We're standing by for news on NASA's decision on what to do about Orion's heat shield. //

The central piece of NASA's second Space Launch System rocket arrived at Kennedy Space Center in Florida this week. Agency officials intend to start stacking the towering launcher in the next couple of months for a mission late next year carrying a team of four astronauts around the Moon.

The Artemis II mission, officially scheduled for September 2025, will be the first voyage by humans to the vicinity of the Moon since the last Apollo lunar landing mission in 1972. NASA astronauts Reid Wiseman, Victor Glover, Christina Koch, and Canadian mission specialist Jeremy Hansen will ride the SLS rocket away from Earth, then fly around the far side of the Moon and return home inside NASA's Orion spacecraft. //

NASA's inspector general reported in 2022 that NASA's first four Artemis missions will each cost $4.1 billion. Subsequent documents, including a Government Accountability Office report last year, suggest the expendable SLS core stage is responsible for at least a quarter of the cost for each Artemis flight.

The core stage for Artemis II is powered by four hydrogen-fueled RS-25 engines produced by Aerojet Rocketdyne. Two of the reusable engines for Artemis II have flown on the space shuttle, and the other two RS-25s were built in the shuttle era but never flew. Each SLS launch will put the core stage and its engines in the Atlantic Ocean. //

Artemis III's launch date is highly uncertain. It primarily hinges on SpaceX's progress in developing a human-rated lunar lander and Axiom Space's work on new spacesuits for astronauts to wear while walking on the Moon.

NASA spent $11.8 billion developing the SLS rocket, and its debut was delayed five years from an original target date in 2017. But for Artemis II, the readiness of the Orion spacecraft is driving the schedule, not the rocket.