Another small Chandrayaan step in India’s space stride

Knowing well that deep-space contact with the spacecraft would be central to the success of India’s maiden unmanned moon mission, ISRO conceived the creation of an Indian Deep Space Network (IDSN) as a part of the Chandrayaan-I project proposals. The success of this plan makes India one among only six nations that have resources to track spacecraft beyond a 1.5 lakh distance from the earth.

“You cannot say you are going to the moon and then go asking other countries for deep space support. Others will be able to help only when they have the time. The costs for hiring out deep space support are also high,” says the director of ISRO’s Telemetry, Tracking and Command Network (ISTRAC) Dr S K Shivakumar.

Commissioned in November 2005, the Indian Deep Space Network, comprising two antennae — one 32 metres high and the other 18 metres — capable of sending and receiving deep space radio signals and remote controlling missions officially began operations with Chandrayaan-I.

Before the moon mission got underway, through September and early October, when the network had been established, engineers and scientists from ISRO spent time testing their newly created systems by using distant radio stars for target practice.

“We tracked many stars like Cygnus, Cassiopeia and the sun and moon, all of which emit radio signals, in the initial phase of preparing for the mission,” the ISTRAC director said.

In the first week of October, the IDSN got a taste of the real thing when the Japan Aerospace Exploration Agency (JAXA), a partner on the Chandrayaan mission, collaborated with ISRO to track its Selene lunar mission.

The 32-metre antenna also came into play in tracking the European Space Agency’s deep-space probe, Rosetta, setting the stage for the completion of calibrations and tests for India’s moon mission, as well as in becoming the only deep space network on this side of the earth.

For the moon mission, the IDSN’s network of computers and systems are connected to central mission systems at ISTRAC in Bangalore, while data received from 12 instruments on the spacecraft are channeled to individual investigators via the Indian Space Science Data Centre, a newly established data-storage facility at the IDSN campus.

According to ISRO officials, the costs saved in having an indigenous deep space network nearly equal the cost of the moon mission spacecraft in the Rs 386-crore, 4-lakh-km Chandrayaan-I project.

External stations, including in the US, are playing support roles in the Indian moon mission by tracking the spacecraft when it is in hidden regions of the moon orbit.

IDSN over the coming years will support future Indian deep space missions like Chandrayaan-II, a manned mission to the moon and probable ventures to the planet Mars.

It is hoped that the IDSN will eventually bring commercial gains to India by allowing other countries and space agencies to use the network for operations and tracking support. “There are already a lot of requests from other agencies for utilisation of the IDSN. This is now considered one of the best deep space networks in the world,” said an ISRO official.