Pragyan (rover)

Pragyan (Sanskrit: प्रज्ञान;; lit: Wisdom[5][6] Pronunciation .[7][8]) was the rover of Chandrayaan-2, a lunar mission developed by the Indian Space Research Organisation (ISRO).[9]

The Vikram lander crash-landed,[10] and communication was lost, so the rover could not be deployed.[2]

Pragyaan Lunar Rover for Chandrayaan-2
Illustration of Chandrayaan's rover Pragyan
Mission typeLunar rover
Mission duration≤ 14 days (intended)
Spacecraft properties
Landing mass27 kg (60 lb)
Dimensions0.9 m (3.0 ft) × 0.75 m (2.5 ft) × 0.85 m (2.8 ft)
Power50 W from solar panels
Start of mission
Launch date22 July 2019 14:43:12 IST, (09:13:12 UTC)
RocketGSLV Mk III M1
Launch siteSDSC Second launch pad
Deployed fromChandrayaan-2/Vikram lander
Deployment dateIntended: 7 September 2019[1]
Result: Never deployed from damaged lander.[2]
Lunar rover
Landing date6 September 2019, 20:00-21:00 UTC[3]
Landing siteBetween 70.90267°S 22.78110°E and 67.87406°S 18.46947°W[4] (Intended)
Hard landing at least 500m away from planned site. (Actual)
Distance covered500 m (1,600 ft) (intended)


The rover's mass was about 27 kg (60 lb) and was designed to operate on solar power.[11][12] The rover was to move on 6 wheels traversing 500 meters on the lunar surface at the rate of 1 cm per second, performing on-site analysis and sending the data to the Vikram lander, which would have relayed it to the Earth station.[13][14][15][16][17] For navigation, the rover was 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 Pragyan rover was one lunar day or around 14 Earth days, as its electronics were not designed to endure the frigid lunar night. Its power system had a solar-powered sleep/wake-up cycle implemented, which could have resulted in longer service time than planned.[21][22]

  • Dimensions: 0.9 × 0.75 × 0.85 m[23]
  • Power: 50 W[23]
  • Travel speed: 1 cm/sec.[23]
  • Mission duration: ≤14 days (one lunar day)

Planned landing site

Landing site [4] Coordinates
Prime landing site 70°54′10″S 22°46′52″E / 70.90267°S 22.78110°E
Alternate landing site 67°52′27″S 18°28′10″W / 67.87406°S 18.46947°W

Two landing sites were selected, each with a landing ellipse of 32 km x 11 km.[4] The prime landing site (PLS54) was at 70.90267 S 22.78110 E (~350 km north of the South Pole-Aitken Basin rim[24][4]), and the alternate landing site (ALS01) was at 67.874064 S 18.46947 W. The prime site was on a high plain between the craters Manzinus C and Simpelius N,[25][24] on the near side of the Moon.[4] The criteria used to select the landing zones were: south polar region, on the near side, slope less than 15 degrees, boulders less than 50 cm (20 in), crater and boulder distribution, sunlit for at least 14 days, nearby ridges do not shadow the site for long durations.[4]

The planned landing site and its alternate 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.[26] The nature of the melt is mostly mafic,[26] meaning it is rich in silicate mineral, 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.[27]

Hard landing

The Vikram lander, carrying the Pragyan rover, 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 on-board computers on Vikram, with mission control unable to make corrections.[28]

The lander's trajectory began to deviate at about 2.1 kilometres (1.3 mi; 6,900 ft) above the surface.[29] The final telemetry readings during ISRO's live-stream show that Vikram's final vertical velocity was 58 m/s (210 km/h) from 330 meters above the surface which, according to the MIT Technology Review, is "quite fast for a lunar landing."[30] Initial reports suggesting a crash,[31][32] have been confirmed by ISRO chairman K. Sivan, stating that the lander location had been found, and "it must had been a hard landing".[10][33][34] The orbiter part of the mission, with eight scientific instruments, remains operational and will continue its seven-year mission to study the Moon.

