Live data from Hacker News

Chandrayaan-3 Soft-landing [video]

isro.gov.in

131–140 of 542 posts

Re: Chandrayaan-3 Soft-landing [video]

#131
post #126
post #86

Earlier quoted context omitted.

If anything they seem to have overcorrected for this. This landing path stopped with a near hover at around 800m, then a prolonged hover at 150m while the lander scoped the situation, then an extremely slow descent that allowed for corrections the whole way down. Very impressive.

Also incredibly inefficient.

A lot of things in the world trade inefficiencies for safety.

Re: Chandrayaan-3 Soft-landing [video]

#132

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).

Writing code for something that flies into space is not nearly as easy as you think it is. Perhaps the next time you write a comment you could first develop the software which you're complaining about first. I'm sure it would be a trivial task for someone of your stature :)

I'm not saying it is easy to handle. But this mode of failure could be expected and prepared for. It's not that uncommon that the spacecraft finds itself in a position which was not calculated.

Or, are you saying that it's expected that the mission did not count with this scenario, and that future missions don't need to account for that either?

Re: Chandrayaan-3 Soft-landing [video]

#133
post #12

Scott Manly has a video on why he thinks the last one failed. It sounds like their landing software didn't have "oh crap, we're way off course, just land wherever". It only had the happy path of "fly to here and land", so when it switched to the landing phase it tried valiently (including flying upside down) to try to fly back to the landing zone, but the landing zone was much further than fuel supplies allowed. Hope…

They also had an issue with the thrust gradient it could only do it increments in 20% which was too much of a change this one was finer which allowed for better control authority.

Re: Chandrayaan-3 Soft-landing [video]

#136

Earlier quoted context omitted.

Why such a long political speech and no views from onboard camera?

> Why such a long political speech ISRO is primary arm of the Department of Space which is headed by the Prime Minister. So in essence, the Prime Minister is the boss. It is not an independent federal agency like NASA.

If my understanding is correct, did the PM in his speech promise to fund a future mission to Saturn?

Re: Chandrayaan-3 Soft-landing [video]

#137
post #12

Scott Manly has a video on why he thinks the last one failed. It sounds like their landing software didn't have "oh crap, we're way off course, just land wherever". It only had the happy path of "fly to here and land", so when it switched to the landing phase it tried valiently (including flying upside down) to try to fly back to the landing zone, but the landing zone was much further than fuel supplies allowed. Hope…

Link to the Scott Manley video - The Real Reason Why Chandrayaan 2 Crashed on the Moon: https://www.youtube.com/watch?v=2ngVl6iO94c

Re: Chandrayaan-3 Soft-landing [video]

#138
post #119

One of the clocks is labeled "IST," which I assume means India Standard Time. Another clocks are labeled "GHY," "HAW," and "BIK." What do they indicate?

Goonhilly, Hawaii, but I can't figure out BIK. They're NASA and ESA tracking stations: https://www.eoportal.org/other-space-activities/estrack , https://www.indiatoday.in/science/chandrayaan-3/story/how-is...

Fwiw the esa time is the same as Amsterdam Time (cest, get +2)
Post reply on HN