13:17 India has something called "Right To Information (RTI)" through which citizens can file a request to get some information from any branch of the government. However, like the Defence sector, the Space sector is deemed as "Strategic Sector" for the government and has legal immunity to not reveal anything to the general public. Not even the courts can force ISRO to release the documents.
@@meetoo594Bro both of them completely different things, Lander needs to soft land , use engines , identify the spot and lot of other things and that too in vaccum .
@@meetoo594 both are incomparable. Although pin point accuracy is desirable, ICBMs don't need the same accuracy as space missions do simply because the former destroys everything in a given radius, even if the missile misses by a few meters. Besides, ICBMs don't have to worry about lunar gravity, lunar atmosphere vs earth gravity, earth atmosphere.
I can understand why some people would worry about embarrassment, but ambitious projects like this don’t succeed without a lot of transparency and willingness to set egos aside. This stuff is HARD and COMPLICATED. No one should have to do it alone.
people laugh at failures even in my own country some people are making fun that America had landed humans on moon decades ago and we are not even able to land a fu*cking rover
Lol I'm from the UK, we have NO rocket programme, I'd kill to have the opportunity India does now. People who don't realise how hard this suff is are always going to laugh sadly. Good luck for a soft landing this month !
@@johnysins69696 what I find funny with that is that having people in the lander did make the landing easier in a sense, as a there was someone who could take over the auto pilot
There's no embarrassment, it happens and can happen. People who think that a missed step is a failure shouldn't be here. Great respect to our scientists. God bless you
That’s great to see India doing this. Good luck India! I work with a lot of Indian engineers in the US aerospace industry. That country is pumping out engineers.
It's interesting seeing all the learnings from Chandrayaan 2 going into Chandrayaan 3. To this extent you could say that mission wasn't a failure because it provided the ISRO lots of learnings they didn't have before. Afterall, what is the purpose of space missions if not to learn new things?
This reminds me of the Falcon 9 CRS-16 water landing a couple years back where the hydraulics on one of the grid fins failed, causing the F9 to oscillate wildly on decent. The engines tried to gimbal, but the flight computer judged that it was a loss, and decided to save the drone ship instead, forcing a water landing. As the Falcon 9 headed to a rough water landing, the speed slowed, and the grid fins didn't affect the spin so much anymore, so the spin slowed as well. Just as the Falcon 9 dropped the last meters into the Atlantic ocean, the engines kept gimbaling and kept fighting, and at the end they actually caused the F9 to make a perfectly straight plopdown into the water. The flight computer had judged the landing was too far out of envelope, but the engines were allowed to keep gimbaling and would have likely been able to cause a softish landing at the end.
That was B1050, an RTLS landing, so it was avoiding RUD on the pad, not on a drone ship. And yes, by the time it hit the water, it had almost corrected its spin by vectored thrust alone. It probably would have been a bad landing anyhow, so the automated abort was the right decision. They later corrected for this by adding redundancy to the grid fins hydraulic system.
Trajectory terminal point isn't nothing to angle, ipso thrusters, if you were able to change where it landed, you had energy expended. Maybe it could vertical on that trajectory, but not on another one.
I watched it live and it was so epic how the computer aborted to water but at the same time kept fighting to land the rocket safely I couldn't resist and turned it into an Interstellar parody, haha. Despite the landing being technically a failure it is one of my favorite moments in modern space flight.
Not to make light of the situation, but 8:00 describes almost every early landing attempt of mine in KSP. I wish Chandrayaan 3 all the best- eagerly awaiting the successful landing 23/8.
Kerbal Space Program friend! It is a Rocket science, space game. If you are here in the comment section of this channel and like this guy, you better have some knowledge of it.🙂🙂 @@WFHermans
Great discussion. I can just see it where the 'nav' system wanted to tilt but the 'camera angle' command overrode that. Then at the end of 'camera coast' phase and that 'clamp' that prevented changing attitude was lifted, and the 'nav' software was like, "Oh crap, too high... too fast... well we can just turn upside down and fire to get our altitude down...." Then was like... "oh wait... now we're descending too fast.....Oh wait.... just a sec... CRASH!!!"
I'm wondering if these engineers are testing their navigation software in some kind of simulator to detect bugs and to see how it react in different situations, or if they just analyse the code and think "Yeah everything looks fine, it should be good enough.". Edit: Nevermind, the screen at 10:10 pretty much answer my question, which was pretty obvious... But I'm still curious to know how good is that simulator, is it just like a spreadsheet of numbers or more like a real flight sim?
@@Alfred-Neuman I think a lot of it boils down to just how 'imaginative' the engineers can get while testing. Coming up with all the possible 'what if?' scenarios. Might have thought, "well it could never get THAT far off course...". But 'what if the engine thrust doesn't modulate correctly"? Or "What if the attitude for navigation conflicts with the 'camera coast' attitude, who should take precendence?" Like with a lot of complex systems, coming up with all the possible scenarios is still "more art than science." IMHO
@@Alfred-Neumanas far as the type of simulator, it's both. Besides software and numerical simulations, there's also HITL (Hardware in the loop) simulations which basically use the real guidance computers but feed it simulated data to see how it reacts.
ISRO works very close to DRDO and actively helps in development of ICBMs, so I don't think ISRO will ever publicly post a detailed explanation of what went wrong in a potential targeting system.
@@MiG82auBut the lessons from this mistake and the ways the design team were thinking are both valuable to enemies . The lessons are useful for avoiding similar mistakes in ICBMs pointed at india by enemies with smaller test budgets . The pattern of thinking mistakes are useful to enemies planning attacks against army units with the same training and to enemy defense systems trying to exploit similar mistakes in guidance systems made by the exact same people before that crash . If they know that incoming indian ICBMs will have a low maximum turning speed in degrees per second, forcing incoming missiles to be massively off course could help force a miss, and so could the tendency to not correct significant errors that happen shortly before a switch to a different attack phase .
The software changes from 2 to 3 sound eerily like several other software control projects I've worked on. The team works hard to get "the happy path" working - then learns the hard way that the real world isn't very happy so has to add error detection and recovery. For the UAV software I've worked on, generic flight control (flying the plane to waypoints) is maybe 30% of the total SLOC and handling various error conditions (lost communications, landing/recovery in bad weather, power management/housekeeping) is the bulk of the software, requiring assloads of multi-team meetings and design documentation and time consuming testing.
That's exactly why you never ever have data scientists, computer scientists or programmers involved in the initial design phase involving control problems or any advanced software.
@@T_Mo271 That's why we always have our mechanical engineers make the initial design. When the specifications are handed to the computer scientists and programmers the first thing they do is to oversimplify the design. Therefore we need some mechanical engineers and control engineers to prevent this from happening.
i hardly see information when a mission fails. lot of space agencies just give small information regarding faulure which is pretty much useless. Kudos to ISRO for transparency
OMG! I woke this morning seeing your RUclips, "Why Chandrayaan 2 Crashed on the Moon" thinking OH NO 😯! But I got the numbers wrong. "3" is still going. Thank god. Such a good explanation, thank you.
CY2 was an optimistic design which depended on everything going as per plan. CY3 the design was converted to more pessimistic, which is the best type of "istic" when it comes to such ambitious technology demonstration projects. I think unless CY3 crashes into the Russian lander, things should be good this time around 🤞
Lord save me from optimistic engineers assuming happy path. Just occasionally ask, "okay, but what about _when_ this doesn't work?" (Deer in headlights look) *sigh*.
