Indian Space Program: News & Discussion - Sept 2016

Amber G. · Post by **Amber G.** » 23 Jun 2017 22:03

shiv wrote:
Here is another similar "GPS for dummies" link just like the one above..

GPS and relativity

A good popular article, as I mentioned it before, is from renowned Prof. Neil Ashby in Physics Today. Here is a link I think will work without subscription.
RELATIVITY AND THE GLOBAL POSITIONING SYSTEM
**
I used to visit U of Colorado, boulder in 70's in summer - (Nice place to spend summer and visit Rockies). Prof Ashby was even then a big shot there. Boulder also had George Gamow on its faculty at one time in the past. George Gamow's "One Two Three Infinity" and "Mr. Tompkins in Wonderland" are two of my most favorite popular books to learn theory of relativity. (Shivji - may remember it, I recommend it long time ago)

Generally we need Einstein's general relativity to understand extreme astrophysical realms.. blackholes and such.. and until recently (before 1975) there was no easy way to confirm it with experiments on earth. In practical every day life GPS is the only application I can think of where the theory turns out to be essential for engineers to worry about.

(In fact I still remember the suspense when first atomic clock went up and many were skeptic that it will confirm Einstein's theory of gravitational time-dilation .. turns out that it did, and it was a big news then)

Unfortunately math needed to understand general theory of relativity is hard, and many results are quite counter intuitive.

The above article, IMO, is quite comprehensive and may able to answer some of the questions raised by JayS, Vina..

abhijitm · Post by **abhijitm** » 23 Jun 2017 22:21

whaat! we had PSLV launch today!!

shiv · Post by **shiv** » 23 Jun 2017 22:27

AmberG - George Gamov was a great favourite of mine. I still have one of his books at home - sadly unused and unlooked at by my own children

JE Menon · Post by **JE Menon** » 23 Jun 2017 22:38

On board camera video is fantastic, but high-res video macha, high-res!!!

Amber G. · Post by **Amber G.** » 23 Jun 2017 23:32

Ignoring emoticons but few points..

Rishi Verma wrote:

Factually Incorrect: First of ALL, Glonass is nearly as perfectly circular orbit at 19,100 km , so the rest of the GENERIC write up is incorrect, see below reference

Reference for Glonass Orbit

(The orbit has higher inclination of about 66 degrees as compared to 55 degrees for GPS)

Thanks for the reference. But, IMO, what is really silly is not understanding the context. BTW "nearly" is not "perfectly circular" (where e=0).
I suspect (by seeing your comments about inclination etc) that there is lack of understanding on you part for even the most basic part (Relativistic Time- dilation for elliptical (or "nearly circular"!) orbits.

The post does not explain anything, except empty words..

Of course! I agree that is does not explain anything unless there is necessary background on the listener's side. I explained that in my "disclaimer". If one does not have sufficient understanding of basic relativistic physics, one can always consult textbooks/professors etc.

For some background: I have learned Special Relativity (gradate level course taught by TV Ramakrisnan at IITK) and have taken a course in General Relativity taught by CN Yang (Noble prize). Have taught physics for last 4 decades.

I challenge you to come up with data such as clock drift of Glonass satellte, clock arrival time corruption (actual numbers) due to gravity

I can try to explain it to you, if you can ask specific question/do not understand a particular thing etc.. provided you answer the following.

So here is a little challenge for you.. Assume there are two identical clocks, one at Bangalore and other on Cartostat-2, perfectly synched today. If you check the time, a year later which clock (if any) will be ahead of the other and by how much? You can assume Cartostat-2 is in a circular orbit, 500 Km above MSL. You are free to use any internet resource, text book(s), computer - except asking and getting the answer from others.

Misra · Post by **Misra** » 24 Jun 2017 00:57

Gagan wrote: ISRO doesn't really need Doordarshan for the broadcast.

indeed, ISRO should think of establishing a 24-hr channel of its own now, ISROTV or whatever

SSridhar · Post by **SSridhar** » 24 Jun 2017 06:59

Did ISRO just put a Chinese satellite into orbit? - AJ Vinayak, Business Line

After the mega launch of 104 satellites in February, ISRO’s relatively modest launch of 31 satellites on Polar Satellite Launch Vehicle (PSLV) C38 on Friday should have attracted little attention. After all, barring the 712-kg Cartosat-2 series satellite, the other passengers were small satellites from different countries, mostly built by universities across the globe (including India) for research purposes.

