Author: Janavi Gupta
In 2012, India’s leading space scientists at the Indian Space Research Organisation (ISRO) put forth an ambitious plan to send an orbiter to Mars. This would be India’s first interplanetary journey and if successful, it would be the fourth space agency and the first Asian country in the world to reach Mars.
So, in 2013 India put this plan into action. ISRO chose the PSLV to be their launch vehicle as it is India’s most reliable rocket. It stands as tall as a 15 storey building, but even with its magnificent size, it was not powerful enough to send Mangalyaan on a direct path to Mars. Complex calculations showed that for a satellite to go from Earth to Mars, the closest rendezvous date at that time was 24th September 2014. The next opportunity would only come 26 months later. Hence it was crucial that the rocket was launched on a precise date in order to make sure that the mission didn’t just become a flyby attempt.
In order to overcome the power issues with the launcher, Indian Scientists came up with a very innovative plan. They would build a Mars orbiter and load it onto the PSLV. It would first be launched into Earth's orbit. They would get it to circle Earth and increase its velocity until it was fast enough to escape Earth's sphere of influence. It would then be set on a path towards Mars, covering about 650 million kilometres in just 300 days hurtling at a speed of 20km per second. During the launch at Sriharikota, several ground stations coordinated and tracked the rocket's progress after which they conveyed data to the mission team. Once it was over the Pacific Ocean, the ground team wouldn't be able to track it so they came up with an innovative solution. Two ships with powerful antenna would be placed in the ocean to collect and send data back to the mission stations.
However, this is where they faced their first setback. The launch was delayed as one of the ships couldn't reach the desired location on time due to bad weather. This was not good news. They still powered on and came up with a new launch date. And Mangalyan was launched.
3, 2, 1, Launch!
...and the orbiter has been launched!
The first ship monitors the ignition of the engine. The second ship monitors the craft separation and Mangalyaan is finally sent into an elliptical orbit around the earth. Considering the amount of fuel it was carrying, the room for error was narrow. Mangalyaan completed three orbit raising steps when scientist hit another snag. The fourth time the engine was reignited, it under performed and did not reach the targeted velocity. This means that Mangalyaan would have to use extra fuel to realign itself. They decided to reignite the engine once again and successfully put it on the desired path. Before leaving the earth’s sphere of influence it sent back its first picture from its cool mars coloured camera. Mangalyaan has now been put on a direct path towards mars. It now hurtles through frictionless vacuum. The engine will now be turned on 300 day later.
Mangalyaan is now nearing Mars. The big moment is near when Mangalyaan has to enter the Earth's orbit. However this part of the journey is fraught with challenges. For one, the same engine is required to work after 300 days. Initially, the scientists task was to increase the velocity but on this day, their job was to reduce the velocity so that instead of flying by the planetary system it would be properly captured around Mars by turning the spacecraft and firing the liquid engine in the opposite direction. If not done properly, it would either fly into pace aimlessly or crash into the martian surface. What makes it even more difficult is that when Mangalyaan enters the martian orbit, it will enter behind the Red Planet cutting of communication with earth. This means it has to function on auto mode. It switched from solar panels to its lithium ion battery and made the maneuver. Few minutes later, Mangalyaan goes behind the Red Planet and all communication is cut off.
After over 25 minutes of pin drop silence and waiting. Without a signal from Mangalyaan, the team could only hope for the best. And….. Success! The Orbiter was successfully put into Martian orbit and today, 5 years later, it is still functioning.
Kasei Valles is known to be the largest outflow channel system on Mars extending more than 2400 km.