@@thewiirocks A lot of modern software is written by assuming everything is working perfectly. No checks, no redundancy, no way to get out of unexpected state, just restart the whole thing and try again. Developers don't get enough time to bullet proof everything unless it's a serious, audited project and human lives depend on it.
Maybe you are a genius! Has that ever crossed your mind? Maybe the missus and kiddos see something you overlooked?? But, you are absolutely correct, I love this channel too! Give those loved ones some hugs, smile and y'all have a fabulous day! Take care @A1FAHx 🍻
Yeah but you kinda are pretty smart by default for learning and understanding these things, it's something that's easy to just pass off as "oh I just know a lot idk" which I used to do a lot, but let's give ourselves some credit yeah?
@@A1FAHx I appreciate that! Just keep on enjoying stuff like this and ya never know.... Maybe you will make the next big discovery, even if by chance, or your kiddos end up being the ones who make a big discovery.... Worst case, y'all learn something and have something to talk about.. who knows! Either way, it's an interesting time, isn't it!? Buckle up y'all, things are only going to get more interesting as we go! Wheeeeeee!!!! ❤️😁🍻
Sounds like a common problem I've seem on software implementations - testing the system using complete, perfect datasets covering only minimal scenarios that bears no resemblance to actual real world data or how end users are likely to use the software in production. Hundreds of thousands of dollars of development work needing to be redone after having gone live.
I hope Chandra-3 makes a successful landing. I'm sure ISRO learned a lot from Chandra-2. Thing is, every space-fairing nation has failed missions, so India shouldn't be embarrassed. Not at all. Just getting to the last few meters above the Moon was a great accomplishment.
Gareeb Scientist also made a video about this topic. Its available with english subtitles. I feel Scott saw that and decided to reach a broader audience. Which is good.
@@gamersupergirl1 Replacing one main thruster with 4 thrusters will make the control more complicated and prone to problems, which is not a good engineering solution.
There's nothing embarrassing. People who Run, falls many times. People who crawl, how can you expect them to fall. Either you Succeed or You learn. There's nothing called failure. As Bharatiya 🇮🇳 we deeply believe in this. Proud on our Scientists and ISRO.
Thanks Scott, for a professional and respectful analysis. This video reminds me why I really really don't want a car that 'drives' itself anytime soon. It's just carrying out pre-programmed responses to sensor inputs, and anything outside the box just isn't catered for. Also proves how technically difficult this kind of automation is, and props to all the teams that get it right. Let's hope for a successful Chandrayaan 3 landing.
I agree, stuff that works on softwares that are preprogrammed get into trouble when they encounter unexpected and (like you said) out of box situations. However are you aware that the final FSD that Tesla is expected to release sometime this year is not preprogrammed but it actually has an artificial intelligence that looks at its surroundings and reacts according to its own understanding! And that is expected to be faster and smarter than any human!
@@balaji-kartha There are certain situations that can lead the AI to misinfer and carry out conflicting maneuvers. An AI is as good as the data it has been trained upon. Needless to say, the Tesla AI will be better than 99% of drivers out there with godly reaction times. But there would be times when you'd wish your pet goldfish was behind the wheel instead of the AI.
It's not pre-programmed response, it's event driven response (to act in real time) the parameters of which (the event) are pre-programmed, within the limits of which, it's being given autonomy to compute a decision. Yes, it can go wrong, if the parameters and/or the software to compute the decision is erroneous, but it is more reliable than a human driver, who has never even got a speeding ticket in his 10 years of driving experience.
Chandrayaan 3 has to land. Because the next Moon Mission of ISRO is with JAXA later this year which has another Lander plus rover. ISRO is in charge of the Lander for which CH3 success is really crucial
Yeah, that's a big issue in software development. People forget to look for user errors and other issues really easily. That was something I always kept in mind when coding anything. Thanks, Scott! 😊 Stay safe there with your family! 🖖😊
quite often we warn about it, and get completely ignored by managers who insist we build the simplest, most bare bones, version without any error checking because that's the way for them to get something out the door most quickly, which makes them look good. Then, when the problems inevitably appear, we programmers get blamed for not putting in those same safeguards we were ordered to leave out in the first place.
@jwenting Well, I never worked for a big company with managers and so on, but I can imagine. I always did freelance, sometimes making stuff for other developers. And some of them were... Well, I don't know how to describe. 🙄 But I had a short career in software development... Because I accepted a job where I was supposed to make a big site, but the contract never came, so they moved me to the sister company. A digital juridic investigation company... And, well, I learned fast, but the stress almost killed me. That and my depression... And I never worked with it anymore. But, fortunately I made some money while working with it, did some smart investments... Now I live from renting houses. And I have cats, they help with the stress. 😬
t @jwenting ...and $5 says THAT is the root of the problem. Well said. I would not be at all surprised that the SW team pointed out the issues and was overridden by management, then they got blamed for it and cereers were ruined so that managers could save face.
@jwenting That’s why you gotta use a control board for your project or some type of history. They do that to me and I show the manager authorized the bypass. Since then they listen to me a lot more, devs a much more stable position than manager, get me a new one I like thanks. One of us has a skill you desperately need.
@@guyincognito1406 oh, we do that. Everything in writing. Doesn't matter when push comes to shove though. All that matters is who has the bigger connections high up in the company.
This is a bit of the problem with robots. Humans could have decided that pointing at the ground was bad and it was better to land elsewhere. For a probe to make this decision, it needs to be programmed in and may not be done
@@aadvaittureMost publicly deployed AI systems are actually Artificial Idiocy . It will blindly continue on false assumptions with no ability to stop, to the infinite frustration of affected humans . Most Google systems are like that .
Dang I was thinking of referring the presentation to you too and felt guilty because I was stuck with work the whole day. I must have known that others would have done it too :)
So happy I have you to break this all down for me, Mr Manley. You’ll never know how how much you’re appreciated by this space enthusiast with no physics background.
I hope India are successful with this landing attempt. Others in the comments have pointed out they would have learned a lot from the first attempt which gives them a better chance now. Go India !
Thanks for passing on a smile Scott (well in addition to great content)! Every video I open with “Hello, it’s Scott Manley here…” and you’re smile with enthusiasm… Just wanted to say def appreciate you my man!
I was watching a ksp RSS/RO playthrough recently, and the guy had the same issue with mechjeb, when the lander overshot it's landing target and tried to correct itself. I found that quite funny to think about
I’m surprised that the engineers went with such an optimistic approach, but maybe they were compelled to do so by an ambitious management team that didn’t like what they were being told by the engineers. This would not surprise me. Indian engineers are super clever. But culturally within an Indian hierarchy they probably don’t have the last word. I’m sure Scott has worked with Indian engineers and management, so he'll know.
Space exploration is fraught with risks. Even James Webb project had around 344 single point failure risks. The only way forward is Cooperation regardless of differences
Tbh as an engineer who works with process control and automation systems every day, the "optimistic approach" sounds absolutely amateurish. I can't believe they (engineering management and project management) actually signed off on a control system concept like that? In a billion dollar prestige project supposed to demonstrate peak technical ability of your nation?? If true, that reflects not just on total lack of experience from teams and managers who should be top of their class people, but also on them not using know how that is used everyday in totally mundane, not-rocket-science control engineering fields. Organizational failure, not just technical failure. Honestly if that really is true then they are still years away from actually getting a space craft to work. You don't climb such a steep learning curve as control software engineering in one iteration step, you need multiple iteration steps and they need to go in sync with the iterations that the hardware guys do. Best of luck but don't get your hopes up for insta fixes.
