For the Mars Mission, one is obliged to thank the Indian Deep Space Network, without which the Mission would not have been possible.

In a village called Byalalu, 40 km from Bangalore, lie two enormous antennae. One has a dish diameter of 18 metres and is the smaller of the two. The other’s dish has a diameter of 32 metres.

These antennae are the devices that facilitate communication between the spacecraft and the Earth. You need to send instructions in the form of radio waves — ‘fire this motor to change the route’, ‘take a picture now’, etc. You also need to receive stuff from them — photographs taken by the craft, data required for manoeuvre. In space parlance, this is called TTC, short for telemetry, telecommand and communication.

It is the bigger one that will be come into play in the Mars Mission. Radio waves (signals) sent from the Mars orbiter will be extremely feeble, as they travel millions of kilometres to the earth. Hence the huge dish.

Big as it may sound, the DSN-32 is a lot smaller compared with its sisters in other countries. China’s Deep Space Network boasts of a 50-metre antenna at Miyun, near Beijing, and is planning to build another, 64-metre one at Jiamusi.

Well, the US is still ahead. Its DSN has a 70-metre antenna in California.

> ramesh.m@thehindu.co.in