Japan: Moon lander Slim comes back to life and resumes mission | Hacker News Reader

Japan: Moon lander Slim comes back to life and resumes mission

bbc.co.uk

296 pointsneversaydie140 comments

Scott Manly did a great explanation. The lander lost a rocket nozzle when it was in the final part of its descent - hovering and taking pictures of the landing site. Nozzles make the rocket's thrust much more effective so basically it lost thrust on one side.

It had very good software which adjusted to this and brought it down softly enough to land but it couldn't stop the pitch over.

The spacecraft landed within 50m of it's target which is exceptionally good accuracy and that part of it's mission was a complete success.

The rocket nozzle problem may have been due to a stuck valve or some other problem and obviously they have work to do on that but apparently something similar has happened on a similar design before.

Thanks for that. I hadn't heard this detail in the mass media sites I read about it. HackerNews as usual has a succinct summary, why can't normal media be this clear? I think it's because most journalists are missing an engineering background. Just adding those few sentences tells us so much more.

When I was interviewed on a technical subject by a local affiliate, I was told they are under specific directive to be as non-technical as possible, even if the result becomes technically incorrect. As a result, my answers were trimmed down to be essentially "be scared of scary things". The news is a product being sold to a demographic and the messaging must appease the demographic or they are out of their jobs.

It's not surprising that they don't want to make it confusing and useless for their viewers as anyone sees all the time, but it's possible to describe it in a way that most people can understand, like the person I replied to.

>I was told they are under specific directive to be as non-technical as possible, even if the result becomes technically incorrect.

There could be a sinister undertone to this, but this is how communication works. Common context is a must for successful communication, and news is communication.

And, yeah, news needs to be sold in a hard competition, so they do whatever to grab the attention.

> why can't normal media be this clear

there is a strong incentive to keep users on a page as long as possible which means burying the information as deeply as possible. even mainstream-reputable sources like CNN have nothing but clickbait headlines on the front page every day, telling you something big has happened without saying exactly what it was. journalism has always been problematic throughout history but i feel it's at new lows today

Scott Manly did a great explanation.

Someone remarked below, "It is just like Kerbal."

In KSP, I've landed a nuclear rocket on the Mun, and had it tip over. Then I put 2 and 2 together, and put landing gear on that side of the craft! This allowed me to use the craft as a lunar rover. To get back, I'd pick a hill to use as a ramp, and do a "Dukes of Hazard" launch.

Once, I even demonstrated this in person to Scott Manley!

Get the mod that lets you carry fuel in your backpack.

Then forget about taking off from Mun. Simply climb out and return to orbit with your jetpack. (It's hard enough getting a good rover anywhere, let alone making one that can climb back to orbit. Stock jetpack is enough on Minmus, you need to refuel once on the way up on Mun.)

Lunar liftoff might be one of the places where SpinLaunch makes sense. Climb in wearing your clean and unused EVA, ride the merry go round until you get sent up to your CSM.

Climb in wearing your clean and unused EVA

And underwear.

Spinlaunch is completely unsuitable for manned craft due to the extreme acceleration. Rather, what you want is a variation on a maglev train. In the lunar vacuum there's not really any speed limit. You can make a very long track. Put another on top upside-down. Your train can ride on either track--once it reaches orbital velocity it will be riding on the top track instead. Human tolerable accelerations with an ejection velocity sufficient to take you anywhere in the solar system.

The video in question: https://www.youtube.com/watch?v=7bFiJvbKyPs

Apparently a similar problem plagued JAXA's mission to Venus, although they're less certain about that because there isn't a clear video of the nozzle departing, as there was in this case!

Should have collaborated with some of the BattleBots/Robot Wars teams to include one of those flippers that up turn an upside-down bot right-side-up again.

Payload...

Self righting combat bots are awesome!

They designed the LEVs like that[1][2] for to deploy them some meters before landing. My guess is they expected it may happen with the main probe and something made them not include it in the design (Perhaps to concentrate all on the testing and analysis of the navigation and therefore it would be extra payload as other user comment, or something else, I do not know).

[1] LEV-2, https://www.youtube.com/watch?v=S_8TwJgKfYQ

[2] LEV-1, https://www.youtube.com/watch?v=Ej4ZMp4a2xw&t=4782s

Pathfinder too - http://tes.asu.edu/PATHFINDER/what_is_p_f.html

> Pathfinder will land during the Martian night. Just before the spacecraft impacts the surface, giant airbags will inflate to cushion the landing. After the spacecraft comes to rest on the surface, the airbags will deflate and three solar panels will unfold. These panels are arranged in a way that will allow the spacecraft to be flipped over if it should land upsidedown. The solar panels will begin providing power to the spacecraft as soon as the sun comes up that first morning on Mars.

Though, that's a different configuration for a different planet with a different budget... and a "it can bounce for a while" rather than the pinpoint accuracy that Slim was demonstrating.

>airbags

I really have to wonder if these are really gasbags, containing something like pure nitrogen or whatever .. but did we introduce Earth gas to Mars' atmosphere in this process?

Digging... Development and evaluation of the mars pathfinder inflatable airbag landing system - https://www.sciencedirect.com/science/article/abs/pii/S00945...

> The Pathfinder gas generators are the product of a significant development effort performed by Thiokol Corp., and ILC Dover subcontractor. The assembly is housed in a double-cone shaped titanium shell. The unit burned its propellant in two stages: the main grain burned for at a high rate for airbag inflation, and the sustain grain burned for at a lower rate for gas make-up during the landing. The gas passed through a coolant chamber before discharge, where pellets of a ...

