Indian Space Capabilities
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The Hindu : National : Antennae turn to Chandrayaan
Antennae turn to Chandrayaan
Divya Gandhi
Bangalore: Training their gaze on India’s maiden moon launch on Wednesday are antennae at Mauritius, Brunei, Biak (Indonesia) and Bearslake (Russia), Goldstone, Maryland, Hawaii (U.S.), Brazil, Russia, Lucknow, Sriharikota, Thiruvananthapuram, Port Blair and, of course, the giant antennae at Byalalu, which will feed ISTRAC with telemetric information on the health of Chandrayaan.
Even as all eyes are on Sriharikota, it is the Bangalore’s industrial suburb, Peenya, which is the nerve centre of the operation. At the space control centre here, scientists prepare to receive data from ground stations around the world on Chandrayaan.
ISRO’s Telemetry, Tracking and Command Network will get data within minutes of Chandrayaan’s launch from 15 ground stations from as far as Brazil and Hawaii, said ISTRAC Director S.K. Shivakumar.
“Within 19 minutes of its launch the spacecraft separates completely from the launch vehicle and begins its independent orbital life, which is when the tracking will begin,” said B.R. Guruprasad, PRO of ISRO.
“For the first 48 hours we will be receiving telemetry data on the health of the satellite from all these stations. Typically these stations have 10 metre antennae which are sufficient to track the satellite at this stage,” said O. Chiranjeevi, Group Director, ISTRAC. The antennae at Byalalu will begin to pick up signals within six hours after its launch, said Dr. Shivakumar. The Indian Deep Space Network Facility includes two antennae – a 32 metre one and an 18 metre one. However, the true work of these antennae will begin later once the satellite reaches a distance of over one lakh kilometres in a couple of days, said Mr. Chiranjeevi.
Antennae turn to Chandrayaan
Divya Gandhi
Bangalore: Training their gaze on India’s maiden moon launch on Wednesday are antennae at Mauritius, Brunei, Biak (Indonesia) and Bearslake (Russia), Goldstone, Maryland, Hawaii (U.S.), Brazil, Russia, Lucknow, Sriharikota, Thiruvananthapuram, Port Blair and, of course, the giant antennae at Byalalu, which will feed ISTRAC with telemetric information on the health of Chandrayaan.
Even as all eyes are on Sriharikota, it is the Bangalore’s industrial suburb, Peenya, which is the nerve centre of the operation. At the space control centre here, scientists prepare to receive data from ground stations around the world on Chandrayaan.
ISRO’s Telemetry, Tracking and Command Network will get data within minutes of Chandrayaan’s launch from 15 ground stations from as far as Brazil and Hawaii, said ISTRAC Director S.K. Shivakumar.
“Within 19 minutes of its launch the spacecraft separates completely from the launch vehicle and begins its independent orbital life, which is when the tracking will begin,” said B.R. Guruprasad, PRO of ISRO.
“For the first 48 hours we will be receiving telemetry data on the health of the satellite from all these stations. Typically these stations have 10 metre antennae which are sufficient to track the satellite at this stage,” said O. Chiranjeevi, Group Director, ISTRAC. The antennae at Byalalu will begin to pick up signals within six hours after its launch, said Dr. Shivakumar. The Indian Deep Space Network Facility includes two antennae – a 32 metre one and an 18 metre one. However, the true work of these antennae will begin later once the satellite reaches a distance of over one lakh kilometres in a couple of days, said Mr. Chiranjeevi.
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Chandrayaan-I launched successfully
SRIHARIKOTA: Chandrayaan-1, India's maiden moon spacecraft, was on Wednesday put into Transfer Orbit around the earth by the Polar Launch Vehicle
Chandrayaan-I has been launched from Sriharikota. (Pic courstesy: Times Now)
More
PSLV-C11 about 19 minutes after it blasted off from the Satish Dhawan Space Centre here. ( Watch )
The 1,380 kg Chandrayaan-1, carrying 11 payloads, was released into a Tansfer Orbit at a perigee (nearest point to earth) of about 250 km and apogee (farthest point from the earth) of about 23,000 km, 18.2 minutes after the PSLV-C11 blasted off as the scientists broke into jubilation at the mission control centre.