See also


  1. ^ "Live media coverage of the landing of Chandrayaan-2 on lunar surface - ISRO". Retrieved 2019-09-02.
  2. ^ a b "Chandrayaan - 2 Latest Update". September 7, 2019. Retrieved September 11, 2019.
  3. ^ "Chandrayaan-2 update: Fifth Lunar Orbit Maneuver". Indian Space Research Organisation. September 1, 2019. Retrieved September 1, 2019.
  4. ^ a b c d e f 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.
  5. ^ "Chandrayaan-2 Spacecraft". Retrieved 24 August 2019. Chandrayaan 2's Rover is a 6-wheeled robotic vehicle named Pragyan, which translates to 'wisdom' in Sanskrit.
  6. ^ Wilson, Horace Hayman (1832). A dictionary in Sanscrit and English. Calcutta: Education Press. p. 561.
  7. ^ Elumalai, V.; Kharge, Mallikarjun (7 Feb 2019). "Chandrayaan - II" (PDF). Archived from the original (PDF) on 7 February 2019. Retrieved 7 Feb 2019. Lander (Vikram) is undergoing final integration tests. Rover (Pragyan) has completed all tests and waiting for the Vikram readiness to undergo further tests.
  8. ^ "Chandrayaan-2 Spacecraft". Retrieved 24 August 2019. Chandrayaan 2's Rover is a 6-wheeled robotic vehicle named Pragyan, which translates to 'wisdom' in Sanskrit.
  9. ^ ""Chandrayaan-2 launch between July 9 and 16: Isro"".
  10. ^ a b Vikram lander located on lunar surface, wasn't a soft landing: Isro. Times of India. 8 September 2019.
  11. ^ "Chandrayaan-2 to Be Launched in January 2019, Says ISRO Chief". Gadgets360. NDTV. Press Trust of India. 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. Retrieved 2019-06-12.
  14. ^ Singh, Surendra; 2019; Ist, 14:02. "Chandrayaan-2 will carry 14 payloads to moon, no foreign module this time". The Times of India – TNN. Retrieved 2019-05-11.
  15. ^ "Payloads for Chandrayaan-2 Mission Finalised" (Press release). Indian Space Research Organisation. 30 August 2010. 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. Retrieved 12 June 2019.
  18. ^ Laha, Jayanta; Dinesh, B.; Selvaraj, P.; Krishnamoorthy, Subhalakshmi (2018). "Realization of Space Grade Miniature Digital Camera for Lunar Navigation" (PDF). International Journal of Pure and Applied Mathematics. 118 (16): 1105–1116. Archived (PDF) from the original on 26 September 2018.
  19. ^ "With robot hands, IIT-K profs bring joy to paralytics". The Times of India. 2019. Retrieved 2019-07-10.
  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 29 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.
  21. ^ "Dr M Annadurai, Project director, Chandrayaan 1: 'Chandrayaan 2 logical extension of what we did in first mission'". The Indian Express. 2019-06-29. Retrieved 2019-06-30.
  22. ^ Payyappilly, Baiju; Muthusamy, Sankaran (17 January 2018). "Design framework of a configurable electrical power system for lunar rover". ResearchGate: 1–6. doi:10.1109/ICPCES.2017.8117660. ISBN 978-1-5090-4426-9.
  23. ^ a b c "Launch kit at a glance".
  24. ^ a b Geological Insights into Chandrayaan-2 Landing Site in the Southern High Latitudes of the Moon. 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).
  25. ^ Chandrayaan-2: How 'Lander Vikram' will touchdown on the moon? Srishti Choudhary, Live Mint 14 July 2019.
  26. ^ a b Update on the Geologic Mapping of the Lunar South Pole Quadrangle (LQ-30): Evaluating Mare, Cryptomare and Impact Melt Deposits. S. C. Mest, D. C. Berman, N.E. Petro, and R. A. Yingst. 46th Lunar and Planetary Science Conference (2015).
  27. ^ As India prepares for another Moon mission, here is what makes Chandrayaan-2 special. Sandhya Ramesh, The Print. 14 July 2019.
  28. ^ Chandrayaan 2: Here's everything about ISRO Moon-landing its Vikram lander. Financial Express. Ribhu Mishra, 7 September 2019.
  29. ^ India Just Found Its Lost Vikram Lander on the Moon, Still No Signal. Tariq Malik ,Space. 8 September 2019.
  30. ^ Neel V. Patel (6 September 2019). "India's Chandrayaan-2 lander likely crashed into the moon's surface". MIT Technology Review. Retrieved 7 September 2019.
  31. ^ India's Moon Mission Continues Despite Apparent Lander Crash. Mike Wall, Space. 7 September 2019. Quote: "India's Moon Mission Continues Despite Apparent Lander Crash."
  32. ^ "India's Vikram Spacecraft Apparently Crash-Lands on Moon". Retrieved 7 September 2019.
  33. ^ "Lander Vikram located: K Sivan". Retrieved 2019-09-08.
  34. ^ Schultz, Kai (8 September 2019). "India Says It Has Located Chandrayaan-2 Lander on Moon's Surface". The New York Times. Retrieved 8 September 2019.

