An undated photo provided by the Korea Aerospace Research Institute of the final inspections at the Daejeon, South Korea, facility of the Danuri before it was shipped to Florida. (Korea Aerospace Research Institute via The New York Times)
South Korea went to the moon on Thursday. But he doesn’t want to stop there.
“We are also considering using the moon as an outpost for space exploration,” Kwon Hyun-joon, director general of space and nuclear energy at South Korea’s Ministry of Science, said in a written response to questions . “While we hope to explore the Moon itself, we also recognize its potential to act as a base for larger exploration of deep space like Mars and beyond.”
South Korea’s lunar spacecraft, named Danuri, launched on a SpaceX Falcon 9 rocket from Florida on a circular but fuel-efficient path that will take it to the moon in mid-December. There, it will begin an orbit at an altitude of 62 miles above the surface of the moon. The main mission is planned to last one year.
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Originally known as the Korea Pathfinder Lunar Orbiter, the mission was named Danuri after it became the winning entry in a naming contest. It is a combination of the Korean words for “moon” and “enjoy”.
Danuri will join spacecraft from NASA, India and China currently exploring Earth’s companion. Like the United Arab Emirates, which launched to Mars on a Japanese rocket in 2020, South Korea is the latest country with a small but ambitious space program to launch an orbit beyond the low Earth. And also like the United Arab Emirates’ Hope orbiter, the Danuri mission aims to make significant scientific contributions to global efforts to explore and understand the solar system.
Kwon said the main goal of the Danuri mission was to develop core technologies such as orbital trajectory design, deep space navigation, a high-thrust propulsion system and a 35-meter antenna to communicate with distant ships
But the spacecraft’s scientific payload is sophisticated and will help scientists in South Korea and around the world study the moon’s magnetic field, measure its amounts of elements and molecules such as uranium, water and ‘heli-3 and photograph the dark craters of the lunar poles, where the sun never shines. In addition to providing one of the instruments, called ShadowCam, NASA chose nine scientists to participate in Danuri.
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One of his most important scientific instruments is the magnetometer. The interior of the moon no longer generates a magnetic field, but it once did, and this primordial field is preserved in lava flows that hardened during this time.
Ian Garrick-Bethell, a professor of planetary science at the University of California, Santa Cruz and a scientist participating in the Danuri mission, said that the early magnetic field appears to have been surprisingly strong, even twice the strength of Earth. current magnetic field.
Garrick-Bethell said it was puzzling that “such a small iron core could have generated such a strong magnetic field”.
He hopes that after the spacecraft’s main year-long mission is over, South Korea might choose to move Danuri much closer to the moon’s surface, within 12 miles or less, where the magnetometer could see much better magnetized rocks.
“Even a few steps at these low altitudes could help limit the magnetized strength of these rocks,” he said.
Garrick-Bethell is also looking to use the magnetometer to study the magnetic fields generated inside the moon as it is buffeted by the solar wind, a stream of charged particles emanating from the sun.
The rise and fall of magnetic field strength in the solar wind induces electric currents on the Moon, and these electric currents in turn generate magnetic fields that will be measured by Danuri. The characteristics of the magnetic field will give clues to the structure and composition of the moon’s interior.
This work also requires combining measurements with those made by two NASA spacecraft, THEMIS-ARTEMIS P1 and P2, which travel around the Moon in highly elliptical orbits, so that they can measure changes in the solar wind while Danuri measures magnetic fields induced closer to the surface.
“What we would learn from this is a kind of global map of the interior temperature and the potential composition and maybe even the water content of the deep parts of the Moon,” Garrick-Bethel said.
Scientists will use another of Danuri’s instruments, a gamma-ray spectrometer, to measure amounts of different elements on the Moon’s surface. Danuri’s device can pick up a wider spectrum of lower-energy gamma rays than similar instruments on previous lunar missions, “and this range is full of new information for detecting elements on the Moon,” said Naoyuki Yamashita, a scientist based in New Mexico who works. for the Arizona Institute of Planetary Sciences. He is also a participating scientist at Danuri.
Yamashita is interested in radon, which is formed from the decay of uranium. Because radon is a gas, it could travel from the Moon’s interior to its surface. (This is the same process that sometimes causes radon, which is also radioactive, to build up in basements of homes.)
The amounts of radioactive elements could provide a story that tells when various parts of the moon’s surface cooled and hardened, Yamashita said, helping scientists figure out which of the moon’s lava flows are older or younger .
The Korea Aerospace Research Institute, South Korea’s equivalent of NASA, will use Danuri’s high-resolution camera to scan the lunar surface for potential sites for a robotic landing mission in 2031, it said. said Kwon.
A second camera will measure polarized sunlight bouncing off the lunar surface, revealing details about the size of the particles that make up the lunar soil. As the constant bombardment of solar wind, radiation and micrometeorites breaks up the ground, the size of the grains found in a crater could give an estimate of its age. (Smaller grains would suggest an older crater.)
Polarized light data will also be used to map abundances of titanium on the Moon, which could one day be mined for use on Earth.
NASA supplied one of the cameras, a ShadowCam, which is sensitive enough to pick up the few photons that bounce off the ground in the moon’s dark, permanently shadowed craters.
These craters, located at the poles of the Moon, remain forever cold, below 300 degrees Fahrenheit, and contain water ice that has accumulated over eons.
The ice could provide a frozen 4.5 billion year history of the solar system. It could also be a great resource for future visiting astronauts. Moon machinery could extract and melt ice to provide water. That water could then be broken down into oxygen and hydrogen, which would provide both breathing air for astronauts and rocket propellants for travelers seeking to travel from the Moon to other destinations.
One of the main purposes of ShadowCam is to find the ice. But even with Danuri’s sophisticated instruments, this could be a challenge. Shuai Li, a researcher at the University of Hawaii and a participating scientist at Danuri, thinks the concentrations could be so low that they won’t be obviously brighter than areas that don’t contain ice.
“If you don’t look carefully, you might not be able to see it,” Li said.
Jean-Pierre Williams, a planetary scientist at the University of California, Los Angeles and another scientist participating in the Danuri mission, hopes to produce detailed temperature maps of the craters by combining the ShadowCam images with data collected by the Lunar Reconnaissance Orbiter NASA.
NASA’s orbiter, which has been studying the Moon since 2009, carries an instrument that records lunar surface temperatures. But these measurements blur over a fairly large area, about 900 feet in diameter. The resolution of a ShadowCam is about 5 feet per pixel. Thus, ShadowCam images used together with computer models could make it possible to find out the temperature variations on the surface.
“With this data we can map local and seasonal temperatures,” Williams said. This, in turn, can help scientists understand the stability of the water and carbon dioxide ices in the crater.
Researchers will have to wait a few months for the science to begin. The spacecraft is taking a long, energy-efficient route to the Moon. First it heads toward the sun, then back to be captured in lunar orbit on December 16. This “ballistic trajectory” takes longer, but does not require a large engine to fire to slow the spacecraft when it reaches the Moon.
South Korea has an extensive military missile program and has placed several communications and Earth observation satellites in low-Earth orbit since launching its first in 1992. And it has been expanding its capabilities to domestic rocket launch so future missions don’t have to depend on SpaceX. , or in other countries, to reach space. In June, the Korea Aerospace Research Institute successfully placed several satellites into orbit with the second flight of Nuri, its homegrown rocket.
“We will take on challenging projects such as lunar landers and asteroid exploration,” Kwon said.
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