Engine falling off during a controlled landing is the most KSP thing I have ever seen. We are in a simulation, and were kerbols lol

Props to the engineer/team who programmed the thing to pull off ANY kind of landing while minus a nozzle. Very impressive!

So: - They lost the nozzle on one of the main two engines, and still managed to land. - They managed to spit out those two more Kerbal than Kerbal, toy-like gizmos - One of those gizmos took a picture of the main craft after it fell or its face and successfully sent it to earth - There is still a decent chance that the main craft will reactivate in the "afternoon". This is simply amazing. Great work, JAXA! 🏆

As a Japanese, though the lander is upside down like KSP, I am proud of this JAXA mission. I really appreciate Scott's detailed explanation. スコットありがとう

"Where should we land, Cap'n?" "Next to the engines, Chief."

Pulling a Kerbal Space Program is arguably far more impressive than sticking the landing, even taking in to account one of the little landers survived and was able to turn around and take a picture. This is art.

"Any landing you can walk away from..." Congrats to Japan on the great success, and thanks for those amazing pictures!

Good on Japan for being quick to bring out what happened, and it is awesome that the failure was mostly obvious. And it is VERY impressive that the computer was able to land softly, if not perfectly.

YES, THEY MADE THE KSP IMAGE ICONIC! This will forever be in the history books!

About the translation😂: In this case the sentence was trying to say "possibility is high" which is written as【可能性が高い】, 可能性 meaning "possibility" and 高い meaning "high". Well, in the report the 可能性 word was separated 可能 and 性 at the end of the row. And google translate (which always has a hard time separating words from Japanese when they go on to next row), thought the part on the next row is a new sentence ( 制が高い) and translated it completely separately. Which can be translated as "the sexuality is high" 😂

Complete success in my opinion. Regardless of how you spin it, Japan will have a glorious upside down lander that will remain on the moon for a long, long time. A worthy landmark for future humans!

Really unfortunate failure, but hats off to the engineers. The software program did a great job of dealing with the situation it was given, and the team did a great job of troubleshooting to get them in the best position to recover as much of the mission as they can. Spaceflight is hard, bravo Japan!

"Task failed successfully" But in all honesty and all joking aside: Losing the engine nozzle and still softlanding within the pre-defined landing area as well as being well below the speed threshold is _very_ impressive. Hope it'll come back to life once the sun comes around, that'd be very sexual.

4:50 Yeah that sexual part is likely a translation error by the line break. The original PDF reads "可能性が高いと考えている" means "considered it's very likely" When you have a word break between 可能 and 性, that part reads "possible, the sexuality is considered high." That aligns to the beginning of the preceding line "It is possible..." which really should be "It is considered the possibility of..." Nonetheless, this error sounds unintentionally VERY Japanese and I fkn love it.

The fact they managed to land after having an engine nozzle fall off is absurd. That is extremely impressive software.

JAXA has just announced that it has resumed operations of the SLIM spacecraft that landed on the Moon, which was unable to generate power from its solar array panels due to an attitude anomaly at the time of the landing on March 20, but is now believed to have resumed power generation. Mineralogical observations of the Moon were also resumed. The landing posture is not upside down, as it was originally planned to rotate 90° and land with the photovoltaic panels facing up. SLIM was not in the planned position with the solar panels directly above the ground, but in a 90-degree tilt, facing west. JAXA predicted that power generation would resume when the sun came to the west. The prediction came true and power generation resumed, so SLIM began its work, although it is still collapsed by 90°.

Relatable. I remember my first Mun landing. I proudly planted my flag and posed for a screenshot as my rocket ever so slowly fell over and gently exploded in the background.

Good job JAXA! And, after all the failures blamed on software, it's very good to see software coping with a potentially catastrophic hardware failure, well enough to get the lander down in one piece, still able to take observations and send them home. 👍

Honestly pretty happy ending, considering how many craft have impacted the moon (or lost in space) recently just because of weird failures and the inability to compensate. Got that feel good survival story of a little craft dealing with a catastrophe and coming out alive :) Have there ever been a craft that has had a major mechanical failure and still managed to land softly and continue operation before? This is kerbal in the best way!

I can't properly express how much I love this. New desktop image inbound!

This honestly makes the fact that it’s mostly still in one piece and deployed its rovers even more impressive! (it’s impressive IRL but in KSP it’s just a usually mission.)

This is cool. I appreciate Japans transparency on this mission. I would point out that although the primary mission failed due to material failure there are several success points as well. They got there. The probe was in proper alignment ( the engine falls off). The seperation camera popped off successfully and was operational. Indications are if engine was intact on landing the craft would have performed as intended. All amazing achievements. Next iteration after lessons learned should work.

Absolutely astounding that they had the foresight to program for making the best attempt even if some system failed. That is just really cool.

The fact that the other engine and guidance systems weren't thrown into chaos is incredible. I expected a cascade of over-compensation!

After losing an engine, being able to soft land at all is amazing.

Outstanding work from Japan. Very novel design for a lander and it seemed to work really well overall.

