this is a neat book on the history of unmanned spaceflight.
Take a look and see how long it took to get a probe into orbit. Into someone else's orbit. All that before they even tried landing anywhere
For moon landings, sourced from wikipedia[0] but you can certainly find the information in the aformentioned book:
> Luna 15, Luna 18, and Luna 23 all crashed [into the moon] on landing; and the U.S. Surveyor 4 lost all radio contact only moments before its landing.
Finally, here's a list of rocket launch failures in 2022
So, moon landings where the craft suddenly and unexpectedly lost comms in the seconds or minutes immediately prior to contact with the surface:
Government: 1 of 25 (4%)
Commercial: 3 of 3 (100%)
I'm saying it's odd, weird, and deserves investigating specifically from the angle of why commercial has this happen, but not government.
I'm saying this because it is odd.
I've not once mentioned conspiracy - though others seem ready to jump to that, probably as a subtle ad hominem instead of engaging with the discussion. Thank you for engaging, it's an interesting topic.
But is it odd? It is just a very hard problem. You need to spend a lot of resources to get it right and you need to spend them in the right way. Also you need to build up to the capability step by step. You can't drum random engineers together and expect them to build a lunar lander. You need to give them progressively harder and harder challenges, and see if they develop the right chops to handle them.
What do you want to investigate? I'm sure the commercial entities did their own investigations about their failures and the factors behind it. They are under no obligation to share anything with me or you.
It is indeed odd to me, that the only and all three missions distinct by funding all failed in exactly the same way, at exactly the same point, where those funded from a different source only did 1 in 25 times in that way.
Perhaps the randomly-drummed up engineers argument could have some merit for overall mission failure, though it doesn't adequately explain failure on only the same, final mode.
Were the same engineers involved? If so, it seems beyond the pale they didn't learn anything?
To be clear, it's not that these landers hit the moon and expired, they all stopped transmitting on the final leg. It's a weird failure and even weirder that it wasn't experienced more frequently in govt funded missions.
I've no plausible theory why, that's why it's interesting.
All reasonable explanations have to be a bit out there, other than the de facto "bad luck", which doesn't wash with me.
I'm not interested in investigating (beyond doing sums on wikipedia numbers). But I am interested in it being investigated by someone more qualified.
> I've no plausible theory why, that's why it's interesting.
These are groups on a shoestring budget trying to do something very hard for the first time. They fail at the hardest part of the task. How about that as an explanation?
> All reasonable explanations have to be a bit out there,
Have you tried hard things before? Failure is the default outcome.
> they all stopped transmitting on the final leg
That tends to happen when you hit a rock the size of the Moon. As these did.
I think you are making a mystery out of this where there is none.
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've made does nothing to convince me this isn't odd or interesting. I've no horse in the race and will continue to be intrigued until someone can give better explanations, rather than "it's hard dude".
> 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 Hakuto-R Mission 1 reports they have telemetry about the craft free falling. They talk about an altitude measurement system possibly miscalculating. They also talk about the thruster running out of fuel. [1]
The Beresheet had an Innertial Measurement Unit fail, then they had communication issues, and they regained communication, but by that time it was too late to save the lander. They also had telemetry up until the impact if I read it right. [2]
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.
> 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.
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:
Only a certain number of launches will be successful. Only a certain number of landings will be successful. Sometimes you just hit a Poisson distribution.
Then do percent successes vs failures, broken down as government and commercial.
Then ask why's only commercial landing the tricky part?
It's not like these people are stupid, nor like they haven't had multiple decades to learn from plus the state of the art.
Three in a row is as weird to me as if there were seven in a row. All only commercial, while govt landed fine.
Would you think that odd too?