You are right sir, space is a toomuch unknown environment to work for even sophisticated machines. So one should ( in this case ISRO) be more cautious than optimistic. Love and respect from India.
Contingency planning, particularly in software algorithms is so important to ensuring the result is a robust system. Testing for such unexpected contingencies is even more critical. Great lesson's to be had in sharing these insight. Not sharing likely means future designs could fall victim to lack of contingency in the design.
Embarrassment is something that gets in the way of openness; the more a place is dictatorial and absolutist, the more it fears embarrassment. Look at the USSR during the race to the moon, look at North Korea… more examples of countries, ideologies and companies will come to your mind. It looks bad when they did not have ways to correct the thrust (turn down the duty percentage of their PWM? Cut thrust after reaching the ΔV required?) and there is, I believe, no good reason a lander should ever point the engine(s) away from the moon - that’s what gravity is doing already! But at least they seem to understand and fix (most? of) the problems found.
@@advorak8529 Failure only becomes embarrassing when you are pretending to be perfect and are more concerned about how your 'perfect public image' is affected by it. Embarrassment is entirely in your own self perception. *Maxim 70:* _Failure is not an option - it is mandatory. The option is whether or not to let failure be the last thing you do._ Also whether or not you admit that you can learn from it. By way of comparison, SpaceX have many 'failures', but treated them all as learning experiences & a source of useful data on what doesn't work, rather than, "Oh no! It didn't work! Don't let anyone know how we messed up, pretend it was something else.", the way those embarrassed by their failures do.
It was quite open from the ISRO side, just not public. They shared data outside isro including academia for inputs and constituted a wide failure analysis board and came up with solutions. ISRO normally releases a brief of failure analysis on its website. However even before that, some left wing ppl in the garb of journalism approached courts, for them everything is politics. Some of these media are now revealed to be funded by chinese; there is a big issue going on now abt these people. ISRO's argument is that, what the general public should know is already released - that there was accumulation of errors and the software could not handle it. Why should a detailed technical failure analysis document be put out in public? I guess in an interview with a youtuber, ISRO chairman said that there are some specifics which are strategic, so they do not want report in public.
Technically? Well, the flight path intersected with the moon and the lander had too much speed at this point. Alternatively: They didn't build it sturdy enough for lithobreaking.
in other words, instead of deciding to get the next best situation and land just somewhere, it really wanted to go back onto the original trajectory. as a kerbal space player, I know that this is delta-v wise a very bad decision and waiting makes the situation worse. well, I hope they learned.
While still a wee nerd an elderly and quite brilliant gent told me to "never test for something you don't know how to handle, never fail to test for something you have to handle." Once you get past the Alice in Wonderland feel of that statement and let it sink in it's really one of the most useful bits of wisdom I ever received. Blows holes in shaky designs very quickly. Saved me from some embarrassing and or expensive failures over the years, let me help sort out a few projects in trouble as well. Right up there with never trusting a chart without hatch marks and perhaps error bands :-)
It is difficult to drive a CAR in a high traffic road even the driver is sitting on the seat, but accident happening. Think a vehicle is escaping from the gravitational boundary of EARTH and travel a lot of distance and enter in to another planet gravitational boundary and manage to land precisely on the pre-defined target without a driver sitting in it. You must appreciate the ISRO scientists who are doing the extra ordinary works sitting in a developing country with available resources.. A big appreciation to all our ISRO scientists who make impossible to possible and make India PROUD. 👏👏👏
So technical yet so lucid. Would love to see a detailed report on the Chandrayaan 3 journey and landing. Plus a separate piece on the Rover and its purpose.
This discussion brought back a memory from the early windows days. There was a moon lander game and if you crashed due to bad energy management, you'd get the message "Nice crater. All that training really paid off" 😂
thanks this is a great review/postmortem! I'm going to school for mechatronics/robotics and this is a great intro to how programming needs to take into account different situations!
I thank you as an Indian to properly get me to properly understand what really happened while nobody else even tried talking abt it. I even couldn't see the NEWS18 Kannada coverage with that quality of streaming. Hats off for literally seeing it and telling us
I think this is the corollary to "If this bit isn't pointing up, you're not going to space today" with "If this bit is pointing down, you're not going to land today."
Which country has revealed their failure details to public, especially when they are working on a newer version of it?? India has been fair and transparent on its global contributions.. whether it is in the field of spacial science or medical science..
Yep. During the live broadcast, I remember catching it, with an involuntary loud laugh, that they said they were landing happily, but the speed was some crazy high value even at 300 meters. So the probe didn't land, it shot itself into the moon. You could see the telemetry on the display for a moment, even if the image was changed. It is likely that one of the root cause is the saturation at the end, and an earlier one is a higher throust, after which it was already known in principle that the probe would not be able to correct...
Thanks for bringing in the information of why Chandrayaan2 failed. Lessons learnt. Chandrayaan 3 will succeed in making a soft landing on the moon 🌙 all eyes up on Aug 23 for the moon shot.
I love the way people in India and other regions, still the old way with whiteboard like a university professor. Often this is better in explaining than too many computer animations.
cause many people dont know how to use a digital screen. In my school , while describing ISRO, I saw only one type of rocket for 30 mins and it was a Crewdragon ver. of falcon 9 with Indian flag strapped on the fulsage
@@thelovertunisia That graph is designed digitally not white board stuff and animation part is not required here , Its meant for scientist and engineers i not for general public, scientist and engineers need calculations not animations
In the Camera coast phase the craft cannot control its thrust or direction and its locked. This was supposed to happen but it got locked at a higher thrust. It was locked because the craft was supposed to calibrate its final landing instruments. They planned it in such a way that it will accumulate some slight errors in the trajectory but in the fine breaking phase after the cam coast phase the accumulated errors will be corrected but the errors were very large in number. Earlier the landing zone was 500m by 500m not they have increased it. And the craft have the controls in the full descend. What in can understand from the lecture.
If something can go wrong it will. In this case the thinking that nothing will go wrong. It is slightly surprising that they didn't run more testing and simulations that might have caught the problem before launch so it could be corrected.
I dont believe they went with only success led testing path... rather they didn't "see" all the possibilities and programmed for those "not seen" scenarios,.. very common occurrence in any first attempt at something brand new... hope they hardened the sw and added more redundancies/alternatives
I find it a bit strange that they have a limit on the rate of rotation but not the attitude. Why would they allow the lander to ever pitch more than +/-90 degrees from pointing upwards?
I note one of the slides says they're adding anti slosh baffles to the fuel tanks as one of the fixes for Chandrayan 3. Not having them in the first place is a failure to learn space history. Apollo 11 thought it was almost out of fuel to land on the moon but actually had more, the issue was the fuel sloshing around and anti slosh baffles were added for later Apollo lunar modules.
The worst part is that they went for a very small landing zone. If CH2 had the same landing zone as CH3, the mission would have probably been a success
@@olasek7972they always take the hard step as budget is limited and getting most out of your missions is priority. As in this case landing at that specific location was important to get necessary scientific data.
