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Pragyan (Chandrayaan-2)

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This article is about the lunar rover from Chandrayaan 2. For the rover from Chandrayaan 3, see Pragyan (Chandrayaan-3).

Pragyan
Pragyan mounted on the ramp of Vikram lander
Mission typeLunar rover
OperatorISRO
Mission duration0 days (landing failure)
Spacecraft properties
ManufacturerISRO
Landing mass27 kg (60 lb)
Dimensions0.9 m × 0.75 m × 0.85 m (3.0 ft × 2.5 ft × 2.8 ft)
Power50 W from solar panels
Start of mission
Launch date22 July 2019 (2019-07-22) 14:43:12 IST (09:13:12 UTC)
RocketLVM3 M1, LVM3 M4
Launch siteSDSC Second launch pad
ContractorISRO
Deployed fromVikram
Deployment date7 September 2019 (intended,[1] never deployed from destroyed lander)[2]
Lunar rover
Landing date6 September 2019, 20:00–21:00 UTC
Landing siteAttempted: 70.90267°S 22.78110°E[3] (Intended)
Crash landing at least 500m away from planned site. (Actual)
Distance driven500 m (1,600 ft) (intended)

Pragyan (from Sanskrit: prajñāna, lit. 'wisdom')[4][5] is a lunar rover that forms part of Chandrayaan-2, a lunar mission developed by the Indian Space Research Organisation (ISRO).[6] The rover was launched as part of Chandrayaan-2 on 22 July 2019 and was destroyed with its lander, Vikram, when it crashed on the Moon on 6 September 2019.[2][7]

In July 2023, Chandrayaan-3 launched, carrying new versions of Vikram and Pragyan,[8] which successfully landed near the lunar south pole on 23 August 2023.[9]

Overview

[edit]

Pragyan has a mass of about 27 kg (60 lb) and dimensions of 0.9 m × 0.75 m × 0.85 m (3.0 ft × 2.5 ft × 2.8 ft), with a power output of 50 watts.[10] It is designed to operate on solar power.[11][12] The rover moves on six wheels and is intended to traverse 500 m (1,600 ft) on the lunar surface at the rate of 1 cm (0.39 in) per second, performing on-site analysis and sending the data to its lander for relay back to the Earth.[13][14][15][16][17] For navigation, the rover is equipped with:

  • Stereoscopic camera-based 3D vision: two 1-megapixel, monochromatic NAVCAMs in front of the rover to provide the ground control team with a 3D view of the surrounding terrain, and help in path-planning by generating a digital elevation model of the terrain.[18] IIT Kanpur contributed to the development of the subsystems for light-based map generation and motion planning for the rover.[19]
  • Control and motor dynamics: the rover design has a rocker-bogie suspension system and six wheels, each driven by independent brushless DC electric motors. Steering is accomplished by differential speed of the wheels or skid steering.[20]

The expected operating time of the rover is one lunar day or around 14 Earth days, as its electronics are not designed to endure the frigid lunar night. Its power system has a solar-powered sleep and wake-up cycle, which could result in a longer operation time than planned.[21][22]

History

[edit]
Further information: Chandrayaan-2

Planned landing site

[edit]

Two landing sites were selected in the lunar south polar region, each with a landing ellipse of 32 km × 11 km (19.9 mi × 6.8 mi).[3] The prime landing site (PLS54) is at 70°54′10″S 22°46′52″E / 70.90267°S 22.78110°E / -70.90267; 22.78110, approximately 350 km (220 mi) north of the rim of the South Pole–Aitken basin.[23][3] The alternative landing site (ALS01) is at 67°52′27″S 18°28′10″W / 67.87406°S 18.46947°W / -67.87406; -18.46947. The prime site is on a high plain between the craters Manzinus C and Simpelius N,[24][23] on the near side of the Moon.[3] The criteria used to select the landing zones were a location in the south polar region and on the near side, a slope less than 15 degrees, with boulders less than 50 cm (20 in) in diameter, a crater and boulder distribution, being sunlit for at least 14 days, and with nearby ridges not shadowing the site for long durations.[3]

Both the planned site and the alternative site are located within the polar LQ30 quadrangle. The surface likely consists of impact melt, possibly mantled by ejecta from the massive South Pole–Aitken basin and mixing by subsequent nearby impacts.[25] The nature of the melt is mostly mafic,[25] meaning it is rich in silicate minerals, magnesium, and iron. The region could also offer scientifically valuable rocks from the lunar mantle if the basin impactor excavated all the way through the crust.[26]

Crash landing

[edit]

The lander Vikram, carrying Pragyan, separated from the Chandrayaan-2 orbiter on 7 September 2019 and was scheduled to land on the Moon at around 1:50 a.m. IST. The initial descent was considered within mission parameters, passing critical braking procedures as planned. The descent and soft-landing was to be done by the onboard computers on Vikram, with mission control unable to make corrections.[27]

