NASA Spacecraft Snaps Korean Orbiter Zipping Past It at 7,200 MPH

NASA’s LRO Finds Photo Op as It Zips Past SKorea’s Danuri Moon Orbiter
At the first imaging opportunity, LRO was oriented down 43 degrees from its typical position of looking down at the lunar surface to capture Danuri (streaked across the middle) from 3 miles, or 5 kilometers, above it. | NASA/Goddard/Arizona State University

NASA’s Lunar Reconnaissance Orbiter (LRO) and the Korea Aerospace Research Institute’s Danuri lunar orbiter crossed paths recently, and the former managed to snap a photo of the latter zipping past it at the relative velocity of 7,200 miles per hour.

The LRO has been in orbit around the Moon for the last 15 years while Danuri has been in lunar orbit since December 2022.

NASA’s LRO Finds Photo Op as It Zips Past SKorea’s Danuri Moon Orbiter

During the next encounter, LRO was closer to Danuri, about 2.5 miles, or 4 kilometers, and oriented 25 degrees toward it. | NASA/Goddard/Arizona State University

The two spacecraft flew past each other in opposite directions between March 5 and 6 this year and one of the LRO’s cameras, the narrow angle LROC, managed to capture photos during all three orbits where it happened to be close enough to Danuri to make such a feat possible. The closest encounter, above, gives the best view of the Korean spacecraft.

“Due to the fast relative velocities between the two spacecraft (about 7,200 miles, or 11,500 kilometers, per hour), the LRO operations team at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, needed exquisite timing in pointing LROC to the right place at the right time to catch a glimpse of Danuri, the Republic of Korea’s first spacecraft at the Moon,” NASA explains.

NASA’s LRO Finds Photo Op as It Zips Past SKorea’s Danuri Moon Orbiter
The dark spot centered in the bottom third of this image is the Korea Aerospace Research Institute’s Danuri orbiter, smudged because it was traveling quickly in the opposite direction of NASA’s LRO (Lunar Reconnaissance Orbiter) when LRO snapped the photo. At the time, Danuri was orbiting 5 miles, or 8 kilometers, below LRO’s orbit, and LRO was about 50 miles, or 80 kilometers, above the Moon’s surface. This image covers an area about 2 miles, or 3 kilometers, wide. | NASA/Goddard/Arizona State University

In the photos, Danuri appears to be stretched and smeared to 10 times its size in the opposite direction of travel because of how fast the two spacecraft were flying past each other — this happened even though the LRO’s camera exposure time was exceedingly short: just 0.338 milliseconds. Neat!

More photos of the encounter can be seen on NASA’s website.

Image credits: Photos and captions courtesy of NASA/Goddard/Arizona State University