another kick to help power its 9 to 19 day journey back to the Earth.

This project has been a labor of love for Berthe, who has been involved with it for nearly two decades and has seen many obstacles come and go. "One of the biggest challenges has been maintaining support across four administrations," he says. Presidents Bush, Obama, Trump and Biden have all wanted to put their spin on it and whether they wanted to go to the moon or Mars. The timeline has also moved around, from a landing in 2028, then 2024 and now 2025. "The mission has changed a lot of times," Berthe says.

On top of the politics came the coronavirus pandemic, although Berthe says it didn't have as big an impact as he feared. "It was difficult for people to cross international borders," he says. For a huge multi-agency project like this that somewhat slowed us down.

There are also plenty of nay-sayers those who argue that sending humans back to the moon is a waste of time, money and resources. We've already done it, why go back? Especially as we've already sent an armada of robotic spacecraft to both scan the moon from orbit and drive across the lunar surface. "An astronaut will do in a 6 hour [moonwalk] what a robot can do in 6 months, Berthe says. It is more expensive, but it is more efficient."

We ultimately also want more than just fleeting visits. "We want to stay permanently and build something sustainable for the long run," Berthe says. To this end, an orbital outpost called Gateway is a big part of the Artemis programme. Think of it like an International Space Station, but in orbit around the moon. A home considerably-further-away from home. It could be ready as soon as November 2024 and it is intended to last for 15 years.

The hope is that it will be ready in time for the crew of Artemis-3 to dock with. While aboard Gateway, astronauts will stay in the Habitation and Logistics Outpost (HALO). There are also additional docking ports for cargo ships to come and go with supplies. Astronauts would then transfer to the Starship Human Landing System (HLS), a lunar lander based on SpaceX's existing Starship. However, if Gateway isn't ready then the crew will transfer directly to the HLS for landing at Artemis Base Camp.

Initially stays will be short and largely inside the lander, but ultimately NASA wants astronauts living on the lunar surface for at least a month at a time in purpose built accommodation. In September 2021 the Agency put out a call for companies to submit their proposals for the next generation of spacesuits that Artemis astronauts will wear during their history-making moonwalks.

Eventually the space between the Earth and the moon could be swarming with spacecraft ferrying goods and astronauts back and forth. Jeff Bezos, the founder of Amazon and CEO of space travel company Blue Origin, has suggested that the moon could be a place to put our heavy industry. The idea being that it would free up living space on Earth and move our atmosphere-polluting infrastructure somewhere where there isn't even an atmosphere.

The moon is also an ideal staging post for deeper solar system exploration. The size and scale of the Space Launch System(SLS) shows just how hard we have to work to escape from Earth's gravitational clutches. The moon's gravity, which is six times weaker than ours, is considerably easier to flee from. There are also huge amounts of water on the moon. As water is H2O, that means an abundant supply of oxygen. In fact, the moon's top layer alone has enough oxygen to sustain 8 billion people for 100,000 years. Liquid oxygen is also rocket propellant.

Related: How rockets work: A complete guide

That's why Artemis Base Camp will be at the moon's South Pole. We already know that there's plenty of water there. Lunar Flashlight, one of the small spacecraft hitching a ride on Artemis-1, will orbit the Moon and shine infrared lasers into permanently shadowed craters near the lunar poles to further reveal the quantity and quality of water ice there.

The sunlight at the South Pole is also favorable it is illuminated approximately ninety per cent of the time, compared to two weeks of daylight followed by two weeks of darkness on the rest of the moon. That's good news for a colony powered by solar panels. The combination of these two factors water and sunlight - may lead to a time when rocket ships routinely fuel up close to Artemis Base Camp and blast off for more distant climes such as Mars and the Asteroid Belt.

Former NASA Administrator Jim Bridenstine certainly sees lunar exploration as a key step on our journey towards becoming an inter-planetary species. He has said that "we need several years in orbit and on the surface of the moon to build operational confidence for conducting long-term work and supporting life away from Earth before we can embark on the first multi-year human mission to Mars."

It's all part of returning to where we came from. The iron in your blood and the calcium in your bones was forged inside stars that blasted them across the universe when they died. Eventually those atoms found themselves inside sentient creatures who dreamed of sailing between the stars and built cathedral-sized rocket ships to take them there. The Artemis-1 launch later this year may only be a small step, but it's an important one. Future historians could look back on it as the moment humanity took a giant leap in its return to the moon, this time for good.

For more information about the Artemis 1 mission and to receive live updates, check out NASAs Artemis 1 webpage. The European Space Agency (ESA) have also put together this animation to visualize the mission.Andrew Doan et al. End-to-End

Assessment of Artemis-1 Development Flight Instrumentation, Sensors and Instrumentation, Aircraft/Aerospace, Energy Harvesting & Dynamic Environments Testing, Volume 7, September 2020,https://doi.org/10.1007/978-3-030-47713-4_4

V. Angelopoulos. The ARTEMIS Mission. Springer (2010)https://doi.org/10.1007/978-1-4614-9554-3_2

Marshall Smith et at, "The Artemis Program: An Overview of NASA's Activities to Return Humans to the Moon,"IEEE Aerospace Conference, pp. 1-10, March 2020,https://doi.org/10.1109/AERO47225.2020.917232

John Honeycutt. NASA's Space Launch System: Progress Toward Launch, Session: On-Earth Spaceports and Launch Systems, November 2020,https://doi.org/10.2514/6.2020-4037

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Artemis 1: Going back to the moon - Space.com