The lander's trajectory began to deviate at about 2.1 kilometers (1.3 mi; 6,900 ft) above the surface.[28] The final telemetry readings during ISRO's live-stream show that Vikram's final vertical velocity was 58 m/s (210 km/h; 130 mph) at 330 m (1,080 ft) above the surface, which according to the MIT Technology Review was "quite fast for a lunar landing".[29] Initial reports suggested a crash,[30][31] and were later confirmed by ISRO chairman K. Sivan, stating that the lander location had been found, and "it must had been a hard landing".[7][32][33] The Lunar Reconnaissance Orbiter took images of the crash site, showing that the lander had been destroyed by the impact, creating an impact site and debris field spanning kilometers.[34]

See also

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References

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  1. ^ "Live media coverage of the landing of Chandrayaan-2 on lunar surface – ISRO". www.isro.gov.in. Archived from the original on 2 September 2019. Retrieved 2 September 2019.
  2. ^ a b "Chandrayaan – 2 Latest Update". isro.gov.in. 7 September 2019. Archived from the original on 8 September 2019. Retrieved 11 September 2019.
  3. ^ a b c d e Amitabh, S.; Srinivasan, T. P.; Suresh, K. (2018). Potential Landing Sites for Chandrayaan-2 Lander in Southern Hemisphere of Moon (PDF). 49th Lunar and Planetary Science Conference. 19–23 March 2018. The Woodlands, Texas. Bibcode:2018LPI....49.1975A. Archived from the original (PDF) on 22 August 2018.
  4. ^ "Chandrayaan-2 Spacecraft". Archived from the original on 18 July 2019. Retrieved 24 August 2019. Chandrayaan 2's Rover is a 6-wheeled robotic vehicle named Pragyan, which translates to 'wisdom' in Sanskrit.
  5. ^ Wilson, Horace Hayman (1832). A dictionary in Sanscrit and English. Calcutta: Education Press. p. 561. Archived from the original on 9 February 2019. Retrieved 1 September 2019.
  6. ^ "Isro: Chandrayaan-2 launch between July 9 and 16 | India News – Times of India". The Times of India. May 2019. Archived from the original on 18 May 2019. Retrieved 1 May 2019.
  7. ^ a b Vikram lander located on lunar surface, wasn't a soft landing: Isro. Archived 2020-11-12 at the Wayback Machine Times of India. 8 September 2019.
  8. ^ "ISRO to launch moon mission Chandrayaan-3 on July 14. Check details". Hindustan Times. 6 July 2023. Archived from the original on 8 July 2023. Retrieved 6 July 2023.
  9. ^ "Chandrayaan-3 launch on 14 July, lunar landing on 23 or 24 August". The Hindu. 6 July 2023. ISSN 0971-751X. Archived from the original on 11 July 2023. Retrieved 14 July 2023.
  10. ^ "Launch Kit at a glance – ISRO". www.isro.gov.in. Archived from the original on 23 July 2019. Retrieved 5 August 2019.
  11. ^ "Chandrayaan-2 to Be Launched in January 2019, Says ISRO Chief". Gadgets360. NDTV. Press Trust of India. 29 August 2018. Archived from the original on 29 August 2018. Retrieved 29 August 2018.
  12. ^ "ISRO to send first Indian into Space by 2022 as announced by PM, says Dr Jitendra Singh" (Press release). Department of Space. 28 August 2018. Retrieved 29 August 2018.
  13. ^ "ISRO to Launch Chandrayaan 2 on July 15, Moon Landing by September 7". The Wire. Archived from the original on 13 June 2019. Retrieved 12 June 2019.
  14. ^ Singh, Surendra (10 May 2019). "Chandrayaan-2 will carry 14 payloads to moon, no foreign module this time". The Times of India. Archived from the original on 10 May 2019. Retrieved 11 May 2019.
  15. ^ "Payloads for Chandrayaan-2 Mission Finalised" (Press release). Indian Space Research Organisation. 30 August 2010. Archived from the original on 13 May 2019. Retrieved 4 January 2010.
  16. ^ "Chandrayaan-2 to get closer to moon". The Economic Times. Times News Network. 2 September 2010. Archived from the original on 12 August 2011.
  17. ^ Ramesh, Sandhya (12 June 2019). "Why Chandrayaan-2 is ISRO's 'most complex mission' so far". ThePrint. Archived from the original on 11 July 2019. Retrieved 12 June 2019.
  18. ^ Laxmiprasad, A.S; Sridhar Raja, V.L.N; Menon, Surya; Goswami, Adwaita; Rao, M.V.H; Lohar, K.A (15 July 2013). "An in situ laser induced breakdown spectroscope (LIBS) for Chandrayaan-2 rover: Ablation kinetics and emissivity estimations". Advances in Space Research. 52 (2): 332–321. Bibcode:2013AdSpR..52..332L. doi:10.1016/j.asr.2013.03.021. Archived from the original on 13 March 2023. Retrieved 13 March 2023 – via ScienceDirect.
