Chandrayaan-2: Late by a week, will still land on moon on planned date
India on Monday launched Chandrayaan-2, the nation’s second unmanned lunar landing mission, taking it “boldly where no country has ever gone before”.
Indian Space Research Agency (Isro) launched Chandrayaan-2 from the Satish Dhawan Space Centre in Andhra Pradesh’s Sriharikota onboard its most powerful launcher, the 640-tonne rocket Geosynchronous Satellite Launch Vehicle-Mark III (GSLV-Mk III) to the cheers of thousands of people. The ambitious moon mission was delayed by a week after a technical snag.
The Chandrayaan-2 will now spend six additional days in Earth’s orbit and 15 fewer days around the moon before it lands on the day that was originally planned, Isro scientists have said.
Scientists have made tweaks that are necessary to keep in place a careful choreography of movements crucial to ensure the spacecraft does not overshoot the moon, crash into surface or land at a spot not designated for the mission.
The adjustments involve keeping the spacecraft in Earth’s orbit for six more days than planned. At this stage, the Chandrayaan-2 will use the Earth’s gravity to slowly gather speed before it slingshots its way to the moon.
The journey to the moon will take place over seven days, two days more than the previous plan.
The biggest change will be in the time the Chandrayaan-2 spends in the lunar orbit. To gain the lost time due to the delayed launch and the additional days around Earth and in the journey in between, the time spent in the lunar orbit will be reduced from 28 days to 13 days.
The 3,850kg Chandrayaan-2 consists of an orbiter that will circle the moon for about a year, taking images and testing the atmosphere; a lander named Vikram, after Vikram Sarabhai, known as the father of India’s space exploration; and a rover named Pragyaan, which means wisdom in Sanskrit.
It will spend 14 days studying topography, seismography and chemical and mineral composition of lunar rocks and look for water deposits -- confirmed by India’s first lunar mission in 2008, Chandrayaan-1, which didn’t land on the moon.
The space mission will be the first to rove on the south pole of the moon looking for water, ice and cold traps that could preserve the history of our solar system.
Chandrayaan-2 will be injected into an Earth parking orbit. A series of manoeuvres will raise its orbit and put it on the lunar transfer trajectory. On entering the Moon’s sphere of influence, thrusters will slow it down for lunar capture.
The orbit of Chandrayaan-2 around the Moon will be circularised to 100km orbit through a series of complex orbital manoeuvres with the help of thrusters.
On the day of landing, the lander – Vikram – will separate from the orbiter and then perform a series of manoeuvres comprising of ‘rough’ and ‘fine’ braking. Imaging of the landing site region prior to landing will be conducted to find hazard-free and safe landing zones.
Vikram will finally land near the moon’s south pole on September 6 or 7, 2019.
On Day 48 after the launch, the lander with scientific gauges and a robotic rover that will roll out onto the surface will detach and begin a five-day descent that will involve “fine” and “rough” braking manoeuvres involving thrusters.
The lander will attempt a soft landing near the south pole between two craters, Manzinus C and Simpelius N, and study the shadowy regions within.
After that, the rover – Pragyan – will roll out and carry out experiments on the moon’s surface for one lunar day (or 14 Earth days).
The orbiter will continue its mission for the duration of one year.
Chandrayaan-2 follows China’s Chang’e-4, which in January became the first spacecraft to successfully land on the far side of the moon. The United States, the erstwhile Soviet Union, and China are the only three countries which have successfully landed missions on the moon.