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Chandrayaan-3 Soft-landing [video]

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Re: Chandrayaan-3 Soft-landing [video]

#331

Post by sirius87 »

dotnet00 wrote: post #188
whoknowswhat11 wrote: post #106

Earlier quoted context omitted.

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

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.

I believe the chairman of the space agency also used the Prime Minister's mention of future projects to note it as confirmation that those projects will indeed happen i.e. be funded. That was pretty smart at @ 01:07:00 in the video.

So it's good to see it work both ways.

Re: Chandrayaan-3 Soft-landing [video]

#332

Post by kensai »

skynetv2 wrote: post #329

Despite all the sour comments trying to find fault and criticize, this is a remarkable achievement, especially on the heels of the failed Chandrayaan-2 mission. Congrats to the team!!! Just 4 years to recover from the failure and achieve a phenomenal success. India just keeps executing despite what others may say. The team deserves even more praise to be able to achieve these wins with limited resources.

And a very inexpensive/frugal attempt for that matter! It has been a miracle of cost effectiveness. This is a wonder on its own.

Re: Chandrayaan-3 Soft-landing [video]

#333

Post by codegeek »

zabana wrote: post #206

I wonder what else India could potentially achieve if they could retain their top talent. Congrats !

Don't think of Brain Drain as a lose lose situation. Lot of Indians who leave India contribute in many ways and in fact bring tons of knowledge and skills from the global world back to India (even if they don't live there physically). Not to mention that amount of money that is exchanged by Non Resident Indians (also known as NRIs).

It is good that Indians are able to go aboard and bring a globalized knowledge back to India.

Re: Chandrayaan-3 Soft-landing [video]

#334

Post by antran22 »

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).

You are saying "gross omission" like this is some Python script, like they are skipping the else clause for a condition. Imagine trying to land a plane that is flying at Mach 2, with no direct control, only a video feed with 4 seconds resolution, a bunch of sensors and a tank of fuel for retrograde burn to slow you down. Can you even fathom the number of scenarios that can happen. Your application may have 1 happy path and 2 sad path. Here you get only 1 happy path, a few not so happy path where your probe land sideway or just roll down a crater; and the rest of them are every other combinations of your probe's orientation and speed vector and collision location.

Hell, you can run a few thousand simulators for every scenario you can think of during descent, including lost of burner, propellant leak, etc, and then during the actual descent a chip get burnt because of a stray cosmic ray. There will still be somebody on HN call you out for cutting corner.

Re: Chandrayaan-3 Soft-landing [video]

#335

Post by tshaddox »

hoseja wrote: post #126
m0llusk wrote: 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.

What numerator and denominator are you using to calculate the efficiency of an unmanned lunar soft landing mission?

Re: Chandrayaan-3 Soft-landing [video]

#336

Post by luminati »

skynetv2 wrote: post #329

Despite all the sour comments trying to find fault and criticize, this is a remarkable achievement, especially on the heels of the failed Chandrayaan-2 mission. Congrats to the team!!! Just 4 years to recover from the failure and achieve a phenomenal success. India just keeps executing despite what others may say. The team deserves even more praise to be able to achieve these wins with limited resources.

re: "Just 4 years to recover" This mission was originally slated for 2021 but COVID ended up delaying it.

Re: Chandrayaan-3 Soft-landing [video]

#337

Post by ironyman »

tjpnz wrote: post #297
goku12 wrote: post #236

Earlier quoted context omitted.

Russian 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 than in a war.

Might be time for China to reconsider its role with Russia in future manned moon missions. Any prestige the Russian program once had has long since faded, even ground operations at Baikonur are now at risk with equipment being impounded by bailiffs from Kazakhstan to service billions in debt.

Russia retains an (rapidly diminishing) edge in certain areas of space. One of them is engine design. China is still keen on buying the best Soviet engines, namely Energia's RD-170 and its variants but of course Russia is less than keen on parting ways with them.

Even CALT, the major launch vehicle provider in China, admits it will be well into the late 2020s/early 2030s before they can get an engine as good as the RD-170. Their YF-130, while technically very good according to recent tests, is still a bit less efficient. Think about that, a 40 year gap. Aerospace is hard.

https://en.wikipedia.org/wiki/RD-170

Re: Chandrayaan-3 Soft-landing [video]

#339

Post by shri_krishna »

seatac76 wrote: post #290
shri_krishna wrote: post #151

Earlier quoted context omitted.

Because: https://news.ycombinator.com/item?id=37235089

I cracked up at the little flag waving by who I assume was the prime minister/president. The duality is interesting serious Indian scientists doing great work and a politician on the screen for no good reason. Here’s to the tribe of scientist prevailing and taking the country forward, prob true everywhere now that I think of it.

> The duality is interesting serious Indian scientists doing great work and a politician on the screen for no good reason

One can say the same about President Nixon talking to the Astronauts who landed on the Moon. At least here ISRO comes directly under the Prime Minister of India while NASA does not come under the President of USA.

Re: Chandrayaan-3 Soft-landing [video]

#340

Post by BossingAround »

darkclouds wrote: post #322
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.

Here Here. It also ironic that a country and population seen as backwards by the British Empire have overtaken the British in landing on the moon. Would be nice to see the African and South American continent achieve a moon landing as well.

Apologies for the OT, but it's "hear hear", not "here here" [0].

[0] https://en.wikipedia.org/wiki/Hear,_hear

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