But the origin of one of the tiny passengers has been causing a buzz among space and satellite launch circles around the globe. Reason: ISRO may well have put a Chinese satellite into space.

Eight of the small satellites deployed on Friday were Cube Sats — miniaturised research satellites — of the QB50 project, sponsored by the European Commission and managed by the Von Karmann Institute from Belgium. Orbiting in a string-of-pearls configuration, the QB50 constellation is a network of 50 Cubesats built by university teams world-over to carry out long-duration exploration of the lower thermosphere.

NASA’s Spaceflight.com website, which lists all payloads launched into space, says one of the QB50 satellites belonged to China’s National University of Defence Technology. “The two satellites which carry INMS (Ion-Neutral Mass Spectrometer) payloads are NUDTSat for China’s National University of Defence Technology and UCLSat for University College London”, it said.

With the two Asian giants being bitter rivals on earth as well as in space (China is way ahead in manned spaceflight; India beat China to Mars), there was consternation in some circles about ISRO carrying a Chinese payload.

According to an entry on social news aggregator Reddit: “There is a bit of confusion as ‘BE06’ isn’t on any list and is probably a typo…”. It noted that BE is a country code for Belgium but that NUDTSAT is from China. The NASA site named the satellite name as CN06.

ISRO denied there was any Chinese satellite aboard PSLV C38. ISRO’s official launch brochure said the satellite in question was Belgian — but that may well be because of the Belgian oversight of the QB50 project.

GBtimes, a website that says it “introduces Chinese businesses to the world”, said that not only was NUDTSat Chinese but that the earlier, record-setting launch of 104 satellites had also included a Chinese passenger — Chen Jiayong 1, another cubesat.

Clearly, it’s Hindi-Cheeni bhai-bhai once more — at least in space.

nirav · Post by **nirav** » 24 Jun 2017 08:52

JE Menon wrote:On board camera video is fantastic, but high-res video macha, high-res!!!

OT.
I have liked ISROs page on Facebook. Saw a contact us with a phone number!
I think it's time us jernails,kernails and nanha mujahids call them up and make a request for better resolution.

Maybe do the same@ DD and write letters to I&B ministry.

I had once written a letter to the goberment in the UPA times, I did get a reply after about 6 months.. but I did get one!

Lilo · Post by **Lilo** » 25 Jun 2017 01:13

CIA director openly speaks of the need to increase the speed of placing US offensive & defensive platforms in space while citing India particularly as one of 11 countries with competing spaceprograms.

https://www.youtube.com/watch?v=4X3-2qUwcCs

Amber G. · Post by **Amber G.** » 25 Jun 2017 01:54

Have to comment on some excellent post made by Vina as some things may have gotten lost while I was trying to focus on some specific technical detail. The relevant post is here.

Vina wrote

Glonass transmits cartesian coordinates (Earth Centered & Earth Focused) for the satellites orbital parameters (ephemeris) while the others (GPS & Galileo, I would guess Navic & Compass as well) transmit Kepler parameters

While I focused on that relevant part is not "orbital parameters" per-se but rather what I described as "clock-correction" due to elliptical nature of the orbit - (The gravitational potential as well as speed changes in elliptical orbit - causing relativistic effects which can not be neglected). That was point was correct but it was a technical comment.

One main point which Vina pointed out needs to be noticed.

In old days (when US atomic clocks were launched) computing power was expensive and US decided not to incorporate such correction/computation inside the GPS sats. Glonass did.

Actually many wanted, and wished US did that too. Though the "eccentricity correction" can be applied by the receiver, having this applied before the broadcast (aka glonass) is much simpler. As said in past this was decided due to the small amount of computing power available in the satellite. And yes, it would actually make more sense to incorporate this (and similar) correction into the time broadcast by the satellites (then the broadcast time events would be much closer to "GPS system time"). It may now be too late to reverse this decision because of the investment that many dozens of receiver manufacturers have in their products.

