Chandrayaan-2 (pronunciationⓘ; from Sanskrit: Chandra, "Moon" and yāna, "craft, vehicle") is the second lunar exploration mission developed by the Indian Space Research Organisation (ISRO) after Chandrayaan-1.

[18] The Indian government approved the mission in a meeting of the Union Cabinet, held on 18 September 2008 and chaired by Prime Minister Manmohan Singh.

[20] Although ISRO finalised the payload for Chandrayaan-2 on schedule,[21] the mission was postponed in January 2013 and rescheduled to 2016 because Russia was unable to develop the lander on time.

[25][18] When Russia cited its inability to provide the lander even by a revised time-frame of 2015 due to technical and financial reasons, India decided to develop the lunar mission independently.

[43] On 6 September 2019, the lander during its landing phase, deviated from its intended trajectory starting at 2.1 km (1.3 mi) altitude,[44] and had lost communication when touchdown confirmation was expected.

[56][57] The mission was launched on a GSLV Mk III M1 with an approximate lift-off mass of 3,850 kg (8,490 lb) from Satish Dhawan Space Centre on Sriharikota Island of Andhra Pradesh.

'Valour' [67]) Pronunciationⓘ named after cosmic ray scientist Vikram Sarabhai (1919–1971), who is widely regarded as the founder of the Indian space programme.

After checking all of its on-board systems it attempted a soft landing that would have deployed the rover, and performed scientific activities for approximately 14 Earth days.

[74][75] Some associated technologies include: Engineering models of the lander began undergoing ground and aerial tests in late October 2016, in Challakere in the Chitradurga district of Karnataka.

ISRO created roughly 10 craters on the surface to help assess the ability of the lander's sensors to select a landing site.

[4][5] The rover was to move on six wheels, traversing 500 m (1,600 ft) on the lunar surface at the rate of 1 cm (0.39 in) per second, perform on-site analyses and send the data to the lander, which would have relayed it to the Mission Control on the Earth.

[91][92] Two aft wheels of the rover had the ISRO logo and the State Emblem of India embossed on them to leave behind patterned tracks on the lunar surface.

[1][3][98] The payloads on the Vikram lander were:[3][98] Pragyan rover carried two instruments to determine the abundance of elements near the landing site:[3][98] The orbiter, which is still active, did experiments on Lunar Atmospheric composition, trace elements, and more The launch of Chandrayaan-2 was initially scheduled for 14 July 2019, 21:21 UTC (15 July 2019 at 02:51 IST local time).

[131] Immediately after launch, multiple observations of a slow-moving bright object over Australia were made, which could be related to upper stage venting of residual LOX / LH2 propellant after the main burn.

In this phase, one perigee-raising and five apogee-raising burns were performed to reach a highly eccentric orbit of 142,975 × 276 km[134] followed by trans-lunar injection on 13 August 2019.

[135] Such a long Earth-bound phase with multiple orbit-raising manoeuvres exploiting the Oberth effect was required because of the limited lifting capacity of the launch vehicle and thrust of the spacecraft's on-board propulsion system.

[136] On 3 August 2019, the first set of Earth images were captured by the LI4 camera on the Vikram lander, showing the North American landmass.

[148] The initial descent was considered within mission parameters, passing critical braking procedures as expected, but the lander's trajectory began to deviate at about 2.1 km (1.3 mi) above the surface.

[164] On 16 November 2019, the Failure Analysis Committee released its report to the Space Commission, concluding that the crash was caused by a software glitch.

The thrust control algorithm was configured to apply corrections towards the end of the phase and not instantaneously allowing large navigation errors to be accumulated.

Other contributing issues were, coarse throttling of main engines,[73] polarity related software error,[166] wrong computation of remaining time of flight by onboard algorithm and very rigid requirement to land inside the planned 500×500 meter landing site regardless of non-nominal flight status.

[194] In the wake of the events surrounding Chandrayaan-2, former ISRO employees criticized unverified statements from chairman K Sivan and what they claimed is the top-down leadership and working culture of the organization.

[195][196][197] S Somanath who succeeded K Sivan as ISRO Chairman also expressed his dissatisfaction at the lack of transparency around landing failure, and misleading representation of it.

It was launched on 14 July 2023;[209] with the designation Chandrayaan-3, which was a second attempt to demonstrate the landing capabilities needed for the Lunar Polar Exploration Mission proposed in partnership with Japan for 2025.

[210][211] The new mission was designed with a detachable propulsion module, also behaving like a communications relay satellite,[212] a lander and a rover,[213][214][215] but with no orbiter.