NASA’s Orion spacecraft is expected to re-enter Earth’s atmosphere and splash down in the Pacific Ocean about 12:40 p.m. Sunday more than 100 miles off the coast of Baja, Mexico, NASA officials said.
Successful splashdown and recovery of the spacecraft are critical objectives of the uncrewed Artemis I test mission that took Orion around the moon just days ago. A successful re-entry will culminate a 26-day mission to help pave the way for future missions to the moon and eventually to Mars with astronauts aboard.
Orion will re-enter at 25,000 mph and generate 5,000 degrees F of heat, about half the heat of the Sun, but the spacecraft will be slowed on entry by a “skip” manuever off the atmosphere, partly to help make the landing more precise.
NASA created a new design for the 16.5-foot diameter heat shield with a material called Avcoat, a reformulation of the material used on the Apollo capsules more than 50 years ago. The top objective of the Artemis I mission is to see how well the heat shield withstands the tremendous temperatures, since it could not be tested on the spacecraft while on Earth prior to flight.
The heat shield “is a safety critical piece of equipment designed to protect the craft and passengers,” said Mike Sarafin, Artemis I mission manager. It will be entering the atmosphere at speeds of Mach 32 , with 5,000 degrees of heat and needs to protect a 20,000 pound spacecraft with astronauts on future missions. “It’s our priority one objective.”
NASA will use sensors embedded in the Avcoat material to certify the Orion heat shield can be used on future flights with astronauts. Temperature sensors will be used as well as sensors for pressure and radiation. The heat shield material underwent 1,000 arc jet tests where extremely hot and fast-moving gases passed over the test material. It is designed to reduce 5,000-degree temperatures on the front side of the shield down to 200 degrees on the back side.
Sarafin said the splashdown site is hundreds of miles from an intended site because a weather forecast indicated there could be rain, wind and large waves in the original location off the coast of San Diego. It will take up to six hours for US Navy crews to recover the ship. “We don’t want to fly [the spaceship] through rain and with a cold front there will be an increase in winds and whip up waves,” he said.
Orion is designed to handle 20 knots of winds and the cold front is predicted to create 17 to 20 knots of wind. “The spacecraft would be OK, but recovery challenging,” he said.
The splashdown will be too far away for people on shore to see, especially in daylight, Sarafin said. “You’re more likely to hear the sonic boom from the vehicle approaching than anything.”