Author Topic: Chandrayaan-1 stops transmitting  (Read 2898 times)

Offline Apollo-phill

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Chandrayaan-1 stops transmitting
« on: 08/29/2009 05:22 PM »
Indian Space Agency says that Chandrayaan-1 (lunar orbiter) has suddenly stopped transmitting.

No other news yet....


Phill

Offline Apollo-phill

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Re: Chandrayaan-1 stops transmitting
« Reply #1 on: 08/29/2009 05:27 PM »
Project Director M Annadurai on Saturday (29 August 2009)  said that Chandrayaan-1 moon mission is over.  Earlier in the day, Chandrayaan-1 spacecraft lost contact with ISRO's ground station, putting a question mark on the fate of country's maiden moon mission launched in October last year.

"The contact was lost at 01.30 IST as the deep space network (DSN) at Byalalu, about 40 km from Bangalore, received the data from the lunarcraft during the previous orbit up to 00.25 IST," according to an Indian Space Research Organisation (ISRO) statement.


Phill

Offline Stephan

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Best regards, Stephan

Offline plutogno

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Re: Chandrayaan-1 stops transmitting
« Reply #3 on: 03/09/2017 05:04 PM »
resurrecting this old topic: Chandrayaan has been located in lunar orbit by JPL's radar
http://spaceref.com/moon/nasa-radar-finds-indias-lost-chandrayaan-1-lunar-spacecraft.html

Offline Archibald

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Re: Chandrayaan-1 stops transmitting
« Reply #4 on: 03/09/2017 07:10 PM »
I don't understand. Why didn't Chandrayaan crashed a long time ago ? 200 km high is peanuts.

Offline russianhalo117

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Re: Chandrayaan-1 stops transmitting
« Reply #5 on: 03/09/2017 07:25 PM »
I don't understand. Why didn't Chandrayaan crashed a long time ago ? 200 km high is peanuts.
because its in a stable orbit compared to say GRAIL.

Offline plutogno

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Re: Chandrayaan-1 stops transmitting
« Reply #6 on: 03/09/2017 07:30 PM »
I think the polar orbit is also more stable than the more or less equatorial orbits of, for example, Apollo

Offline donaldp

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Re: Chandrayaan-1 stops transmitting
« Reply #7 on: 03/09/2017 07:32 PM »
Also the GRAIL probes were deliberatly deorbited.

http://solarsystem.nasa.gov/missions/grail/indepth

Quote
At the end of an extended mission, Ebb and Flow were sent purposely into the lunar surface because their low orbit and low fuel levels preclude further scientific operations. They impacted at mountain near Goldschmidt crater on the lunar near side.

Offline Sam Ho

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Re: Chandrayaan-1 stops transmitting
« Reply #8 on: 03/09/2017 11:14 PM »

Offline bad_astra

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Re: Chandrayaan-1 stops transmitting
« Reply #9 on: 03/10/2017 06:01 PM »
I know there are some "frozen orbits" for LLO, but I did not know that they lasted this long. PFS-1 did not last so long, if I recall. Chandrayaan-1 must have hit the bullseye.
"Contact Light" -Buzz Aldrin

Online Phil Stooke

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Re: Chandrayaan-1 stops transmitting
« Reply #10 on: 03/10/2017 08:11 PM »
I was also surprised by this.  It was said at the time (2009) to be likely to crash in 3 years.  They did not go into a frozen orbit deliberately, so it must have been by chance that the orbit was quite stable. 
« Last Edit: 04/03/2017 09:24 PM by Phil Stooke »

Offline russianhalo117

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Re: Chandrayaan-1 stops transmitting
« Reply #11 on: 03/11/2017 06:17 AM »
I was also surprised by this.  It was said at the time (2009) to be likely to crash in 3 years.  They did not go into a frozen orbit deliberately, so it must have been by chance that the orbit were quite stable. 
there is the remote possibility that Chandrayaan-1 despite loss of all communication could have maintained functionality including its ACS for a bit thus delaying the start of its decay rate.

Offline denis

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Re: Chandrayaan-1 stops transmitting
« Reply #12 on: 04/03/2017 09:22 PM »
there is the remote possibility that Chandrayaan-1 despite loss of all communication could have maintained functionality including its ACS for a bit thus delaying the start of its decay rate.

Even if was still working it would not have done anything to maintain its orbit.
ACS/AOCS normally only controls spacecraft attitude autonomously, not orbit.
On-board autonomous orbit control is pretty unusual and for a spacecraft in orbit around the moon, how would it even know its own orbit ?
« Last Edit: 04/03/2017 09:23 PM by denis »

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