South Korea is shooting for the Moon
On August 4th, the Korea Pathfinder Lunar Orbiter (KPLO), also known as Danuri, launched towards the Moon. As the name suggests, this mission is a lunar orbiter from South Korea. It is South Korea's first mission to go beyond earth orbit and enter deep space. Danuri launched on a SpaceX Falcon 9 from Cape Canaveral, Florida. Danuri's purpose is to demonstrate the technologies that South Korea has been developing, and collect scientific data about the Moon's surface and magnetosphere.
Danuri will take until December to arrive in its near-polar orbit with a height of about 100km around the Moon. To conserve fuel the spacecraft will take a Weak Stability Boundary/Ballistic Lunar Transfer trajectory. This will require the spacecraft to go beyond the Moon's orbit and then come back. If the spacecraft successfully makes it to lunar orbit then South Korea will become the ninth to do so. Danuri will then spend a year conducting science, and possibly longer if its mission gets extended.
South Korea's space program has grown largely unnoticed until recently, and now they are stepping out as a significant space player. They have bold plans to build a local space economy and explore the solar system, and this is their next step beyond Earth's atmosphere.
South Korea's Space Program
Only a small handful of countries, the USA, USSR, European Union, China, Japan, Luxembourg, India, and Israel have successfully orbited the Moon. South Korea hopes to become number nine.
South Korea's space agency, the Korea Aerospace Research Institute (KARI), was founded in 1989. South Korea became the 11th country capable of orbital launch in 2013 with the first successful launch of their Naro-1 rocket. Naro-1 was built in collaboration with Russia, but its successor, Nuri, is completely South Korean. KARI successfully used Nuri to launch five satellites into orbit on their second attempt on June 21st, 2022. KARI currently operates 4 Earth observation and 3 meteorology satellites. So the launch of Danuri, previously known as the Korean Pathfinder Lunar Orbiter (KPLO), is their next big step.
Along the way KARI has had a lot of help from NASA. NASA helped plan the mission and design the spacecraft. They also sent 9 scientists to live and work in South Korea and help the Danuri team. The American space agency also allowed KARI to use the Deep Space Network, a system of 14 large communication antennas spread throughout the world.
The Science
During its year orbiting the Moon, Danuri will study the topography, resources, and environment of the Lunar surface. The five science instruments that Danuri is equipped with are all designed to help with this goal.
Danuri has 3 cameras, a gamma-ray spectrometer, and a magnetometer. All of the instruments except for one were built in South Korea. The KPLO Magnetometer (KMAG) is made up of three magnetometers, one on the spacecraft, and two on a 1.5 meter long boom. KMAG will measure the fragments of a magnetic field that the Moon has.
The KPLO Gamma Ray Spectrometer (KGRS) will measure the gamma rays coming from the surface of the Moon. Based on how much energy the gamma rays have the elemental composition of the Moon's surface can be measured.
The Wide-Angle Polarimetric Camera (PolCam) will image large sections of the Moon at once. KARI wants to use this camera to image the entire surface of the Moon, excluding the polar regions. It can image ultraviolet, violet, and red light. The Lunar Terrain Imager (LUTI) will take higher resolution images of interesting parts of the Moon, including potential landing sites. South Korean scientists hope to take images from multiple angles and possibly make 3D images of parts of the surface using these cameras.
The final instrument is the one built by NASA. ShadowCam is based on a camera currently on the Lunar Reconnaissance Orbiter (LRO), but is 200 times more sensitive. The goal of the camera is to search for and map the water ice that is at the Moon's North and South Poles. There are a few other missions scheduled to launch soon that will also be searching for lunar ice. LunaH-Map, Lunar Flashlight, and Lunar Trailblazer are some of them. If data from all these missions are combined then we could get very accurate information about lunar ice.
Building off of what previous Moon missions have done, KARI wants to use Danuri to map the lunar resources and topography of the lunar surface. This data will be very useful for scientists selecting sites for future lunar landings. Why the emphasis on future landing sites? Because KARI hopes to send a follow on to Danuri around 2030. This mission will consist of an orbiter, lander and rover, and will be launched on a South Korean built rocket.
Communications
This mission is more than just a scientific mission. The Danuri mission has allowed for KARI to develop multiple new technologies that it can now use on future space missions. In the process of building Danuri, KARI designed a more powerful rocket engine, electronics that weigh less, and systems that use less electricity. In order to communicate with Danuri when it is at the Moon, the Korean Deep-Space Antenna was built. The 35-meter radio dish is located in Yeoju, Gyeonggi Province. Danuri will use this antenna in addition to NASA's Deep Space Network.
Danuri is also testing Delay Tolerant Networking (DTN). An internet protocol designed for systems with unstable connections and frequent disconnections, such as space. The Delay Tolerant Network Payload (DTNPL) is a space internet device installed on Danuri that will attempt to send data back to the Korean Deep-Space Antenna and NASA's Deep Space Network. If it is successful, then this technology can be used on South Korea's next Moon mission.
These technologies set South Korea ahead of other developing space agencies and will allow them to perform more advanced missions in the future.
A Milestone for South Korea
This mission is a major accomplishment for South Korea's ambitious space program. And it is only the beginning. With this mission, KARI has developed a strong relationship with NASA and KARI seems open to continue collaborating with them.
Danuri is not officially associated with or connected to NASA's Artemis program, the plan to return humans to the Moon. South Korea is a signatory of the Artemis Accords but hasn't made any official contributions to the program. But Danuri could help the Artemis program in multiple ways. The data that will be collected by Danuri can be used by NASA to select spots for both robotic and manned lunar landings. Lunar ice can be used for drinking water and to make rocket fuel, so knowing where it is can help Artemis program leaders decide exactly where to build the Artemis Base Camp. Danuri could also potentially be used as a relay satellite. KARI could also help the Artemis program by allowing NASA to use their newly built deep-space antenna.
The best space exploration is done together.
Danuri has also shown that the South Korean space program is filled with excellent leaders, engineers, and scientists. This mission has been developed in a reasonable amount of time and hasn't been filled with copious delays. The mission has cost only $180 million, which is very low considering the scope of the mission. For comparison, missions in NASA's Discovery program, which builds robotic spacecraft that perform comparable levels of science, cost about $512 million (adjusted for inflation) on average. KARI engineers have developed useful technologies and have been willing to cooperate with the most experienced space agency in the world, NASA.
KARI also has the forethought to emphasize technologies and make long-term goals. In addition to planning an orbiter/lander/rover combo to follow-on Danuri, KARI has other plans. They want to continue to launch Nuri and have plans for additional Earth observation satellites. They have plans to build the Korean Positioning System, a group of satellites that will work similar to GPS, by 2035.
This is the stuff that great space agencies are made of. They have visionary leaders, creative engineers, and intelligent scientists. They can perform science within a budget and persevere through crises, such as global pandemics. They can inspire people. And that is what Danuri is doing, inspiring the people of South Korea, and it won't be the last time that this happens.
South Korea is going places, places beyond the Earth.