What to watch for as NASA’s historic Artemis II crew prepares to lift off toward the moon | CNN

The countdown clock is officially rolling at Kennedy Space Center in Florida, where four astronauts are preparing to take off on the mission of a lifetime — circumnavigating the moon and returning humans to deep space for the first time in five decades as part of Artemis II. After nearly two months of tests and troubleshooting, NASA appears to be on the cusp of firing its 322-foot-tall (98-meter) Space Launch System rocket to orbit. The current target for takeoff is a two-hour launch window that opens at 6:24 p.m. ET on Wednesday. Rockets launch fairly frequently from the United States’ Space Coast, as the area surrounding NASA’s KSC facilities is called, but this mission is an obvious standout. NASA’s Reid Wiseman, Victor Glover, and Christina Koch along with Canadian Space Agency astronaut Jeremy Hansen will climb aboard the Orion spacecraft — which sits atop the Space Launch System rocket — and blast toward space, reaching supersonic speeds — or 768 miles per hour (1,236 kilometers per hour) — in one minute. Within three and a half hours after liftoff, the Orion capsule will be fully separated from the rocket, and the astronauts will get a chance to manually pilo