Chandrayaan-3 soft landing as planned at 6:04 pm on Wednesday, no changes: ISRO chief

'We are not looking at any postponement or Plan B. The landing is confirmed on Wednesday evening as originally planned,' said ISRO chief

BySumit Jha

Published Aug 23, 2023 | 2:16 PM Updated Aug 23, 2023 | 2:16 PM

Chandrayaan-3 landing

India’s third lunar mission, Chandrayaan-3, is set for its scheduled soft landing on the moon’s South Polar region on Wednesday, 23 August.

According to ISRO Chairman Dr S Somanath, there are no plans for postponement or alternatives.

The ISRO team is focused on landing the lander module (LM) and remains confident about the original Wednesday evening landing time of 6.04 pm.

The landing can be watched live here.

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‘No postponement or Plan B’

“We are not looking at any postponement or Plan B. The landing is confirmed on Wednesday evening as originally planned,” he said.

Responding to reports of a potential 27 August postponement due to lander system issues, Dr Somanath reaffirmed the mission’s progress and smooth trajectory.

The Mission Operations Complex (MOX) is vibrant with energy and enthusiasm, as the systems undergo regular checks.

ISRO sources mentioned that the powered descent for a soft landing will occur from a height of approximately 25 km, at a speed of 1.6 km per second. This descent aims to reduce speed and account for the Moon’s gravitational force.

The challenging “17 minutes of terror” will begin between 1745-1750 hours, with the LM landing at 6.04 pm after telemetry signals are analysed. The landing involves intricate manoeuvres, including rough and fine braking, as the lander moves from a horizontal to a vertical position.

The MOX team at ISTRAC, Bengaluru, will control the lander’s commands. Rough braking will last around 11 minutes, followed by fine braking. Once vertical, the lander will hover, capture images, survey the landing zone, and determine the safest landing spot.

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Journey to the Moon: The logbook

14 July: LVM3 M4 vehicle successfully launches Chandrayaan-3 into orbit from Sriharikota in Andhra Pradesh. Chandrayaan-3 starts its journey into precise orbit.

15 July: First orbit-raising manoeuvre (Earthbound firing-1) successfully performed from ISTRAC/ISRO, Bengaluru. The spacecraft is in 41762 km x 173 km orbit.

17 July: Second orbit-raising manoeuvre performed. Spacecraft is in 41603 km x 226 km orbit.

22 July: Another orbit-raising manoeuvre completed using earth-bound perigee firing.

25 July: ISRO performs one more orbit-raising manoeuvre. Spacecraft is in 71351 km x 233 km orbit.

1 August: ISRO performs Translunar Injection successfully and inserts the spacecraft into translunar orbit. The orbit achieved is 288 km x 369328 km.

5 August: Lunar-Orbit Insertion of Chandrayaan-3 performed successfully. The orbit achieved is 164 km x 18074 km, as intended.

6 August: ISRO performs the second Lunar Bound Phase (LBN). With this, the spacecraft is in a 170 km x 4313 km orbit around the Moon. The space agency releases a video of the Moon as viewed by Chandrayaan-3 during lunar orbit insertion.

9 August: Chandrayaan-3’s orbit is reduced to 174 km x 1437 km after a manoeuvre is performed.

14 August: Mission is in orbit circularisation phase after another manoeuvre. The spacecraft is in a 151 km x 179 km orbit.

16 August: Spacecraft brought down to an orbit of 153 km x 163 km after firing is completed.

17 August: Lander module is successfully separated from the propulsion module.

19 August: ISRO performs de-boosting of the lander module to reduce its orbit. The lander module is in a 113 km x 157 km orbit around the Moon.

20 August: One more de-boosting or orbit reduction manoeuvre on the lander module is performed. The lander module is in a 25 km x 134 km orbit.

21 August: Chandrayaan-2 orbiter formally welcomes Chandrayaan-3 lander module saying Welcome, buddy!’. Two-way communication between the two is established. Mission Operations Complex (MOX) now has more ways to communicate with the lander module.

22 August: ISRO releases images of the Moon captured by the Lander Position Detection Camera (LPDC) of the Chandrayaan-3 mission from an altitude of about 70 km. Systems are undergoing regular checks. Smooth sailing is continuing.

23 August: Safe and soft landing of Chandrayaan-3’s lander module on the southern pole of the lunar surface expected at 6.04 pm.