Artemis II returned to Earth on April 10, 2026. Reentry is perhaps the most dangerous phase of the mission. The Orion spacecraft entered Earth’s atmosphere traveling at some 40,000 km (25,000 miles) per hour. This generated intense heat of about 2,760 ℃ (5,000 ℉). The spacecraft was outfitted with a heat shield designed to protect it. Although the heat shield for the unmanned Artemis I exhibited unexpected cracking and charring, analysis determined that it performed within safety limits. However, a different reentry path was chosen for Artemis II. Orion had a steeper flight path, which lessened the friction and heat. Another complication of reentry is a temporary loss of radio communication. For up to several minutes, a plasma sheath—generated by the intense friction—blocks radio waves.
During descent, the spacecraft also slowed dramatically. When Orion reached about 563 km (350 miles) per hour, the parachutes began deploying. There were 11, and they opened at different stages. By the time the spacecraft splashed down in the Pacific Ocean, it was traveling at a speed of 27 km (17 miles) per hour.