ISRO announced that India’s Chandrayaan-3 spacecraft entered a new, higher orbit around the Earth on Thursday, following the successful completion of its fourth orbit-raising manoeuvre.
“India commemorates International Moon Day 2023 by advancing Chandrayaan-3 towards the moon. ISRO tweeted that the fourth orbit raising manoeuvre (Earth-bound perigee firing) was effectively executed from ISTRAC/ISRO (ISRO Telemetry, Tracking and Command Network).
The spacecraft has attained a 51400 km x 228 km orbit, as planned.
— ISRO (@isro) July 18, 2023
Chandrayaan-3, which is scheduled to make a soft landing on the Moon’s surface next month, is presently in elliptical orbits around the Earth, with the altitudes of these orbits gradually increasing.
Prior to commencing its direct approach to the moon, the spacecraft is expected to perform five orbit-raising manoeuvres to continuously ascend into higher orbits. Once there, it would perform similar manoeuvres to gradually enter lower and lower orbits around the moon, eventually settling into a circular orbit approximately 100 kilometres from the lunar surface. On August 23 or 24, the final descent to the Moon’s surface would begin from this circular orbit.
Chandrayaan-3 will not travel directly to the Moon, but will instead take a circuitous route in order to save money on the voyage. A direct trip to the Moon, which takes approximately four days, would necessitate much heavier rockets and enormous amounts of fuel to exit Earth’s orbit. Instead, Chandrayaan-3 was placed in a near-Earth orbit, where it has been using gravity to gather momentum and then firing thrusters to reach a higher orbit.
This method requires significantly less propellant, but it takes much longer to reach the Moon.
ISRO stated that the fifth and final orbit-raising manoeuvre in the earth’s orbit will occur between 2 and 3 p.m. on July 25.