Testing and advancement like this need to be open and honest as much as possible to help in making improvements and even better advancements in the future. Thanks, Scott, for doing what you do. 😊 On a side (but very important) note, please, please take time to tell your loved ones you love them EVERY chance you get. Tomorrow is not a given; you're never promised the next sunrise. ~ ~ ~ ~ "And don't let it break your heart. I know it feels hopeless sometimes. But they're never really gone as long as there's a memory in your mind." _Hold On To Memories_ Dave Draiman, Disturbed 💔💔
Chandrayan-2 needed 2 more sec to rotate to desired angle but the rotation rate was so slow compare to the time he had to touched down 😅 otherwise it would have been a success story more like Mangalyan🇮🇳🫡.... Hope we break the jinx 🤞😇🤞
The building of failure oriented backup system comes with cost, the assumption was we dont need to build a backup system if we do things right in the primary system by doing a lot of simulations and forseeing any problems, thats just how ISRO works, and that is one of the reason the cost is low.
Assuming that dark matter is a particle, I have some questions: 1. Do dark matter particles (DMPs) have momentum? 2. Do DMPs have temperature? 3. Do DMPs orbit each other and regular matter? 4. Do DMP clouds have angular momemtum? 5. Does the angular momentum of DMP clouds act as a stabilizing influence on the direction of the net angular momentum of galaxies? 6. At the beginning of the universe (or shortly thereafter) did the universe as a whole (DMPs and normal matter) have a net angular momentum with a net preferred direction? 7. If the universe as a whole had a net momentum at it's beginning, is there any way that the net momentum of the universe could change in magnitude or direction? Since to change the angular momentum of an object requires the application of an EXTERNAL force and the universe is everything, where would such an EXTERNAL force come from? 8. If we look at a number of small patches of sky similar to the Hubble deep field and calculate the net angular momentum in each patch, would we expect the preferred direction of all of these angular momentum vectors to be the same? Or not necessarily? 9. If we consider the universe around Earth in terms of concentric shells, the first being from 0 to 1 billion light-years away, the second from 1 billion to 2 billion and so on, would we expect the preferred direction of the net angular momentum of each shell to be the same or could it vary over the shells?
Scott, Thanks for the intelligent content. It’s refreshing after listening to the other under-informed “space” channels to hear from someone fluent in physics and engineering.
13:17 India has something called "Right To Information (RTI)" through which citizens can file a request to get some information from any branch of the government. However, like the Defence sector, the Space sector is deemed as "Strategic Sector" for the government and has legal immunity to not reveal anything to the general public. Not even the courts can force ISRO to release the documents.
Makes me wonder if the landing targeting software was a variant of an icbm guidance system, hence the secrecy.
It's 'Right to information'
@@meetoo594Bro both of them completely different things, Lander needs to soft land , use engines , identify the spot and lot of other things and that too in vaccum .
@@kunjukunjunil1481 yeahh.. lemme edit it. I got confused with Indian Militarys' RFI process 😅
@@meetoo594 both are incomparable. Although pin point accuracy is desirable, ICBMs don't need the same accuracy as space missions do simply because the former destroys everything in a given radius, even if the missile misses by a few meters. Besides, ICBMs don't have to worry about lunar gravity, lunar atmosphere vs earth gravity, earth atmosphere.
I can understand why some people would worry about embarrassment, but ambitious projects like this don’t succeed without a lot of transparency and willingness to set egos aside. This stuff is HARD and COMPLICATED. No one should have to do it alone.
+
people laugh at failures even in my own country some people are making fun that America had landed humans on moon decades ago and we are not even able to land a fu*cking rover
Lol I'm from the UK, we have NO rocket programme, I'd kill to have the opportunity India does now.
People who don't realise how hard this suff is are always going to laugh sadly.
Good luck for a soft landing this month !
@@johnysins69696 what I find funny with that is that having people in the lander did make the landing easier in a sense, as a there was someone who could take over the auto pilot
@@paullambert9720you HAD a rocket program. I don't remember why your govt decided to close it though
There's no embarrassment, it happens and can happen. People who think that a missed step is a failure shouldn't be here. Great respect to our scientists. God bless you
Modi was embarrassed, another failure under his leadership 😂
@@toolzshedCope harder 😭😭😭 He's coming again next year :)
Accha😂?
You giving god blessing to scientists as if they need God more then trusting there knowledge.😅
@@SarovKun No harm trusting in both GOD and knowledge..any problem with that?
That’s great to see India doing this. Good luck India! I work with a lot of Indian engineers in the US aerospace industry. That country is pumping out engineers.
Indian engineers work for white people, not for themselves 😂😂
🇮🇳🇮🇳🇮🇳
Only if there was no brain drain...
My condolences that you have to work with them 😢
@@Grandremone They are the highest earning group in the US. They come with their college degrees and skills. It must be delaying India’s progress.
It's interesting seeing all the learnings from Chandrayaan 2 going into Chandrayaan 3. To this extent you could say that mission wasn't a failure because it provided the ISRO lots of learnings they didn't have before. Afterall, what is the purpose of space missions if not to learn new things?
expensive lesson
@@expectationlost but a lesson none the less
To boldly blow stuff up and learn new things…
Space flight is hard
@@expectationlostThe history of spaceflight is mostly made of expensive lessons
This reminds me of the Falcon 9 CRS-16 water landing a couple years back where the hydraulics on one of the grid fins failed, causing the F9 to oscillate wildly on decent. The engines tried to gimbal, but the flight computer judged that it was a loss, and decided to save the drone ship instead, forcing a water landing. As the Falcon 9 headed to a rough water landing, the speed slowed, and the grid fins didn't affect the spin so much anymore, so the spin slowed as well. Just as the Falcon 9 dropped the last meters into the Atlantic ocean, the engines kept gimbaling and kept fighting, and at the end they actually caused the F9 to make a perfectly straight plopdown into the water.
The flight computer had judged the landing was too far out of envelope, but the engines were allowed to keep gimbaling and would have likely been able to cause a softish landing at the end.
I remember that! Small correction though, It was a launch site return rather than the drone ship.
That was B1050, an RTLS landing, so it was avoiding RUD on the pad, not on a drone ship. And yes, by the time it hit the water, it had almost corrected its spin by vectored thrust alone. It probably would have been a bad landing anyhow, so the automated abort was the right decision. They later corrected for this by adding redundancy to the grid fins hydraulic system.
Trajectory terminal point isn't nothing to angle, ipso thrusters, if you were able to change where it landed, you had energy expended. Maybe it could vertical on that trajectory, but not on another one.
I watched it live and it was so epic how the computer aborted to water but at the same time kept fighting to land the rocket safely I couldn't resist and turned it into an Interstellar parody, haha. Despite the landing being technically a failure it is one of my favorite moments in modern space flight.
I remember that one well. :)
Not to make light of the situation, but 8:00 describes almost every early landing attempt of mine in KSP. I wish Chandrayaan 3 all the best- eagerly awaiting the successful landing 23/8.
KSP?
Kerbal Space Program friend! It is a Rocket science, space game. If you are here in the comment section of this channel and like this guy, you better have some knowledge of it.🙂🙂 @@WFHermans
@@WFHermans kerbal space program
ffs felt that
That was my first thought!