After a series of procedures over the next two weeks, the spacecraft would reach its desired Lunar orbit and placed at a height of 100 km from the Lunar surface, marking the operational phase of the mission which would put India in the elite lunar club.
Earlier, at the end of the 49-hour countdown, the 44.4 meter tall four-stage PSLV-11 lifted off from the second launch pad into a cloudy sky.
This is the 14th flight of ISRO's workhorse PSLV, which had launched 29 satellites into a variety of orbits since 1993, and 13th successive one in a row.
Chandrayaan-1 is carrying 11 payloads, five entirely designed and developed in India, three from European Space Agency, one from Bulgaria and two from US, which would explore the Moon over the next two years.
Chandrayaan-I launched successfully-India-The Times of India
SRIHARIKOTA: Chandrayaan-1, India's maiden moon spacecraft, was on Wednesday put into Transfer Orbit around the earth by the Polar Launch Vehicle
Chandrayaan-I has been launched from Sriharikota. (Pic courstesy: Times Now)
More
PSLV-C11 about 19 minutes after it blasted off from the Satish Dhawan Space Centre here. ( Watch )
The 1,380 kg Chandrayaan-1, carrying 11 payloads, was released into a Tansfer Orbit at a perigee (nearest point to earth) of about 250 km and apogee (farthest point from the earth) of about 23,000 km, 18.2 minutes after the PSLV-C11 blasted off as the scientists broke into jubilation at the mission control centre.
After a series of procedures over the next two weeks, the spacecraft would reach its desired Lunar orbit and placed at a height of 100 km from the Lunar surface, marking the operational phase of the mission which would put India in the elite lunar club.
Earlier, at the end of the 49-hour countdown, the 44.4 meter tall four-stage PSLV-11 lifted off from the second launch pad into a cloudy sky.
This is the 14th flight of ISRO's workhorse PSLV, which had launched 29 satellites into a variety of orbits since 1993, and 13th successive one in a row.
Chandrayaan-1 is carrying 11 payloads, five entirely designed and developed in India, three from European Space Agency, one from Bulgaria and two from US, which would explore the Moon over the next two years.
Chandrayaan-I launched successfully-India-The Times of India
nitesh
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The Hindu : Opinion / Interviews : ‘Once Chandrayaan goes near the moon, we will be there to track it’
‘Once Chandrayaan goes near the moon, we will be there to track it’
The 32-metre antenna in Bangalore will allow us to collect the signals from Chandrayaan about 4,00,000 km away both in terms of satellite control capability and the science data coming from the various onboard experiments.
After its expected launch on Tuesday morning, Chandrayaan-1, the Indian lunar orbiter, will be injected into its first orbit around the earth in just 17 minutes. {This part is done} During its subsequent course to the final orbit around the moon, and during the orbiter’s lifetime of two years, a critical element of the mission will be the constant communication link from the ground to the satellite for tracking it as well as for its orbit control and house-keeping — the Telemetry, Tracking and Command (TTC) operations — and receiving data from the 11 onboard experiments.
Missions that go beyond a distance of 1,00,000 km from the Earth are usually termed as deep space missions and Chandrayaan-1 is the first such for the Indian Space Research Organisation (ISRO). For deep space missions, ISRO has established an impressive communications infrastructure called the Indian Deep Space Network (IDSN) at Byalalu, a village located about 45 km from Bangalore, as part of the ISRO Telemetry Tracking and Command (ISTRAC) system. Comprising a massive indigenously built 32-m antenna and a German 18-m antenna, the IDSN will be the centre of activity for the entire duration of the mission.
