Chandrayaan-2: How is it different from India's first moon mission Chandrayaan-1
New Delhi, July 11: Ten years after India's first mission to the Moon, Chandrayaan-1, Indian Space Research Organisation (ISRO) is all set to launch the second and more ambitious Chandrayaan-2. Chandrayaan-2, India's second mission to the moon, is scheduled for a July 15 launch.
The fundamental difference of course is that Chandrayaan-1 did not involve landing on the surface of earth's only natural satellite, whereas in Chandrayaan-2, a lander will make a soft landing on the surface of the moon which would then send out a rover to explore and collect scientific data.
Apart from this there are many other differences between both the missions. To begin with, the net weight of the spacecraft which was carried by PSLV (Polar Satellite Launch Vehicle) for Chandrayaan-1 on October 22, 2008, was 1380 kgs. The Chandrayaan-2 spacecraft weighs approximately 3290 kilograms and it would launched by the Geosynchronous Satellite Launch Vehicle Mk-III (or GSLV Mk) rocket.
Chandrayaan-1 was carried a range of scientific equipments, both Indian and international, to the lunar orbit. The probe collected a lot of significant data over its mission. During Chandrayaan-1, the Mini-Synthetic Aperture Radar (Mini-SAR) found water-ice deposits in craters on the far side of the moon which was considered as a significant finding.
Chandrayaan-1 orbited the moon a distance of 100 kilometres from its surface, with a mission of chemical, mineralogical and photo-geologic mapping of the lunar satellite.
Chandrayaan-2 has three modules namely Orbiter, Lander (Vikram) and Rover (Pragyan). The Chandrayaan-2 orbiter will circle the moon and provide information about its surface.
The Lander will soft-land on the lunar surface and unload the Rover to study and take measurements from the surface. The lander and rover on Chandrayaan-2 will touchdown at a site 600 kilometers from the lunar South pole. All previous lunar crafts have landed near the equator and this is the first time one will landed near the south pole.
Objectives and payloads:
Chandrayaan-1 carried five ISRO payloads and six payloads from other space agencies including NASA, ESA, and the Bulgarian Aerospace Agency.
In Chandrayaan-2, a total of 13 payloads are distributed across the three modules where the Orbiter and Vikram Lander are stacked upon each other whereas the Pragyan Rover is housed inside the lander.
Chandarayan-1, involved surveying the lunar surface to produce a complete map of its chemical characteristics and three-dimensional topography. Chandrayaan-1 was in operation for 312 days.
Chandrayaan-2, equipped with a lander and rover, will observe the lunar surface and send back data which will be useful for analysis of the lunar soil. The lander will carry instruments like a seismometer and a thermal probe, and the rover will carry spectrometers to analyse the lunar soil. The lander and rover have nominal lifetimes of one lunar daytime (14 Earth days).
Method of placing in orbit:
Chandrayaan-1 was first made to circle the Earth in its transfer orbit, and then was put into elliptical "extended transfer orbits" by repeatedly firing its liquid engine in a pre-determined sequence.
Consequently, the liquid engine was once more fired to make the spacecraft travel to the vicinity of the Moon by following a path called the "Lunar Transfer Trajectory (LTT).
" When it reached near the Moon and passed at a few hundred kilometers from it, its liquid engine was fired again so that the spacecraft slowed down sufficiently to enable the gravity of the Moon to capture it into an elliptical orbit
The GSLV will place Chandrayaan-2 into an elliptical Earth parking orbit, enlarging it over days or weeks with thrusts to raise the orbit apogee.
Eventually, the apogee will be high enough that a thrust can send the spacecraft on to a lunar transfer trajectory. A lunar orbit insertion burn will place Chandrayaan-2 into an elliptical orbit and the spacecraft will begin braking to reduce its orbit to a 100-kilometer circle.