Great discussion. I can just see it where the 'nav' system wanted to tilt but the 'camera angle' command overrode that. Then at the end of 'camera coast' phase and that 'clamp' that prevented changing attitude was lifted, and the 'nav' software was like, "Oh crap, too high... too fast... well we can just turn upside down and fire to get our altitude down...." Then was like... "oh wait... now we're descending too fast.....Oh wait.... just a sec... CRASH!!!"
Lol correct.
I'm wondering if these engineers are testing their navigation software in some kind of simulator to detect bugs and to see how it react in different situations, or if they just analyse the code and think "Yeah everything looks fine, it should be good enough.".
Edit: Nevermind, the screen at 10:10 pretty much answer my question, which was pretty obvious... But I'm still curious to know how good is that simulator, is it just like a spreadsheet of numbers or more like a real flight sim?
lol this made me chuckle
@@Alfred-Neuman I think a lot of it boils down to just how 'imaginative' the engineers can get while testing. Coming up with all the possible 'what if?' scenarios. Might have thought, "well it could never get THAT far off course...". But 'what if the engine thrust doesn't modulate correctly"? Or "What if the attitude for navigation conflicts with the 'camera coast' attitude, who should take precendence?" Like with a lot of complex systems, coming up with all the possible scenarios is still "more art than science." IMHO
@@Alfred-Neumanas far as the type of simulator, it's both. Besides software and numerical simulations, there's also HITL (Hardware in the loop) simulations which basically use the real guidance computers but feed it simulated data to see how it reacts.
Now Chandrayaan 3 safely landed on the Moon. Proud to be an Indian. 🇮🇳
ISRO works very close to DRDO and actively helps in development of ICBMs, so I don't think ISRO will ever publicly post a detailed explanation of what went wrong in a potential targeting system.
Yes, this is the more likely scenario.
As if this system is a good example
mirv bus could use this control regime
@@evanfinch4987 yeah but you'd go with best practice examples not a poorly designed failure
@@MiG82auBut the lessons from this mistake and the ways the design team were thinking are both valuable to enemies . The lessons are useful for avoiding similar mistakes in ICBMs pointed at india by enemies with smaller test budgets . The pattern of thinking mistakes are useful to enemies planning attacks against army units with the same training and to enemy defense systems trying to exploit similar mistakes in guidance systems made by the exact same people before that crash . If they know that incoming indian ICBMs will have a low maximum turning speed in degrees per second, forcing incoming missiles to be massively off course could help force a miss, and so could the tendency to not correct significant errors that happen shortly before a switch to a different attack phase .
A case where a perfect landing was the enemy of a good enough landing.
The software changes from 2 to 3 sound eerily like several other software control projects I've worked on. The team works hard to get "the happy path" working - then learns the hard way that the real world isn't very happy so has to add error detection and recovery. For the UAV software I've worked on, generic flight control (flying the plane to waypoints) is maybe 30% of the total SLOC and handling various error conditions (lost communications, landing/recovery in bad weather, power management/housekeeping) is the bulk of the software, requiring assloads of multi-team meetings and design documentation and time consuming testing.
Agreed, it's only when you try and fail and assess why, that you learn how complicated the problem is, and how naive your initial design was.
How to become like you?
And then the code to fix the problems that only rarely happen causes a while slew of it's own bugs that upset normal operations😂
That's exactly why you never ever have data scientists, computer scientists or programmers involved in the initial design phase involving control problems or any advanced software.
@@T_Mo271 That's why we always have our mechanical engineers make the initial design. When the specifications are handed to the computer scientists and programmers the first thing they do is to oversimplify the design. Therefore we need some mechanical engineers and control engineers to prevent this from happening.
i hardly see information when a mission fails. lot of space agencies just give small information regarding faulure which is pretty much useless. Kudos to ISRO for transparency
OMG! I woke this morning seeing your RUclips, "Why Chandrayaan 2 Crashed on the Moon" thinking OH NO 😯! But I got the numbers wrong. "3" is still going. Thank god. Such a good explanation, thank you.
CY2 was an optimistic design which depended on everything going as per plan. CY3 the design was converted to more pessimistic, which is the best type of "istic" when it comes to such ambitious technology demonstration projects. I think unless CY3 crashes into the Russian lander, things should be good this time around 🤞
One is occasionally reminded not to let perfect get in the way of good.
Lord save me from optimistic engineers assuming happy path. Just occasionally ask, "okay, but what about _when_ this doesn't work?" (Deer in headlights look) *sigh*.
@@thewiirocks A lot of modern software is written by assuming everything is working perfectly. No checks, no redundancy, no way to get out of unexpected state, just restart the whole thing and try again. Developers don't get enough time to bullet proof everything unless it's a serious, audited project and human lives depend on it.
In cy2, they designed everything on success based, in cy3 its all failure based
That sounds so exactly like India. All confidence all talk but not the skill to back it up.. then get humbled by reality and forced to be humble. Lol.
I love this guy! Always lays out the facts (or maybe a best guess if warranted) and stays on point with the story, without the BS.
Scott, I love your content! I tell many of your stories at our family dinner table - the missus and kids look at me like I’m a physics genius! 🤣😂
Pretty cool😂
Maybe you are a genius! Has that ever crossed your mind? Maybe the missus and kiddos see something you overlooked?? But, you are absolutely correct, I love this channel too! Give those loved ones some hugs, smile and y'all have a fabulous day! Take care @A1FAHx 🍻
Yeah but you kinda are pretty smart by default for learning and understanding these things, it's something that's easy to just pass off as "oh I just know a lot idk" which I used to do a lot, but let's give ourselves some credit yeah?
@@dancingwiththedogsdj Thank you so much for your comment! It is very refreshing to be on a channel with intelligent, kind folks like you!
@@A1FAHx I appreciate that! Just keep on enjoying stuff like this and ya never know.... Maybe you will make the next big discovery, even if by chance, or your kiddos end up being the ones who make a big discovery.... Worst case, y'all learn something and have something to talk about.. who knows! Either way, it's an interesting time, isn't it!? Buckle up y'all, things are only going to get more interesting as we go! Wheeeeeee!!!! ❤️😁🍻
Space is hard, and so is the Moon.
Good luck to Chandrayaan on the upcoming Moon landing!
I don’t like space. It’s coarse and rough and irritating… and it gets everywhere. Not like the moon. There everything is soft and smooth.
@@galfisk, Yeah, it's like a big fluffy marshmallow that's been lightly toasted over a campfire.
The moon is still in one piece 👍
So was our landing
yes, but the moon has moved on from this.@@ronald3836
Sounds like a common problem I've seem on software implementations - testing the system using complete, perfect datasets covering only minimal scenarios that bears no resemblance to actual real world data or how end users are likely to use the software in production. Hundreds of thousands of dollars of development work needing to be redone after having gone live.
Damn man you are so right lol
thanks for your effort finally RUclips is recommending me good things
I hope Chandra-3 makes a successful landing. I'm sure ISRO learned a lot from Chandra-2. Thing is, every space-fairing nation has failed missions, so India shouldn't be embarrassed. Not at all. Just getting to the last few meters above the Moon was a great accomplishment.
There will be another problem ----- crash again.
Gareeb Scientist also made a video about this topic. Its available with english subtitles. I feel Scott saw that and decided to reach a broader audience. Which is good.
@@hanfucolorful9656 nice one god bless you
@@hanfucolorful9656why 🤔
@@gamersupergirl1 Replacing one main thruster with 4 thrusters will make the control more complicated and prone to problems, which is not a good engineering solution.