Excerpts from an interview of ISTRAC Director S.K. Shiva Kumar with Science Correspondent R. Ramachandran:
Dr. Shiva Kumar, what are the critical issues involved in telemetry, tracking and communications in general associated with deep space missions?
When we talk of satellites in near earth orbit, we mean about 1,000 km altitude or more, or near earth space of about 2,000-2,500 km in range from the Earth’s surface. But when we say deep space mission, we mean lakhs of kilometres. For example, when we talk of the Moon mission, it means that the distance is not less than the Earth-Moon distance, which is about 4,00,000 km. Internationally, there is a way of categorising deep space and near earth, but a common way of defining would be the moon distance and beyond.
In deep space missions, as the space probe moves farther away from the Earth, the strength of the signals from it become weaker and weaker. The real challenge is to catch those weak signals. Mathematically, from antenna theory, we know that we have to put up larger and larger dishes. ISTRAC has so far been involved with smaller dimension 10-11-metre diameter dishes. But now for a deep space mission, it jumps to something like 32 m. To make such an antenna, especially through the indigenous industry, was a big challenge for us. We looked at [systems] the world over and found that the nominally working deep space antenna you get to see is 30m-plus. We decided to make a 32-m antenna in Bangalore, which would give us the strength to talk to our satellite from our own soil and also to collect the signals from Chandrayaan about 4,00,000 km away both in terms of satellite control capability and the science data coming from the various onboard experiments.
But wisely this DSN-32 has not been done only for the Chandrayaan mission but for all deep space missions to come in the future. It puts us in the category of deep space antennae found anywhere else in the world. That is the whole essence of building an Indian Deep Space Network facility. Starting with Chandrayaan we are pretty sure that we can track any other object deeper than this. If we are doing a Mars mission we do not have to worry at that point of time whether we have to build some more things. We have built a world standard facility that meets all the international standards. That means it can track any other [deep space] object. Simply stated, it is state-of-the-art interoperable and cross-support compatible facility that meets the Indian requirements with good margins and also the requirements of any other space agency.
For deep space applications, when we say that we are capable of receiving signals of weaker strengths with this antenna, we should similarly be able to pump fairly strong signals to the satellite for commanding the spacecraft. Once the diameter of the dish is increased, that is very easily done with higher power amplifiers. About 2 kW was our normal usage. This time we have put up a 20 kW high power amplifier. That much power with a big dish is enough for the satellite to receive and execute the command functions. This is another world standard that has been met by IDSN. This antenna will also be capable of doing what is called the two-way ranging required for determining the position of the spacecraft. In addition, we have put up a reception facility for the science experiments [next to the antennae at Byalalu].
All the data will be sent to the spacecraft control centre [of ISTRAC] and the science data will be sent from this facility to the Space Science Data Centre (SSDC). The science data received here can then be sent to different processing systems for producing the various data products. All this needed a lot of critical technologies to be done and everything had to be done through the Indian industry.
In terms of the amount of data that you would be receiving, what would be the bandwidth requirements? Could you give a comparison with what you handle in LEO missions?
Of course, in deep space everything is [at] a premium. Actually, IRS satellites, which are in 700-900-km orbit, produce much more data than what Chandrayaan will produce. For the imagery that you collect with 1-m and 5-m resolutions, that data is quite voluminous. But we are [already] in the higher level of data transmission from Chandrayaan. We will be transmitting data at 8.4 Mbps, whereas many people are doing it at much lower rates. Just for comparison, IRS satellites transmit at 100 Mbps data rate. Since we have handled high bit-rate data links, there is no issue in handling these lower bit-rates. For Chandrayaan, since the incoming data is at 8.4 Mbps, we have organised ourselves well for transmitting the data. The data we receive from Chandrayaan at our SSDC will be redistributed [for which] we have put up really high-speed dedicated links [up to 16 Mbps depending upon the experiment and the location]. In addition to that, since some people did not want dedicated links because they wanted [their data] to be in the public domain, we have put up a high-speed internet link of 16 Mbps. These are all, I would say, first in our domain. ISTRAC has never handled so many high-speed links.
