If I read correctly, this is now the most watched live video on YouTube! Congratulations to India and the team on this fantastic feat of an achievement.
I thought it was 8M earlier. I didn't see this cross 6M though.
Chandrayaan-3 Soft-landing [video]
111–120 of 542 posts
Re: Chandrayaan-3 Soft-landing [video]
#112Scott 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
I really ought to dig up a reference for this, but there are strong echoes from the past here. Margaret Hamilton (who coined the term 'software engineering' and can be seen standing next to a tall pile of green bar printouts of the Apollo software) brought her daughter to work one weekend during the Apollo program and she (daughter) fiddled with the buttons and caused an error condition. Hamilton, based on this, argued that the software should account for the possibility of mistakes. Management's view was that the highly-trained astronauts wouldn't make mistakes. In time, Hamilton prevailed, and was proven correct.
Re: Chandrayaan-3 Soft-landing [video]
#113Earlier 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).
> seems like such a gross omission. Almost all space mission code only ever has the so-called 'happy path'. We rely on extremely tight mechanical and aerospace engineering tolerances to achieve that happy path. The Hubble Space Telescope's primary mirror grinding was off by a matter of micrometres, and resulted in blurry images. Consider all the Mars rovers. Imagine some wind gust threw the descending module off cour…
That can't still be the case these days, can it? Extremely tight mechanical and engineering tolerances are very expensive compared with merely 'very very' tight tolerances, and I'd imagine the difference between the two can be bridged with more intelligent software in place of "gyroscope + clock + maybe PID loop"?
Re: Chandrayaan-3 Soft-landing [video]
#114Not 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?
- Only 3 other countries have landed on the moon
- Its landing on the south pole where nobody's ever landed before
- Russia failed to land on the moon a week or two back
Re: Chandrayaan-3 Soft-landing [video]
#115Re: Chandrayaan-3 Soft-landing [video]
#116congrats ISRO and India for this great achievement.
Re: Chandrayaan-3 Soft-landing [video]
#117Not 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?
Besides what others said, it gets extra spice from the fact Russia failed to do the same just days ago.
And the BRICS summit is going on right now... What a powerful display of softpower.
Re: Chandrayaan-3 Soft-landing [video]
#118Not 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?
It's a big deal because India has never landed on the moon before; only three nations have.
This is the first time India soft-landed anything outside of Earth. That by itself is a big deal. Soft-landing guidance on a body without atmosphere is much more complex than launch guidance.
Re: Chandrayaan-3 Soft-landing [video]
#119One 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...
Re: Chandrayaan-3 Soft-landing [video]
#120It’s landed! Congratulations to India on this great achievement!
very good, congratulations on the achievement!