It is NOT a shame that we have failed. But the more important thing is to learn from that failure and improve on that!
Thank you, Scott. The poor C2 lander just couldn't keep up with everything. Wishing India the best with C3.
Good engineers learn from their mistakes and sometimes they learn a lot.
There's nothing embarrassing.
People who Run, falls many times.
People who crawl, how can you expect them to fall.
Either you Succeed or You learn.
There's nothing called failure.
As Bharatiya 🇮🇳 we deeply believe in this.
Proud on our Scientists and ISRO.
Thanks Scott, for a professional and respectful analysis. This video reminds me why I really really don't want a car that 'drives' itself anytime soon. It's just carrying out pre-programmed responses to sensor inputs, and anything outside the box just isn't catered for. Also proves how technically difficult this kind of automation is, and props to all the teams that get it right. Let's hope for a successful Chandrayaan 3 landing.
You drive in self driving cars as well it just over rides your command in case of accidents
Altho I will never use it because I like manual
I agree, stuff that works on softwares that are preprogrammed get into trouble when they encounter unexpected and (like you said) out of box situations. However are you aware that the final FSD that Tesla is expected to release sometime this year is not preprogrammed but it actually has an artificial intelligence that looks at its surroundings and reacts according to its own understanding! And that is expected to be faster and smarter than any human!
@@balaji-kartha There are certain situations that can lead the AI to misinfer and carry out conflicting maneuvers. An AI is as good as the data it has been trained upon. Needless to say, the Tesla AI will be better than 99% of drivers out there with godly reaction times. But there would be times when you'd wish your pet goldfish was behind the wheel instead of the AI.
It's not pre-programmed response, it's event driven response (to act in real time) the parameters of which (the event) are pre-programmed, within the limits of which, it's being given autonomy to compute a decision. Yes, it can go wrong, if the parameters and/or the software to compute the decision is erroneous, but it is more reliable than a human driver, who has never even got a speeding ticket in his 10 years of driving experience.
BTW, Chandrayaan 3 just landed successfully.
Chandrayaan 3 has to land. Because the next Moon Mission of ISRO is with JAXA later this year which has another Lander plus rover. ISRO is in charge of the Lander for which CH3 success is really crucial
What's the status of new Japanese rocket?
@@QuantumNinja1.9last lauch was failed ig
Thank you Scott for making content about isro 🙌
I don't understand why some people post negative things about the ISRO. If they had more funding, they would have landed humans on the Sun already.
Sun ? @@laimejannister5627
@@laimejannister5627if ISRO had money they would have sent humans to heavens to be partying with god.
@@striker44😂😂
@@laimejannister5627 yes, and they would have most definitely died from the heat lol
Yeah, that's a big issue in software development. People forget to look for user errors and other issues really easily. That was something I always kept in mind when coding anything.
Thanks, Scott! 😊
Stay safe there with your family! 🖖😊
quite often we warn about it, and get completely ignored by managers who insist we build the simplest, most bare bones, version without any error checking because that's the way for them to get something out the door most quickly, which makes them look good.
Then, when the problems inevitably appear, we programmers get blamed for not putting in those same safeguards we were ordered to leave out in the first place.
@jwenting Well, I never worked for a big company with managers and so on, but I can imagine.
I always did freelance, sometimes making stuff for other developers. And some of them were... Well, I don't know how to describe. 🙄
But I had a short career in software development... Because I accepted a job where I was supposed to make a big site, but the contract never came, so they moved me to the sister company. A digital juridic investigation company... And, well, I learned fast, but the stress almost killed me.
That and my depression... And I never worked with it anymore. But, fortunately I made some money while working with it, did some smart investments... Now I live from renting houses. And I have cats, they help with the stress. 😬
t @jwenting ...and $5 says THAT is the root of the problem. Well said. I would not be at all surprised that the SW team pointed out the issues and was overridden by management, then they got blamed for it and cereers were ruined so that managers could save face.
@jwenting
That’s why you gotta use a control board for your project or some type of history.
They do that to me and I show the manager authorized the bypass.
Since then they listen to me a lot more, devs a much more stable position than manager, get me a new one I like thanks. One of us has a skill you desperately need.
@@guyincognito1406 oh, we do that. Everything in writing. Doesn't matter when push comes to shove though. All that matters is who has the bigger connections high up in the company.
Hey Scott!
Thanks for bringing this up!
Off-target soft landing definitely beats a well-placed pile of wreckage!
The landing zone has changed to 4.5×2.5 km this time. Should be easy to find alternative sites provided shit doesn't go bad really early on
@@Silent_Shishyait's 4.5*4.5 ? Right
@@omkaringalgiyes 4.5 x 4.5
Scott, thank you for this thoughtful and well-reasoned hypothesis of the previous Indian Moon Lander crashed. Great Job.
This is a bit of the problem with robots. Humans could have decided that pointing at the ground was bad and it was better to land elsewhere. For a probe to make this decision, it needs to be programmed in and may not be done
nah, the programming was not made w.r.t failure, other wise robots and A.I are way better at landing stuff
@@aadvaittureMost publicly deployed AI systems are actually Artificial Idiocy . It will blindly continue on false assumptions with no ability to stop, to the infinite frustration of affected humans . Most Google systems are like that .
Dang I was thinking of referring the presentation to you too and felt guilty because I was stuck with work the whole day. I must have known that others would have done it too :)
So Chandrayaan 2 had the same issue as HAL 9000
Conflicting mission priorities causing a breakdown in its normal behavior... :)
Also Dr. Chandra was involved.
So happy I have you to break this all down for me, Mr Manley. You’ll never know how how much you’re appreciated by this space enthusiast with no physics background.
I hope India are successful with this landing attempt. Others in the comments have pointed out they would have learned a lot from the first attempt which gives them a better chance now. Go India !
India did it. sucessfully landed
@@friendlyatheist9589 👍👍👍👍👍👍👍👍❤❤❤❤
Thanks for passing on a smile Scott (well in addition to great content)! Every video I open with “Hello, it’s Scott Manley here…” and you’re smile with enthusiasm… Just wanted to say def appreciate you my man!
I was watching a ksp RSS/RO playthrough recently, and the guy had the same issue with mechjeb, when the lander overshot it's landing target and tried to correct itself. I found that quite funny to think about
i had watched another video regarding this, so i knew the basics of why it crashed. thanks for putting more info into my knowledge base.
I’m surprised that the engineers went with such an optimistic approach, but maybe they were compelled to do so by an ambitious management team that didn’t like what they were being told by the engineers. This would not surprise me. Indian engineers are super clever. But culturally within an Indian hierarchy they probably don’t have the last word. I’m sure Scott has worked with Indian engineers and management, so he'll know.
Space exploration is fraught with risks. Even James Webb project had around 344 single point failure risks. The only way forward is Cooperation regardless of differences
Tbh as an engineer who works with process control and automation systems every day, the "optimistic approach" sounds absolutely amateurish. I can't believe they (engineering management and project management) actually signed off on a control system concept like that? In a billion dollar prestige project supposed to demonstrate peak technical ability of your nation?? If true, that reflects not just on total lack of experience from teams and managers who should be top of their class people, but also on them not using know how that is used everyday in totally mundane, not-rocket-science control engineering fields. Organizational failure, not just technical failure. Honestly if that really is true then they are still years away from actually getting a space craft to work. You don't climb such a steep learning curve as control software engineering in one iteration step, you need multiple iteration steps and they need to go in sync with the iterations that the hardware guys do. Best of luck but don't get your hopes up for insta fixes.
