Why Do We Have to Go to the Moon... 8 Days Until Danuri Launch [Reading Science]

Korean Reader Space Development Pioneer Conquers All Three Major Areas
Serves as Guide for Humanity's Second Moon Landing
Expected to Unravel Moon's Mysteries with Magnetometer and Gamma-ray Detector
Contributes to Establishing International Space Communication Network Standards through Space Internet Testing
Scheduled to Perform Historic First Full Moon Polarization Imaging and Other Key Missions
Likely to Explore Lunar Surface Geology and Resources, Confirm Presence of Water

[Asia Economy Reporter Kim Bong-su] South Korea's first celestial exploration spacecraft, 'Danuri (KPLO)', will be launched on the 3rd of next month. It plays the pioneering role in Korean space exploration as well as the important role of guiding humanity's second moon landing. There is also significant international interest. Let's take a preliminary look at the launch process of Danuri. What mission does Danuri carry and what significance does it hold?

◇ Why do we need to go to the Moon?

The launch of Danuri is highly significant as it is Korea's first independently developed space exploration mission. The space development field broadly consists of three major areas: launch vehicles, satellites, and space exploration. Korea has been recognized for considerable capability in satellite development. Furthermore, with the successful second launch of the independent space launch vehicle Nuri on July 21, Korea now possesses launch vehicles as well. However, there has been no record of space exploration missions until now. If Danuri successfully enters lunar orbit and begins exploration, 2022 will become a historic year when Korea steps into all three major areas of space development for the first time in its history.

◇ The international lunar exploration boom

The Moon had fallen out of humanity's focus for a while after the manned Apollo missions in the 1960s and 70s succeeded in landing and sample collection. However, since the 2000s, with advances in science and technology reducing the cost of space launch vehicles and the rise of deep space exploration interests such as lunar resource extraction and Mars colonization, attention has intensified. There are 18 major lunar exploration plans scheduled after this year, including Korea's planned lunar lander launch in 2030.

This 'return to the Moon' by humanity is primarily driven by 'curiosity.' Professor Lee Kang-hwan, adjunct professor of physics and astronomy at Seoul National University, recently explained on a YouTube broadcast, "If humanity had no curiosity, we would have only lived in Africa and never spread across the Earth," adding, "NASA also pursues lunar missions not because of profit but to inspire children with dreams and hopes about space." The development and application of cutting-edge technology that advances by pushing limits is a secondary effect. As deep space exploration such as Mars colonization becomes more active, the Moon can serve as an intermediate base. Establishing a forward base on the Moon can significantly reduce the burden on launch vehicles overcoming Earth's gravity, thus lowering costs. Other uses mentioned include resource extraction such as helium-3, energy production like space solar power plants, medical and scientific experiments, and waste disposal facilities.

◇ Preview of Danuri launch

Danuri will be launched at 7:20 PM on August 2nd, Korean time 8:20 AM on August 3rd. It will head to space from Launch Pad 40 at the U.S. Space Force base in Cape Canaveral, Florida. The launch vehicle planned is SpaceX's Falcon 9. On July 6th, Danuri was transported by airplane from Incheon Airport, Korea, and arrived at Cape Canaveral two days later. After undergoing inspection, it will be erected on the launch pad and enter standby status on August 1st, with launch scheduled the following day.

◇ Why does it take 4.5 months to travel a 3-day distance?

There are three routes to the Moon. The first is the direct transfer used during the Apollo missions, which heads straight from Earth to the Moon. After escaping Earth's gravity, the orbit is adjusted en route to the Moon, consuming a tremendous amount of fuel. This method can reach the Moon within 5 days and is suitable for manned missions vulnerable to space environments. Another method is the phasing orbit transfer, which involves several revolutions in a very elongated elliptical orbit near Earth before gently entering lunar orbit. This takes about a month. Although it consumes less fuel than direct transfer, a considerable amount is still needed to enter lunar orbit. Korea uses neither of these two methods but employs the Ballistic Lunar Transfer (BLT) method. After leaving the atmosphere, it moves out to the Lagrange point where Earth's and Sun's gravity balance (up to 1.56 million km). Then it changes direction, using Earth's gravity to return and approach the Moon's Earth orbit before entering lunar orbit. This is a long route taking about 4.5 months. Although it takes the longest time, it consumes the least fuel. Due to the fuel load limit imposed by Danuri's weight, Korea chose the BLT method to conserve fuel and extend operation time as much as possible.

