What NASA mission, carrying four astronauts, returned to Launch Complex-39B on March 20, 2026, after maintenance?

The NASA mission that returned to Launch Complex-39B on March 20, 2026, after undergoing maintenance, is Artemis 2. This crucial step brought the Space Launch System (SLS) rocket and Orion spacecraft, along with the mobile launcher, back to the launchpad in preparation for its upcoming crewed lunar flyby mission. The rollout, which was briefly delayed by high winds, saw the massive 11-million-pound stack travel approximately four miles from the Vehicle Assembly Building (VAB) to the pad.

The return to Launch Complex-39B followed a period in the VAB where engineers addressed a helium flow issue in the rocket's upper stage, discovered during a wet dress rehearsal in February. Additionally, ground teams performed other vital maintenance, including replacing batteries across the core stage and solid rocket boosters, and refreshing a seal on the liquid oxygen feed line. These extensive checks ensure the rocket and spacecraft are in optimal condition for the journey ahead.

Artemis 2 is a historic mission, marking the first time humans will venture toward the Moon since Apollo 17 in 1972. The four astronauts, NASA's Reid Wiseman, Victor Glover, and Christina Koch, along with Canadian Space Agency astronaut Jeremy Hansen, will embark on a roughly 10-day mission to orbit the Moon and return to Earth. This mission is designed to test the Orion spacecraft's systems, including life support and communications, and gather essential data for future deep-space exploration, ultimately paving the way for human landings on the lunar surface. The launch window for Artemis 2 is currently targeted to open as early as April 1, 2026.