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Chandrayaan-3 Soft-landing [video]

isro.gov.in

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Re: Chandrayaan-3 Soft-landing [video]

#481

Post by 8thcross »

dotnet00 wrote: post #347
lenkite wrote: post #330

Earlier quoted context omitted.

Might want to update your general knowledge. The ISRO Chief explained this in an interview. It wasn't just passed off as "software glitch" with no explanation. Chairman S Somanath has given three main reasons that led to the crash-landing of the Vikram lander on September 6, 2019 just minutes before the touchdown. The ISRO chairman said, “The primary issues were: One, we had five engines which were used to reduce the…

Huh, I missed that, thanks for the info!

There was a JWST doc on netflix; that explained a NASA technique for Points of failure strategy. ISRO may be using similar.

Re: Chandrayaan-3 Soft-landing [video]

#482

Post by FpUser »

goku12 wrote: post #225
thyrox wrote: post #47

Not asking rhetorically but why is this a big deal? Is it because it's going to the south pole? What are some other benefits to be gained from this?

A look at the previous lunar missions [1] should give an idea. There have been 7 lander missions since 1976 (not including impactors): - 3 by China: All success - 1 by Japan (along with a rover from UAE): Failed - 1 by Israel: Failed - 1 by Russia: Failed - 2 by India: Previous one failed. This one succeeded I can see why the entire world would be excited by something like this. I hope that there will be routine land…

why 1976 is a starting point? Why not counting successful Lunokhod rover missions? Looks like you're trying to to fit facts to narrative.

Re: Chandrayaan-3 Soft-landing [video]

#486

Post by dotnet00 »

chpatrick wrote: post #479
dotnet00 wrote: post #477

Earlier quoted context omitted.

Using Russian engines, like the ISS collaboration was an attempt by the US to keep soviet rocket scientists in business in civilian roles so they wouldn't be incentivized to spread around the world proliferating ICBM tech. In the process the US paid a huge price (decay of domestic design capability) and it's debatable if the goal was achieved. Edit: Thankfully the decay has been made up for over recent years with the…

Very interesting, do you know where I can read more about that?

This feels like a good writeup untainted by more recent events on the US-Russian cooperation https://www.nasa.gov/sites/default/files/atoms/files/partner...

Re: Chandrayaan-3 Soft-landing [video]

#487

Post by viableSprocket1 »

kypro wrote: post #483

[flagged]

I get this is tongue in cheek, and it's true that everyone's brown, but a couple of points of note:

1. ISRO has reserved spots for Scheduled Castes / Tribes (historically under-represented castes and tribes), which is far more explicit than having a DEI committee [1]

2. There are probably 10-15 primary languages spoken across the teams given regional differences in India. I would guess society is closer to EU than US in terms of homogeneity but that's pure speculation.

No opinion on whether or not it helps anyone soft-land on the moon, though.

[1] https://www.reddit.com/r/IndiaSpeaks/comments/cjnf07/clarifi...

Re: Chandrayaan-3 Soft-landing [video]

#488

Post by cpursley »

dotnet00 wrote: post #480
cpursley wrote: post #459

Earlier quoted context omitted.

American space program is a shadow of what it once was. Their history is full of daring missions and extraordinary achievements. I wish they would engage in a space race rather than constant illegal, brutal, destructive and absolutely unnecessary war. https://en.wikipedia.org/wiki/List_of_wars_involving_the_Uni...

It isn't really the gotcha you think it is when you see Falcon 9s flying and landing multiple times a week, the most advanced conventional rocket engines ever being mass produced, two scifi-esque lunar landers under serious development and all the other things. The American space program is far and away the world leader by a huge margin, while almost 2 decades ago things were dicey, the current Ameircan space program…

I agree with everything you wrote. But you missed my point - America has an incredible space program despite their wars. If wars were the cause of space program degradation, Russia would actually be ahead.

Re: Chandrayaan-3 Soft-landing [video]

#489

Post by Aeolun »

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.

I think he was just expanding on your science vs fuel comment?

Re: Chandrayaan-3 Soft-landing [video]

#490

Post by astrange »

delta_p_delta_x wrote: post #38
The_Colonel wrote: post #28

Earlier quoted context omitted.

Not considering such a basic error condition seems like a gross omission. This can't even come from the software engineering, but must be some kind of managerial failure (e.g. we're short on time, but have to report great progress to my boss, so skip this scenario).

> seems like such a gross omission. Almost all space mission code only ever has the so-called 'happy path'. We rely on extremely tight mechanical and aerospace engineering tolerances to achieve that happy path. The Hubble Space Telescope's primary mirror grinding was off by a matter of micrometres, and resulted in blurry images. Consider all the Mars rovers. Imagine some wind gust threw the descending module off cour…

If you write the failure path, then you also have to ensure it doesn't fire when there wasn't really a failure and do unnecessary heroics.

Same reason you can't program a self driving car to save a person by sacrificing a squirrel. It's just going to run over the squirrel when it didn't need to.

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