English: This image highlights the boat-tail structure in production for the core stage of NASA’s Space Launch System rocket for Artemis II, the first crewed mission of NASA’s Artemis program at NASA’s Michoud Assembly Facility. The boat-tail joins with the engine section to comprise the lowest portion of the core stage. The structure is designed to protect the bottom end of the core stage and the RS-25 engines.

Together with its four RS-25 engines, the rocket’s massive 212-foot-tall core stage — the largest stage NASA has ever built — and its twin solid rocket boosters will produce 8.8 million pounds of thrust to send NASA’s Orion spacecraft, astronauts and supplies beyond Earth’s orbit to the Moon and, ultimately, Mars. Offering more payload mass, volume capability and energy to speed missions through space, the SLS rocket, along with NASA’s Gateway in lunar orbit, the Human Landing System, and Orion spacecraft, is part of NASA’s backbone for deep space exploration and the Artemis lunar program. No other rocket is capable of carrying astronauts in Orion around the Moon in a single mission. Photographed on Wednesday, June 9, 2021.

Image credit: NASA/Michael DeMocker