You are right sir, space is a toomuch unknown environment to work for even sophisticated machines. So one should ( in this case ISRO) be more cautious than optimistic. Love and respect from India.
@@MrDael01SIR SIR INDIA IS BEST OK SIR YOU DON'T KNOW PERFECTION KIND REGARDS FROM INDIA SIR 🇮🇳🇮🇳🇮🇳
You brought out the problem with engineers working in India - hierarchy....
Contingency planning, particularly in software algorithms is so important to ensuring the result is a robust system. Testing for such unexpected contingencies is even more critical. Great lesson's to be had in sharing these insight. Not sharing likely means future designs could fall victim to lack of contingency in the design.
Brilliant review, well wishes for ISRO and Chandrayaan 3.
All the best to my ISRO colleagues working on CH3! Here's looking forward to a happy Landing Day.
There can be grace in failure, but only if you deal with it openly.
Some Indians said it's China sabotage......ha....ha..... Xi Jin Ping use black magic to control C 2 from his house....
Embarrassment is something that gets in the way of openness; the more a place is dictatorial and absolutist, the more it fears embarrassment. Look at the USSR during the race to the moon, look at North Korea… more examples of countries, ideologies and companies will come to your mind.
It looks bad when they did not have ways to correct the thrust (turn down the duty percentage of their PWM? Cut thrust after reaching the ΔV required?) and there is, I believe, no good reason a lander should ever point the engine(s) away from the moon - that’s what gravity is doing already!
But at least they seem to understand and fix (most? of) the problems found.
@@advorak8529 Failure only becomes embarrassing when you are pretending to be perfect and are more concerned about how your 'perfect public image' is affected by it. Embarrassment is entirely in your own self perception.
*Maxim 70:* _Failure is not an option - it is mandatory. The option is whether or not to let failure be the last thing you do._
Also whether or not you admit that you can learn from it. By way of comparison, SpaceX have many 'failures', but treated them all as learning experiences & a source of useful data on what doesn't work, rather than, "Oh no! It didn't work! Don't let anyone know how we messed up, pretend it was something else.", the way those embarrassed by their failures do.
Mercury 7 fire deaths, Apollo 1 tragedy - pls check how long it took for NASA to disclose the details to the public.
It was quite open from the ISRO side, just not public. They shared data outside isro including academia for inputs and constituted a wide failure analysis board and came up with solutions. ISRO normally releases a brief of failure analysis on its website. However even before that, some left wing ppl in the garb of journalism approached courts, for them everything is politics. Some of these media are now revealed to be funded by chinese; there is a big issue going on now abt these people.
ISRO's argument is that, what the general public should know is already released - that there was accumulation of errors and the software could not handle it. Why should a detailed technical failure analysis document be put out in public? I guess in an interview with a youtuber, ISRO chairman said that there are some specifics which are strategic, so they do not want report in public.
I don't often 'like' youtube videos, but i can't help but thumbs up every Scott Manley video.
Chandrayan 2 wasmaprtial success and India learned a lot from that failure.
Chandrayan 3 is improved now. Hopefully they will make it now.
Here after watching India become the first nation to successfully land on the moon's south pole.
Here before the haters delete their comments.
Technically? Well, the flight path intersected with the moon and the lander had too much speed at this point. Alternatively: They didn't build it sturdy enough for lithobreaking.
Technically, the moon is like a truck.
Technically, the moon moved faster towards the craft than anticipated.
So imagine the moon is a spherical cow...
Moon is a deer
Failure & success r both sides of a coin, letting ego gets in the way will only impede future success on space ventures.!
Mechjeb used to do this kind of maneuver in earlier iterations in KSP especially if you time warped
in other words, instead of deciding to get the next best situation and land just somewhere, it really wanted to go back onto the original trajectory. as a kerbal space player, I know that this is delta-v wise a very bad decision and waiting makes the situation worse.
well, I hope they learned.
They should have played a few games tbh
While still a wee nerd an elderly and quite brilliant gent told me to "never test for something you don't know how to handle, never fail to test for something you have to handle." Once you get past the Alice in Wonderland feel of that statement and let it sink in it's really one of the most useful bits of wisdom I ever received. Blows holes in shaky designs very quickly. Saved me from some embarrassing and or expensive failures over the years, let me help sort out a few projects in trouble as well. Right up there with never trusting a chart without hatch marks and perhaps error bands :-)
landing on another celestial body is STILL DIFFICULT, even with all the advancements in technology and software.
So true and so many people think it should be easy.
They just should've used ArduPilot :p
@@iamjadedhobo lol
Or because of them. Luna and Surveyor landed ok in the 60s with no computer
@@JohnBlackburn1975 how many times did it take
It is difficult to drive a CAR in a high traffic road even the driver is sitting on the seat, but accident happening. Think a vehicle is escaping from the gravitational boundary of EARTH and travel a lot of distance and enter in to another planet gravitational boundary and manage to land precisely on the pre-defined target without a driver sitting in it. You must appreciate the ISRO scientists who are doing the extra ordinary works sitting in a developing country with available resources.. A big appreciation to all our ISRO scientists who make impossible to possible and make India PROUD. 👏👏👏
This is some high level rocket forensics. I tip my hat to you Sir.
So technical yet so lucid. Would love to see a detailed report on the Chandrayaan 3 journey and landing. Plus a separate piece on the Rover and its purpose.
This discussion brought back a memory from the early windows days. There was a moon lander game and if you crashed due to bad energy management, you'd get the message "Nice crater. All that training really paid off" 😂
If I had a dollar for every time I got that message, I'd be a space tourist on the ISS right now.
Which game?
Great content as always Scott-thank you!
Thing about space is, you would rather ride a rocket model that's crashed a thousand times in the past than one that's never crashed yet.
thanks this is a great review/postmortem! I'm going to school for mechatronics/robotics and this is a great intro to how programming needs to take into account different situations!
Hopefully Chandrayaan 3 will fly safe 😉
"Land safe" would be better :P
I thank you as an Indian to properly get me to properly understand what really happened while nobody else even tried talking abt it.
I even couldn't see the NEWS18 Kannada coverage with that quality of streaming. Hats off for literally seeing it and telling us
An Indian RUclipsr "Gareeb Scientist" already made a detailed video on this.
@@abhi_shek_saini I don't get that HINDI and his way of addressing the topic
@@JaiMahismatiTrue but I think he includes subtitles right?
He has english captions ....
@@afkass4965 Bro he's clearly not the best creator compared to Scott
I think this is the corollary to "If this bit isn't pointing up, you're not going to space today" with "If this bit is pointing down, you're not going to land today."
Thanks Scott! Very interesting deep dive into the Indian Space Agency lunar lander! Thanks!
Which country has revealed their failure details to public, especially when they are working on a newer version of it?? India has been fair and transparent on its global contributions.. whether it is in the field of spacial science or medical science..
USA, Europe, Japan, even the Soviet Union have all published detailed reports on spacecraft failures.