Chandrayaan-2 (candra-yāna, transl. "mooncraft"; pronunciation ) is the second lunar exploration mission developed by the Indian Space Research Organisation (ISRO), after Chandrayaan-1. It consists of a lunar orbiter, the Vikram lander, and the Pragyan lunar rover, all of which were developed in India. The main scientific objective is to map and study the variations in lunar surface composition, as well as the location and abundance of lunar water.The mission was launched on its course to the Moon from the second launch pad at Satish Dhawan Space Centre on 22 July 2019 at 2.43 PM IST (09:13 UTC) by a Geosynchronous Satellite Launch Vehicle Mark III (GSLV Mk III). The craft reached the Moon's orbit on 20 August 2019 and began orbital positioning manoeuvres for the landing of the Vikram lander. Vikram and the rover were scheduled to land on the near side of the Moon, in the south polar region at a latitude of about 70° south at approximately 20:23 UTC on 6 September 2019 and conduct scientific experiments for one lunar day, which approximates two Earth weeks.

However, the lander deviated from its intended trajectory starting at 2.1 kilometres (1.3 mi) altitude, and had lost communication when touchdown confirmation was expected. Initial reports suggesting a crash have been confirmed by ISRO chairman K. Sivan, stating that the lander location had been found, and "it must have been a hard landing".As of 8 September 2019, on-going efforts are being made by ISRO in hopes of restoring communications with Vikram. Both ISRO and NASA are in the process of trying to restore communications through their respective Deep Space Networks. Communication attempts will likely cease on 21 September 2019, fourteen days after Vikram's landing attempt. The orbiter, part of the mission with eight scientific instruments, remains operational and is expected to continue its seven-year mission to study the Moon.

