Ilaria Rosella Pagliaro How NASA's Lunar Reconnaissance Orbiter immortalized the Danuri lunar satellite in an incredible series of photographs during a high-speed flyby: an example of technological precision and international collaboration
©NASA/GSFC/Arizona State University
Have you ever wondered what happens when two satellites cross paths in orbit around the Moon?How do you capture a clear image of an object moving at speeds over 6,835 miles per hour? These are the challenges that the team behind NASA’s Lunar Reconnaissance Orbiter (LRO) faced and overcame, capturing the South Korean Aerospace Research Institute’s Danuri satellite in an unprecedented space rendezvous.
Precision in space: the LRO-Danuri encounter
This close encounter took place as the two spacecraft traveled in nearly parallel orbits but in opposite directions, on March 5 and 6, 2024. The precision timing of this event enabled the capture of detailed images despite the high relative speed of approximately 2.0 mi/s (7,146 mph).
Technology and techniques for extreme conditions
To successfully capture images of Danuri, the LRO team at NASA’s Goddard Space Flight Center had to calculate the exact time and place to take the photographs. During three specific orbits, the LRO’s Narrow Angle Camera, part of the Lunar Reconnaissance Orbiter Camera (LROC) system, had the opportunity to photograph Danuri at an appropriate distance. Despite an exposure time of only 0.338 milliseconds, the images appear stretched up to 10 times Danuri’s actual size due to the relative velocity between the two celestial bodies.
In orbit since late 2022, Danuri marks South Korea’s first lunar satellite and signifies a significant milestone for the country’s aerospace research. The success of these photography operations not only demonstrates the technical skill of the teams involved but also highlights the growing importance of international cooperation in space study and exploration.
