Chandrayaan-2 : Updates

Let's think logically

comms stopped while the lander was still descending

Due to inappropriate functioning of the thrusters the lander was most probably subjected to high G forces and related stress and strain while still in flight when the comms snapped.

this means some components inside lander were subjected to higher than rated g forces.

So as i previously alluded lander must have landed , but there was comms failure due to possible malfunction of some comms equipment . Higher that expected G forces might have induced anomalous behaviour in the comms component like displaced linkages or unintended transient voltage transfer / voltage spike causing shut down. unfortunately I have no understanding of the working of the same in space systems. So not 100% sure.but Similar power failures happened with isro satellites power bus.

The onboard TX/RX system requires the onboard data processing package to process data and format it for transmission over the same and vice versa after receiving the data. TX/RX system is working but the backend system which processes the data to be sent or be received seems not to be working at the moment.

The power supply from battery if bypassed for the secondary power source the solar panels , then there exists a possibility that the anomalous condition with the effected components of the comms system might get resolved and the system might reboot.

Eg in a normal oscilloscope if it is subjected to out of range voltage beyond instrumented range , the output readings flatlines and shuts down to recover and then reboots if the surge voltage is no longer present.

So same recovery can happen with the landers malfunctioning components provided the anomalous cause ceases to exist .
As I had stated in my earlier posts, the decision to remove side thruster have cost us dearly.

The preliminary configuration study of the lander was completed in 2013 by the Space Applications Centre (SAC) in Ahmedabad.[35] The lander's propulsion system consists of eight 50 N (11 lbf) thrusters for attitude control and five 800 N (180 lbf) liquid main engines derived from ISRO's 440 N (99 lbf) Liquid Apogee Motor.[60][61] Initially, the lander design employed four main liquid engines, but a centrally mounted engine was added to handle new requirements of having to orbit the Moon before landing. The additional engine was expected to mitigate upward draft of lunar dust during the soft landing.[48] Vikram was designed to safely land on slopes up to 12°.[62][63]
 
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Good news India now is the defacto 4th nation to land its own lander on the moon. Landing might not have been the smoothest but still it landed on its 4 legs. And if the ISRO lander is temperamental and refuses to communicate what can one do. Our lander will come around to being a good boy I am sure.
 
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Thermal image confirms it , why would ISRO try to re-establish comms if the lander is sideways or upsidedown ?

they have not said anything. You are just speculating. In fact NDTV reported that it seems to have been a hard landing. Not a crash, but not soft either.
 
Let's think logically

comms stopped while the lander was still descending

Due to inappropriate functioning of the thrusters the lander was most probably subjected to high G forces and related stress and strain while still in flight when the comms snapped.

this means some components inside lander were subjected to higher than rated g forces.

So as i previously alluded lander must have landed , but there was comms failure due to possible malfunction of some comms equipment . Higher that expected G forces might have induced anomalous behaviour in the comms component like displaced linkages or unintended transient voltage transfer / voltage spike causing shut down. unfortunately I have no understanding of the working of the same in space systems. So not 100% sure.but Similar power failures happened with isro satellites power bus.

The onboard TX/RX system requires the onboard data processing package to process data and format it for transmission over the same and vice versa after receiving the data. TX/RX system is working but the backend system which processes the data to be sent or be received seems not to be working at the moment.

Communication link is open but no data is being sent or received at the landers end atleast for now.

The power supply from battery if bypassed for the secondary power source the solar panels , then there exists a possibility that the anomalous condition with the effected components of the comms system might get resolved and the system might reboot.

Eg in a normal oscilloscope if it is subjected to out of range voltage beyond instrumented range , the output readings flatlines and shuts down to recover and then reboots if the surge voltage is no longer present.

So same recovery can happen with the landers malfunctioning components provided the anomalous cause ceases to exist .


Former ISRO director Sasikumar also thinks that the communication channel between the lander and the orbiter is on, which indicates the lander may be intact even after the hard landing. However if the damage was only to the communication system and everything else was working fine, then the lander Vikram would have deployed the ramp and the Pragyaan rover would have rolled out. It could be , like you said, the power system failed too and this has crippled the other operations like communication and ramp deployment.
 
Thermal image confirms it , why would ISRO try to re-establish comms if the lander is sideways or upsidedown ?
ISRO chief says "Yes, we have located the lander on the lunar surface. It must have been a hard-landing", he added. So, it might not be on its 4 legs
 
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ISRO chief says "Yes, we have located the lander on the lunar surface. It must have been a hard-landing", he added. So, it might not be on its 4 legs
It might be, it might not be. Let's give them enough time to do analsis, then we can do our thing always as we do. Thank you.
 
There are rumors on web that it might be fake twitter handle and some saying it is original. However national broadcaster is original which has said same thing.

only things said are
- we have identified the lander
- we are trying to establish communication

- it speculated that it is likely that the lander was not significantly damaged/ completely crashed or else they will not attempt to communicate- you can't communicate with rubble
- some people say that it is 500 mts away from landing site. It is unconfirmed and speculation until confirmed.
 
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only things said are
- we have identified the lander
- we are trying to establish communication

- it speculated that it is likely that the lander was not significantly damaged/ completely crashed or else they will not attempt to communicate- you can't communicate with rubble
- some people say that it is 500 mts away from landing site. It is unconfirmed and speculation until confirmed.
I don't where we differ!