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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Chandrayaan-4 | 2/2 | https://en.wikipedia.org/wiki/Chandrayaan-4 | reference | science, encyclopedia | 2026-05-05T12:59:54.766588+00:00 | kb-cron |
Propulsion Module is similar to the propulsion module on Chandrayaan-3. It will ferry the combined modular spacecraft to the moon. Lander Module will land on the Moon with instrumentation. It supports the ascent stage along with the soil sampling instrumentation. It is designed to last 1 lunar day or 14 Earth days on the moon. The Lander module will be equipped with a scoop and a drill to obtain lunar samples. Ascender Module will eject from the lander and launch from the Moon using the lander as a launch pad after the samples from the Moon are collected and stored. It will then enter low-lunar orbit. Transfer Module will collect the samples from the ascent stage, transfer them to the re-entry module, fire its engine to set both itself and the re-entry module towards Earth, release the payload and loop back around the Earth. Re-entry Module will hold the sample from lunar orbit. It is designed to survive atmospheric re-entry and land with the lunar regoliths. The first launch is planned to carry the ascender module and descender module. The second launch would carry the transfer module, re-entry module, and propulsion module.The final spacecraft will be assembled into an integrated module by docking in Earth orbit before proceeding to the Moon. This will be done via Earth-orbit docking maneuvers. Once the spacecraft reaches lunar orbit, the lander/ascender stack will descent to the lunar surface. It is planned that after touchdown, a robotic arm, mounted on the Lander Module, will scoop about 2-3 kg of samples from around the landing site and transfer them to a container on the Ascent Module. In addition, a drilling mechanism will collect sub-surface samples and transfer them to another container in the Ascent Module. The Ascent module would lift-off just prior to the end of a lunar day for a lunar orbit rendezvous with the Transfer module, which will transfer the payload to a Re-entry module before departing from the moon and landing on earth. Apart from the propulsion module, the transfer module is also equipped with an onboard Liquid Apogee Motor (LAM) for return operation manoeuvres, including the trans-Earth injection. As per earlier reports, the lander module will have six throttleable landing thrusters capable of producing 800 newtons of thrust each, while the ascender module will have two lift off thrusters capable of producing 800 newtons of fixed thrust each. The integrated assembly of all modules after docking in Earth orbit is expected to weigh at least 9,200 kg (20,300 lb).
== Landing site == The landing site was initially planned near to Station Shiv Shakti, the landing site of Chandrayaan-3 which is located between the Manzinus P and Boguslawsky M lunar craters near to the south pole region. ISRO had conducted comprehensive study of this landing site region regarding morphology, hydration and gravity anomalies using data obtained from payloads of Chandrayaan-2 orbiter, Lunar Reconnaissance Orbiter (LRO), Lunar Prospector and GRAIL. ISRO also evaluated landing the spacecraft at Chandrayaan-3's and Chandrayaan-2's alternate landing sites. It was proposed in 2026 to land the spacecraft in the Mountainous plains near Mons Mouton of the moon, based on data from the OHRC instrument on the Chandrayaan-2 orbiter and SIS datasets, located even closer to the lunar south pole.Five sites were evaluated of which four were selected, after it was discovered that one of them was in a shadowed region,impeding solar power generation. Of the other given sites, MM4 was suggested as the landing site. Researchers from IIT Kharagpur and PRL surveyed the sites for iron and titanium-rich rocks known as ilmenite-bearing cumulates (IBC), about 4.3-4.4 billion years old that may have preserved records of the moon's early history. There is also potential for samples to have lunar water content within them. All the newly proposed sites are expected to be near Permenently Shadowed regions on the moon.
Factors affecting landing site selection include
Slope less than or up to 10 degrees Boulders less than 0.32 meter Low Crater and boulder distribution in local topography Sunlit for at least 11-12 days. Local terrain features don’t shadow the site for long Distribution of safe grid of 24m x 24m inside 1km x 1 km landing area
== See also ==
Chandrayaan programme List of missions to the Moon Lunar Polar Exploration Mission
=== Similar missions === Chang'e 5 Chang'e 6 Luna 16 Luna 20 Luna 24
== References ==