Yep. During the live broadcast, I remember catching it, with an involuntary loud laugh, that they said they were landing happily, but the speed was some crazy high value even at 300 meters. So the probe didn't land, it shot itself into the moon. You could see the telemetry on the display for a moment, even if the image was changed. It is likely that one of the root cause is the saturation at the end, and an earlier one is a higher throust, after which it was already known in principle that the probe would not be able to correct...
Well done! As always 😄
Scott, whats also interesting, is lazarus hacking KNPP and ISRO, days before the event! Love your content!
We did it😭
India did it🇮🇳
ISRO did it🎉
Waiting for your video 🙏🇮🇳
I'm glad to see that a rocket scientist is no better at drawing arrows on a computer screen than I am.
Hi Scott!
Fly safe!
Thanks for bringing in the information of why Chandrayaan2 failed. Lessons learnt. Chandrayaan 3 will succeed in making a soft landing on the moon 🌙 all eyes up on Aug 23 for the moon shot.
Brilliant effort to put together the details of the crash. Great job indeed.
I love the way people in India and other regions, still the old way with whiteboard like a university professor. Often this is better in explaining than too many computer animations.
cause many people dont know how to use a digital screen. In my school , while describing ISRO, I saw only one type of rocket for 30 mins and it was a Crewdragon ver. of falcon 9 with Indian flag strapped on the fulsage
@@aadvaitture no not really. Old school is often better didactically.
@@thelovertunisia That graph is designed digitally not white board stuff and animation part is not required here , Its meant for scientist and engineers i not for general public, scientist and engineers need calculations not animations
damn i as an indian cannot relate to it, i studied in a private school, digital screens were very common and everybody knew how to use it@@aadvaitture
Great video. I saw the presentation but this was more comprehensible for me. Thank you.
In the Camera coast phase the craft cannot control its thrust or direction and its locked. This was supposed to happen but it got locked at a higher thrust. It was locked because the craft was supposed to calibrate its final landing instruments. They planned it in such a way that it will accumulate some slight errors in the trajectory but in the fine breaking phase after the cam coast phase the accumulated errors will be corrected but the errors were very large in number. Earlier the landing zone was 500m by 500m not they have increased it. And the craft have the controls in the full descend. What in can understand from the lecture.
In the world of science while doing experiments we should never use the term ' failure'...every time we do something new we lewrn from them
Thanks for video Scott. It was very informative. I am thinking that It would be more illustrative if you animate with KSP. 😊
I love the outro music. Almost as good as the original and a big step back in the right direction!
If something can go wrong it will. In this case the thinking that nothing will go wrong. It is slightly surprising that they didn't run more testing and simulations that might have caught the problem before launch so it could be corrected.
Yea they went with success based approach now they have learnt the lesson and are going for failure based approach
It was a hurried job and less budget.
I dont believe they went with only success led testing path... rather they didn't "see" all the possibilities and programmed for those "not seen" scenarios,.. very common occurrence in any first attempt at something brand new... hope they hardened the sw and added more redundancies/alternatives
Great content scott ! My school classmates always talk about you ....
I find it a bit strange that they have a limit on the rate of rotation but not the attitude. Why would they allow the lander to ever pitch more than +/-90 degrees from pointing upwards?
Because India.
I note one of the slides says they're adding anti slosh baffles to the fuel tanks as one of the fixes for Chandrayan 3. Not having them in the first place is a failure to learn space history. Apollo 11 thought it was almost out of fuel to land on the moon but actually had more, the issue was the fuel sloshing around and anti slosh baffles were added for later Apollo lunar modules.
So they failed because they didn't anticipate the possibility that they could fail.
That sounds like a classical error.
Some Indians said it's China sabotage......ha....ha..... Xi Jin Ping use black magic to control C 2 from his house....
The worst part is that they went for a very small landing zone. If CH2 had the same landing zone as CH3, the mission would have probably been a success
I think it's more like they didn't anticipate some possibilities of which one possibility led them to fail.
@@Silent_Shishya. It is absolutely mind boggling that for them highest priority is to hit specific landing zone rather than land at all
@@olasek7972they always take the hard step as budget is limited and getting most out of your missions is priority.
As in this case landing at that specific location was important to get necessary scientific data.
Can you have a isro spacecraft model at your background please 😊
Thanks for the video Scott, very well explained! Im hoping as everyone else for a successful CH-3 landing. 2 more weeks to go
Never give up India.trials and errors are fact of science. No singular nation on earth has the monopoly of space exploration. For India' efforts,❤
Another excellent video sir. 👍🏻
Testing and advancement like this need to be open and honest as much as possible to help in making improvements and even better advancements in the future. Thanks, Scott, for doing what you do. 😊
On a side (but very important) note, please, please take time to tell your loved ones you love them EVERY chance you get. Tomorrow is not a given; you're never promised the next sunrise.
~ ~ ~ ~
"And don't let it break your heart. I know it feels hopeless sometimes. But they're never really gone as long as there's a memory in your mind." _Hold On To Memories_ Dave Draiman, Disturbed
💔💔
Chandrayan-2 needed 2 more sec to rotate to desired angle but the rotation rate was so slow compare to the time he had to touched down 😅 otherwise it would have been a success story more like Mangalyan🇮🇳🫡....
Hope we break the jinx 🤞😇🤞
Brag. Indian Mangalyan never landed on Mars.
Mangalyaan was not a lander
@@AwardQueue who said it was???🫤 Bro i was just comparing the success rate with Mangalyan's 🥲IF
@@shahanshahpolonium ai nooo😗
Telemetry: too high, descending too slowly
Software: I can fix this (turns upside down)
The building of failure oriented backup system comes with cost, the assumption was we dont need to build a backup system if we do things right in the primary system by doing a lot of simulations and forseeing any problems, thats just how ISRO works, and that is one of the reason the cost is low.
Assuming that dark matter is a particle, I have some questions:
1. Do dark matter particles (DMPs) have momentum?
2. Do DMPs have temperature?
3. Do DMPs orbit each other and regular matter?
4. Do DMP clouds have angular momemtum?
5. Does the angular momentum of DMP clouds act as a stabilizing influence on the direction of the net angular momentum of galaxies?
6. At the beginning of the universe (or shortly thereafter) did the universe as a whole (DMPs and normal matter) have a net angular momentum with a net preferred direction?
7. If the universe as a whole had a net momentum at it's beginning, is there any way that the net momentum of the universe could change in magnitude or direction? Since to change the angular momentum of an object requires the application of an EXTERNAL force and the universe is everything, where would such an EXTERNAL force come from?
8. If we look at a number of small patches of sky similar to the Hubble deep field and calculate the net angular momentum in each patch, would we expect the preferred direction of all of these angular momentum vectors to be the same? Or not necessarily?
9. If we consider the universe around Earth in terms of concentric shells, the first being from 0 to 1 billion light-years away, the second from 1 billion to 2 billion and so on, would we expect the preferred direction of the net angular momentum of each shell to be the same or could it vary over the shells?
My first thought was that they didn't test enough "what if" situations in their testing program. I'm sure they'll figure it out.
It was a typo in the software.
They wanted braking thrust and got breaking thrust.
Great & Nicely Explained. Best of Luck ISRO for Chandrayaan-3.
Let us wait and see how will the the Chandrayaan 3 will do in one week and good luck to it and Indian people! Thanks for the program.
Scott, Thanks for the intelligent content. It’s refreshing after listening to the other under-informed “space” channels to hear from someone fluent in physics and engineering.
@12:38 what is news 18 Kannada doing there 🤔