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Danuri

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This article is about the South Korean lunar space probe. For the Indonesian police officer, see Bambang Hendarso Danuri.

The Korea Pathfinder Lunar Orbiter (KPLO), officially Danuri,[8] is South Korea's first lunar orbiter. The orbiter, its science payload and ground control infrastructure are technology demonstrators. The orbiter will also be tasked with surveying lunar resources such as water ice, uranium, helium-3, silicon, and aluminium, and produce a topographic map to help select future lunar landing sites.

Korea Pathfinder Lunar Orbiter (KPLO)
A rendered image of KPLO
NamesKPLO
Mission typeLunar orbiter
OperatorKorea Aerospace Research Institute (KARI)
COSPAR ID2022-094A Edit this at Wikidata
SATCAT no.53365Edit this on Wikidata
Websitewww.kari.re.kr/eng/sub03_07_01.do
Mission duration846 days, 19 hours and 55 minutes (elapsed)
Spacecraft properties
ManufacturerKorea Aerospace Research Institute (KARI)
Launch mass678 kg (1,495 lb)[1][2]
Dry massc. 550 kg (1,210 lb) [3]
Payload mass40 kg (88 lb)
Power760 watts[4]
Start of mission
Launch date4 August 2022, 23:08:48 UTC[5]
RocketFalcon 9 Block 5
Launch siteCape Canaveral (CCSFS),
SLC-40
ContractorSpaceX
Moon orbiter
Orbital insertion17 December 2022 KST (1st)
28 December 2022 KST (5th)[6]
Orbital parameters
Periselene altitude100 km[6]
Aposelene altitude100 km
Inclination90° (polar)
Transponders
BandS-band, X-band[4][7]
Instruments
Lunar Terrain Imager (LUTI)
Wide-Angle Polarimetric Camera (PolCam)
KPLO Magnetometer (KMAG)
KPLO Gamma Ray Spectrometer (KGRS)
Delay-Tolerant Networking experiment (DTNPL)
ShadowCam (NASA)
Phase 2: lander and rover →

The mission was launched on 4 August 2022 on a Falcon 9 Block 5 launch vehicle.[5] It was inserted into orbit around the Moon on 16 December 2022 (UTC).[9]

Name

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On 23 May 2022, the South Korean Ministry of Science and ICT officially named the Korea Pathfinder Lunar Orbiter (시험용 달 궤도선, 試驗用月軌道船) as "Danuri" (다누리). Danuri is a portmanteau of two Korean words, dal (달) which means moon and nurida (누리다) which means enjoy. According to the ministry, this new name implies a big hope and desire for the success of South Korea's first Moon mission.[10]

Overview

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South Korea's space agency, called Korea Aerospace Research Institute (KARI), together with NASA produced a lunar orbiter feasibility study in July 2014.[11] The two agencies signed an agreement in December 2016 where NASA will collaborate with one science instrument payload, telecommunications, navigation, and mission design.[12][13][14]

The Korean Lunar Exploration Program (KLEP) is divided in two phases.[13][15] Phase 1 is the launch and operation of KPLO, which is the first lunar probe by South Korea,[12] meant to develop and enhance South Korea's technological capabilities, as well as map natural resources from orbit. The key goals of the KPLO orbiter mission include investigation of lunar geology and space environment, exploration of lunar resources, and testing of future space technology which will assist in future human activities on the Moon and beyond.

Phase 2 will include a lunar orbiter, a lunar lander, and a 20 kg rover,[16] to be launched together on a KSLV-3 [1] South Korean launch vehicle from the Naro Space Center,[14][15] by 2032.[17][18]

Objectives

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The main objectives of this mission are to enhance the South Korean technological capabilities on the ground and in outer space, and to "increase both the national brand value and national pride".[19] The specific technological objectives are:[7]

From the lunar science perspective, understanding the water cycle on the Moon is critical to mapping and exploitation.[20] Solar wind protons can chemically reduce the abundant iron oxides present the lunar soil, producing native metal iron (Fe0) and a hydroxyl ion (OH−) that can readily capture a proton to form water (H2O). Hydroxyl and water molecules are thought to be transported throughout the lunar surface by mysterious unknown mechanisms, and they seem to accumulate at permanently shadowed areas that offer protection from heat and solar radiation.[20]

Space Internet

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To test the experimental system of the “space Internet”, Danuri successfully forwarded a number of photos taken, as well as several video files, including, BTS’ “Dynamite” from outer space to Earth at Korea's Ministry of Science and ICT, Korea Aerospace Research Institute (KARI), and the Electronics and Telecommunications Research Institute (ETRI) on 7 November 2022.[21][22]

Science payload

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KPLO carries six science instruments with a total mass of approximately 40 kg (88 lb).[7] Five instruments are from South Korea and one from NASA:[23][14][20]

  • Lunar Terrain Imager (LUTI) will take images of probable landing sites for the second stage lunar exploration mission and special target sites of the lunar surfaces with a high spatial resolution (<5 m).
  • Wide-Angle Polarimetric Camera (PolCam) will acquire the polarimetric images of the entire lunar surface except for the polar regions with medium spatial resolution in order to investigate the detailed characteristics of lunar regolith.
  • KPLO Magnetometer (KMAG) is a magnetometer that will measure the magnetic strength of the lunar environment (up to ~100 km above the lunar surface) with ultra-sensitive magnetic sensors.
  • KPLO Gamma Ray Spectrometer (KGRS) is a gamma-ray spectrometer that will investigate the chemical composition of lunar surface materials within a gamma-ray energy range from 10 keV to 10 MeV, and map their spatial distribution.[3][24]
  • Delay-Tolerant Networking experiment (DTNPL) will perform a communication experiment on delay-tolerant networking (DTN), a type of interplanetary Internet for communication with landed assets.[7]
  • NASA's ShadowCam will map the reflectance within the permanently shadowed regions to search for evidence of water ice deposits.[25]

ShadowCam

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ShadowCam is a hypersensitive optical camera designed to collect images of permanently shadowed regions (PSRs) near the Moon's poles. This allows ShadowCam to map the reflectance of these regions to search for evidence of ice deposits, observe seasonal changes, and measure the terrain inside the craters.[26] The instrument is based on the Lunar Reconnaissance Orbiter LROC narrow angle camera (NAC), but it is 200 times more sensitive[27] to allow for capturing details within the permanently shadowed regions. ShadowCam was developed by scientists at Arizona State University and Malin Space Science Systems.[28] The first released ShadowCam image showed the wall the and floor of Shackleton crater.[29]

 
First photo by ShadowCam, Shackleton crater[29]

Science objectives of the ShadowCam experiment:[30][31]

Map albedo patterns in PSRs and interpret their nature
ShadowCam will search for frost, ice, and lag deposits by mapping reflectance with resolution and signal-to-noise ratios comparable to LROC NAC images of illuminated terrain.
Investigate the origin of anomalous radar signatures associated with some polar craters
ShadowCam will determine whether high-purity ice or rocky deposits are present inside PSRs.
Document and interpret temporal changes of PSR albedo units
ShadowCam will search for seasonal changes in volatile abundance in PSRs by acquiring monthly observations.
Provide hazard and trafficability information within PSRs for future landed elements
ShadowCam will provide optimal terrain information necessary for polar exploration.
Map the morphology of PSRs to search for and characterize landforms that may be indicative of permafrost-like processes
ShadowCam will provide unprecedented images of PSR geomorphology at scales that enable detailed comparisons with terrain anywhere on the Moon.

Launch

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Originally planned for a December 2018 launch,[14][28] KPLO was placed into orbit by a Falcon 9 launch vehicle on 4 August 2022.[5] Because Danuri was launched as a dedicated Falcon 9 mission, the payload along with Falcon 9's second stage was placed directly on an Earth escape trajectory and into heliocentric orbit when the second stage reignited for a second engine startup or escape burn.

 
The trajectory of KPLO (Danuri) via the ballistic lunar transfer (BLT)

As KPLO uses ballistic lunar transfer (BLT) to transfer to a Moon orbit, it took the spacecraft about 135 days to reach the Moon, with a lunar-orbit insertion on 16 December 2022 (UTC).[32][9] After insertion, the spacecraft will conduct a set of phasing-burns to reduce the orbit's eccentricity from elliptic to circular, reaching low-lunar orbit. This was a change of plan from the previous one, where the orbiter would have performed at least three highly elliptical orbits of Earth, each time increasing its velocity and altitude until it reaches escape velocity, initiating a trans-lunar injection.[14][33]

The spacecraft's main propulsion is from four 30-newton thrusters, and for attitude control (orientation) it uses four 5-newton thrusters.[7][14]

