ISRO General News and Updates

delbruky

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I am unable to find any statement made by Isro on it's website or any social networking site WRT the lost connectivity with GSAT-6A. Can any one paste a link?
 

Kshithij

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I am unable to find any statement made by Isro on it's website or any social networking site WRT the lost connectivity with GSAT-6A. Can any one paste a link?
Here the link posted in this comment should help:
yesterday, the rumor that there was something wrong with the satellite has been spreaded on twitter...even we have heard about it on our Space enthusiast forums.

someone said the apogee is around 5000km and the Perigee Altitude was also raised although the initial orbit sent into by the GSLV was not very high. so the Sat could be able to stay in the current orbit for quite a while and there is quite some time for the scientists and Engineers to try to save it according to the pre-arranged planning before the reentry


and ISRO did have the confirmation this afternoon
-------------------
https://www.isro.gov.in/update/01-apr-2018/status-update-of-gsat-6a

Status Update of GSAT-6A .... Apr 01, 2018

The second orbit raising operation of GSAT-6A satellite has been successfully carried out by LAM Engine firing for about 53 minutes on March 31, 2018 in the morning.

After the successful long duration firings, when the satellite was on course to normal operating configuration for the third and the final firing, scheduled for April 1, 2018, communication from the satellite was lost.

Efforts are underway to establish the link with the satellite.
 

shiphone

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someone said the apogee is around 5000km and the Perigee Altitude was also raised although the initial orbit sent into by the GSLV was not very high. so the Sat could be able to stay in the current orbit for quite a while and there is quite some time for the scientists and Engineers to try to save it according to the pre-arranged planning before the reentry
a correction here:

1. the initial orbit is 35975 km X 170 km.

2. after the first orbit raising operation: 36412 km X 5054 km.( https://www.isro.gov.in/update/30-m...at-6a-satellite-has-been-successfully-carried )

3. and second raising was also happened .so the Perigee height should be much higher than 5000 kms.
-----
there is no any risk of reentry for quite a long term.

 

Screambowl

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LOL
they might have forgotten to copy the correct command from western helpers
 

delbruky

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As per the statement by K Sivan, Chairman Isro "Even if the satellite’s primary power has failed, we can use the back-up power like solar power if we are able to re-establish the contact with it.”
It seems that the primary power AKA batteries have failed. In my opinion In the event of a battery failure a sudden big discharge happens causing current and the temperature to increase dramatically for a short period of time, this sudden discharge can short the mother board particularly the Capacitors and the Solid State Drives, due to lack of atmosphere the temps can shoot even higher. So, this mission can only be salvaged only if redundancies had been built not only with power supply but also with the circuits. If there is only one MB GSAT 6A as we know it is TOAST.
 
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Screambowl

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As per the statement by K Sivan, Chairman Isro "Even if the satellite’s primary power has failed, we can use the back-up power like solar power if we are able to re-establish the contact with it.”
It seems that the primary power AKA batteries have failed. In my opinion In the event of a battery failure a a sudden big discharge happens causing current to increase dramatically for a short period of time, this sudden discharge can short the mother board particularly the capacitors, due to lack of atmosphere the temps can shoot even higher. So, this mission can only be salvaged only if redundancies had been built not only with power supply but also with the circuits. If there is only one MB GSAT 6A as we know it is toast.

It has failed yesterday only trust me

no hope

...................................................
 

delbruky

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It has failed yesterday only trust me

no hope

...................................................
Dikh raha hain, is liye sab chup baithe hain. just think about it, WRT the earth based command center the satellite revolves around the earth every 90 minutes, ideally they would have had so many opportunities to activate alternative mechanisms. Nahi kar paye, GSAT 6A ho gaya TOAST.
 

delbruky

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In my opinion there could be quality control issues with the newly developed and deployed lithium ion batteries. All the previous GSATs had Japanese Li-K batteries.
 

G10

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Batteries dont die suddenly. They show low voltage/current indicators.toast thing makes sense.
 

Rahul Singh

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Two military-specific satellites in less than 6 months declared failures. Is this a sabotage or a cover-up? Are we putting something in orbit which we don't want to disclose?
 