How will the operations be sequenced? Will it be that the normal ISTRAC network would track up to 1,00,000 km and then switch over to DSN?
That’s rightly perceived. Actually, the satellite will be first put into an orbit with an apogee of 22,800 km. This is quite close to Earth. Since ISTRAC has a fairly big network, all our stations commonly used in our IRS missions will be deployed. None of these stations has a big antenna but they are good enough for tracking up to 1,00,000 km without any problem. Once we cross the 1,00,000-km barrier, the big antenna will come in. Notwithstanding this [nominal procedure], since we are deploying the big antenna for the first time, we cannot be waiting till 1,00,000 km. So, for most part of the trajectory we will be tracking it with both DSN-18 and DSN-32, even earlier than 1,00,000 km. But beyond 1,00,000 km, we will be doing specifically by the mission-assured IDSN.
Are there any issues with regard to calibration that you need to do before you start your operations?
First, there are the standard test and evaluation procedures that we have in ISTRAC. Then we have tracked some of the LEO satellites like Cartosat and IRS-P4/Oceansat with the big antenna. But, of course, this does not satisfy anybody because you have to track something nearer to moon. Very recently, we have started tracking SELENE, the Japanese lunar orbiting satellite [launched in September 2007], thanks to cooperation from JAXA [the Japan Aerospace Exploration Agency]. We have been able to track the satellite continuously with this antenna. That has given us ample confidence to say ‘Yes. Once Chandrayaan goes near the moon, we will be there to track it.’ To that extent, our comfort level is quite high because if you have tracked a similar object that is closer to moon and you have been able to establish links with good margins and all that, we don’t have to speak much about our ability to do [the same] with Chandrayaan. In addition, we are planning to track another deep space [cometary] probe ROSETTA [launched in 2004]. This was another opportunity that was created thanks to the European Space Agency.
That is one part of it. We have also tracked radio stars, which are quite good in S-band and X-band [the frequencies that will be used for TTC operations and science experiments respectively], like Cygnus, Cassiopeia, as well as Sun and Moon. This has given us ample experience in terms of pointing the beam on such a far off object, a major thing in my opinion. It also gives us ample scope for measurements because their movements are quite slow and we now know how to maximise our signals.
What are the critical technologies that had to be developed to establish this set-up?
The realisation of the entire antenna system itself was a big challenge because we were doing it for the first time. ISTRAC was responsible for building this. We chose ECIL [Electronics Corporation of India Ltd.] as the prime contractor who had the primary responsibility for the reflector and the mount of the antenna. In turn we worked with ECIL very closely. Along with that we chose BARC for antenna control servo system, the major subsystem. The RF design was entrusted to the ISRO Satellite Centre (ISAC). ISTRAC and ISAC together developed the feed system. These three are the heart of the whole system and these four agencies constituted the core team for executing the project. But that is not all because many subsystems had to be realised. So we went around scouting different industries in the country. We could identify sources with good capability within the country — L&T, Godrej & Boyce, SLN Technologies in Bangalore, HAL and many others. I think we had interface with 40 industries to do this work.
‘Once Chandrayaan goes near the moon, we will be there to track it’
The 32-metre antenna in Bangalore will allow us to collect the signals from Chandrayaan about 4,00,000 km away both in terms of satellite control capability and the science data coming from the various onboard experiments.
After its expected launch on Tuesday morning, Chandrayaan-1, the Indian lunar orbiter, will be injected into its first orbit around the earth in just 17 minutes. {This part is done} During its subsequent course to the final orbit around the moon, and during the orbiter’s lifetime of two years, a critical element of the mission will be the constant communication link from the ground to the satellite for tracking it as well as for its orbit control and house-keeping — the Telemetry, Tracking and Command (TTC) operations — and receiving data from the 11 onboard experiments.
