NASA’s Artemis II SLS (Space Launch System) rocket lifted off from Launch Complex 39B in Florida at 6:35 p.m. EDT, marking the start of a historic journey into deep space.

Artemis II will pose a greater test of Orion and the SLS rocket. Boeing and Northrop Grumman have led the development of SLS since 2010, a program partly known for its ballooning costs at an estimated $US2 billion ($A2.9 billion) to $US4 billion ($A5.8 billion) per launch.

NASA's Artemis II mission will launch with SLS rocket engines that have flown multiple times on past space shuttle missions. Here's their story.

Live coverage of NASA’s Artemis II launch with liftoff targeting 6:24 p.m. The mission will send four astronauts on a 10-day, lunar fly by, marking the first humans to return to deep space since 1972.

NASA's giant moon rocket is back on the launch pad in Florida, setting the stage for what appears to be an imminent launch of the Artemis 2 mission.

Artemis II mission around moon scheduled to launch at 6:24 p.m. tonight.

The Saturn V was meant for deep space missions like the SLS and Starship but was very different from the modern rockets.