In 2009, NASA began detailed investigation of the lunar surface with the launch of the Lunar Reconnaissance Orbiter (LRO), aiming to identify potential landing sites, natural resources, and notable features such as lava tubes. This spacecraft has already mapped a large part of the lunar surface, excluding the deeply shadowed polar areas.
In 2024, the LRO captured images of something resembling a 'surfboard' moving rapidly while orbiting the celestial body. This object was the Danuri spacecraft, launched by South Korea in August 2022.
Danuri is the country's first lunar orbiter, and its mission covers the development and testing of technologies, including space internet, in addition to creating a topographic map of the lunar surface. According to the Korea Aerospace Research Institute (KARI), which is responsible for the mission, the data collected by the Danuri satellite will aid in selecting future landing sites and identifying resources such as uranium, helium-3, silicon, aluminum, and water ice.
Among the equipment onboard the South Korean orbiter are a spectrometer, a magnetometer, and several cameras. One of these cameras, called Shadowcam, has the capability to photograph the obscured polar regions that the LRO cannot map, and this instrument was developed by NASA itself.
Orbital Encounter Between the Orbiters
In March 2024, the two orbiters crossed trajectories at a combined speed of 11,500 km/h. Three orbits were identified that allowed the LRO to record Danuri in accelerated motion. The vertical distance between the two vehicles varied during each pass.
In the first photograph, the LRO was five kilometers above the Korean spacecraft, requiring the NASA orbiter to adjust its aiming angle to 43 degrees below standard. In the second orbit, the separation was reduced to only four kilometers. In the third and final orbit, the distance was eight kilometers, at which point the LRO was positioned at a 60-degree angle.
This was not the first photographic record between the two bodies in lunar orbit. In April 2023, using the ShadowCam, it was Danuri that filmed the LRO, with the latter being 18 kilometers above the American satellite.

