Washington (AFP) – NASA on Friday began a critical two-day-long test of its giant Space Launch System (SLS) rocket complete with a simulated countdown, as the agency gears up to return humans to the Moon. Known as the “wet dress rehearsal,” it is the final major test before the Artemis-1 mission this summer: an uncrewed lunar flight that will eventually be followed by boots on the ground, likely no sooner than 2026. “The countdown is now underway,” NASA said in its Artemis blog at 5:00 pm Eastern Time (2100 GMT), confirming members of the launch control team had been issued their “call to stat…