  19. ^ "With robot hands, IIT-K profs bring joy to paralytics". The Times of India. 2019. Archived from the original on 20 July 2019. Retrieved 10 July 2019.
  20. ^ Annadurai, Mylswami; Nagesh, G.; Vanitha, Muthayaa (28 June 2017). ""Chandrayaan-2: Lunar Orbiter & Lander Mission", 10th IAA Symposium on The Future of Space Exploration: Towards the Moon Village and Beyond, Torin, Italy". Archived from the original on 28 June 2017. Retrieved 14 June 2019. Mobility of the Rover in the unknown lunar terrain is accomplished by a Rocker bogie suspension system driven by six wheels. Brushless DC motors are used to drive the wheels to move along the desired path and steering is accomplished by differential speed of the wheels. The wheels are designed after extensive modelling of the wheel-soil interaction, considering the lunar soil properties, sinkage and slippage results from a single wheel test bed. The Rover's mobility has been tested in the Lunar test facility wherein the soil simulant, terrain and the gravity of the moon are simulated. The limitations w.r.t slope, obstacles, pits in view of slippage/sinkage have been experimentally verified with the analysis results. Alt URL
  21. ^ "Dr M Annadurai, Project director, Chandrayaan 1: 'Chandrayaan 2 logical extension of what we did in first mission'". The Indian Express. 29 June 2019. Archived from the original on 29 June 2019. Retrieved 30 June 2019.
  22. ^ Payyappilly, Baiju; Muthusamy, Sankaran (17 January 2018). "Design framework of a configurable electrical power system for lunar rover". 2017 4th International Conference on Power, Control & Embedded Systems (ICPCES). pp. 1–6. doi:10.1109/ICPCES.2017.8117660. ISBN 978-1-5090-4426-9. S2CID 38638820. Archived from the original on 20 July 2021. Retrieved 5 August 2019.
  23. ^ a b Geological Insights into Chandrayaan-2 Landing Site in the Southern High Latitudes of the Moon. Archived 2020-06-19 at the Wayback Machine Rishitosh K. Sinha, Vijayan Sivaprahasam, Megha Bhatt, Harish Nandal, Nandita Kumari, Neeraj Srivastava, Indhu Varatharajan, Dwijesh Ray, Christian Wöhler, and Anil Bhardwaj. 50th Lunar and Planetary Science Conference 2019 (LPI Contrib. No. 2132).
  24. ^ Chandrayaan-2: How 'Lander Vikram' will touchdown on the moon? Archived 2019-07-19 at the Wayback Machine Srishti Choudhary, Live Mint 14 July 2019.
  25. ^ a b Update on the Geologic Mapping of the Lunar South Pole Quadrangle (LQ-30): Evaluating Mare, Cryptomare and Impact Melt Deposits. Archived 2022-06-16 at the Wayback Machine S. C. Mest, D. C. Berman, N.E. Petro, and R. A. Yingst. 46th Lunar and Planetary Science Conference (2015).
  26. ^ As India prepares for another Moon mission, here is what makes Chandrayaan-2 special. Archived 2019-08-06 at the Wayback Machine Sandhya Ramesh, The Print. 14 July 2019.
  27. ^ Chandrayaan 2: Here's everything about ISRO Moon-landing its Vikram lander. Archived 2019-09-11 at the Wayback Machine Financial Express. Ribhu Mishra, 7 September 2019.
  28. ^ India Just Found Its Lost Vikram Lander on the Moon, Still No Signal. Archived 2019-09-09 at the Wayback Machine Tariq Malik ,Space. 8 September 2019.
  29. ^ Neel V. Patel (6 September 2019). "India's Chandrayaan-2 lander likely crashed into the moon's surface". MIT Technology Review. Archived from the original on 6 September 2019. Retrieved 7 September 2019.
  30. ^ India's Moon Mission Continues Despite Apparent Lander Crash. Archived 2019-09-09 at the Wayback Machine Mike Wall, Space. 7 September 2019. Quote: "India's Moon Mission Continues Despite Apparent Lander Crash."
  31. ^ "India's Vikram Spacecraft Apparently Crash-Lands on Moon". www.planetary.org. Archived from the original on 10 September 2019. Retrieved 7 September 2019.
  32. ^ "Lander Vikram located: K Sivan". www.aninews.in. Archived from the original on 8 September 2019. Retrieved 8 September 2019.
  33. ^ Schultz, Kai (8 September 2019). "India Says It Has Located Chandrayaan-2 Lander on Moon's Surface". The New York Times. Archived from the original on 8 September 2019. Retrieved 8 September 2019.
  34. ^ "India's crashed Vikram moon lander spotted on lunar surface". the Guardian. Agence France-Presse. 3 December 2019. Archived from the original on 6 October 2021. Retrieved 5 October 2021.
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