How to watch the Artemis I mission lift off to the moon
Video above: NASA astronauts set sights on moon and beyond
For the first time in 50 years, a spacecraft is preparing to launch on a journey to the moon.
The uncrewed Artemis I mission, including the Space Launch System Rocket and Orion spacecraft, was scheduled to launch on Monday morning, but was postponed due to fuel leaks.
The next launch attempt will not take place until Friday at the earliest.
Although there is no human crew aboard the mission, it's the first step of the Artemis program, which aims to return humans to the moon and eventually land them on Mars.
The Orion spacecraft will enter a distant retrograde orbit of the moon and travel 40,000 miles beyond it, going further than any spacecraft intended to carry humans. Crews will ride aboard Artemis II on a similar trajectory in 2024, and the first woman and the next man to land on the moon are slated to arrive at the lunar south pole in late 2025 on the Artemis III mission.
The agency will share live views and coverage in English and before, during and after the Artemis I launch on its and on NASA TV.
Video above: NASA discusses upcoming uncrewed moon shot
Appearances by celebrities like Jack Black, Chris Evans and Keke Palmer and performances of "The Star-Spangled Banner" by Josh Groban and Herbie Hancock and "America the Beautiful" by The Philadelphia Orchestra and cellist Yo-Yo Ma are also part of the program.
Once the launch has occurred, NASA will conduct a post-launch briefing, and later in the day, the agency will share the first Earth views from cameras aboard the Orion spacecraft.
Orion's journey will last 42 days as it travels to the moon, loops around it and returns to Earth -- traveling a total of 1.3 million miles. The capsule will splash down in the Pacific Ocean off the coast of San Diego.
Cameras inside and outside of Orion will share images and video throughout the mission, including live views from the Callisto experiment, which will capture a stream of a mannequin called Commander Moonikin Campos sitting in the commander's seat. If you have an Amazon Alexa-enabled device, you can ask it about the mission's location each day.
Journey to the moon
After liftoff, the solid rocket boosters will separate from the spacecraft about two minutes into the flight and splash down in the Atlantic Ocean, with other components also jettisoning shortly after. The core stage of the rocket will separate about eight minutes later and fall toward the Pacific Ocean, allowing for Orion's solar array wings to deploy.
The perigree raise maneuver will occur about 12 minutes after launch, when the ICPS experiences a burn to raise Orion's altitude so it doesn't reenter the Earth's atmosphere. Shortly after that is the trans-lunar Injection burn, when the ICPS boosts Orion's speed from 17,500 miles per hour to 22,600 miles per hour to escape the pull of Earth's gravity and set off for the moon.
After this burn, the ICPS will separate from Orion.
Then, Orion will make its first outbound trajectory correction burn using the European Service Module, which provides the spacecraft with power, propulsion and thermal control. This maneuver will put Orion on a path to the moon.
The next few days after launch, Orion will venture out to the moon, coming within 60 miles during its closest approach of the lunar surface on day six of the journey. The service module will place Orion in a distant retrograde orbit around the moon on day 10.
Orion will surpass the distance record of 248,654 miles -- set by Apollo 13 in 1970 -- when it loops around the moon. The spacecraft will achieve its maximum distance from Earth of 280,000 miles when it ventures 40,000 miles beyond the moon.
Video above: NASA talks Artemis mission to moon and beyond
This is 30,000 miles farther than Apollo 13's record.
Orion will make its second-closest approach of the lunar surface, coming within 500 miles. The service module will experience a burn that enables the moon's gravity to slingshot Orion back on its way to Earth.
Just before reentering Earth's atmosphere, the service module will separate from Orion. The spacecraft will hit the top of Earth's atmosphere moving at about 25,000 miles per hour, and its heat shield will experience temperatures of nearly 5,000 degrees Fahrenheit.
The atmosphere will slow Orion down to about 300 miles per hour, and a series of parachutes will slow it down to less than 20 miles per hour before it splashes down in the Pacific Ocean.
Splashdown will stream live from NASA's website, collecting views from the 17 cameras aboard the recovery ship and helicopters that will be waiting for Orion's return.
The landing and recovery team will collect the Orion capsule, and the data collected by the spacecraft will determine what lessons have been learned before humans return to the moon.