How well you predict possible sources of failure and how you prepare for them dictates how capable the craft ends up being. Cudos to the Japanese team.

I absolutely love how Scott is giving us an extremely detailed breakdown of the whole situation while sitting in his bathrobe. It just shows how great this community is and how everyone is just listening to him giving us the best information, with his vast knowledge! Keep it going!

5:12 "I think it's highly sexual." Gotta reuse that line for future space accomplishments.

it is in fact very arousing to know nitty gritty stuff about a falling nozzle out of a moon lander

As always this was clear, interesting and very informative. The shot showing the falling nozzle was amazing.

Well done Manly. The way you kept your composure during the translation error was truly masterful.

After a bit of effort I bought a toy version of SORA-Q from Amazon Japan. After shenanigans with setting up an Apple ID in Japan, I downloaded the app....used another app to translate the instructions and.....I get to drive an honest to goodness lunar rover around my carpet. What's life without whimsy?

Those pictures are amazing. And successfully landing even after one of your engines asplode is remarkable. I do feel like they should take a hard look at those ceramic nozzles, though...

The nozzle floating in the middle of the navigation image got me :D "yeah this aint supposed to be there"

The little lander that could. That image is priceless!

Love your content Scott, thanks for all your hard work

Scott, you didn't give yourself enough credit. You nailed it with your last video on this spacecraft! You said it landed upside down, and when I saw this photo last night I jumped up and yelled 'Scott Manley nailed it! it really did land upside down!' And now we know why. Another reason you are my favorite space you tuber, keep up the great videos!

Hats off to Japan for getting as far as they did. The nav software sounds robust and well executed for it to save SLIM from total failure. On a side note, Scott, if you actually make it this far into the comments - I've been watching your coverage of this landing, and just at the end of this one was the first time I realized that the intended final orientation for the lander was on its side. You probably said as much in another video, but I must have missed it?

Thank you scott, once again a wonderfully concise video packed with information.

With every failure of new-comers to space missions abroad it becomes more obvious how special the first manned lunar missions were.

The lander knows where it is at all times.

Yet again, another great assessment here Scott. Thanks

thank you for the informative and enjoyable video!

I think you're right to think that the fuel/oxidiser ratio may have contributed to the nozzle failure. If the same thing happened in an internal combustion engine, i.e. too much air and not enough fuel, then the lean mixture would burn hot and possibly result in a burnt valve or holed piston.

I love that translation, I saw it just before you mentioned it and I was also cracking up.

Thanks for the update. It looks like they have identified their weak link which is always useful in developing your next craft. Hope to see more from Japan space exploration in the future

Hi Scott! Land safe!

Only halfway through the video, the computer software on this craft is incredible! Especially when comparing it to other spacecraft that failed from relatively small software issues

First as a KSP player my question is why don't they try to use the RCS thrusters to at least point the solar panel straight up? Secondly kudos to the autopilot that managed to land the whole thing in one peace even after the loss of the engine, which brings me to my third point they really must redesign those bloody engines!

Please keep us informed more about this mission🙏

Thank you, Scott! Another very entertaining and informative session! No doubt: You sure are among the 3 foremost space commentators ( or...2 or...1???;-))

As others have partially noted, that entertaining bullet on page 14 ACTUALLY reads: "Based on the above, the project [team] believes that there is a high possibility that some external factor other than the main engine itself affected the minus-X side main engine."

This is so impressive, and more Kerbal than most Kerbal Landings. Full Props to them for absolutely nailing a landing after losing one engine. Thats incredible

I want to see the unit tests for that guidance software. Nice job Jaxa!

Great investigation, Scott!

Great video, very impressive and successful mission, artful photography, first class translation error. I give this series of events a 10/10.

One of my thoughts was whether they could use the RCS thrusters to help right the craft but I realized they are probably too weak to do much as they are meant to adjust the craft while it is in space.

nicely explained, many thanks.

Love your deep analytical/investigative videos 👏

Nailed it

Ya know what I see? An intact vehicle on the lunar surface! It might have gone a little wonky but I still count it as a win

Scott, thank you for updating the situation with the Japanese lunar lander. Great that we got at least a snapshot of the main lander from the little rovers.

Mr Manley hope you are working on a follow-up with recent developments. No rush your explanations worth a wait.

It wasn't mentioned explicitly in the video but the report says: "The cause of [the loss of the -X engine nozzle] is currently under investigation and will be announced once the details are known."

I say that picture of a real life "Mun or Bust!" rocket makes this project already well-worth the money and a huge success.

Great analysis as always Scott. Silicon nitride is very good for high temperature applications and good abrasion/corrosion resistance as required in a nozzle but its brittleness can be challenging. Having a second ceramic nozzle drop of a Japanese spacecraft maybe more than coincidental.

It is always great getting in the box!

Even before the report I had my suspicions that the failure was highly sexual. Good to see that confirmed, hope they figure out a solution in the future

Computers are very cool, and this (the spacecraft landing even with a catastrophic failure of a vital component) is why good software is so important and so powerful.

