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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Chandrayaan programme | 3/7 | https://en.wikipedia.org/wiki/Chandrayaan_programme | reference | science, encyclopedia | 2026-05-05T12:59:47.013443+00:00 | kb-cron |
==== Development ==== Two months after the failure of Chandrayaan-2, the third mission was proposed with the lander and rover being the primary components of the mission, unlike previously where the orbiter carried a greater scientific payload. The Chandrayaan-3 would be a re-attempt to demonstrate the landing capabilities needed for the LUPEX mission, a proposed partnership with Japan that was planned for 2025-26 time frame. ISRO sought ₹75 crore (US$7.9 million) from the government as initial funding for the Chandrayaan-3 project that included a propulsion module, a lander, and a rover. It was expected to launch a year later in November 2020. On 19 December 2019, P Veeramuthuvel was appointed as the director of the mission. The work on the project was underway come January 2020 and K. Sivan revealed that the launch may happen in early 2021 with the total cost of the project being ₹615 crore (US$65 million). Later in March, the government confirmed that the launch could take place in the first half of 2021. The earlier addition of the fifth engine in the Chandrayaan-2's lander that caused the additional thrust was now removed from the design of Chandrayaan-3. Like Chandrayaan-2, the testing for the lander was to be conducted in Challakere where ISRO's previously built Moon like site with craters had deteriorated. A total of ₹24.2 lakh (US$26,000) was spent on recreating the site with craters of similar dimensions (10 m (33 ft) wide and 3 m (9.8 ft) deep). The launch which was planned for early 2021, was then delayed to 2022 due to COVID-19 pandemic in India. The propulsion module which was ready before the pandemic had begun its testing, following which the lander and rover tests were to be conducted but the pandemic delayed the project and pushed its tentative launch date to the third quarter of 2022. Few more changes with strengthening the landing legs, improvisation in instruments, a failure-proof configuration and additional testing meant that the new schedule for the launch was moved to second quarter of 2023. In May 2023, the spacecraft was in its final stage of the assembly of payloads at the U R Rao Satellite Centre with the launch targeted for the first or second week of July.
==== Successful soft landing ==== On 14 July 2023, Chandrayaan-3 was successfully launched on LVM3 and was inserted in the lunar sphere of gravitational influence on 5 August 2023. On 23 August 2023, the lander Vikram successfully soft landed in the lunar south pole region, achieving humanity's first soft landing in the region and making India the fourth country to soft land on the Moon after Soviet Union, United States and China. Soon after the touchdown, the rover Pragyan got down of the ramp and drove 8 m (26 ft) making India only the third country to operate a robotic rover on the Moon after Soviet Union and China.
== Spacecraft == The Chandrayaan programme consists of robotic explorers such as the Moon Impact Probe (MIP) an impactor, Chandrayaan-1 and 2 the orbiters, Vikram lander and Pragyaan rover.
=== Impactor: Moon Impact Probe ===
The Moon Impact Probe (MIP) weighed 35 kg (77 lb) with 25 minutes of expected operating duration. It carried a Radar altimeter to record the altitude data which would be used in qualifying technologies for future soft landing missions, a Video imaging system to acquire close-range pictures of the lunar surface, and a Mass spectrometer to study the tenuous atmosphere of the Moon. On 12 November 2008, the MIP separated from the orbiter and impacted near the lunar south pole's Shackleton crater. While descending, the probe's Chandra's Altitudinal Composition Explorer (CHACE) instrument detected the presence of water.
=== Orbiters ===
==== Chandrayaan-1 ====
Chandrayaan-1 launched on 22 October 2008 aboard PSLV-XL was a solar-powered cuboid orbiter that weighed 1,380 kg (3,042 lb) along with the Moon Impact Probe. It was powered by a single-sided solar array during the day and supported by lithium-ion batteries at night. The attitude of the spacecraft was controlled by three-axis stabilization method using two star sensors, gyroscopes and four reaction wheels. The scientific data transmission was conducted in X band frequencies while telemetry tracking was done in S band frequencies. To store these data, two solid-state recorders (SSR) were used with SSR-1 carrying 32 GB dedicated capacity for scientific data while SSR-2 carrying 8 GB capacity for the rest of the scientific data and attitude information. Moon Mineralogy Mapper, an American scientific payload onboard carried its own SSR with 10 GB capacity. The orbiter-impactor composite entered the lunar sphere of gravitational influence on 8 November 2008. After orbital reduction manoeuvres, it attained an elliptical polar orbit of 100 km (62 mi), upon which, two of the eleven scientific payloads, the Terrain Mapping Camera (TMC) which had a spatial resolution of 5 m (16 ft) and Radiation Dose Monitor (RADOM) were switched on for operations. Post deployment of MIP, rest of the nine scientific instruments began operations. On 25 November 2008, just a couple of weeks after entering lunar orbit, the orbiter's temperature rose to 50 °C (122 °F) after receiving equal amounts of heat from the sun as well as the moon (due to its Albedo). Efforts such as rotating the craft by 20 degrees, shutting down the mission computers, and increasing its orbit to 200 km (120 mi) were made to bring its temperature down and to avoid damaging the onboard instruments. A year later, the overheating problem was responsible for ending the mission as it damaged the star sensors which maintained the orientation of craft. The orientation was then barely maintained with the help of gyroscopes as a temporary measure before losing contact on 28 August 2009, which ended the mission a year before its intended duration. However, the mission was analyzed to be 95% successful with its intended operations.
==== Chandrayaan-2 ====