Former NASA astronaut Susan Kilrain says the first day of launch for Artemis II is the "busiest day of the entire mission" for the crew. "They're not even allowed a full night of sleep, they get two little four-hour naps." ––– Subscribe to ABC News on YouTube: https://abcnews.visitlink.me/59aJ1G ABC News is your daily source of breaking national and world news, exclusive interviews and 24/7 live streaming coverage. https://abcnews.com Download the ABC News app for the latest headlines and