Who first thought of gravitational pull?
Chandrayan 2 was launched yesterday and it uses the same technology of gravitational pull that was used by Mars mission spcecraft, Mangalyan. The reported mission is stated by ISRO as under:
July 22, 2019 at 14:43 hrs IST from Satish Dhawan Space Center at Sriharikota on-board GSLV Mk-III. It will be injected into an earth parking 170 x 39120 km orbit. A series of maneuvers will be carried out to raise its orbit and put Chandrayaan-2 on Lunar Transfer Trajectory. On entering Moon’s sphere of influence, on-board thrusters will slow down the spacecraft for Lunar Capture. The Orbit of Chandrayaan-2 around the moon will be circularized to 100×100 km orbit through a series of orbital maneuvers. On the day of landing, the lander will separate from the Orbiter and then perform a series of complex maneuvers comprising of rough braking and fine braking. Imaging of the landing site region prior to landing will be done for finding safe and hazard-free zones. The lander-Vikram will finally land near South Pole of the moon on Sep 7, 2019. Subsequently, Rover will roll out and carry out experiments on Lunar surface for a period of 1 Lunar day which is equal to 14 Earth days. Orbiter will continue its mission for a duration of one year.
To understand the technique of using gravitational pull, this picture uploaded by ISRO explains better: