Smile! South Korea's moon orbiter sends back first snaps of Earth

Danuri probe is ready to spend its planned year testing space internet, spotting radiation and/or water

South Korea's Pathfinder Lunar Orbiter, Danuri, which launched in August 2022, has sent back its first images of Earth's sole natural satellite, plus some shots of our home planet as seen from lunar orbit.

Here's one of the latter – part of a series of snaps Danuri captured of Earth across a month of observations.

The phases of Earth as seen from the Moon, captured by South Korea's Danuri lunar orbiter – Click to enlarge

The probe's images of the Moon, as shared on Facebook, show Luna in all its gray lack of glory.

South Korea's Aeronautics Research Institute (KARI) said the images were captured during trials of the Danuri orbiter staged between January 2 and February 3.

Those trials commenced after the craft reached its intended orbit around 100km above the lunar surface in December 2022.

KARI is satisfied that the photos and other evidence prove that Danuri has successfully switched from Earth-lunar navigation mode to mission operation mode. Data transmissions were tested and found to be shipshape. That's important because one of Danuri’s missions is to test Delay-Tolerant Networking (DTN) – a networking technology designed to extend internet standards into the high-latency environment.

The craft will also capture polarized images of the Moon's surface, observe its magnetic fields, and conduct other observations it's hoped will find indications of water.

Danuri's mission plan calls for a year of such observations.

Readers may have noticed the lengthy delay between Danuri's August launch and December arrival in lunar orbit. That long journey was by design: Danuri was the sole payload aboard a SpaceX Falcon 9 launcher – a vehicle that had sufficient power and fuel to propel the 678kg craft into an Earth escape orbit but not enough to slot it straight into a lunar orbit.

The probe was therefore swung around the Moon several times on a journey that reached nearly six million kilometers, before using close approaches to perform maneuverers that nudged the craft into its current trajectory.

South Korea's space program is currently modest, as the nation mostly relies on other nations' launch platforms. That changed in 2022 when the home-grown Nuri launcher succesfully placed a payload in orbit. ®