As India holds its breath for the historic soft landing of Chandrayaan-2 on Moon tonight, top scientists at ISRO will be closely monitoring the ‘most terrifying’ 15 minutes of the final phase of the lunar mission tonight. Travelling at the speed of 6 km per second, Chandrayaan-2 will begin its final descent on Moon sometime between 1:30 am and 2:30 am tonight. Prime Minister Narendra Modi along with 70 students selected from schools across the country will also watch the epic touchdown at the Bengaluru-based headquarters of the Indian Space Research Organisation headquarters during post-midnight hours on Saturday.
Here are 10 important points about ISRO’s Chandrayaan-2 that you must know:
1: Vikram, the lander module of Chandrayaan-2, which has already detached itself from the main spacecraft will select its soft-landing site tonight. Vikram will select the touchdown spot when it would be just 100 metres above Moon. The scientists at ISRO say that the preferred landing site of Vikram will be between two craters on Moon. These two craters are known as Manzinus and Simpelius. These two craters are located around 350 km north of Moon’s south pole.
2: The crucial landing of ‘Vikram’, Chandrayaan-2’s moon lander, will be carried out by at least eight onboard equipment in a coordinated manner. In a video released on Thursday, ISRO had explained how the powered landing will take place. The space agency explained that the machine will be fitted with at least three cameras, Lander Position Detection Camera (LPDC), Lander Horizontal Velocity Camera (LHVC) and Lander Hazardous Detection and Avoidance Camera (LHDAC), to ensure its soft landing on the lunar surface.
3: There will be two KA Band Altimeter-1 and KA Band Altimeter-2. The KA Band stands for Kurtz-above band, which is part of the Kurtz (K) band in the microwave band of the electromagnetic spectrum. There will be a Laser Altimeter (LASA), an instrument that is used to learn about the topography, or the shape of the surface of a planet. It will operate through the orbitor revolving around the moon above the lander. The lander will have five 800N Liquid thruster engines, touchdown sensors and solar panels.
4: During the rough braking Phase at an altitude of 100 km, the four engines on four sides of the cubical shaped lander will be switched on. At this stage of the Absolute Navigation Phase, KA Band-1, Laser Altimeter and Lander Position Detection Camera will be activated to ensure that the lander is positioned in the space just above the moon surface to sit perfectly on the ground. The Lander Position Detection Camera will be switched on to identify the perfect place to sit cozily on the ground.
5: At this hovering stage of lander, about 400 metres above the moon surface, two engines will be ignited. Subsequently LASA, KA-Band 2 and LHVC will be activated. There will be a retargeting phase where LASA, KA Band-2, LHVC, LHDAC will be activated to coordinate for the perfect landing. Further, at an altitude of 10 metres, the ISRO will carry out the landers parabolic descent for soft landing by igniting the central engine and using the touchdown sensor at the bottom of the stand.
6: Soon after touchdown, ISRO will deploy the three payloads, named Chaste, Rambha and Ilsa. Chaste is located just at the lower edge of the cubical Vikram lander which will extend like one of the stands touching the ground. Rambha will be at the upper side of the outer wall of the lander extending like a rod while Ilsa will be at the bottom.
7: The 3,84,000 km journey that began on July 22 at Sriharikota launchpad will culminate with the soft-landing.
8: Chandrayaan-2, launched on July 22 by GSLV MkIII-M1 vehicle, had entered the Lunar Transfer Trajectory on August 14 after final orbit raising manoeuvre of the spacecraft was successfully carried out.
9: According to ISRO, Lunar South Pole’s regolith has traces of hydrogen, ammonia, methane, sodium, mercury and silver making it an untapped source of essential resources.
10: If successful, India will become fourth nation in the world to land its spacecraft on Moon. Before this, only the US, Russia and China have achieved this feat.
(With agency inputs)