Chandrayaan-3 Soft-landing [video] • Hacker News Board

Re: Chandrayaan-3 Soft-landing [video]

#301

Post by firesteelrain » Wed, Aug 23, 2023, 3:20 PM UTC

abhayhegde wrote: post #226

actuator wrote: post #193

Earlier quoted context omitted.

I believe Chandrayaan 1 has detected water, but not sure if it was the first one to do so

The definitive discovery of Moon water came from Chandrayaan-1 which carried with it a NASA-provided science instrument called the Moon Mineralogical Mapper—M3 for short—that observed how the surface absorbed infrared light. Using this data, M3 determined that previously suspected water molecules were ice inside the Moon’s polar craters [0]. However, the first direct evidence of water vapor near the Moon was obtained…

NASA LCROSS confirmed it before the Indian mission (which NASA instruments also on the Indian mission confirmed first). After NASA confirmed, Indian officials came out with their own announcement

Re: Chandrayaan-3 Soft-landing [video]

#302

Post by fnordpiglet » Wed, Aug 23, 2023, 3:20 PM UTC

psychphysic wrote: post #172

Congratulations India! And everyone. Actually congratulations to all countries still running space programmes including Russia's failure. The more the merrier. This is a stupendously difficult thing to do, India is truly a superpower.

In science and exploration the only losers are the ones who don’t try to begin with.

Re: Chandrayaan-3 Soft-landing [video]

#303

Post by russdill » Wed, Aug 23, 2023, 3:20 PM UTC

TuringNYC wrote: post #163

Firstly - congratulations to the whole team on this achievement I'm also curious - Why the south pole of the moon? does it have an added significance vs other locations on the moon? - Is a landing on the south pole more difficult to achieve? Seems so according to this article: https://www.reuters.com/science/why-are-space-agencies-racin...

It's 69° south, so it's not so much the south pole as the polar region. For reference, the major landmass of Antarctica starts around that point on Earth. McMurdo Station is at around 78° South.

Re: Chandrayaan-3 Soft-landing [video]

#304

Post by hackernewds » Wed, Aug 23, 2023, 3:20 PM UTC

mrtksn wrote: post #216

confuseddesi wrote: post #75

It’s landed! Congratulations to India on this great achievement!

One of the most populous countries has become a strong contender in space exploration. Hopefully, it will inspire so many more Indians to push it further and elevate the humanity, just like USA and USSR once did. It's great.

Also here come the British news lamenting about how India is wasting money instead of focusing on their poor. Slumdog Millionaire mentality.

Re: Chandrayaan-3 Soft-landing [video]

#305

Post by AlbertCory » Wed, Aug 23, 2023, 3:21 PM UTC

sph wrote: post #215

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).

This is the software engineering version of "I am very badass", passing judgement on software at the cutting edge of science, while sitting at home writing React code.

In football journalism they call that Monday Morning Quarterbacking.

Re: Chandrayaan-3 Soft-landing [video]

#306

Post by mercurialsolo » Wed, Aug 23, 2023, 3:25 PM UTC

Any space mission is fairly complex no matter the agency private or public.

For me the most interesting part to watch personally was the telemetry. What's the latency involved here, do they have agency in terms of manual overrides and intervention in case things go wrong?

What does RTT look like, are there more efficient encoding of data to allow minimal information?

Re: Chandrayaan-3 Soft-landing [video]

#307

Post by lenkite » Wed, Aug 23, 2023, 3:27 PM UTC

dotnet00 wrote: post #44

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).

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 o…

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

What do you mean by "they haven't officially straight-up announced the issue." ? They did so - several times actually.

Re: Chandrayaan-3 Soft-landing [video]

#308

Post by btbuildem » Wed, Aug 23, 2023, 3:29 PM UTC

haolez wrote: post #248

btbuildem wrote: post #246

The moment of landing: https://www.youtube.com/watch?v=dim8elzo5vE When I look at this, it seems it's a long-range optical feed of the moon surface with lander graphics laid over it. Has anyone found footage of the actual craft touching down? It would be amazing to see.

On the dark side of the moon?

Not sure if you're joking.. but there's light on the dark side of the Moon, it's just called that because it's never visible from Earth.

I assumed the craft that brought the lander into orbit would have some sort of visual tracking, but maybe the distances involved make that impossible and all we get is telemetry + a rendering to visualize it.

Re: Chandrayaan-3 Soft-landing [video]

#309

Post by georgeecollins » Wed, Aug 23, 2023, 3:29 PM UTC

pyeri wrote: post #242

dotnet00 wrote: post #188

Earlier quoted context omitted.

Unfortunately all the national space agencies seem to suffer from this. Both NASA and ESA also seem to think that people are tuning in to watch the smarmy politician talk rather than the robot making its way to space/landing on another body. Had the same issue with JWST for example.

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)

I think it is a sign of habitual cynicism that you assume "One small step for man, one giant leap for mankind." was said by a politician. I think people feel like they are defending themselves from being manipulated by not accepting anything on its face as sincere. Sometimes a pipe is just a pipe.

Re: Chandrayaan-3 Soft-landing [video]

#310

Post by 0xffff2 » Wed, Aug 23, 2023, 3:33 PM UTC

mercurialsolo wrote: post #306

Any space mission is fairly complex no matter the agency private or public. For me the most interesting part to watch personally was the telemetry. What's the latency involved here, do they have agency in terms of manual overrides and intervention in case things go wrong? What does RTT look like, are there more efficient encoding of data to allow minimal information?

Latency is dominated by speed of light delays, which are about 2.5 seconds round trip. Encoding is generally more concerned with data integrity than data minimization.

I'm not sure about the details of this mission and whether the Indians have negotiated usage of the Deep Space Network, but with the large antennas of the DSN multi megabit rates are quite achievable.