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Chandrayaan-3 Soft-landing [video]

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Re: Chandrayaan-3 Soft-landing [video]

#41

Post by [deleted] »

The_Colonel wrote: post #28
jvm___ wrote: 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…

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).

[deleted]

Re: Chandrayaan-3 Soft-landing [video]

#42

Post by rob74 »

raverbashing wrote: post #17
jvm___ wrote: 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…

This applies to general software development but is especially true in this case While we think "this cannot ever happen" in a lot of cases it can, in ways you did not consider. Both for good and bad

In general software development it's usually not a problem if your program crashes, then you can fix the bug and run it again. If the thing that crashes is a lunar lander however, you should put a bit more effort into covering all the eventualities...

Re: Chandrayaan-3 Soft-landing [video]

#44

Post by dotnet00 »

The_Colonel wrote: post #28
jvm___ wrote: 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…

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).

That's probably why they haven't officially straight-up announced the issue.

This wouldn't be the first time that a mission failed due to embarrassing failures in basic software practices (eg Starliner's initial software bugs emerging from a lack of integrated testing).

Main difference is that you aren't triggering a billion overly sensitive nationalistic folks when you point out similar embarrassing errors in most other countries' programs. Eg the time NASA lost a probe due to miscommunicated units, the Apollo 1 disaster, the space shuttle disasters, or the tape around the wiring in Starliner, which was intended to be fire retardant actually turning out to be flammable...

Hell, Japan's Hakuto-R also failed because the software's error detection was buggy, and they openly admitted as much without any bluster about how no one but other people with experience writing code for space probes can criticize them.

Re: Chandrayaan-3 Soft-landing [video]

#45

Post by the-dude »

imglorp wrote: post #20
the-dude wrote: post #11

Does anybody know if we will be watching a simulation or actual footage? I am asking because the livestream of the last failed moonlanding this year didn't feature a single second of footage. None.

This one has onboard cameras and there are curated videos from other phases of flight at the OP link.

Thank you, I missed that.

Re: Chandrayaan-3 Soft-landing [video]

#46

Post by _visgean »

jvm___ wrote: post #13
the-dude wrote: post #11

Does anybody know if we will be watching a simulation or actual footage? I am asking because the livestream of the last failed moonlanding this year didn't feature a single second of footage. None.

Why won't the people landing on the moon cater to me ?

but seriously why would they not? If they have something nice to show of why not? This is publicly paid project (by indian tax payers) that is political in its nature. Why not show as much as possible?

Re: Chandrayaan-3 Soft-landing [video]

#48

Post by ethbr1 »

fractalb wrote: post #14
the-dude wrote: post #11

Does anybody know if we will be watching a simulation or actual footage? I am asking because the livestream of the last failed moonlanding this year didn't feature a single second of footage. None.

It's simulation for sure. Would there be sunlight to view it live?

Yes. For solar panel purposes they're landing in the lunar day (14 Earth days?).

Edit: At the start of a lunar day, which equals 28 Earth days. (Source: BBC https://www.bbc.com/news/live/world-asia-india-66576580 )

Re: Chandrayaan-3 Soft-landing [video]

#49

Post by mmx4332 »

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?

This may not be a popular question, but given the amount of poverty in India, is a space program really the best expenditure?

As a geek, I love the space program.

As a human, I don't think it makes sense given the poverty.

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