Introduction Conceived for the Moon, Adsum is a cubic glass sculpture inside of which symbols are laser engraved. The symbols are positioned one in front of the other, thus forming a spatial poem inside the solid glass cube that can be read in any direction. 'Adsum' means “Here I am” in Latin, as used to indicate that the speaker is present (equivalent to the exclamation "here!" in a roll call). Adsum is an ongoing project that evolves through five phases. Phase 1 Proof-of-Concept version 2019 [completed] Adsum (PofC) is the first version of the work. It measures 4x4x4 in (10x10x10 cm) and was published in an edition of five. Made of optically pure glass, it was laser engraved by Kac in Paris in 2019. This first version demonstrated the feasibility of the project, the durability of the material, and the multiple reading directions of the symbols. Phase 2 Flight-Ready version 2019–2022 [completed] In preparation for its flight to the International Space Station, Kac reduced the original cube at a 10:1 scale and laser-engraved the miniaturized optical cube at the limit of legibility. The Flight-Ready Adsum measures 0.4 x 04 x 0.4 in (1x1x1 cm) and weights 0.08 ounces (2.5 grams). It was published in an edition of five. The work flew to the ISS on February 19, 2022, on an Antares 230+ rocket from NASA’s Wallops Flight Facility, Virginia. The Flight-Ready Adsum has orbited the Earth aboard the ISS for eleven months and returned to Earth on January 11, 2023, aboard a SpaceX Dragon 2 spacecraft, splashing down off the coast of Florida. Phase 3 Regex version 2022 [completed] The Regex version of Kac’s artwork Adsum is a typographic interpretation of the visual symbols that make up the work, as stipulated by NASA through a ‘regular expression’ script when the agency collected “symbols of cultural significance” for the flight (per NASA’s press release of Aug 5, 2022). As such, Kac’s Adsum (Regex) was included in a USB drive that was placed aboard Orion for travel around the Moon during Artemis 1. Orion was launched atop the agency's Space Launch System (SLS) on November 16, 2022. Before returning to Earth on December 11, the Orion spacecraft spent 26 days in space, including 6 days in orbit around the Moon. Phase 4 Planar version NET August 2023 [in progress] Kac’s Adsum (Planar) is an original ink on paper drawing that has been scanned, miniaturized, and engraved on a disc that will actually reach the Moon’s surface mounted on a lander no earlier than June 2023. The landing site is Malapert A, a crater near the south pole. The original drawing measures 12 x 16.5 inches (29.7 x 42 cm). Stay tuned for more details. Phase 5 Lander version NET 2024 [in progress] Scheduled to fly to the Moon aboard a lander, this will be the final version of Adsum. It is identical in material, technique, and scale to the Flight-Ready version, with the significant difference that the Lander version will stay on the surface of the Moon, protected aboard the lander, for endless time. Stay tuned for more details.