NASA is aiming to send the most powerful rocket ever made to the Moon.
The Artemis I mission has been delayed slightly but intends to lead the way for Artemis III, which will see the first woman and the first person of color stand on the Moon.
The Artemis I Moon mission is something that hasn't been done for the past 50 years so its success would be groundbreaking.
Unfortunately, the Monday 29 launch date had to be cancelled but Nasa has its sights set on a date in the near future.
The US space agency should reveal that new date soon.
Nasa astronaut Stan Love spoke to The Sun about the most important part of the mission.
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He revealed a key component that Nasa is looking to test and its failure could ruin the schedules for future missions.
Love told The Sun: "The most important part of this mission is testing the heatshield on Orion. That's why we're flying it.
"Everything else is gravy."
Orion is the crew capsule that has been designed to carry humans to the Moon and Mars.
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Artemis 1 isn't a crewed mission but it needs to loop around the Moon to test three key components for future human space travel.
These components are Nasa's Space Launch System (SLS), its Orion spacecraft, and the European Service Module (ESM).
Love continued: "We have not built a big heatshield that can withstand the re-entry temperatures that you get when you hit the atmosphere after falling from the Moon and we really really really want to make sure that works.
"That is the key piece of technology that allows the rest of the Artemis program to happen.
"Now, we're going to take data on thousands of parameters.
"We're going to have millions of test points during this flight so we understand every aspect of that vehicle before we put my friends onboard.
"The number one goal is to test that heatshield."
The astronaut added that the headshield failing is "overwhelmingly unlikely".
He says Nasa is very good at creating heatshields that can protect their crafts and crew.
Love explained: "Few people know, we once dropped a heatshield on Jupiter and the entry velocity for Jupiter is something like four or five times the entry velocity coming back from the Moon to Earth."
He says that the Jupiter heatshield survived so things look positive for a less intense re-entry of the Orion capsule to Earth.
Love warned: "If the heatshield fails though and the capsule burns up, that's when we'll go back to the drawing board and Artemis II will be substantially delayed and we'll have to do another flight test.
"I hope that doesn't happen."
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How can I watch Artemis I launch?
You'll be able to watch the Artemis I launch live as it takes off from Kennedy Space Center in Cape Canaveral.
A new launch date should be revealed by Nasa soon.