Indian Space Research Organisation

The Indian Space Research Organisation (ISRO, ) (Hindi; IAST: bhārtīya antrikṣ anusandhān saṅgṭhan) is the space agency of the Government of India headquartered in the city of Bengaluru. Its vision is to "harness space technology for national development while pursuing space science research and planetary exploration". The Indian National Committee for Space Research (INCOSPAR) was established in the tenure of Jawaharlal Nehru under the Department of Atomic Energy (DAE) in 1962, with the urging of scientist Vikram Sarabhai recognizing the need in space research. INCOSPAR grew and became ISRO in 1969, also under the DAE. In 1972, Government of India setup a Space Commission and the Department of Space (DOS), bringing ISRO under the DOS. The establishment of ISRO thus institutionalized space research activities in India. It is managed by the DOS, which reports to the prime minister of India.ISRO built India's first satellite, Aryabhata, which was launched by the Soviet Union on 19 April 1975. It was named after the mathematician Aryabhata. In 1980, Rohini became the first satellite to be placed in orbit by an Indian-made launch vehicle, SLV-3. ISRO subsequently developed two other rockets: the Polar Satellite Launch Vehicle (PSLV) for launching satellites into polar orbits and the Geosynchronous Satellite Launch Vehicle (GSLV) for placing satellites into geostationary orbits. These rockets have launched numerous communications satellites and Earth observation satellites. Satellite navigation systems like GAGAN and IRNSS have been deployed. In January 2014, ISRO used an indigenous cryogenic engine in a GSLV-D5 launch of the GSAT-14.ISRO sent a lunar orbiter, Chandrayaan-1, on 22 October 2008, which discovered lunar water in the form of ice, and the Mars Orbiter Mission, on 5 November 2013, which entered Mars orbit on 24 September 2014, making India the first nation to succeed on its maiden attempt to Mars, as well as the first space agency in Asia to reach Mars orbit. On 18 June 2016, ISRO launched twenty satellites in a single vehicle, and on 15 February 2017, ISRO launched one hundred and four satellites in a single rocket (PSLV-C37), a world record. ISRO launched its heaviest rocket, Geosynchronous Satellite Launch Vehicle-Mark III (GSLV-Mk III), on 5 June 2017 and placed a communications satellite GSAT-19 in orbit. With this launch, ISRO became capable of launching 4-ton heavy satellites into GTO. On 22 July 2019, ISRO launched its second lunar mission Chandrayaan-2, which consists of an orbiter, lander and rover, to study the lunar geology and the distribution of lunar water.

Future plans include development of the Unified Launch Vehicle, Small Satellite Launch Vehicle, development of a reusable launch vehicle, human spaceflight, a space station, interplanetary probes, and a solar spacecraft mission.

List of artificial objects on the Moon

This is a partial list of artificial materials left on the Moon. The table below does not separately list lesser artificial objects such as retroreflectors, Apollo Lunar Surface Experiment Packages, tools such as a hammer, or the commemorative, artistic, and personal objects left there by Apollo astronauts, such as the US flags, commemorative plaques attached to the ladders of the Apollo Lunar Modules, the silver astronaut pin left by Alan Bean in honor of Clifton C. Williams whom he replaced, the Bible left by David Scott, the Fallen Astronaut statuette and memorial plaque left by the crew of Apollo 15, the Apollo 11 goodwill messages disc, or the golf balls Alan Shepard hit during an Apollo 14 moonwalk.

The remains of five S-IVB third stages of Saturn V rockets from the Apollo program are the heaviest single pieces sent to the lunar surface. Humans have left over 187,400 kilograms (413,100 lb) of material on the Moon, and 380 kilograms (838 lb) of Moon rock was brought back to Earth by Apollo and Luna missions. The only artificial objects on the Moon that are still in use are the retroreflectors for the lunar laser ranging experiments left there by the Apollo 11, 14 and 15 astronauts, and by the Lunokhod 1 and Lunokhod 2 missions.Objects at greater than 90 degrees east or west are on the far side of the Moon, including Ranger 4, Lunar Orbiter 1, Lunar Orbiter 2 and Lunar Orbiter 3.

List of lunar probes

This is a list of robotic space probes that have flown by, impacted, orbited or landed on the Moon for the purpose of lunar exploration, as well as probes launched toward the Moon that failed to reach their target.

The crewed Apollo missions are listed at List of missions to the Moon.

India Indian space programme
Space observatories
Lunar and
planetary spacecraft
Crewed spacecraft
Space probes
Human spaceflight
Cancelled /
See also
21st-century space probes
Active space probes
(deep space missions)
Completed after 2000
(by termination date)


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