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Chandrayaan-3 Soft-landing [video]

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Re: Chandrayaan-3 Soft-landing [video]

#471

Post by ChuckMcM »

bluGill wrote: post #441
ChuckMcM wrote: post #428

Earlier quoted context omitted.

The whole hover and look around thing was super impressive to me. That choice to spend mass on fuel for such maneuvers vs science instruments seems to always go to science in NASA debates and we end up with "either it will land here, or it will die." :-) Great outcome and I look forward to the pictures sent back by the rover!

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.

Re: Chandrayaan-3 Soft-landing [video]

#473

Post by pests »

mattigames wrote: post #465
edpichler wrote: post #432

This is such a difficult achievement. And they did it spending USD 75 Million, almost 2x less the costs of production of the Interestelar movie. Very well done, India. Respect!

It made much less on profits than Interstellar tho.

Ah yes, the same way USPS is unprofitable.

Re: Chandrayaan-3 Soft-landing [video]

#474

Post by silisili »

RajT88 wrote: post #355
AlbertCory wrote: post #305

Earlier quoted context omitted.

In football journalism they call that Monday Morning Quarterbacking.

In any kind of aggressive manly kind of story, especially involving the military, they're "Keyboard Cowboys". Or some new ones I've heard kicked around: - Gravy Seals - 101st Chairborn - Chair Force pilots ...And so on...

You're mixing up terms here. Gravy seals is an insult term, used for typically out of shape people who are heavy into gun/militia/i-am-very-badass type culture.

The latter two are just ribbing jokes about the Air Force, from the other branches usually. My old (Army) boss used to tell me to 'take off your air force gloves' if he ever saw me with my hands in my pockets.

Re: Chandrayaan-3 Soft-landing [video]

#475

Post by AlbertCory »

silisili wrote: post #474
RajT88 wrote: post #355

Earlier quoted context omitted.

In any kind of aggressive manly kind of story, especially involving the military, they're "Keyboard Cowboys". Or some new ones I've heard kicked around: - Gravy Seals - 101st Chairborn - Chair Force pilots ...And so on...

You're mixing up terms here. Gravy seals is an insult term, used for typically out of shape people who are heavy into gun/militia/i-am-very-badass type culture. The latter two are just ribbing jokes about the Air Force, from the other branches usually. My old (Army) boss used to tell me to 'take off your air force gloves' if he ever saw me with my hands in my pockets.

Not having served (but I did help out on Operation Code for a couple years):

"Chair Force" does sound like something they would say about armchair generals. No?

Re: Chandrayaan-3 Soft-landing [video]

#476

Post by silisili »

AlbertCory wrote: post #475
silisili wrote: post #474

Earlier quoted context omitted.

You're mixing up terms here. Gravy seals is an insult term, used for typically out of shape people who are heavy into gun/militia/i-am-very-badass type culture. The latter two are just ribbing jokes about the Air Force, from the other branches usually. My old (Army) boss used to tell me to 'take off your air force gloves' if he ever saw me with my hands in my pockets.

Not having served (but I did help out on Operation Code for a couple years): "Chair Force" does sound like something they would say about armchair generals. No?

Absolutely. Just pointing out that one is strictly a pejorative, while the others would likely be viewed as 'someone in the airforce.' I think OP was wanting things more of the former, like gravy seals, meal team six, y'all queda, etc.

Re: Chandrayaan-3 Soft-landing [video]

#477

Post by dotnet00 »

chpatrick wrote: post #434
ironyman wrote: post #337

Earlier quoted context omitted.

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 R…

I'm surprised that the Atlas V's first stage has these Russian engines.

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 boom in private launch companies and of course, SpaceX's work.

Re: Chandrayaan-3 Soft-landing [video]

#478

Post by ggop »

itake wrote: post #457
gourabmi wrote: post #429

Earlier quoted context omitted.

If you understand Hindi, Gareeb Scientist has an amazing video about the landing algorithm issues of Chandrayaan-2 https://youtu.be/4oUdD_QSgRs

Is there a TLDW?

IIUC, the salient points are: - target area was very small (500m x 500m) for CY2. With CY3 they've made it bigger at 4km x 4km, allows for larger margin of error.

- CY2 lander had limited leeway in fixing issues, by design. CY3 has more and has landed itself, no assistance from base.

- CY2 lander had limited time to fix itself, apparently it was just a few seconds short of making it fine

Re: Chandrayaan-3 Soft-landing [video]

#479

Post by chpatrick »

dotnet00 wrote: post #477
chpatrick wrote: post #434

Earlier quoted context omitted.

I'm surprised that the Atlas V's first stage has these Russian engines.

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?

Re: Chandrayaan-3 Soft-landing [video]

#480

Post by dotnet00 »

cpursley wrote: post #459
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.

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 is definitely befitting of its glory during the mid/late 19th century.

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