CHENNAI/BENGALURU: The countdown for Chandrayaan 3 has begun with the ISRO review committee giving its clearance for the lift-off from Satish Dhawan Space Centre (SDSC SHAR) at Sriharikota on Friday at 2.35 pm. The Launch Vehicle Mark-III-M4 (LVM3-M4) rocket, dubbed as ‘Fat Boy’ by space scientists for its ability to carry heavy payloads, is the operational heavy lift launch vehicle that will carry an integrated package of three modules: the propulsion module, the lander module, and the rover module.
The mission will aim to soft-land the lander module carrying the rover near the lunar south pole after separating from the propulsion module. On landing, it will deploy the rover to conduct on-site scientific experiments on the lunar surface for 14 days (1 lunar day). The soft-landing is expected to happen on August 23 or 24.
The LVM3-M4 of ISRO has a “pedigree of completing six consecutive successful missions.” This is the fourth operational flight of LVM3, and will be launched from the second launch pad (SLP), SDSC, SHAR, ISRO said.
About 16 minutes after launch on Friday, the propulsion module will separate from ‘Fat Boy’, and the earth-centric mission phase will begin. In this phase, over the next few days, the propulsion module (with the lander carrying the rover attached to it) will make five increasingly larger elliptical orbits around the earth, with the final orbit’s farthest point being 36,500 km and closest point to earth being 170 km. The idea is to use the earth’s gravity like a sling swung multiple times to gain momentum for its 3,84,400-km journey to the moon and get captured by the lunar gravity.
India could be 4th country to soft-land spacecraft on moon
In the sixth orbit — the injection orbit — it will be propelled into a lunar transfer trajectory before the lunar gravity capture happens.Once in lunar gravity field, the propulsion module will make seven orbits, progressively lowered until it settles in an circular polar orbit 100 km from the lunar surface. Here, it will release the lander, which will find a suitable landing spot using sensors to make a soft-landing near the lunar south pole.
The main function of the propulsion module is to carry the lander module till its separation to make a soft-landing. However, the propulsion module carries a Spectro-polarimetry of Habitable Planetary Earth (SHAPE) payload to study the spectral and polarimetric measurements of earth while in lunar orbit.
Achieving a successful soft-landing in Chandrayaan 3 mission would mean redemption for ISRO after Chandrayaan 2 failed to make a soft-landing on September 7, 2019, when lander Vikram crashed to the lunar surface while attempting a touchdown. Also, if successful, India will be the fourth country to soft-land a spacecraft on the moon after the US, former Soviet Union and China. If all goes well, India may become the first country to touch down near the moon’s south pole – a hitherto unexplored region that is critical for future lunar crewed missions because of the presence of abundant water, ice and minerals.
ISRO chairman Sreedhara Panicker Somanath arrived at SDSC on Wednesday to oversee the mission countdown. “The propellants are being loaded with the beginning of the countdown. There is jubilance and anxiety as ISRO heads for the big day. A huge crowd of scientists is at SHAR,” sources told TNIE.
Observing the customary pre-launch tradition, senior scientists from ISRO paid obeisance at Tirupati Venkatachalapathy Temple in Tirumala, Andhra Pradesh, with a miniature model of Chandrayaan 3 and sought divine blessings for the successful launch of the ambitious unmanned moon mission.