K-RadCube, a Korean miniature (cube) satellite that headed into space aboard the United States' crewed lunar mission "Artemis II," failed to establish normal contact on the second day after launch.
Korea AeroSpace Administration said in a 2:30 p.m. notice on the 4th that the K-RadCube mission operations team, considering the satellite's survivability, continued trying to communicate with the satellite after the first perigee but could not detect a signal.
K-RadCube was launched with Artemis II at 7:35 a.m. on the 2nd, Korea time. It separated at around 12:58 p.m. the same day at an altitude of about 40,000 kilometers. Afterward, Korea AeroSpace Administration attempted initial contact using overseas ground station antennas. At 9:57 p.m., the U.S. Hawaii ground station received an abnormal telemetry signal from the satellite. The data expected for reception did not come in normally.
Korea Astronomy and Space Science Institute (KASI), the project's lead institution, kept initial operations going with the operating agencies KT SAT and Nara Space until 12:30 p.m. on the 4th with the satellite's survivability in mind, but ultimately failed to make contact. K-RadCube was to fly in an elliptical orbit rising to 70,000 kilometers in altitude and perform an altitude-raising maneuver at perigee, but whether the perigee altitude-raising mission succeeded could not be confirmed.
K-RadCube is a 12-unit (U; 1U is 10 centimeters on a side) satellite weighing 19 kilograms, aimed at measuring space radiation in the Van Allen radiation belts around Earth by altitude for crewed exploration. As secondary payloads, semiconductors from Samsung Electronics and SK hynix were also aboard to verify operation in Earth's high-orbit radiation environment.