GPS too has modernised and like I pointed out, the Block II (later versions) and Block III have significant compute and other capabilities that are needed for autonomous mode.
The only thing I am saying is that since these satellites anyway can compute their ephemeris data (in normal course that data will be uploaded by the ground stations), a newer GPS like system, could, given the advances in computing, now ,nor will it be.

Will agree -- the part about sats having significant computing power and broadcasting what is most efficient.

One significant point - In all GPS systems, apart from sender and receiver unit, there is a "control system" made of few ground stations with known accurate positions, accurate clocks and computing power which "calculates" ephemeris which one can use to predict position (say for next few hours - accurately in all reference systems). These are uploaded to sats to be broadcasted by them back to receiver.

A good ground control system is even more critical for Rb clocks (NaviC) . Cs clocks are relatively more "stable" while a sat is being launched, There is more need for Rb clocks to be calibrated from ground stations as they get more affected by shock etc.

Hope this helps.

Muns · Post by **Muns** » 25 Jun 2017 01:55

History made as NASA launches 64 gram world’s lightest satellite designed by 18-year old Indian student

http://www.india-aware.com/history-made ... n-student/

History has been made on thursday as the world’s smallest and lightest satellite, named KalamSat was carried by a NASA sounding rocket from Wallops Island, a NASA facility at around 3pm (IST). An experiment of an 18-year-old Indian student is carried out by NASA for the first time.

The little satellite weighs in at just about 64 grams. This tiny satellite was flown into space in a NASA rocket from a facility in Wallops Island, according to sources.With this launch, India has created a record.

Kalamsat is a microsatelliter named after former Indian President and one of India’s greatest nuclear scientists Dr.A.P.J.Abdul Kalam built by an Indian High school student team for participation in the Cubes in Space, a STEM-based education program by NASA, with an objective to teach school students (ages 11-18) how to design and compete to launch an experiment into space with a free opportunity to design experiments to be launched into space on a NASA rocket or balloon if there project is selected.

disha · Post by **disha** » 26 Jun 2017 00:17

Blink and you missed the PSLV launch., that is the way PSLV and GSLV mkII and mkIII will go. With that., there will be more discussions on sat payloads., which is actually a welcome change!

Thanks ISRO and members here for posting the video (the 1 hour long) with interesting details., the only time I felt that the rocket was at risk was if it heard the well-prepared and nice & poetic essay in Hindi by the commentator., it would have committed harakiri. My computer survived., not my hair. I was tearing my hair out. DD needs to realize that there are times (like retrospectives) where they can put such flowery commentary. And there are times when aam-janta is interested in technical details (or telemetry) and further., there are times when they want to see the rocket in flight with several charts including range vs. altitude., coasting phase and apogee and perigee and inclination and trac information etc.

Not the face of the person making the announcement. Keep that record for some thing like retrospectives.

ISRO really needs to invest in very fast very high fidelity ground cameras. The ones that can be shown in IMAX and records at 1000s of fps such that when viewed in normal time it gives a nice slow motion of the boosters getting ignited and the gaarajta hua rocket clearing the launch pad.

Somebody please tell ISRO., at the non-rate of ISRO investing in high fidelity ground cameras., even Kakkarat'ji might end up doing a IMAX release of ISRO's rockets from his backyard* (*more power to him or rather more power to his lenses and cameras).

It was interesting to hear that ISRO plans to do 8-10 launches per year. If they can do 2 MkII and 1 Mk III every year and 7-8 PSLV per year., y-o-y., that is a remarkable boost in reliable launch capacity. In effect., that is @30 tonnes of capacity per year to LEO! That is serious space capacity! If all of that is used for EO, Nav and Comm., that is really some serious capacity - particularly with sat weight coming down - that is more than (or is it @50 tonnes) of equivalent capacity in 1997 (or two decades back).

Also MCF, Hasan was mentioned. Yes., once the sats are launched they are commissioned as soon as possible and handed over to MCF for 24x7 operations. That is an important step!