AMCA

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Two military-specific satellites in less than 6 months declared failures. Is this a sabotage or a cover-up? Are we putting something in orbit which we don't want to disclose?
US Zuma military satellite was also lost in a similar way earlier this year.
 

Kshithij

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Two military-specific satellites in less than 6 months declared failures. Is this a sabotage or a cover-up? Are we putting something in orbit which we don't want to disclose?
Both the satellites are not in proper orbit. The IRNSS satellite did not open up and hence its orbit was much lower than desired. There was also danger of the orbit decaying due to closeness of the satellite orbit to atmosphere. This was also observed by international agencies. Hence, it is confirmed that IRNSS is not in proper orbit

The GSAT 6A is also not in Geocentric orbit. It only went into 2 orbit raising maneuver and has an orbit of 36000x5000km which is a useless orbit. This also can be verified by other agencies.

I don't see how it is a cover up. Both of these satellites were communication based or navigation based and not exactly high end military ones. The real military satellite was launched previously - CARTOSAT. If there was a cover up, it should have been for CARTOSAT
 

shiphone

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The GSAT 6A is also not in Geocentric orbit. It only went into 2 orbit raising maneuver and has an orbit of 36000x5000km which is a useless orbit. This also can be verified by other agencies.
that orbit is the one after the first orbit raising operation.

the engine on the satellite burned more than 50 minutes during the second raising...so

the Sat has been observed on a 25978 x 36368 km; 3.3° orbit.

1 43241U 18027A 18092.74402963 -.00000163 00000-0 00000+0 0 9997
2 43241 3.3060 292.9397 1383409 184.3291 197.1267 1.19305157 88

----------------
someone of BR also gave the info of NORAD ID: 43241 there.
Re: Indian Space Programme Discussion - Sept 2016
Postby rrao » 03 Apr 2018 15:39

n2yo is showing the following data of GSAT- 6A NORAD ID: 43241
Int'l Code: 2018-027A
Perigee: 25,985.8 km
Apogee: 36,375.3 km
Inclination: 3.3 °
Period: 1,207.0 minutes
Semi major axis: 37551 km
RCS: Unknown
Launch date: March 29, 2018
Source: India (IND)
Launch site: SRIHARIKOTA
 
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Prashant12

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India completes NavIC constellation with 7th satellite

BENGALURU: India early on Thursday put into space a new satellite under its regional navigation satellite system — also called NavIC — adding to the constellation of six operational satellites. The Indian Space Research Organisation (Isro) thus completed the constellation, which needed seven functional satellites to provide foolproof satellite-based navigation signals.

Isro carried out a textbook launch of the Indian Indian Regional Navigation Satellite System-1I (IRNSS-1I), the latest satellite for the NavIC system, which replaces a faulty spacecraft (IRNSS-1A) in orbit more than seven months after its intended replacement could not be deployed due to a heat-shield failure of the Polar Satellite Launch Vehicle (PSLV).

The 1,425-kg satellite made by Bengaluru-headquartered Alpha Design Technologies, in collaboration with Isro, is the second satellite to be actively built by private industry. The first one, IRNSS-1H, could not be put into space because of its failure in August last year.

On Thursday, the PSLV-C41 lifted off at 4.04am, and the spacecraft’s final separation happened about 20 minutes later putting it into a geosynchronous orbit, exactly as planned by Isro.

Like its predecessors, IRNSS-1I carried two types of payloads: Navigation and Ranging.

The navigation payload of IRNSS-1I transmits signals for the determination of position, velocity and time and operated in the L5-band and S-band.

The Rubidium atomic clocks are part of the navigation payload of the satellite, while the ranging payload consists of a C-band transponder, which facilitates accurate determination of the range of the satellite and it also carries Corner Cube Retroreflectors for Laser ranging.

Serving both military and civilian needs, NavIC’s seven satellites will broadcast highly-accurate timing signals that a receiver can use to triangulate its location.

