Looking spaceward, feet firmly on the ground

Updated - June 24, 2016 04:20 pm IST

Published - October 23, 2012 12:56 am IST

K. RADHAKRISHNAN: ‘I would like to stress that applications are our thrust unlike, say, in Russia, the United States or China which are after human space flights, space stations and such activities.’

K. RADHAKRISHNAN: ‘I would like to stress that applications are our thrust unlike, say, in Russia, the United States or China which are after human space flights, space stations and such activities.’

Dr. K. Radhakrishnan, Chairman of the Indian Space Research Organisation (ISRO) and Secretary, Department of Space, spoke to Madhumathi D.S. on the national space programme’s present concerns and what is in store for it as it grapples with global competition and rising internal demand. Excerpts:

The national space programme faces a double whammy: a transponder deficit on communication satellites and a delay in achieving the capability to launch our own communication satellites. How is ISRO addressing this problem?

First, I would like to stress that applications are our thrust unlike, say, in Russia, the United States or China which are after human space flights, space stations and such activities. We are very clear about being down to earth.

We have a capacity augmentation plan. Increasing capacity, enhancing capability and creating advanced technologies, these are all taking place in parallel. Thanks to the promotion of satellite communication and new services in it, there is a large demand [for transponders]. One objective is to increase capacity in the Ku and C bands. The other is to enhance capability, for example, with digital multimedia broadcasting on GSAT-6.

To remain state-of-the-art in communication satellites, we are going in for high power and higher frequencies like the Ka band. A multi-beam system with 24 footprints and uplink in the high-power Ka band will come with GSAT-11 in two years. Our target is to be contemporary in this area in five or six years.

Then there are the GSAT-6, 7 and 11 series, and GSAT-15 and 16. In remote sensing, the continuity of services is important for institutional and infrastructure planning, water resources, agriculture, afforestation, disaster management and the like. You need to improve spatial resolution from the present 0.8 metre to 0.6 metre and 0.3 metre. In microwave remote sensing we have to get into L, X and S bands.

We have two established application areas in communication and remote sensing. Now navigation satellites will add a new dimension of location-based services. Gagan is our space-based augmentation to GPS mainly for the civil aviation sector. GSAT-10 carries the second of three Gagan payloads. The first satellite of our own regional navigation system, the Indian Regional Navigational Satellite System, will go in 2013.

What is being done to mitigate the transponder shortage on Insat/GSATs for broadcasting and telecommunication purposes? Of the 263 transponders available today, ISRO has leased 95 on foreign satellites.

A [few] weeks ago we released advertisements for leasing transponders because VSAT and direct-to-home (DTH) operators require them. The process may take up to two months.

Today we are not talking about replacements of the leased capacity but about how to meet requirements. We have 168 transponders of our own [provided by the domestic Insat/GSAT fleet].

If you look at the upcoming satellites, you get more than 100 [Indian] transponders [in the short term]. GSAT-10 [launched on September 29] is going to immediately give us 30 transponders from November onwards. GSAT-14 will give another 12 if [its launch vehicle] GSLV performs well. GSAT-9 will mean another 12 transponders, GSAT-15 will add 24 in the Ku band and GSAT-16 another 36.

With these 100 transponders being added, will the leases go back?

I don’t think they will go back but the usage will be more. There is nothing wrong in using [them] provided they are available at a reasonable price.

Has the queue for DTH levelled out? There are seven DTH operators now and these and new players want more satellite capacity.

India is a large market. Today you have some 600 TV channels and DTH has revolutionised the services. Every [broadcaster] is looking for enhanced capacity, because high-definition TV is coming in. This is a worldwide phenomenon. There will always be some gap between what they want and what is available. This is dynamic. The positive thing is, the demand is very high today.

Where do we stand in the launch vehicle programme, particularly the delayed GSLV?

If you look at the queue, the GSLV cryogenic stage has to get ready and fly. The GSLV Mark III cryogenic stage has to be developed and then the semi-cryogenic stage which is approved. All are progressing. First we have to prove the GSLV. We had problems due to small issues. There is nothing wrong with the vehicle per se, but the problems were attributable to certain components. Of course, GSLV cryogenics have to be developed and tested. The next thing is to improve the reliability of the vehicle which will take us to [a capability to lift] 2.2-tonne satellites to geostationary transfer orbits.

Cryogenic testing for the next GSLV-D5 vehicle is going on. Two crucial tests have to be completed: testing in vacuum and the endurance of the fuel booster turbo pump. If they are successful we can say it is flying on the ground.

GSLV Mk III is making good progress. It will take us to four tonnes. Its cryogenics are to be developed fully. During the 12th Plan period we want to do two to three flights of Mk III.

What improvements are happening with communication and remote-sensing satellites? Our Insat/GSAT communication satellites, for example, are in the 3,000-kg, 36-transponder class, while the world has moved towards spacecraft double and triple that size and capacity.

We, too, have to [do that]. Not [just] larger, it is in terms of power, bandwidth, mass and features like having 100 transponders in one satellite. Whether it is six or ten tonnes is one aspect, how much power it can carry is another.

[Elsewhere] today there are satellites with power levels of 16-17 kilowatts. From the 100-watt Ariane Passenger PayLoad Experiment (APPLE) experiment [in 1981], we moved on to 5,500 watts of power in GSAT-8 [in 2011].

In 1995 we were the best civilian remote sensing satellite operator with IRS 1C and 1D. TES and the Cartosat-2 series have 0.8 m resolution. We, too, are getting to 0.6 m, 0.5 m and better.

You have spoken of nearly 60 satellite and launch missions in the next five years, planetary exploration and more. What are the plans for infrastructure and manpower to make future programmes possible?

ISRO has to enhance capability for the next five years. We also have to sow the seeds now for what we will do 10 years on; for R&D, for future technologies. We need to identify groups in the country and within the organisation for such activity.

The Space Research Complex [coming up] on 540 acres in the Science City near Challakere in Chitradurga will be ISRO’s resource for the next 25-50 years. What we will do there will evolve in one or two years. It could be planetary explorations, space habitat; astrobiology. The Department of Atomic Energy, the Defence Research & Development Organisation, the Indian Institute of Science, ISRO and the Karnataka government are working together there on a township and common amenities.

Right from the 1980s our manpower has remained around 16,000 while the number of missions has grown because of the industry participation. That number will increase by 2,000-3,000 to both replace and supplement our people.

Because of the actions taken in the 1970s on partnering the industry, today we have almost 500 firms contributing to the space programme. Where things are standardised and operational one can look for a larger role for industry in realising goals or taking responsibility for it. This is a major initiative that we are working on.


0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in


Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.