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Commercial lunar lander presumed lost after moon landing attempt

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Re: Commercial lunar lander presumed lost after moon landing attempt

#181

Post by ghaff »

mrguyorama wrote: post #179
moffkalast wrote: post #160

Earlier quoted context omitted.

Smh, Americans will literally convert into metric and back to keep using their bald eagles per shotgun squared units.

Since the 60s, America has literally been officially a conversion of standard SI units. A yard is defined as most of a meter (exactly 0.9144 meters) and an inch is derived from that.

Since the 60s? The yard measurement dates to sometime before the Norman invasion of England. And it's not even used that widely in the US outside of some specific contexts like sports. A gallon, from which a quart is derived is of a similar vintage. Without digging into history, I assume some SI volume and length measurements roughly mirrored existing Imperial units as opposed to the other way round.

Re: Commercial lunar lander presumed lost after moon landing attempt

#182

Post by detrites »

krisoft wrote: post #180
detrites wrote: post #173

Earlier quoted context omitted.

They didn't lose contact on impact, but minutes prior. The hardest part is the landing, not necessarily specifically the communicating with the lander on the way down - which in some sense is trivial depending how it's done. Indeed, it's an assumption they didn't land and instead impacted, until confirmed visually - as the landing is typically an automated process at that point. Continually breezing past the points I…

> Continually breezing past the points I've made does nothing to convince me this isn't odd or interesting. I’m sorry that it feels like that to you. I’m doing my best to adress your points to the best of my abilities. If you feel I am breezing by your point that just means I haven’t understood you yet. > They didn't lose contact on impact, but minutes prior. I see what you are saying, but that is not true. The Hakut…

Great - this is some decent information. Thank you!

So, I've formed my opinions on both of these based on initial reports which all said similar things - contact was lost with the lander during the descent.

If that's reliably revised now I'd have to reconsider. Though it still strikes me as odd all initial reports were identical across the board. Why is that?

The third one is of course the subject of this article though we have come some way, so it's well understandable were it to become lost in the background.

Anyway, I appreciate your good natured engagement.

Re: Commercial lunar lander presumed lost after moon landing attempt

#183

Post by zamnos »

belter wrote: post #8
noisy_boy wrote: post #6

Beautiful images of Earth from the lander: https://twitter.com/ispace_inc/status/1650506233575604227/ph... and https://twitter.com/ispace_inc/status/1649707714447306753/ph...

If you look carefully at Earth, as the image was taken during the eclipse, you see the shadow of the Moon on Earth.

Reminds me of the 1999 photo of the solar eclipse from Mir, which is my favorite space picture.

https://astro.unl.edu/classaction/images/lunarcycles/solarec...

Re: Commercial lunar lander presumed lost after moon landing attempt

#184

Post by dredmorbius »

jacquesm wrote: post #162
dredmorbius wrote: post #110

Earlier quoted context omitted.

Many failures of complex systems originate in fabrication / maintenance rather than in operation. Flights are doomed from the start due to such defects. The Columbia disaster is a partial exception --- the proximate triggering factor occurred during (very early) flight, but a deeper-cause analysis would include factors that originated on the ground in design, operations, and assessments of earlier incidents.

And don't forget 'culture', which I think was a huge contributing non-technical factor.

Quite.

And also typically occurring on the ground / before the flight. Even where considerations such as crew resource management / cultures of deference (still a factor in recent air incidents, see Asiana 214 in 2013, for example).

Which itself encompasses a whole slew of factors: false beliefs, groupthink, politics, cultures of fear (or simply conformity), etc., etc.

What I find most interesting about discussions of all of these is that they are so broadly applicable, and are often the parts of incident post morta which are most generalisable to other domains and situations.

Re: Commercial lunar lander presumed lost after moon landing attempt

#185

Post by rad_gruchalski »

ihatepython wrote: post #171
rad_gruchalski wrote: post #97

Earlier quoted context omitted.

We can’t stay here forever. This planet is 4.5 billion years old and has 1 billion years left. That’s assuming that our species will be able to survive so long.

A billion years from now, time travel should have been invented. Your view of time is too linear.

I believe that we watched the same Futurama episode.

Re: Commercial lunar lander presumed lost after moon landing attempt

#186

Post by krisoft »

detrites wrote: post #182
krisoft wrote: post #180

Earlier quoted context omitted.

> Continually breezing past the points I've made does nothing to convince me this isn't odd or interesting. I’m sorry that it feels like that to you. I’m doing my best to adress your points to the best of my abilities. If you feel I am breezing by your point that just means I haven’t understood you yet. > They didn't lose contact on impact, but minutes prior. I see what you are saying, but that is not true. The Hakut…

Great - this is some decent information. Thank you! So, I've formed my opinions on both of these based on initial reports which all said similar things - contact was lost with the lander during the descent. If that's reliably revised now I'd have to reconsider. Though it still strikes me as odd all initial reports were identical across the board. Why is that? The third one is of course the subject of this article tho…

> Though it still strikes me as odd all initial reports were identical across the board. Why is that?

