Search found 380 matches

by juvva
29 Feb 2024 21:15
Forum: Science, Economics & Technology Forum
Topic: Indian Space Program: News & Discussion
Replies: 1010
Views: 591704

Re: Indian Space Program: News & Discussion

Japan's SLIM lander has managed to survive the cold lunar night, even though our lander could not https://www.youtube.com/watch?v=Ac8PKjYWKv4 I'd really like to know what they did better, to make this possible landed at a latitude north of cy3 landing site, night temperature a little more moderate ...
by juvva
08 Dec 2023 17:42
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

arvin wrote: 06 Dec 2023 19:27

Although orbiting earth, looks like apogee of PM is quite close to Moon's SoI (Sphere of influence).
Interesting they didnt bring it close to earth.
could be due to limited fuel left in pm.
by juvva
20 Oct 2023 11:38
Forum: Science, Economics & Technology Forum
Topic: Indian Space Program: News & Discussion
Replies: 1010
Views: 591704

Re: Indian Space Program: News & Discussion

JTull wrote: 19 Oct 2023 15:55 I hope it's a clear day and we get some great videos of the abort test. Recent Russian abort video was amazing.
any link to the video please?
by juvva
29 Sep 2023 09:20
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

https://youtu.be/QtsCwdsK0XM?feature=shared

not to be missed , a treasure trove of details explained in simple language, by THE experts.
by juvva
22 Sep 2023 08:56
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

are you sure ?, saw some (subsequent?) posts from scott indicating signal is sideband of lro, hence a false alarm.
by juvva
21 Sep 2023 18:15
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

what is this trace ? (ground trace ?)

no one was concerned about the deviation during landing or post landing.

Image
by juvva
21 Sep 2023 09:13
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

is this real time? if so which orbiter ?
Amber G. wrote: 21 Sep 2023 08:03 It is September 21, 2023 (UTC- 00) -- All quiet.

Probably it is programmed so that when it wakes up and gets command from ISRO it may start sending back its radio transmission...
by juvva
21 Sep 2023 09:09
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

SriKumar wrote: 21 Sep 2023 08:46 They said Pragyan (or Vikram) was tested for cold temperatures. I assume it must have been soaked in liquid nitrogen or something colder. Both have to survive.
not the flight model, for sure.
by juvva
14 Sep 2023 17:37
Forum: Science, Economics & Technology Forum
Topic: Aditya-L1 (आदित्य -L1): Launch and Discussions
Replies: 119
Views: 31560

Re: Aditya-L1 (आदित्य -L1): Launch and Discussions

same would be the case with L2 , when the moon is on the sunward side of earth ?
am i missing something here ?


added later:

ok i think i got it, it is the L2 point of the earth-moon system, not L2 point of the sun-earth system.
by juvva
14 Sep 2023 09:07
Forum: Science, Economics & Technology Forum
Topic: Aditya-L1 (आदित्य -L1): Launch and Discussions
Replies: 119
Views: 31560

Re: Aditya-L1 (आदित्य -L1): Launch and Discussions

is it possible to use aditya l1 as a radio relay for any future indian lander missions to the far side of the moon ?
by juvva
10 Sep 2023 17:50
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

wouldn't the apparent size of earth be greater than the apparent size of sun as seen from moon?
by juvva
10 Sep 2023 11:25
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

^ lunar eclipse at 0:35 s ??
by juvva
04 Sep 2023 20:04
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

---- I wonder if the slight repositioning helped with slight inclination/orientation to sun or earth.. The pics look nice ! And @calculating thrust to lift off from the moon - I doubt that this was particularly relevant.. for the actual calculations.. does not look like any significant orientation ...
by juvva
04 Sep 2023 19:54
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

did not know that the ramp could be folded back and the science payloads pulled up back in.

what a detailed far sighted design !!!! and a very robust hardware !!!!
by juvva
04 Sep 2023 19:48
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

Vikram soft-landed again! https://twitter.com/isro/status/1698570774385205621?t=NahcNIZWvh9syahBc5l6mg&s=19 Did we know this was planned? Wow! What a nice surprise. :D :D :D looks like considerable dust was kicked up, but it seemed to settle down quiet fast. or was it mostly thruster fumes and ...
by juvva
03 Sep 2023 19:53
Forum: Science, Economics & Technology Forum
Topic: Aditya-L1 (आदित्य -L1): Launch and Discussions
Replies: 119
Views: 31560

Re: Aditya-L1 (आदित्य -L1): Launch and Discussions

Thanks, I got the saddle point analogy. So moving away in certain directions results in a restoring force, but in other directions, it tends to pull the object away. Orbiting a gravitational well like the earth or the moon, I guess one can just keep track of altitude from the surface (or center) of...
by juvva
02 Sep 2023 20:30
Forum: Science, Economics & Technology Forum
Topic: Aditya-L1 (आदित्य -L1): Launch and Discussions
Replies: 119
Views: 31560

Re: Aditya-L1 (आदित्य -L1): Launch and Discussions

looks like aditya will have quiet a few neighbours, should isro be wary of close encounters?
by juvva
02 Sep 2023 13:09
Forum: Science, Economics & Technology Forum
Topic: Aditya-L1 (आदित्य -L1): Launch and Discussions
Replies: 119
Views: 31560