◇ How will the mission be carried out?

Danuri has attracted worldwide attention, being named the most notable lunar exploration plan of this year in the international academic journal 'Nature' last May. This is because it will allow humanity to observe the Moon more closely, precisely, and in diverse ways than ever since the Apollo project that landed directly on the Moon. Danuri will operate in a circular orbit 100 km above the Moon, passing over the lunar poles. It will orbit the Moon 12 times a day, conducting lunar observations and scientific and technological missions, and transmit observation data to Earth via antenna. Danuri's first mission is to find candidate landing sites for Korea's lunar landing exploration planned after 2030. Scientific goals also include measuring the Moon's magnetic field and radiation, and verifying space internet technology.

To achieve this, Danuri carries six scientific instruments: five developed by domestic research institutes and universities, and NASA's Shadowcam, a camera for permanently shadowed regions. The Korea Astronomy and Space Science Institute's wide-field polarization camera will create the world's first polarization map of the entire lunar surface. It will observe the lunar surface in detail and produce high-resolution (100m) titanium maps and helium-3 distribution maps. The magnetometer is expected to solve the mystery of the Moon, whose core has cooled, yet some parts of the surface retain magnetic fields. The gamma-ray spectrometer will analyze the characteristics and quantity of dust distributed across the Moon. NASA's Shadowcam is an ultra-high-performance camera with 1.7m resolution that will capture high-precision images of the permanently shadowed regions near the lunar poles. It will provide basic data for future U.S. lunar polar landing missions. The presence of water will also be confirmed. The space internet equipment will be used for various experiments such as observation data and message transmission and reception, and real-time video streaming demonstrations, contributing to the establishment of international space exploration standard communication networks in the future.

◇ Building a cooperative relationship with NASA, once disregarded

In the Danuri launch, Korea experienced a full-fledged working cooperation with NASA for the first time. NASA had not treated Korea, which lacked proper space launch vehicles or space exploration experience, seriously. Cooperation between KARI and NASA began in earnest when NASA's Shadowcam was mounted on Danuri to save costs. NASA advised and shared know-how with KARI, which had no space exploration experience, to boldly choose the BLT transfer orbit for Danuri's journey to the Moon. NASA is also assisting in establishing a communication network with Danuri, which will be up to 1.56 million km away from Earth. NASA provided critical help in building a deep space communication network by linking deep space antennas located in Goldstone, Los Angeles, and Madrid, Spain, with the deep space antenna installed by KARI in Yeoju, Gyeonggi Province, Korea, enabling communication with Danuri. Kim Dae-kwan, head of KARI's lunar exploration project team, explained, "Although there was no financial exchange with the U.S., we gained a lot of technical advice and cooperation on the condition of mounting Shadowcam," adding, "Being able to collaborate seriously with NASA was very helpful."

Researchers are inspecting South Korea's lunar orbiter 'Danuri' at the Korea Aerospace Research Institute in Yuseong-gu, Daejeon. Danuri will be loaded into a specially made container and transported to the U.S. Space Force Base at Cape Canaveral, Florida, on July 5, and is scheduled to be launched into space at 8:20 a.m. on August 3.
Daejeon ? Photo by Kang Jin-hyung aymsdream@

◇ Why is Danuri black?

The surface of Danuri is wrapped in a black multilayer thin-film insulation material to effectively discharge electric charge and withstand extreme cold and heat. It is made of polyimide material capable of enduring deep space beyond geostationary orbit (about 36,000 km) far from Earth. Danuri will operate in its target orbit for one year, and if fuel permits, the operation period may be extended. The extension decision will be made in July next year. At that time, KARI will also decide on measures such as lunar surface impact and image acquisition, and continued operation after entering a frozen lunar orbit.