All in all., an excellent quarter (90 days) for ISRO and India.

schinnas · Post by **schinnas** » 26 Jun 2017 00:34

SSridhar wrote:Did ISRO just put a Chinese satellite into orbit? - AJ Vinayak, Business Line
After the mega launch of 104 satellites in February, ISRO’s relatively modest launch of 31 satellites on Polar Satellite Launch Vehicle (PSLV) C38 on Friday should have attracted little attention. After all, barring the 712-kg Cartosat-2 series satellite, the other passengers were small satellites from different countries, mostly built by universities across the globe (including India) for research purposes.

But the origin of one of the tiny passengers has been causing a buzz among space and satellite launch circles around the globe. Reason: ISRO may well have put a Chinese satellite into space.

Eight of the small satellites deployed on Friday were Cube Sats — miniaturised research satellites — of the QB50 project, sponsored by the European Commission and managed by the Von Karmann Institute from Belgium. Orbiting in a string-of-pearls configuration, the QB50 constellation is a network of 50 Cubesats built by university teams world-over to carry out long-duration exploration of the lower thermosphere.

NASA’s Spaceflight.com website, which lists all payloads launched into space, says one of the QB50 satellites belonged to China’s National University of Defence Technology. “The two satellites which carry INMS (Ion-Neutral Mass Spectrometer) payloads are NUDTSat for China’s National University of Defence Technology and UCLSat for University College London”, it said.

With the two Asian giants being bitter rivals on earth as well as in space (China is way ahead in manned spaceflight; India beat China to Mars), there was consternation in some circles about ISRO carrying a Chinese payload.

According to an entry on social news aggregator Reddit: “There is a bit of confusion as ‘BE06’ isn’t on any list and is probably a typo…”. It noted that BE is a country code for Belgium but that NUDTSAT is from China. The NASA site named the satellite name as CN06.

ISRO denied there was any Chinese satellite aboard PSLV C38. ISRO’s official launch brochure said the satellite in question was Belgian — but that may well be because of the Belgian oversight of the QB50 project.

GBtimes, a website that says it “introduces Chinese businesses to the world”, said that not only was NUDTSat Chinese but that the earlier, record-setting launch of 104 satellites had also included a Chinese passenger — Chen Jiayong 1, another cubesat.

Clearly, it’s Hindi-Cheeni bhai-bhai once more — at least in space.

Is it possible that Chinese are doing some industrial espionage - in terms of getting the finer details of commercial launches of ISRO - how much time ISRO takes, how it communiates with clients, processes orders, etc. They will improve on all these aspects and offer an even more competitively priced program. They have done this all over India. Even in Kancheepuram, they came, placed orders for the famous Kanchi silk sarees that are hand made, studied all the patterns (took pictures and samples provided by trader looking for business) and cloned them at half the cost and are now exporting it to Indian textile houses. Many silk sarees sold in India under Kanchi, Benaras, etc., branding are now are actually from China.

Something does not sit right with this news. ISRO better wake up.

SSSalvi · Post by **SSSalvi** » 26 Jun 2017 02:08

NAVIC, GAGAN, IRNSS for common man.. by a friend:

https://www.geospatialworld.net/article ... r-systems/

vasu raya · Post by **vasu raya** » 26 Jun 2017 03:25

^^^
good article, they should deny the NAVIC feature on the imported Chinese handsets and hopefully the dongle based solution is a short term one

disha · Post by **disha** » 26 Jun 2017 07:02

schinnas wrote:Is it possible that Chinese are doing some industrial espionage - in terms of getting the finer details of commercial launches of ISRO - how much time ISRO takes, how it communiates with clients, processes orders, etc. They will improve on all these aspects and offer an even more competitively priced program.

It is possible., and if they have figured out how ISRO operates via its commercial corp Antrix on intricacies of clients/processes etc and comes up with an improved process., then all the more better. First ISRO will have to tighten any loose information going out of its commercial Antrix line and second, the commercial space will have a healthy competition. But we are making several seikh-chilli arguments just based on a "fear" because the commercial sats that ISRO launched may have been based on chinese bus.

Think about it., they can provide sat bus but not able to provide commercial launch services such that the customers have to book a launch w/ ISRO!! If that is indeed the case then it says more about lack of commercial options with Chinese.

