[과학을읽다]Why did NASA praise ‘Danuri Shadow Cam’ out of nowhere?

NASA takes close-ups of the moon’s south pole to select the Artemis 3 landing site
200 times the performance of existing cameras, using reflected light and ground light to eliminate the flesh of the permanent shadow zone
President Yoon Seok-yeol’s visit to NASA Headquarters 4 days later, deliver ‘attention’ achievements

“ShadowCam Danuri (Korea) does its job well.”

On the 29th of last month (local time), the US National Aeronautics and Space Administration (NASA) released the results of a detailed examination of the lunar surface taken by Korea’s first lunar probe Danuri via the Shadow Cam payload on a main her website page. On the 25th of the same month, the President of South Korea, Yoon Seok-yeol, visited NASA headquarters, and this material, which was uploaded to the main page four days later, continues to decorate the main homepage of NASA from the 1st.

Regarding this, NASA said, “(Late last year) the success of Artemis 1 and the recent selection of Artemis 2 crew members (after 2025), preparations for Artemis 3 to explore the south pole of the moon for the first time in human history. has long begun.” “We are learning as much as possible about the lunar shadow zone, which promises deep space exploration and scientific discoveries that will help us understand Earth.”

At the same time, NASA focused on the introduction of Danuri and Shadow Cam. NASA said, “One of the ways to gather information (about the permanent shadow zone) is to use a high-sensitivity optical camera called the Shadow Cam.” It was installed on the Danuri (Korea Pathfinder Lunar Orbiter, KPLO) along with five other Korean-made scientific instruments.”

The Shadow Cam installed on Danuri is a symbolic project of Korean-US space cooperation. Until now, Korea, which has only a handful of experience in space development, has never had a cooperative relationship with the United States other than to request a satellite launch. Rather, the United States has ‘almost’ interfered with the development of the Nuri, citing the Missile Technology Control Regime (MTCR) and the International Traffic in Arms Regulations (ITAR). However, Danuri’s production and launch process was different. This is the first full case of cooperation between South Korea and the United States in the space sector. Hangwoon accepted an offer from NASA and installed a shielding stage. The money was not received, but Danuri deep space navigation technology and information, and a deep space communication network were supported. To save fuel and extend the life of the mission as much as possible, Danuri successfully entered lunar orbit after four months of deep space navigation via a ballistic lunar transfer (BLT) orbit, which had never been attempted before. It was a technology she had never tried by coincidence, had no experience other than launching and operating satellites. It is known that navigation technology, such as difficult direction changes and delicate propulsion operation for lunar orbit, would have been impossible without NASA’s cooperation. In addition to the deep space antenna network he built for communication with Danuri, Hangwooyeon also received support from the United States.

[이미지출처=연합뉴스]

Shadow Cam, a symbol of Korea-US space cooperation, was jointly developed by Marlin Space Science Systems, a private US company, and Arizona State University (ASU). Compared to other previous lunar observation cameras, it has excellent light sensitivity. This is to photograph the Permanent Shadow Zone at the Moon’s South Pole, where sunlight has never been exposed. The main mission is to select a candidate area for the Artemis 3 lunar landing, the second human lunar landing exploration project after 2025. It intends to take high-resolution images and map them for exploration and operation of the Permanent Shadow Zone at Pole South of the Moon, ice-like water is believed to be buried underground. To this end, it has more than 200 times better performance than the camera (NAC) installed on the LRO lunar orbiter launched by NASA in 2009.

On the same day, four days after President Yoon’s visit to the headquarters in Washington, DC, NASA released representative images taken so far through Shadow Cam. The first image is a high resolution image taken by ShadowCam of Skeleton Crater located near the south pole of the moon. The topographic features of the surface are clearly revealed to the extent that the remains of rocks that are rolled down are intact. NASA said, “The Shadow Cam can operate in extremely low light conditions, so it is possible to take images of this level.” In particular, regarding the clearly recorded remains of rocks that have fallen from the high walls of the crater, he emphasized that “we can improve our understanding of the moon’s geotechnical features by discovering the shape, speed and characteristics of the topsoil rocks. .”

‘Shadow Cam’ found in Danuri. Image source = Provided by the Ministry of Science and ICT

NASA also released detailed pictures of the lunar surface using weak reflected light or an earthquake. The moon is illuminated by ‘earth black’, just like the moonlight on Earth. From the moon, when it looks like a ‘crescent moon’ from the earth, the whole earth is seen as a ‘full moon’, and the ‘light of the earth’ is the strongest as ‘moonlight’ ‘. However, the intensity of reflected sunlight is only 1/10. During the test, Shadow Cam was able to capture inside Bruce Crater near the lunar equator by using it during the new moon phase when the earth’s light was strongest, showing its excellent performance. In addition, images of detailed images such as the Marvin crater were also released using light reflected in the permanent shadow zone, 26 km from the moon’s south pole.

Correspondent Kim Bong-soo bskim@asiae.co.kr