Thanks Scott! 🙂😎🤓

I think it's incredible they even have any telemetry given they lost an engine. It's enough damage and enough of a bad landing that we all would've reloaded a save on KSP, but they've salvaged the situation and have some functional hardware on the Moon. Which is not something every space agency can say. Definitely a win for JAXA.

The latest is that they have reestablished communication with the lander.

Its great that the little rover was able to take a picture confirming what happened to the spacecraft.📸

Thanks I've been wanting to see a photo and know what's going on.

Congrats on Japan making a successful landing on the Moons. Despite being Kerbal, still Kounts.

Tremendously impressed / relieved to see a photo of the lander from one of Japan's rovers this morning. I want to be from a country that lands on the Moon!

Can you do a video explanation of what happened to Astrobiotics lander that missed the rendezvous a few weeks ago. ? Loved ur explanation of this here Great work 🤙🤙

This is exactly why space research is so fascinating- the weirdest things happen and always at the worst possible time. It is the ultimate puzzle for the ultimate engineer!

Just got kerbaled

I've had this problem a dozen times in KSP. I wonder if they could use RCS to roll the craft and expose the panels.

Nicely done JAXA... it would've been great if it'd landed right side up but considering the problem it experienced it did fantastically well! I wonder if there's a way to use the manuevering thrusters to roll it onto the side so that the solar panel faces up and gets it a bit more power?

Great overview. There was success and we will learn from this and fail forward. Well done. Alain Faber

Congratulations to Japan and JAX. Well done, well done.

For those less nerdy types, the importance of too rich in oxygen is a matter of increased combustion temperature. Cutting torches are made to be oxygen rich and the effect is the same for nozzles and nozzle throats.

@11:00 Akatski means dawn or morning light (appropriate for Venus, the morning star). Pronunciation tip for Westerners: Japanese (like most east Asian languages) has no stress whatsoever on any syllables. A close approximation for English natives who have a hard time with that is to stress the very first syllable, resulting in the bulk of the word being fairly even. Kaguya (their other orbiter) is a moon goddess, and a popular girl's name. Rough equivalent of Diana/Selene.

Request not related to this video, but related to satellite nav: Could you do a video about TERCOM navigation? Using radar to detect topographic features to orient and guide. I've been fascinated by it but can't find a lot of great resources out there. Thanks!

Do you think they could use the side control thrusters to attempt to spin it around or pivot it a little to better align the solar panels towards the sunlight?

Can attitude control thrusters be used on a landed lander? Perhaps there's not enough heft in those things to get it to roll to the correct orientation. Also, lots of regolith will be kicked up, I think it's fair to assume.

Top and bottom charts shown starting at 4:42 into video show that engine mixture ratio (MR) on the -X side axial descent engine ("OME-MX") was declining at at rate such that at about 1500 seconds engine firing time it would have crossed the lower red line of MR = 0.725 . . . that's very fuel rich for the N2O4/N2H4 propellant combination (usual design MR for N2O4/N2H4 engines is in the range of 1.0 to 1.2 for best combination of Isp and combustion chamber/nozzle throat temperatures) and likely resulted in the -X side descent engine headend and/or combustion chamber exploding, leaving the rocket's nozzle as the only large remaining piece projected down onto the Moon's surface. Also, the vehicle acceleration chart shown starting at 3:42 into the video clearly indicates one of the two main descent engines failing at about 1490 seconds elapsed engine firing time, consistent with the predicted time of crossing over the mixture ratio red line for the -X engine. Why JAXA chose a N2O4/N2H4 rocket engine with such a low design mixture ratio ( the descent engines start firing with MRs ~ 0.80) is a mystery . . . it might have something to do with fact that the two 500N descent engines used on this lander were a relatively new "ceramic" design.

Thanks for the Kudo Scott on my translation effort. I glad you caught the ""I think it's highly sexual." I didn't see that initially, but I got poke at all day long by members at NSF. It made my day. Best Tony.

I'm sure someone else has asked the same question but.... can the reaction control thrusters still be used to reorient the craft?

Is it possible to reorient the Lander using any of the Thrusters, and would the Risk/Reward analysis warrant such a maneuver to the overall success of the mission?

That funny translation doesn't seem far of, because that one engine was quite obviously effed. xD Thanks for covering this. Been waiting for a report since the landing

wow, such a detailed analysis of a very short mission... how long will your next vid about the now grounded mars helicopter drone be? RIP Ingenuity

I'm just glad we have more countries and companies looking towards the moon. Last year we had Russia, India, already this month we had Japan and 2 US companies, and soon we'll have Artemis and the Chinese manned mission too!

You were absolutely correct that it was upside-down 😊

Like the Apollo spacecraft, it has both a "Stable 1" and "Stable 2" landing orientation. This was an amazing result in the face of a failure like this!

immediately on touchdown i noticed that the oxidizer and propellant meters dis not match, there was much more in one tank than the other, they had been equal just a bit prior. Also u can see that there was a big correction burn moment before touchdown with a full engine burn, if only one main rocket was working this would try to flip the spacecraft

If possible I'd reach out to David of the channel Usagi Electric as Japanese translation of technical documents is his day job. He's a great retro electronics and computer channel