Animation of Danuri
 
Around the Earth
 
Around the Sun - Frame rotating with the Earth
 
Around the Moon
  Earth ·   Danuri ·   Moon ·   L1 point

See also

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References

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  1. ^ Kang, Il-yong (17 May 2022). "[K-스페이스 시대] ② 한국 최초 달 탐사선 오는 8월 발사...7번째 달 탐사국 이름 올린다" [[K-Space Era] ② Korea's first lunar probe to be launched in August... 7th lunar probe to be named]. Aju Business Daily (in Korean). Retrieved 22 May 2022.
  2. ^ Clark, Stephen (20 September 2019). "Launch of South Korean lunar orbiter delayed to 2022". Spaceflight Now. Retrieved 27 September 2020.
  3. ^ a b Introduction to the lunar gamma-ray spectrometer for Korea Pathfinder Lunar Orbiter Kim, Kyeong; Min, Kyoung Wook; et al. 42nd COSPAR Scientific Assembly July 2018; Bibcode: 2018cosp...42E1755K
  4. ^ a b "Korea Pathfinder Lunar Orbiter (KPLO)". NASA. 10 February 2021. Retrieved 27 February 2021.   This article incorporates text from this source, which is in the public domain.
  5. ^ a b c S.Korean Spaceflight [@KOR_Spaceflight] (28 July 2022). "Danuri(KPLO) launch now scheduled for August 5th 08:08 KST, according to MSIT/KARI" (Tweet) – via Twitter.
  6. ^ a b "다누리, 달 임무궤도 진입 시작" [Danuri begins entering lunar mission orbit]. Ministry of Science and ICT. 15 December 2022.
  7. ^ a b c d e Korean Pathfinder Lunar Orbiter (KPLO) Status Update Korea Aerospace Research Institute (KARI) 10 October 2017
  8. ^ Kan, Hyeong-woo (23 May 2022). "Korea's first lunar mission named 'Danuri'". The Korea Herald. Retrieved 26 May 2022.
  9. ^ a b "South Korea's 1st moon probe Danuri begins to enter lunar orbit". Space.com. 17 December 2022.
  10. ^ Hyeong-woo, Kan (23 May 2022). "Korea's first lunar mission named 'Danuri'". The Korea Herald. Retrieved 23 May 2022.
  11. ^ "Opening of a New Chapter for Korea-US Space Cooperation" Signing of Korea-US Lunar Probe Implementation Agreement Korea Aerospace Research Institute (KARI) 31 December 2016
  12. ^ a b KPLO Lunar Exploration Program Korea Aerospace Research Institute (KARI) Accessed on 25 January 2019
  13. ^ a b SpaceX selected to assist 2020 South Korean lunar orbiter voyage Lee Keun-young, Hankyoreh 30 December 2017
  14. ^ a b c d e f South Korea's first lunar mission planned for 2020 Emily Lakdawalla, The Planetary Society 7 December 2017
  15. ^ a b Korean Lunar Exploration Program Korean Aerospace Research Institute (KARI) Accessed on 25 January 2019
  16. ^ Kim, K.; Wohler, C.; Hyeok Ju, G.; Lee, S.; Rodriguez, A.; Berezhnoy, A.; Gasselt, S.; Grumpe, A.; and Aymaz, R.; (2016) Korean lunar lander – Concept study for landing-site selection for lunar resource exploration. The International Archives Of The Photogrammetry, Remote Sensing And Spatial Information Sciences, Vol XLI-B4, pp 417–423 (2016), 417. doi:10.5194/isprs-archives-XLI-B4-417-2016
  17. ^ Pak, Han-pyol (1 July 2013). "핵전지 실은 한국형 로버 … 지구서 우주인터넷 통해 조종". JoongAng Ilbo. Retrieved 19 July 2013.
  18. ^ Kim, Jack (20 November 2007). "South Korea eyes moon orbiter in 2020, landing 2025". Reuters. Retrieved 25 January 2019.
  19. ^ Prospective of Korean space project, Lunar Exploration. Korea Aerospace Research Institute (KARI), South Korea. Accessed on 25 January 2019.
  20. ^ a b c South Korea's 2018 Lunar Mission. Paul D. Spudis, Air and Space Magazine. 26 September 2016.
  21. ^ "The South Korean probe "Danuri" sent a music video of the BTS group". 17 November 2022.
  22. ^ 우주에서 보내온 BTS 다이너마이트 뮤직비디오ㅣ다누리 우주 인터넷 탑재체, retrieved 18 December 2022
  23. ^ Krebs, Gunter (16 March 2020). "KPLO". Gunter's Space Page. Retrieved 27 September 2020.
  24. ^ Shin, J.; Jin, H.; Lee, H.; Lee, S.; Lee, S.; Lee, M.; Jeong, B.; Lee, J.-K.; Lee, D.; Son, D.; Kim, K.-H.; Garrick-Bethell, I.; Kim, E. (18–22 March 2019). KMAG: The Magnetometer of the Korea Pathfinder Lunar Orbiter (KPLO) Mission (PDF). Lunar and Planetary Science Conference. Universities Space Research Association (USRA). Bibcode:2019LPI....50.2276S. Retrieved 27 September 2020.
  25. ^ "ShadowCam: Seeing into the Shadow". Arizona State University. 2018. Retrieved 27 September 2020.
  26. ^ "NASA's ShadowCam Launches Aboard Korea Pathfinder Lunar Orbiter – Artemis". blogs.nasa.gov. 4 August 2022. Retrieved 6 August 2022.  This article incorporates text from this source, which is in the public domain.
  27. ^ "ShadowCam - Seeing in the Shadows". 19 December 2018.
  28. ^ a b Clark, Stephen (28 April 2017). "U.S. instrument team to fly camera on South Korean moon mission". Spaceflight Now. Retrieved 27 September 2020.
  29. ^ a b "ShadowCam • Seeing in the Shadows". shadowcam.sese.asu.edu. Retrieved 12 January 2023.
  30. ^ "ShadowCam • Seeing in the Shadows". shadowcam.sese.asu.edu. Retrieved 6 August 2022.
  31. ^ "ShadowCam Factsheet" (PDF). shadowcam.sese.asu.edu. Archived from the original (PDF) on 8 August 2022. Retrieved 6 August 2022.
  32. ^ "다누리호 (KPLO-Korea Pathfinder Lunar Orbiter)". www.kari.re.kr. Retrieved 6 September 2022.
  33. ^ "[ home > R&D > Lunar Exploration > Korea's first step toward lunar exploration ]". www.kari.re.kr. Retrieved 29 June 2022.
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