Nasa gave the four Artemis astronauts circling Earth the green light on Thursday to head for the moon and carry out the first crewed lunar fly-by in more than 50 years.Nasa Flight Director Jeff Radigan told the astronauts the mission management team had approved firing up the engine of their Orion capsule to send the spacecraft on a trajectory towards the moon.The 5 min and 49 second burn is scheduled to take place at 7.49pm Eastern Time and send the astronauts out of Earth orbit to begin the...