Artemis II closing in on Earth return

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After a groundbreaking 10-day mission that carried humans farther from Earth than ever before, the four astronauts of NASA’s Artemis II are heading into their final day in space ahead of splashdown in the Pacific Ocean off the coast of San Diego on Friday.

The Orion spacecraft, named Integrity, will have traveled approximately 700,000 miles (about 1.1 million kilometers) from its launch at Kennedy Space Center’s Launch Complex 39B in Florida, looping around the far side of the Moon and back.

The crew — NASA astronauts Reid Wiseman (commander), Victor Glover (pilot), Christina Koch (mission specialist), and Canadian Space Agency astronaut Jeremy Hansen — are the first humans to venture beyond low-Earth orbit since the Apollo era more than five decades ago.

The mission reached its dramatic high point on Monday, April 6 (Flight Day 6), with a close lunar flyby that took the crew behind the Moon and to a record distance of roughly 252,756 miles (406,771 km) from Earth — surpassing the previous mark set by Apollo 13.

During the flyby, the astronauts conducted observations, captured thousands of images and videos (many transmitted via Orion’s advanced optical laser communications system), and experienced a total solar eclipse as viewed from their vantage point.

The return leg proved equally eventful. On Flight Day 7, Orion exited the Moon’s sphere of influence, with Earth’s gravity once again becoming the dominant force guiding the spacecraft home.

Hours later, the crew made history by completing the first ship-to-ship call between a lunar mission and the International Space Station, speaking with Expedition 74 astronauts despite noticeable communication delays caused by the vast distance.

The astronauts followed up with a science debrief reviewing their lunar observations before entering a well-deserved off-duty period.

Additional trajectory correction burns using the European Service Module’s reaction control thrusters helped fine-tune the path, with a nine second 5.2ft/s burn on Flight Day 9.

Throughout the coast back to Earth, the crew participated in numerous public affairs events, connecting with world leaders—including the U.S. President and Canadian Prime Minister—as well as schoolchildren and media outlets.

A scheduled final manual piloting demonstration was not performed as planned, in favour of thruster testing to “characterize” a helium leak that has been under observation.

The helium leak is internal to the oxidizer (nitrogen tetroxide) side of the propulsion system that powers the AJ10. This was identified before launch, but because Artemis II is on a free-return trajectory, it was not of concern (due to minimal burn time on the AJ10). Amit Kshatriya said that this will need to be addressed before Artemis IV, however.

On Flight Day 10, the crew will focus on re-entry preparations: re-installing seats, stowing equipment for proper spacecraft balance, and donning their bright orange entry suits for the third time on the mission.

The European Service Module—powered in part by an AJ-10 engine previously flown on Space Shuttle Atlantis—will separate from the Crew Module, which will then execute a final raise burn to align for atmospheric entry.

This is a key part of the mission, as explained by Artemis II Lead Flight Director Jeff Radigan, who noted that the vehicle has to hit a precise angle for entry.

“Let’s not beat around the bush; we have to hit that angle correctly, otherwise we’re not going to have a successful re-entry.”

Entry interface is expected at an altitude of about 122 km (76 miles), with the spacecraft hitting a peak velocity of approximately 23,839 mph (38,365 km/h), or 6.6 miles per second. The crew will experience a maximum of about 3.9 G’s during the fiery descent.

The forward bay cover will jettison below 36,000 feet, followed by drogue parachutes below 25,000 feet and main parachutes that slow Integrity to roughly 20 mph for a splashdown.

Recovery teams aboard the USS John P. Murtha, a San Antonio-class amphibious transport dock, will quickly extract the astronauts, and NASA confirmed Orion engineers will be onboard to immediately check on key items on the vehicle, such as the heatshield that has been a topic of conversation following issues during Artemis I.

Once Artemis II is complete, attention turns rapidly to Artemis III, the first crewed lunar landing in the modern era. NASA Administrator Jared Isaacman has emphasized accelerating the Space Launch System (SLS) cadence.

The Crawler-Transporter is already positioned to move the Mobile Launcher back to the Vehicle Assembly Building for refurbishment, with stacking of Artemis III’s solid rocket boosters potentially beginning this summer.

The core stage for the next SLS is expected to roll out from the Michoud Assembly Facility in Louisiana soon, while upcoming commercial launches—including Blue Origin’s New Glenn (attempting its first booster reflight) and a Falcon Heavy with dual booster landings at separate zones—will keep the pace of spaceflight high.

Starship’s Flight 12 is anticipated in May, with Booster 19 and Ship 39 expected to roll to Pad 2 and Massey’s, respectively, for their pre-flight full engine Static Fire tests.

Artemis III and subsequent missions will rely on human landing systems from Blue Origin (Blue Moon) and SpaceX (Starship), setting the stage for sustained lunar exploration and eventual crewed missions to Mars.

Lead Image via NASA.

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