Re: Aditya-L1 (आदित्य -L1): Launch and Discussions

phew !!!!! how i wish dd doesn't leave us in the dark on tenterhooks in the middle of a mission, the discussion could have waited...

that to on a day on which dilbu has taken day off.
by juvva
27 Aug 2023 21:55
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

assuming depth is measured in positive units ( more deeper greater the positive number ) , any explanation on why temperature increases with depth ?
by juvva
27 Aug 2023 20:38
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

^^not sure if some international body like iaea needs to be informed and kept in loop.
by juvva
27 Aug 2023 20:31
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

Ye to kaam karna chalu kiya !!! https://twitter.com/isro/status/1695725102166671448/photo/1 Why would the temperature increase above the lunar surface relative to the surface. The heat on moon surface is entirely due to the solar radiation absorbed by the moon surface. I guess the above-the-surface...
by juvva
27 Aug 2023 15:44
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

According to people quoting people quoting other people, Team ISRO have tried taking pics using both lander and rover. One of the problems with taking pics from the rover is that the partial shadowing of the rover is causing optical effects. So turning the rover toward better angles is required, bu...
by juvva
26 Aug 2023 19:52
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

did isro say explicitly at any time that vikram landed in nominal orientation?
by juvva
26 Aug 2023 19:30
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

Obviously this is guesswork based on pictures, but all pictures tell a story. Yes they do. In fact, the lack of an atmosphere on the moon makes it easier to infer more of that story. For example - the shadow of the rover wheel is roughly 2 to 2.5 times longer than the wheel itself. So - assuming le...
by juvva
26 Aug 2023 12:34
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

https://www.google.com/amp/s/www.scientificamerican.com/article/chandrayaan-3-makes-historic-touchdown-on-the-moon/%3famp=true the above is from a scientific american article. I think, Scientific American got it wrong . Some of this articles are written prior to the event and they do copy paste fro...
by juvva
25 Aug 2023 23:37
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

to me it ( intuitively) feels a safer strategy to shut off engines after confirming physical contact with the surface ,rather than depend on a altimeter to indicate almost there signal. i think isro basically said damn the dust, we dont care , when they removed the central engine - we want to land s...
by juvva
25 Aug 2023 23:25
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

disha wrote: 25 Aug 2023 23:20

Juvvaji' what will be your take if we prove scientific american wrong?
i will stop reading scientific american :)
by juvva
25 Aug 2023 22:47
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

Image

wiring visible at landing pads maybe related to the sensors.
by juvva
25 Aug 2023 22:25
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

i revisited landing video was unable to make out any sudden drop of lander in the animation of lander at touch down, after engine cut off.

same was the case in the footage of lander camera, no definitive sudden drop evident.
by juvva
25 Aug 2023 22:18
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

Engines cutoff a meter of two above the surface seems excessive in my opinion especially if there is a possibility of a bounce( in low lunar gravity) with uneven time of touchdown (due to uneven weight distribution of the LM) of the each of the four legs. Thx for doing the calculations. The engines...
by juvva
25 Aug 2023 19:37
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

https://twitter.com/chandrayaan_3/status/1695058057682628884 Chandrayaan-3 Mission update: All planned Rover movements have been verified. The Rover has successfully traversed a distance of about 8 meters. Rover payloads LIBS and APXS are turned ON. All payloads on the propulsion module, lander mod...
by juvva
25 Aug 2023 19:33
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

amber:

^^i suppose an earth eclipse, would be just a round dot traversing a path on the fully sunlit earth(?).
by juvva
25 Aug 2023 19:06
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

how often , will the earth eclipse the sun as seen from the moon ?
will such eclipses come in all the varieties - full, partial, annular - and depend on the location of the observer on the moon?
by juvva
25 Aug 2023 14:56
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

SSSalvi wrote: 25 Aug 2023 10:46 Curiously ,ISRO Tweeted but withdrew this

Image of CH3 Lander by CH2 Orbiter camera

Image
note the long shadows at dawn.
imagine india ( virtually ) standing on a alien landscape , with the sun low on the horizon.
by juvva
25 Aug 2023 09:08
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

The reddit post on this is has a clearer image at touchdown THe altitude in this screenshot reads 3.46m at landing. time is shown as 0.00. The entire lander is only 1.1m high and yet Altitude is 3.46 m and it has 'landed'? Measurement error (unlikely, a 3 meter error is too large) or something else...
by juvva
24 Aug 2023 22:03
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

let us enjoy the heart burn of the british ( sorry if you feel i misspellt the last word):

https://youtu.be/lcS8afETDr8?feature=shared
by juvva
24 Aug 2023 21:01
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

Gold mine interview with Somnath (even though title says Sivan but Somnath interview in the second half). No redundancies were required or used by VIKRAM, Landing was handled by the inertial unit. The LXXXX cameras were not used is what I understood which is a bit odd because VIKRAM did re-target. ...
by juvva
24 Aug 2023 16:30
Forum: Science, Economics & Technology Forum
Topic: Chandrayaan 3: Launch and Discussions
Replies: 1352
Views: 541477

Re: Chandrayaan 3: Launch and Discussions

i hope they are not waiting for some vip to release rover pics.