How to Watch the Launch of NASA's Artemis I Lunar Mission

After safety concerns, exacerbated in part by bad weather, delayed the launch of NASA's Artemis I, the event has been rescheduled for Saturday, September 3 at 2:15 PM ET.

On Aug. 29, the launch team began to identify problems with the launch plan at NASA, after it "was unable to cool the four RS -25 engines down to about minus 420 degrees, with Engine 3 having higher temperatures than the other engines." A leak was also found, causing further delays to the mission.

Artemis I, a mission to the moon to test a trio of key systems from NASA 's Artemis program, was scheduled to launch Aug. 29. The uncrewed flight will test the Orion astronaut capsule, the 98-meter Space Launch System (SLS) rocket and ground systems at Kennedy Space Center in Cape Canaveral, Florida, in advance of a crewed mission to the moon planned for 2025.

Artemis aims to end 50-year wait to return to the moon

Launched in 2017, the Artemis program aims to put humans on the moon for the first time since the Apollo 17 mission in 1972 and then establish a base camp on the surface and a mini-space station in lunar orbit to enable extended stays on Earth's satellite. Artemis is also intended to lay the groundwork for future manned missions to Mars.

Artemis' original goal was to land humans on the moon in 2024, but NASA Administrator Bill Nelson said in November that goal will not be met. "2024 was not a goal that was really technically feasible," Nelson told reporters. "We are looking at 2025 at the earliest." The planned launch in 2025 will have four crew members, two of whom will spend about a week on the lunar surface after arrival using the Human Landing System (HLS). NASA has previously stated that the plan for the Artemis III mission calls for the landing crew to include at least one female astronaut.

Artemis I mission

On launch day, Artemis I will lift off from Launch Complex 39B at Kennedy Space Center, with the SLS rocket generating about 8.8 million pounds of thrust during liftoff. The SLS will propel Orion into Earth orbit before the rocket's core stage separates from the spacecraft. The SLS's cryogenic intermediate stage will then generate the thrust needed to propel Orion from Earth orbit to the Moon.

Once Orion reaches the Moon, it will come within 62 miles of the lunar surface before entering orbit at an altitude of about 40,000 miles. After six days in lunar orbit, the journey back to Earth will begin, where the final phase of the mission will test the spacecraft's ability to ensure a safe return home. After re-entering Earth's atmosphere - with the heat shield withstanding temperatures of about 5,000ºF, which is about half as hot as the sun - Orion is scheduled to touch down near a U.S. Navy salvage ship off the coast of Baja, Calif.

"This is a mission where we are really doing what has not been done before and learning what has not been known," said Artemis mission manager Mike Sarafin. Orion will stay in space longer than any other astronaut spacecraft without docking with a space station - up to 42 days if all goes according to plan - and will return home "faster and hotter than ever before," according to NASA.

Artemis III first manned lunar landing flight since 1972

As part of Artemis, NASA has committed to landing the first woman and the first person of color on the Moon. Artemis III is expected to be the program's first manned lunar landing mission. The first Artemis flights will include short stays on the Moon, with the crew transferring directly from Orion to a lunar landing vehicle that will take them to the surface. Upon arrival on the Moon, the lander will serve as a base for the crew.

NASA recently awarded development contracts for initial design concepts to develop fission energy systems that could have a life expectancy of 10 years on the lunar surface. NASA hopes to send such a system to the Moon for testing before the end of the 2020s. One of the goals of nuclear fission surface technology is to help NASA develop nuclear propulsion systems that can be used for deep space missions, such as a manned mission to Mars.

Once the mini-space station (called the 'gateway') is built, astronauts will transfer to the lander via this station. Once the base camp takes shape - to be built near the moon's south pole - the facility will replace the lander as the crew's living space. The base camp will also contain a lunar rover and a mobile house. It is planned that the duration of subsequent Artemis missions will increase to up to two months.

How to watch the launch of Artemis I

Artemis I is scheduled to lift off from Launch Pad 39B at Kennedy Space Center in Florida on Saturday, Sept. 3, during a two-hour window beginning at 2:17 p.m. ET.

The launch will be broadcast by NASA Television, the app NASA and the agency's website, nasa.gov. The broadcast will also be available on Facebook, Twitch and the agency's YouTube channel, NASA, and in 4k on the UHD channel, NASA.

The launch countdown begins Saturday, Sept. 3, at 4:37 a.m. ET.

NASA will also provide a live stream of the launch and provide an audio commentator for launch control, accessible via cell phone and radio.

If bad weather or a minor technical problem delays the launch again this Saturday, the mission could be rescheduled for Sept. 5 or later.