Astro Bob: How to watch the Artemis I launch
NASA shoves off to the moon early Wednesday morning, Nov. 16.
Barring more engine snafus, hydrogen leaks or hurricanes, NASA's Artemis I moon mission is scheduled to launch just after midnight Central Time Wednesday morning, Nov. 16. You can watch it live on NASA Live TV with programming starting at 9:30 p.m. CST Tuesday night (Nov. 15).
After initially orbiting the Earth, the Space Launch System rocket, the largest and most powerful ever built (including the Apollo-era Saturn V), will propel the Orion spacecraft on its way to the moon. The 25.5-day mission will test every aspect of the flight in preparation for a human mission. Want to see en route to its destination? Italian astronomer Gianluca Masi will share images of the Orion spacecraft in real time via his robotic telescopes starting at 9:30 p.m. CST (Nov. 16) on his Virtual Telescope site .
NASA will send the Orion into a distant retrograde orbit, or DRO, a highly stable orbit where little fuel is required to stay for an extended trip in deep space. Outbound, it will swoop to within about 60 miles of the lunar surface for a gravity assist that will slingshot the probe some 40,000 miles (64,000 km) beyond the moon. That's the "D" (for distant) in DRO. The "R" stands for retrograde, a fancy word for "backward." Orion will travel around the moon opposite the direction the moon travels around Earth.
On the return trip, the spacecraft will again pass about 60 miles from the lunar surface for a gravity assist that will fling it back toward Earth at around 25,000 mph (40,000 kph). That extreme speed will test the durability of the crew module's heat shield which will be heated to 5,000° F (2,760° C) upon reentry into Earth's atmosphere on Dec. 11. That's half as hot as the surface of the sun!
“Artemis I is a true stress test of the Orion spacecraft in the deep space environment,” said Mike Sarafin, Artemis Mission Manager. “Without crew aboard the first mission, DRO allows Orion to spend more time in deep space for a rigorous mission to ensure spacecraft systems, like guidance, navigation, communication, power, thermal control and others are ready to keep astronauts safe on future crewed missions.”
Three manikins will be strapped in for the ride, one of which is dressed in the same suit that future crews will wear. Each is fitted with thousands of sensors to measure radiation levels, acceleration and vibrations that real astronauts will experience when their time comes.
Two of the manikins, nicknamed Helga and Zohar, are modeled on the female body. Both are "made from materials that mimic the human bones, soft tissues and organs of an adult woman," according to Thomas Berger, who headed up the project to create the manikins in partnership with NASA.
Radiation exposure is always a concern in space, and the female body is more sensitive to its effects than the male. Crucially, Zohar will be wearing an AstroRad protective vest, while Helga will fly unprotected. Critical points of exposure during the mission will occur when Orion makes brief passages through Earth's V an Allen radiation belts on its way out and again upon return. Once in deep space, cosmic radiation from the sun and other sources come into play.
Should Artemis I be a success, the first crewed Artemis II mission will launch in May 2024. Astronauts will travel to the moon and back without landing in a dress rehearsal similar to Apollos 8 and 10 before the Apollo 11 moon landing. We'll finally get boots on the ground with Artemis III, which launches in 2025. Unlike Apollo, the Artemis program will establish a permanent human presence on the moon. We're going to stay this time around.