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Pragyan (Chandrayaan-3)

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

Pragyan
Pragyan roll out on Moon
Mission typeLunar rover
OperatorISRO
Mission duration12 days (final)
Spacecraft properties
ManufacturerISRO
Landing mass26 kg (57 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 date14 July 2023 (2023-07-14) 14:35 IST (09:05 UTC)[1]
RocketLVM3 M4
Launch siteSDSC Second launch pad
ContractorISRO
Deployed fromVikram
Deployment date23 August 2023[2]
Lunar rover
Landing date23 August 2023, 12:32 UTC[3]
Distance driven101.4 m (333 ft)

Pragyan (from Sanskrit: prajñāna, lit. 'wisdom')[4][5] is a lunar rover that forms part of Chandrayaan-3, a lunar mission developed by the Indian Space Research Organisation (ISRO).[6]

A previous iteration of the rover, also named Pragyan, 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.[7][8] Chandrayaan-3 launched on 14 July 2023, carrying new versions of Vikram and Pragyan,[1] which successfully landed near the lunar south pole on 23 August 2023.[9]

Overview

[edit]
Schematic view of the rover

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 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]
A four-meter diameter crater, as captured by the Navigation camera onboard the rover.

Chandrayaan-3 was launched aboard an LVM3-M4 rocket on 14 July 2023, at 09:05 UTC from Satish Dhawan Space Centre Second Launch Pad in Sriharikota, Andhra Pradesh, India. On 23 August 2023, as the lander approached the low point of its orbit, its four engines fired as a braking manoeuvre at 30 kilometres (19 mi) above the Moon's surface. After 11.5 minutes, the lander was 7.2 km (4.5 miles) above the surface; it maintained this altitude for about 10 seconds, then stabilized itself using eight smaller thrusters and rotated from a horizontal to a vertical position while continuing its descent.

It then used two of its four engines to slow its descent to roughly 150 metres (490 ft); it hovered there for about 30 seconds and located an optimal landing spot before continuing downward and touching down at 12:32 UTC.[23][24]

After reaching the Moon's south pole, Chandrayaan-3 deployed the rover to explore the cratered surface, harnessed integrated cameras to send back videos of its environment, and started working on the research objectives planned for a two-week exploration of the Moon.[25]

The first video of the rover, posted on 25 August 2023, showed it leaving the Vikram lander on a ramp and driving onto the Moon. ISRO posted the video in a thread on Twitter that also included footage from the lander approaching its landing site and kicking up dust as it touched down on the surface. ISRO wrote afterwards that the rover's two scientific instruments had been turned on and that it had moved eight meters.[26]

On 26 August, the ISRO posted a new video, shot from the lander, of the rover's drive away, moving almost out of the lander's sight.[27] On 27 August, it published two pictures after the rover encountered a large crater positioned three metres ahead of its location. However, the rover safely headed on a new path afterwards.[28][29]

Later on 30 August, at 7:35 am, the rover took a picture of the Vikram lander, showing its two payloads, Chaste and ILSA, had deployed.[30] Another image was captured at 11:04 the same day, from a distance of 15 m.[31]

On September 2, the rover finished all assignments and entered into a sleep mode in preparation for wake up on September 22, however, it was not expected to continue working.[32] Its battery was fully charged when it went into hibernation.[33] However, after more than two weeks, both the rover and its lander's reactivations were delayed to the 23rd for unspecified reasons.[34] As of 28 September 2023, the rover still had not woken[35] and no updates have been provided by ISRO since. The Pragyan rover is presumed to be dead.