“The NavIC system enables providing position, navigation and timing information that could be utilised for a large range of civil and strategic applications and services that include terrestrial, aerial and marine navigation; precise timing; disaster management and alert messages; mapping and Geodetic data capture; vehicle tracking and fleet management; visual & voice navigation for drivers, etc,” according to the Department of Space (DoS).
The constellation will also provide signals in a space covering India and its surroundings, which could be utilised by using receivers on ground to determine position and time accurately.

According to the DoS: “Signal in space is provided globally by GPS of USA, GLONASS of Russia, Galileo of Europe and Beiden of China. Current global trend is to make use of ground receivers which utilises as many signals as available for providing timing and position solutions.”

https://timesofindia.indiatimes.com...com&utm_medium=social&utm_campaign=TOIDesktop
 

indiatester

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India completes NavIC constellation with 7th satellite

BENGALURU: India early on Thursday put into space a new satellite under its regional navigation satellite system — also called NavIC — adding to the constellation of six operational satellites. The Indian Space Research Organisation (Isro) thus completed the constellation, which needed seven functional satellites to provide foolproof satellite-based navigation signals.

Isro carried out a textbook launch of the Indian Indian Regional Navigation Satellite System-1I (IRNSS-1I), the latest satellite for the NavIC system, which replaces a faulty spacecraft (IRNSS-1A) in orbit more than seven months after its intended replacement could not be deployed due to a heat-shield failure of the Polar Satellite Launch Vehicle (PSLV).

The 1,425-kg satellite made by Bengaluru-headquartered Alpha Design Technologies, in collaboration with Isro, is the second satellite to be actively built by private industry. The first one, IRNSS-1H, could not be put into space because of its failure in August last year.

On Thursday, the PSLV-C41 lifted off at 4.04am, and the spacecraft’s final separation happened about 20 minutes later putting it into a geosynchronous orbit, exactly as planned by Isro.

Like its predecessors, IRNSS-1I carried two types of payloads: Navigation and Ranging.

The navigation payload of IRNSS-1I transmits signals for the determination of position, velocity and time and operated in the L5-band and S-band.

The Rubidium atomic clocks are part of the navigation payload of the satellite, while the ranging payload consists of a C-band transponder, which facilitates accurate determination of the range of the satellite and it also carries Corner Cube Retroreflectors for Laser ranging.

Serving both military and civilian needs, NavIC’s seven satellites will broadcast highly-accurate timing signals that a receiver can use to triangulate its location.

“The NavIC system enables providing position, navigation and timing information that could be utilised for a large range of civil and strategic applications and services that include terrestrial, aerial and marine navigation; precise timing; disaster management and alert messages; mapping and Geodetic data capture; vehicle tracking and fleet management; visual & voice navigation for drivers, etc,” according to the Department of Space (DoS).
The constellation will also provide signals in a space covering India and its surroundings, which could be utilised by using receivers on ground to determine position and time accurately.

According to the DoS: “Signal in space is provided globally by GPS of USA, GLONASS of Russia, Galileo of Europe and Beiden of China. Current global trend is to make use of ground receivers which utilises as many signals as available for providing timing and position solutions.”

https://timesofindia.indiatimes.com...com&utm_medium=social&utm_campaign=TOIDesktop
Was driving to Hyderabad and missed this launch.
While upset at missing it, I am happy that such launches have become routine and are not grabbing headlines.
Way to go ISRO!
 

kunal1123

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Isro plans orbital re-entry test for re-usable vehicle – Indian Defence Research Wing
1-2 minutes
SOURCE: TNN



Isro is set to follow up the successful tests of the re-usable launch vehicle technology demonstrator (RLV-TD) with a major experiment, though the immediate priority is the Chandrayaan-II mission slated for an October launch. It has completed the wind tunnel model with landing gear and low subsonic tests at the IIT-Kanpur

In the next phase, Isro has proposed to design and develop a scaled-up version of RLV and carry out an orbital re-entry experiment.“Site has been identified for the experiment and configuring landing runway with navigational aids for an autonomous descent. For unmanned landing, navigational aids and associated systems have to be established,” scientists working on the project said.

Isro chief K Sivan, while confirming there are multiple experiments of RLV-TD in the pipeline, said: “That will happen only next year. This year, our focus is on various other missions.”
 

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