Missions that go beyond a distance of 1,00,000 km from the Earth are usually termed as deep space missions and Chandrayaan-1 is the first such for the Indian Space Research Organisation (ISRO). For deep space missions, ISRO has established an impressive communications infrastructure called the Indian Deep Space Network (IDSN) at Byalalu, a village located about 45 km from Bangalore, as part of the ISRO Telemetry Tracking and Command (ISTRAC) system. Comprising a massive indigenously built 32-m antenna and a German 18-m antenna, the IDSN will be the centre of activity for the entire duration of the mission.
Excerpts from an interview of ISTRAC Director S.K. Shiva Kumar with Science Correspondent R. Ramachandran:
Dr. Shiva Kumar, what are the critical issues involved in telemetry, tracking and communications in general associated with deep space missions?
When we talk of satellites in near earth orbit, we mean about 1,000 km altitude or more, or near earth space of about 2,000-2,500 km in range from the Earth’s surface. But when we say deep space mission, we mean lakhs of kilometres. For example, when we talk of the Moon mission, it means that the distance is not less than the Earth-Moon distance, which is about 4,00,000 km. Internationally, there is a way of categorising deep space and near earth, but a common way of defining would be the moon distance and beyond.
In deep space missions, as the space probe moves farther away from the Earth, the strength of the signals from it become weaker and weaker. The real challenge is to catch those weak signals. Mathematically, from antenna theory, we know that we have to put up larger and larger dishes. ISTRAC has so far been involved with smaller dimension 10-11-metre diameter dishes. But now for a deep space mission, it jumps to something like 32 m. To make such an antenna, especially through the indigenous industry, was a big challenge for us. We looked at [systems] the world over and found that the nominally working deep space antenna you get to see is 30m-plus. We decided to make a 32-m antenna in Bangalore, which would give us the strength to talk to our satellite from our own soil and also to collect the signals from Chandrayaan about 4,00,000 km away both in terms of satellite control capability and the science data coming from the various onboard experiments.
But wisely this DSN-32 has not been done only for the Chandrayaan mission but for all deep space missions to come in the future. It puts us in the category of deep space antennae found anywhere else in the world. That is the whole essence of building an Indian Deep Space Network facility. Starting with Chandrayaan we are pretty sure that we can track any other object deeper than this. If we are doing a Mars mission we do not have to worry at that point of time whether we have to build some more things. We have built a world standard facility that meets all the international standards. That means it can track any other [deep space] object. Simply stated, it is state-of-the-art interoperable and cross-support compatible facility that meets the Indian requirements with good margins and also the requirements of any other space agency.
For deep space applications, when we say that we are capable of receiving signals of weaker strengths with this antenna, we should similarly be able to pump fairly strong signals to the satellite for commanding the spacecraft. Once the diameter of the dish is increased, that is very easily done with higher power amplifiers. About 2 kW was our normal usage. This time we have put up a 20 kW high power amplifier. That much power with a big dish is enough for the satellite to receive and execute the command functions. This is another world standard that has been met by IDSN. This antenna will also be capable of doing what is called the two-way ranging required for determining the position of the spacecraft. In addition, we have put up a reception facility for the science experiments [next to the antennae at Byalalu].
All the data will be sent to the spacecraft control centre [of ISTRAC] and the science data will be sent from this facility to the Space Science Data Centre (SSDC). The science data received here can then be sent to different processing systems for producing the various data products. All this needed a lot of critical technologies to be done and everything had to be done through the Indian industry.
In terms of the amount of data that you would be receiving, what would be the bandwidth requirements? Could you give a comparison with what you handle in LEO missions?
