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Chandrayaan-3 Soft-landing [video]

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Re: Chandrayaan-3 Soft-landing [video]

#531

Post by taneq »

bregma wrote: post #407
taneq wrote: post #113

Earlier quoted context omitted.

That can't still be the case these days, can it? Extremely tight mechanical and engineering tolerances are very expensive compared with merely 'very very' tight tolerances, and I'd imagine the difference between the two can be bridged with more intelligent software in place of "gyroscope + clock + maybe PID loop"?

The classic hardware engineering response of "we'll just fix it in software". Turns out fixing things in software is even more expensive because it's just so easy to make changes that a combinatoric number of changes sneak in.

Ohhhh yes. I've been on the receiving end of this one. Designing a system which can accommodate higher tolerances on some hardware components through software controls is one thing. Being handed a poorly performing piece of hardware and told to "just fix it in software" is quite another.

Re: Chandrayaan-3 Soft-landing [video]

#532

Post by Sohcahtoa82 »

goodbyesf wrote: post #321
Ayesh wrote: post #88

If I read correctly, this is now the most watched live video on YouTube! Congratulations to India and the team on this fantastic feat of an achievement.

> If I read correctly, this is now the most watched live video on YouTube! Which is disappointing. India should have their own video sharing/livestream platform.

Why?

Re: Chandrayaan-3 Soft-landing [video]

#533

Post by rdsubhas »

ChuckMcM wrote: post #471
bluGill wrote: post #441

Earlier quoted context omitted.

A very large number of missions to other planets have failed because they crashed on the planet. Thus anyone who is serious about getting a mission to a different planet will put a lot of effort into the landing system. The fuel burn is cheap compared to a crash landing on the moon (as Russia just had a couple days ago). The above is even at NASA, they have done a lot of complex landing systems over the years. Most m…

Just checking in here, did you find something in my writing that suggested I was being disparaging or dismissive of what an awesome accomplishment this is? If so would love to know how you got there so that I could be more clear in the future.

To neutral readers, it appears complementary — not contradictory. It adds more info about the cost of failure when trying to optimize for more science.

If you can't see it that way, try picturing the reply prefixed as "to add to that, ..."

Re: Chandrayaan-3 Soft-landing [video]

#534

Post by ChuckMcM »

bluGill wrote: post #526
ChuckMcM wrote: post #471

Earlier quoted context omitted.

Just checking in here, did you find something in my writing that suggested I was being disparaging or dismissive of what an awesome accomplishment this is? If so would love to know how you got there so that I could be more clear in the future.

My impression is you were trying to say too much effort and fuel was used for landing and they should have put a bit more into science. If that isn't what you meant, my mistake, but it is how I understood it.

Thanks! That helps a lot. It was not what I meant but re-reading it I can see how you got that impression. I find the orbital entry/landing phases of exploratory missions to be the most interesting technically as they always have bunch of technical challenges with engineers making trade-offs. The "sky crane" idea NASA came up with blew me away (as an example). I think the ISRO team really did a fabulous job on the landing here. Watching the numbers touch down was so delicate.

Re: Chandrayaan-3 Soft-landing [video]

#535

Post by goodbyesf »

Sohcahtoa82 wrote: post #532
goodbyesf wrote: post #321

Earlier quoted context omitted.

> If I read correctly, this is now the most watched live video on YouTube! Which is disappointing. India should have their own video sharing/livestream platform.

Why?

Economic development? Control over your own media? Surely this is not a serious question. Heck, controlling your own media and tech stack is far more important to a country like india than landing probes on the moon. Ideally india should do both. Not sure why they are lagging so far behind in the tech sector when so much of the tech industry is powered by indians.

Re: Chandrayaan-3 Soft-landing [video]

#536

Post by firebat45 »

adolph wrote: post #272
pyeri wrote: post #242

Earlier quoted context omitted.

On the other hand, political speeches on such occasions go down as most remembered historically. The infamous quote "One small step for man, one giant leap for mankind." was obviously said by some politician! (or at least with non-technical motives)

> The infamous quote "One small step for man, one giant leap for mankind." What makes the quote in famous rather than just famous?

It's like flammable and inflammable. They mean the same thing and nobody knows why we have different words for it.

At least, this is my head-canon.

Re: Chandrayaan-3 Soft-landing [video]

#537

Post by NKosmatos »

downboots wrote: post #528
NKosmatos wrote: post #60

Earlier quoted context omitted.

The lander external view is simulation, but they have a camera (Lander Imager Display) looking downwards that is transmitting live photos every couple of seconds (center, top right on the main screen).

can the frames received be stitched into an animation video using some kind of image interpolation algorithm?

They did it officially from ISRO: https://twitter.com/isro/status/1694713817916473530

Re: Chandrayaan-3 Soft-landing [video]

#538

Post by downboots »

NKosmatos wrote: post #537
downboots wrote: post #528

Earlier quoted context omitted.

can the frames received be stitched into an animation video using some kind of image interpolation algorithm?

They did it officially from ISRO: https://twitter.com/isro/status/1694713817916473530

Nice . I was wondering about the algorithm

Re: Chandrayaan-3 Soft-landing [video]

#539

Post by oaktowner »

gora_mohanty wrote: post #517
oaktowner wrote: post #456

Earlier quoted context omitted.

While I worked at Google I once searched for "//this should never happen" in the code base. It was in there. A lot.

That might still be OK if that path literally should never happen in normal operation, but us used, e.g., to handle an error, or at least log it, if the impossible happens because the software is deployed in some unexpected configuration

Yes! Totally agreed.

Re: Chandrayaan-3 Soft-landing [video]

#540

Post by pyeri »

firebat45 wrote: post #536
adolph wrote: post #272

Earlier quoted context omitted.

> The infamous quote "One small step for man, one giant leap for mankind." What makes the quote in famous rather than just famous?

It's like flammable and inflammable. They mean the same thing and nobody knows why we have different words for it. At least, this is my head-canon.

Exactly! This has been my own head canon too since like decades! I was actually surprised to read in this thread that "infamous" is a negative interpretation of famous which seems like a revisionist and recent interpretation. The English language also evolves through the ages and so do the meanings and interpretations.
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