If you are asking why the initial report was about loss of signal then it is simple:

Crashing a lander leads to signal loss. The media wants to report on the situation and demands an imediate answer. “We lost the signal.” is a simple statement of fact the engineers can make without any further analysis. So they make that statement and the media reports it.

You were earlier saying that the initial reports all said the signal was lost minutes earlier than the landing? I don’t recall seeing anything about the timing.

> The third one is of course the subject of this article

No. The subject of the article is the first one in my list, the Hakuto-R Mission 1. Then there is the second on my list the Beresheet. And then it sounded like you were refering to a third comercial lander?

> Anyway, I appreciate your good natured engagement.

Thank you. I try my best. And thank you for yours too.

Re: Commercial lunar lander presumed lost after moon landing attempt

#187

Post by WalterBright »

danielodievich wrote: post #124
WalterBright wrote: post #113

Earlier quoted context omitted.

Dropping it 5cm shifted the position of the tube assembly far enough to cause more problems? Why wouldn't that disqualify the part for flight?

2 pages of the book are dedicated to this. This was reviewed for 2 weeks by dozens of dedicated people, and was signed off by everyone on the mission control and mission commanders. Absolutely fantastic writing and I am sure a distillation of 100s of pages of RCA notes.

I bought the version of the book without the pictures for about $3. I'm looking forward to seeing this section.

Re: Commercial lunar lander presumed lost after moon landing attempt

#188

Post by anigbrowl »

philipwhiuk wrote: post #169
anigbrowl wrote: post #50

Maybe they should be focusing on building something robust enough to land or even crash on the moon's surface and keep transmitting for a while, then work on the cool rover payload after that. It's perplexing to me not that it failed, but that they don't (so far) have any idea why or how.

Maybe you should wait for more than 10 minutes after projected touchdown so they have time to review the data?

Maybe you should read the comment more closely. I'm not saying they should have all the answers to hand immediately. I'm saying I'm surprised they don't prioritize hardened communications that can survive a crash or an explosion, much like the black boxes on aircraft. I suspect that when they were first proposed people hooted at the idea as well and said things like 'flight is hard.'

Re: Commercial lunar lander presumed lost after moon landing attempt

#189

Post by detrites »

krisoft wrote: post #186
detrites wrote: post #182

Earlier quoted context omitted.

Great - this is some decent information. Thank you! So, I've formed my opinions on both of these based on initial reports which all said similar things - contact was lost with the lander during the descent. If that's reliably revised now I'd have to reconsider. Though it still strikes me as odd all initial reports were identical across the board. Why is that? The third one is of course the subject of this article tho…

> Though it still strikes me as odd all initial reports were identical across the board. Why is that? If you are asking why the initial report was about loss of signal then it is simple: Crashing a lander leads to signal loss. The media wants to report on the situation and demands an imediate answer. “We lost the signal.” is a simple statement of fact the engineers can make without any further analysis. So they make…

Sorry, this is the other on my list, but while it had the most oddities of all in terms of aftermath, looking deeper it was not commercial:

https://en.wikipedia.org/wiki/Chandraydaan-2

I can't find it, but at the time Antrix Corporation (India's commercial space contractor) was reported as responsible for it. This appears to be incorrect. Which throws the base premise here somewhat out the window.

Thanks for prompting me to look into it again. The corrected stats for failed lunar landers would be:

  Government: 2/26 (7.7%)
  Commercial: 2/2 (100%)
Not nearly as odd, but worth tracking.

Re: Commercial lunar lander presumed lost after moon landing attempt

#190

Post by aezart »

ghaff wrote: post #181
mrguyorama wrote: post #179

Earlier quoted context omitted.

Since the 60s, America has literally been officially a conversion of standard SI units. A yard is defined as most of a meter (exactly 0.9144 meters) and an inch is derived from that.

Since the 60s? The yard measurement dates to sometime before the Norman invasion of England. And it's not even used that widely in the US outside of some specific contexts like sports. A gallon, from which a quart is derived is of a similar vintage. Without digging into history, I assume some SI volume and length measurements roughly mirrored existing Imperial units as opposed to the other way round.

The point is that the American units are now defined relative to metric units.

As recently as the 1800s, the yard was defined as:

"the Straight Line or Distance between the Centres of the Two Points in the Gold Studs of the Straight Brass Rod now in the Custody of the Clerk of the House of Commons whereon the Words and Figures "Standard Yard 1760" are engraved"

... That standard yard was destroyed in a fire in 1834, and a new standard yard was made using several copies of the original standard yard as reference.

But now, it's just defined as an exact fraction of a meter. First as 36/39.370113 m, now as exactly 0.9144 meters.

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