Of course, in deep space everything is [at] a premium. Actually, IRS satellites, which are in 700-900-km orbit, produce much more data than what Chandrayaan will produce. For the imagery that you collect with 1-m and 5-m resolutions, that data is quite voluminous. But we are [already] in the higher level of data transmission from Chandrayaan. We will be transmitting data at 8.4 Mbps, whereas many people are doing it at much lower rates. Just for comparison, IRS satellites transmit at 100 Mbps data rate. Since we have handled high bit-rate data links, there is no issue in handling these lower bit-rates. For Chandrayaan, since the incoming data is at 8.4 Mbps, we have organised ourselves well for transmitting the data. The data we receive from Chandrayaan at our SSDC will be redistributed [for which] we have put up really high-speed dedicated links [up to 16 Mbps depending upon the experiment and the location]. In addition to that, since some people did not want dedicated links because they wanted [their data] to be in the public domain, we have put up a high-speed internet link of 16 Mbps. These are all, I would say, first in our domain. ISTRAC has never handled so many high-speed links.
How will the operations be sequenced? Will it be that the normal ISTRAC network would track up to 1,00,000 km and then switch over to DSN?
That’s rightly perceived. Actually, the satellite will be first put into an orbit with an apogee of 22,800 km. This is quite close to Earth. Since ISTRAC has a fairly big network, all our stations commonly used in our IRS missions will be deployed. None of these stations has a big antenna but they are good enough for tracking up to 1,00,000 km without any problem. Once we cross the 1,00,000-km barrier, the big antenna will come in. Notwithstanding this [nominal procedure], since we are deploying the big antenna for the first time, we cannot be waiting till 1,00,000 km. So, for most part of the trajectory we will be tracking it with both DSN-18 and DSN-32, even earlier than 1,00,000 km. But beyond 1,00,000 km, we will be doing specifically by the mission-assured IDSN.
Are there any issues with regard to calibration that you need to do before you start your operations?
First, there are the standard test and evaluation procedures that we have in ISTRAC. Then we have tracked some of the LEO satellites like Cartosat and IRS-P4/Oceansat with the big antenna. But, of course, this does not satisfy anybody because you have to track something nearer to moon. Very recently, we have started tracking SELENE, the Japanese lunar orbiting satellite [launched in September 2007], thanks to cooperation from JAXA [the Japan Aerospace Exploration Agency]. We have been able to track the satellite continuously with this antenna. That has given us ample confidence to say ‘Yes. Once Chandrayaan goes near the moon, we will be there to track it.’ To that extent, our comfort level is quite high because if you have tracked a similar object that is closer to moon and you have been able to establish links with good margins and all that, we don’t have to speak much about our ability to do [the same] with Chandrayaan. In addition, we are planning to track another deep space [cometary] probe ROSETTA [launched in 2004]. This was another opportunity that was created thanks to the European Space Agency.
That is one part of it. We have also tracked radio stars, which are quite good in S-band and X-band [the frequencies that will be used for TTC operations and science experiments respectively], like Cygnus, Cassiopeia, as well as Sun and Moon. This has given us ample experience in terms of pointing the beam on such a far off object, a major thing in my opinion. It also gives us ample scope for measurements because their movements are quite slow and we now know how to maximise our signals.
What are the critical technologies that had to be developed to establish this set-up?
The realisation of the entire antenna system itself was a big challenge because we were doing it for the first time. ISTRAC was responsible for building this. We chose ECIL [Electronics Corporation of India Ltd.] as the prime contractor who had the primary responsibility for the reflector and the mount of the antenna. In turn we worked with ECIL very closely. Along with that we chose BARC for antenna control servo system, the major subsystem. The RF design was entrusted to the ISRO Satellite Centre (ISAC). ISTRAC and ISAC together developed the feed system. These three are the heart of the whole system and these four agencies constituted the core team for executing the project. But that is not all because many subsystems had to be realised. So we went around scouting different industries in the country. We could identify sources with good capability within the country — L&T, Godrej & Boyce, SLN Technologies in Bangalore, HAL and many others. I think we had interface with 40 industries to do this work.
digitaltiger
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India Rocks.... Kudos to ISRO.. 
Next in the series is a probe on moon ..........
Next in the series is a probe on moon ..........
Black Stone
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Congratulations on the launch.
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