They have done this all over India. Even in Kancheepuram, they came, placed orders for the famous Kanchi silk sarees that are hand made, studied all the patterns (took pictures and samples provided by trader looking for business) and cloned them at half the cost and are now exporting it to Indian textile houses. Many silk sarees sold in India under Kanchi, Benaras, etc., branding are now are actually from China.

What has textiles to do with space? It is like the chinese scotch., here the Indian textile houses which are selling chinese "Benaras" silk needs to be shutdown (and they are run by Indians- right?) and the textile ministry needs to enforce the Kanchi and Benaras geo-patents more forcefully. This is an issue with tex min and you must take it up with them. Just because the tex min screws up somewhere we do a rona-dhona and apply to space sciences is a vast and wrong stretch. Just like chinese scotch.

Something does not sit right with this news. ISRO better wake up.

Just based on some report and based on our fear we are now giving gratuitous advice about "ISRO better wake up".

Singha · Post by **Singha** » 26 Jun 2017 08:21

good video from latest spaceX launch. the red hot nozzle of 2nd stage clearly shown as also the puff puff thrusters the 1st stage uses on its way down before braking rockets fire

in terms of using minimal non-tfta chalu launchpad and a launch center that looks like a regular itvity canteen, they are demystifying the whole launch thing

and the thin rocket put 10 iridium sats up

williams · Post by **williams** » 26 Jun 2017 11:11

http://timesofindia.indiatimes.com/indi ... 314610.cms

Not sure if this is DDM or leaked sensitive information. I think the 13 satellites include RISAT, Oceansat and Cartosat series.

SSSalvi · Post by **SSSalvi** » 26 Jun 2017 21:37

^^^
13 may also include some non-ISRO sats.

Amber G. · Post by **Amber G.** » 26 Jun 2017 23:54

williams wrote:http://timesofindia.indiatimes.com/indi ... 314610.cms

Not sure if this is DDM or leaked sensitive information. I think the 13 satellites include RISAT, Oceansat and Cartosat series.

Direct impact of Carotstat and other sats on much better "eye-on-foes" ought not to come as a surprise. (No secret that tremendous increase in capability is already paying rewards -- and is going to be increasingly helpful to keep an eye across LOC activities)

Varoon Shekhar · Post by **Varoon Shekhar** » 27 Jun 2017 17:12

http://www.isro.gov.in/discovery-of-new ... ndrayaan-1

Nice to see that results are still coming in from Chandrayaan-1. This instrument was produced jointly by ISRO and the Swedish space agency.

Gagan · Post by **Gagan** » 27 Jun 2017 18:38

Must watch

https://youtu.be/eCt6irXX970

SSSalvi · Post by **SSSalvi** » 27 Jun 2017 21:39

SwamyG · Post by **SwamyG** » 28 Jun 2017 03:19

Sorry if these were already posted.
First day Images from Cartosat -2 Series Satellite

Lots of potential onlee....two samples

Gagan · Post by **Gagan** » 28 Jun 2017 05:31

SSSalvi wrote:^^^

Hazaar Shukriya Saar !!!

Wow! What an image capture by Cartosat. This is 0.6m resolution?
That second image of Doha, Qatar, looks good!
Roos had the Yantar-4K2M, series of satellites, which use Film camera (Because of better resolution)
The roosis launch a satellite when needed, it stayed in orbit for like a 130 days, then ejects the film capsule as needed which is recovered and analyzed.
The image resolution was reportedly 0.3 m

They then had the Persona series that were electro-optical

Now they have the Razdan series (7 ton launch weight!) with a 2m mirror, and 20-30 cm/pixel resolution, and can see a person at these resolutions. The roosis are releasing 121 megapixel panchromatic images of earth taken by their weather sats now

India's upcoming Cartosat 3 series is hoped to touch 0.25m - internet rumour?

shravanp · Post by **shravanp** » 28 Jun 2017 05:52

Snaps are phenomenal! Unbelievable resolution and what a clarity. Bakistan and it's cheepack will be viewed nicely.

