South Korea's K-RadCube, a space radiation measurement cube satellite being developed, will be aboard NASA's lunar exploration rocket 'Artemis 2'. The satellite is expected to investigate the effects of high-energy particles on space-based semiconductor devices and components in a geostationary orbit at an altitude of 70,000 km.
The Korea Aerospace Agency (KAA) announced on the 2nd that it has signed an implementation agreement for cooperation with NASA to mount K-RadCube on Artemis 2. The implementation agreement specifies the roles, responsibilities, and procedures for implementation of activities based on the agreements or contracts that both institutions had previously signed.
The United States has resumed manned lunar exploration with the Artemis program, which had been halted since Apollo 17 in 1972. In 2022, Artemis 1 entered lunar orbit carrying a mannequin, and Artemis 2 is scheduled to carry four astronauts, orbit the Moon, and return to Earth in April next year.
The signing of the K-RadCube implementation agreement had been delayed due to the complete halt of new agreements between the U.S. and foreign governments since the start of the Trump administration. KAA Administrator Yoon Young-bin reportedly resolved the issue of the delay in the implementation agreement by meeting Janet Petro, the Acting Director General of NASA, last month during the '2025 Space Symposium' held in Colorado Springs.
◇Overcome the Van Allen radiation belts filled with high-energy particles
K-RadCube is a scientific mission cube satellite that measures cosmic radiation in the Van Allen radiation belts around Earth and analyzes the effects of radiation on astronauts and space-based semiconductor devices and components.
Cube satellites, which are miniature satellites the size of a shoe box, were originally developed for educational purposes but have recently taken on the tasks once performed by large satellites due to advancements in electronics. The basic unit (U) measures 10 cm in width, length, and height. K-RadCube weighs 19.6 kg and is considered large among cube satellites at 12U.
K-RadCube is being developed by Naraspace under the auspices of the Korea Astronomy and Space Science Institute. The space agency plans to deliver K-RadCube to NASA by July this year once production and various experimental and verification procedures are completed. After being launched aboard NASA's Space Launch System (SLS) in April next year, K-RadCube will be deployed into space from the Orion spacecraft carrying astronauts.
NASA initially requested South Korea to participate by developing a cube satellite for Artemis 2, which was originally scheduled to launch in 2024, but the South Korean government declined due to budget constraints and tight timelines. Fortunately, as the Artemis 2 launch has been delayed, South Korea has been given another opportunity.
KAA’s Space Science Exploration Division Head Kang Kyung-in noted, “In January 2024, with the postponement of the launch schedule for Artemis 2, NASA requested additional participation, and the South Korean government proposed the cube satellite mounting mission, which led to its selection in May of that year. The entry of a satellite made by South Korea into geostationary orbit is significant both scientifically and as a concrete achievement of cooperation in the field of space with the United States.”
◇“No issues with U.S.-South Korea space cooperation… We will increase participation in Artemis”
Choi Young-jun, Deputy Director of the Korea Astronomy and Space Science Institute, said, “The cube satellite will automatically deploy its solar panels right after deployment and will begin attitude control about two hours later. It will reach an altitude of 70,000 km, which is higher than the geostationary orbit (35,000 km) generally reached by satellites, to conduct scientific experiments analyzing the cosmic radiation environment.”
K-RadCube is expected to be the first satellite made by South Korea to pass through the Van Allen radiation belts. The Van Allen belts are radiation zones composed of high-energy particles trapped by Earth's magnetic field. They also serve as a protective shield against solar wind but can cause severe damage to satellites. Because of these risks, most satellites avoid them, but K-RadCube intentionally approaches the Van Allen belts.
KAA expects that the cube satellite will experience the high-risk space environment of continuous exposure to high-energy particles and gather data necessary for future manned space exploration missions. Kang Kyung-in stated, “As we expand the scope of space exploration, understanding high-risk space environments will become increasingly important. While experiments can be conducted on Earth to simulate space conditions, this cannot surpass the value of conducting experiments in actual geostationary orbit under various variables.”
The space agency plans to make the scientific data obtained from K-RadCube publicly accessible for relevant researchers to utilize. It believes that this data can play an important role not only for South Korea but also in international deep space exploration cooperation with the United States and beyond. Kang Kyung-in emphasized, “Since signing the Artemis research agreement with NASA in October of last year, we are exploring various cooperation avenues and intend to continue expanding U.S.-South Korea space exploration initiatives.”