See also

[edit]

References

[edit]
  1. ^ a b "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.
  2. ^ "Chandrayaan-3 launch on July 14; August 23–24 preferred landing dates". THE TIMES OF INDIA. 6 July 2023. Archived from the original on 25 August 2023. Retrieved 7 July 2023.
  3. ^ "Chandrayaan-2 update: Fifth Lunar Orbit Maneuver". Indian Space Research Organisation. 1 September 2019. Archived from the original on 3 September 2019. Retrieved 1 September 2019.
  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. ^ "Chandrayaan – 2 Latest Update". isro.gov.in. 7 September 2019. Archived from the original on 8 September 2019. Retrieved 11 September 2019.
  8. ^ 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.
  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. (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): 332–341. Bibcode:2013AdSpR..52..332L. doi:10.1016/j.asr.2013.03.021.
  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 mobility has been tested in the Lunar test facility wherein the soil simulant, terrain and the gravity of 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. ^ Mehta, Jatan. "Chandrayaan-3 Makes Historic Touchdown on the Moon". Scientific American. Archived from the original on 24 August 2023. Retrieved 23 August 2023.
  24. ^ "India Is on the Moon: Lander's Success Moves Nation to Next Space Chapter". The New York Times. 23 August 2023. Archived from the original on 23 August 2023. Retrieved 23 August 2023.
  25. ^ Monisha Ravisetti (28 August 2023). "India's Chandrayaan-3 takes the moon's temperature near lunar south pole for 1st time". Space.com. Retrieved 29 August 2023.
  26. ^ ISRO [@isro] (25 August 2023). "... ... and here is how the Chandrayaan-3 Rover ramped down from the Lander to the Lunar surface" (Tweet). Retrieved 29 August 2023 – via Twitter.
  27. ^ ISRO [@isro] (26 August 2023). "Chandrayaan-3 Mission:
    🔍What's new here?
    Pragyan rover roams around Shiv Shakti Point in pursuit of lunar secrets at the South Pole 🌗!"     (Tweet). Retrieved 29 August 2023 – via Twitter.
  28. ^ ISRO [@isro] (28 August 2023). "Chandrayaan-3 Mission:
    On August 27, 2023, the Rover came across a 4-meter diameter crater positioned 3 meters ahead of its location.
    The Rover was commanded to retrace the path.
    It's now safely heading on a new path"     (Tweet). Retrieved 29 August 2023 – via Twitter.
  29. ^ Davis, Wes (28 August 2023). "India's lunar mission beams back video and images from the Moon's south pole". The Verge. Retrieved 29 August 2023.
  30. ^ ISRO [@isro] (30 August 2023). "Chandrayaan-3 Mission:
    Smile, please📸!
    Pragyan Rover clicked an image of Vikram Lander this morning.
    The 'image of the mission' was taken by the Navigation Camera onboard the Rover (NavCam).
    NavCams for the Chandrayaan-3 Mission are developed by the Laboratory for Electro-Optics Systems (LEOS)
    https://isro.gov.in/LEOS.html"     (Tweet). Retrieved 31 August 2023 – via Twitter.
  31. ^ ISRO [@isro] (30 August 2023). "Beyond Borders, Across Moonscapes:
    India's Majesty knows no bounds!.
    Once more, co-traveller Pragyan captures Vikram in a Snap!
    This iconic snap was taken today around 11 am IST from about 15 m.
    The data from the NavCams is processed by SAC/ISRO, Ahmedabad"     (Tweet). Retrieved 31 August 2023 – via Twitter.
  32. ^ ""Hopeful Chandrayaan-3 lander and rover will awake": space scientist Suvendu Patnayak". ANI News. 21 September 2023. Retrieved 23 September 2023.
  33. ^ "Chandrayaan 3: Pragyan goes to sleep, may 'wake up' on next sunrise on Sept 22". Hindustan Times. 2 September 2023. Retrieved 3 September 2023.
  34. ^ "Reactivation of Chandrayaan-3 lander, rover deferred by a day". Hindustan Times. 22 September 2023. Retrieved 23 September 2023.
  35. ^ "Hope Fades for India's Historic Moon Lander After It Fails to 'Wake Up'". Voice of America. 28 September 2023. Retrieved 21 January 2024.
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