New NASA Administrator Jared Isaacman announced a major overhaul of the agency's Artemis moon program Friday, acknowledging that the agency's plan to land astronauts on the moon in 2028 was not realistic without another preparatory mission first to lay the groundwork. He said NASA will now add an additional flight in 2027 in which astronauts will dock with new commercial moon landers in low-Earth orbit for detailed tests of navigation, communications, propulsion and life support systems and to v...