ISRO tweaks Chandrayaan-2 timeline to offset time loss

ISRO tweaks Chandrayaan-2 timeline to offset time loss

Agency News

Sriharikota, (AP), July 22 : The week-long delay in the launch of Chandrayaan-2 due to a technical glitch prompted the ISRO to adjust the module's Earth and Moon-bound phases to make up for the lost time, for a soft landing on hitherto unexplored territory--Moon's South Pole region.

The space agency is aiming to put the Lander (Vikram) and Rover (Pragyan) on the lunar surface on September seven, just one day behind the earlier schedule, to ensure that the duo get their  planned full schedule of operating for nearly 14 Earth Days by tweaking the Chandrayaan-2’s timelines in space when it travels from one phase to another.

Under the old plan, the soft-landing of Vikram and Pragyan was planned to be executed on Day 54 from the lift-off date. But with a ‘technical snag’ deferring the launch, ISRO had to improvise or risk losing precious time for the mission.

As per the new timeline, the Earth-bound phase is increased by six days to 23 days (earlier it was 17). Under the old schedule, the Lunar Orbit Insertion (LOI) was to take place on Day 22, but now it will be on Day 30. The Lunar Bound Phase (LBN), which under the previous launch schedule was to have taken 28 days, has now shrunk to just 13, between Day 30 and Day 42 after lift-off.

The Lander-Orbiter Separation will be executed on Day 43, while deboosting will be initiated on Day 44, with the powered descent of the Lander and Rover on Day 48 to the lunar surface.

It is crucial for ISRO to land during this window, as the touchdown will be done at the high plain between two craters, Manzinus C and Simpelius N that will be at a point facing the Earth and would have started receiving sunlight by then.

Following is the journey schedule of Chandrayaan-2 :
Phase July 15 Lift off July 22 Lift off
Earth bound phase : Day 1-17 (17 days) Day 1-23 (23 days)
Trans Lunar Injection : Day 17 Day 23
Lunar Transfer
Trajectory : Day 17-22 Day 23-30
Lunar Orbit Insertion : Day 22 Day 30
Lunar Bound Phase : Day 22-49 Day 30-42
(28 days) (13 days)
Lunar Orbit Separation : Day 50 Day 43
Deboosting : Day 51 Day 44
Powered Descent start : Day 54 Day 48
Landing : Day 54 Day 48. (UNI)