NASA’s Artemis II astronauts are now heading into what may be the hardest part of their mission, surviving re-entry heat of around 3,000 degrees Celsius and then readjusting to Earth’s gravity after days in space. As NASA stated in its latest post on X, the crew is “halfway home” and on the course to splash down in the Pacific Ocean near San Diego. But while the mission has already made history by taking humans farther from Earth than ever before, the final stretch will bring two serious challenges. One is the extreme heat outside the spacecraft, and the second one is physical shock to the body once the crew returns to normal gravity.
Why re-entry into Earth’s atmosphere is such a serious test?
As Orion re-enters Earth’s atmosphere, it will be travelling at more than 30 times the speed of sound, according to a report by The Conversation. At that speed, the capsule’s heat shield is expected to face temperatures of about 3,000 degrees Celsius, while the air around the spacecraft can heat to around 10,000 degrees Celsius. It will create a plasma layer that can briefly block radio signals.
The Conversation report explains that Orion survives this through a specially designed thermal protection system. The heat shield is made to absorb heat, glow red hot and slowly wear off, helping protect the astronaut inside. As per the Associated Press, NASA has been monitoring Orion’s heat shield closely after the uncrewed Artemis I mission showed more damage than expected during the re-entry.
Gravity will be another major challenge
Even after getting through the atmosphere, the astronauts will still have to deal with Earth’s gravity again. As per the New York Post, astronauts returning from space can struggle with balance, weakness, nausea and disorientation because the body has adapted to microgravity. Astronaut Andreas Mogensen stated that with his “eyes closed, it was almost impossible to walk in a straight line” after a long mission, as quoted by The New York Post. Other astronauts have also spoken of feeling unstable and physically drained in the first hours after landing, showing that the return home does not end when the spacecraft hits the water.
Final stretch before splashdown
Pilot Victor Glover said that, “There are so many pictures, so many more stories.” He further added that “rising a fireball through the atmosphere is profound as well.” Commander Reid Wiseman described the experience as “surreal” and “a true gift.”
Meanwhile, Artemis II has already set a new record for the farthest human spaceflight, reaching 252,756 miles from Earth. After splashdown, the US Navy John P. Murtha is expected to recover both the astronauts and the Orion capsule.