SwamyG · Post by **SwamyG** » 28 Jun 2017 07:50

What are the practical usefulness of such Roosi resolution? If a camel is going to be destroyed in the desert, do they really care if it has 2 humps or 1 ?

sanjaykumar · Post by **sanjaykumar** » 28 Jun 2017 08:18

A two hump camel would imply material help from central Asian republics and presumably Arab influence in Russia's underbelly.

prasannasimha · Post by **prasannasimha** » 28 Jun 2017 09:49

The actual military grade resolution if cartosat is supposed to be higher. That value will obviously be classified

SSSalvi · Post by **SSSalvi** » 28 Jun 2017 11:11

Right now they would not have applied all corrections .. still the resolution seems to be V good.

Compare with GE

sum · Post by **sum** » 28 Jun 2017 12:53

Gagan wrote:Must watch

https://youtu.be/eCt6irXX970

Beautiful Beautiful video.

As i have always mentioned, even a million shastang namaskars to the stalwarts like Sarabhai, Prof Dhawan etc who left every comfort behind just for the Nations cause would not be enough since these are who single handedly carried us to where we are now

Neela · Post by **Neela** » 28 Jun 2017 13:34

prasannasimha wrote:The actual military grade resolution if cartosat is supposed to be higher. That value will obviously be classified

And Cartosat 3 resolution is going to be 0.25m.

This is a club where India leads the rest of the pack.

chilarai · Post by **chilarai** » 28 Jun 2017 18:07

Gagan wrote:Must watch

https://youtu.be/eCt6irXX970

early in the video Dr Sarabhai says

"in my opinion the aspect of space research which I would like to stress most is in relation to national capability and the self confidence this will generate "

amazing foresight and vision !

SSSalvi · Post by **SSSalvi** » 28 Jun 2017 19:17

The last image released must be one of the calibration image.

The structure in middle ( Dark and bright squares ) is the calibration site for imaging satellites.

Structure at right top has nothing ( directly ) to do with calibration.

Details of CAL sight.

Sridhar · Post by **Sridhar** » 28 Jun 2017 23:07

I was hesitating to post my own articles here, but am posting here since they have not been posted earlier. These were blog posts on the Planetary Society blog just before and just after the GSLV-MK3 launch.

Curtain raiser on the launch
http://www.planetary.org/blogs/guest-bl ... eague.html

Post-launch update
http://www.planetary.org/blogs/guest-bl ... ocket.html

SwamyG · Post by **SwamyG** » 28 Jun 2017 23:21

chilarai wrote: early in the video Dr Sarabhai says

"in my opinion the aspect of space research which I would like to stress most is in relation to national capability and the self confidence this will generate "
amazing foresight and vision !

He goes on to acknowledge that urbanization has its own set of problems, and that the quality of lives have to be improved in the millions of villages. Hats off.

Sorry an OT, Dr Sarabhai and Dr Dhavan, seem to have a foreign accent. Any clues?

SwamyG · Post by **SwamyG** » 28 Jun 2017 23:25

Multi-spectral Image of Bhidaurya, UP taken on June 27, 2017

Lisa · Post by **Lisa** » 28 Jun 2017 23:30

Neela wrote:
prasannasimha wrote:The actual military grade resolution if cartosat is supposed to be higher. That value will obviously be classified
And Cartosat 3 resolution is going to be 0.25m.

This is a club where India leads the rest of the pack.

Could someone tell me if the cameras are actually made in India. Also with regards to the previous discussion on clocks in space, does anyone know where Russia gets its clocks from. Thank you in advance.

rahulm · Post by **rahulm** » 28 Jun 2017 23:32

I could be wrong and my info outdated but IIRC Indian EO satellites use Zeiss optics. Happy to be corrected.

ramana · Post by **ramana** » 29 Jun 2017 00:46

Sridhar wrote:I was hesitating to post my own articles here, but am posting here since they have not been posted earlier. These were blog posts on the Planetary Society blog just before and just after the GSLV-MK3 launch.

Curtain raiser on the launch
http://www.planetary.org/blogs/guest-bl ... eague.html

Post-launch update
http://www.planetary.org/blogs/guest-bl ... ocket.html

No need for hesitation!!!

Thanks for linking.