Which brings me to: https://en.wikipedia.org/wiki/Thiokol

> Thiokol pioneered the short-burn rocket motors used in aircraft ejection seats. The company also produced a number of the earliest practical airbag systems, building the high-speed sodium azide exothermic gas generators used to inflate the bags. Thiokol bags were first used in U.S. military aircraft, before being adapted to space exploration (Mars Pathfinder bounced down on Mars on Thiokol airbags) and automotive airbags. Thiokol's generators form the core of more than 60% of airbags sold worldwide.

And the assembly can be seen on Wikipedia - https://upload.wikimedia.org/wikipedia/commons/1/13/Jfader_p...

These are essentially air bags like the ones in a car... and scaled up. It is not Earth air, or even air but the exhaust of a particular high speed chemical reaction.

(can't edit the original anymore)

Sodium azide is crazy stuff. https://en.wikipedia.org/wiki/Sodium_azide

    N- = N+ = N-
         Na+

> This colorless salt is the gas-forming component in some car airbag systems. It is used for the preparation of other azide compounds. It is an ionic substance, is highly soluble in water, and is very acutely poisonous.

> Sodium azide can be fatally toxic, and even minute amounts can cause symptoms. The toxicity of this compound is comparable to that of soluble alkali cyanides, although no toxicity has been reported from spent airbags.

(and since people are going to wonder)

> While sodium azide is still used in evacuation slides on modern aircraft, newer-generation automotive air bags contain less sensitive explosives such as nitroguanidine or guanidine nitrate.

It's got a few big numbers on the fire diamond (3s and 4s are things I would rather not be in the same room with for any length of time).

And some related compounds:

https://www.science.org/content/blog-post/things-i-won-t-wor...

This must be a common problem in space travel. The tiny spaceship in Men in black 2 also landed upside-down, but it has movable legs to correct position.

"The spacecraft ran on battery power for several hours before authorities decided to turn it off to allow for a possible recovery of electricity when the angle of sunlight changed. (..)

The lander will analyse the composition of rocks in its search for clues about the origin of the moon, Jaxa said."

Not so quick.. does this involve correcting its orientation? Or should this be read as "remains toppled over, but some camera work possible" ?

Available solar power must be a big constraint in remainder of this mission, probably?

Not getting up but wait for the sun to get just above the horizon sometime and then turn on

The solar panels were pointing away from the sun at the time. But the moon is rotating, and the solar panels are now pointing the right way to get power.

The moon is rotating?

technically yes, 1 rotation takes the roughly the same time as 1 revolution around the earth which as you were probably hinting at is tidally locked

Related is the infamous 1982 SAT question:

The radius of circle B is three times the radius of circle A. Starting from the position shown in the figure, circle A rolls around circle B. When circle A returns to its starting point, how many rotations will it have completed?

https://www.scientificamerican.com/article/the-sat-problem-t...

It still has day/night cycles [0] so that any moon-based solar panels should ideally be on swivels so that you can point them at the "moving" sun. (Or in this case, wait until the sun in shining on the fixed panel.)

It just happens to turn at a rate that keeps one side always facing us on Earth [1]

[0] https://en.wikipedia.org/wiki/Lunar_day

[1] https://en.wikipedia.org/wiki/Tidal_locking

I'm just laughing at the Japanese scientist who downloads the image data, converts it to a regular file format and then goes into photo viewer and clicks the "Rotate" button twice to flip the image so that it's the right way up.

It would only be once - the spacecraft is 90 degrees off from the orientation it is supposed to be.

There's two smaller robots launched from SLIM (lev1 and soraq) continuing the mission on the surface, taking photos etc.

In particular at least one of them can directly talk to earth.

Available solar power must be a big constraint in remainder of this mission, probably?

I guess Slim isn't all in the shady!

The armchairism in this thread is something else. Happy the mission is not lost and kudos to JAXA.

To be honest I had read the entire article and did not get the very important fact that it landed upside down.

Perhaps people are reacting to the very bad reporting by the BBC, not at the slim mission team itself.

It didn't land upside down, it landed upside vertical - 90 degrees off, not 180.

It landed upside-down relative to how it descended. it was supposed to roll over 90 degrees, but turned 180 instead.

The armchairism in this thread is something else.

Right. Now we need more comments starting with, "What about...?"

Landing upside down is what they call "the glitch"? How could that be fixed, did it have some way to restore its position? Or only the solar cells were turned upside up? What happened there in the end?

Its the second sentence in the Article. It is still in the original position but the angle of sunlight has shifted so light is now hitting the solar panels of the lander.

I assume it has actuators to correct the upside down position issue as soon as it has access to solar power? Or it has to stay in this position?

No actuators. It’s basically a box

It has the exact same actuators to correct upside down position issues as does the Toyota Camry.

The probe is expected to operate during lunar daylight, i.e., until 2/1. (Note the main mission of SLIM is a "pinpoint landing" and the observation by the probe is just a bonus.)

During the remaining three days, JAXA has announced that they will focus on optical observations of the surrounding environment (specifically, some rocks in the surrounding area). So it is hard to imagine they will do this hard schedule of risky additional operations to restore the attitude.

> optical observations of the surrounding environment

turn cam on. take pictures of rocks.

I wish someday we could take our camera to the moon as easily as our replying ;)

Has attitude thrusters, but they might be worried about it ending up in a worse position.

So they fixed the sun position? Ok I'm joking, but they said "we fixed the glitch" which assumes some action on their part. Waiting for the sun to rotate doesn't count for me as a "fix", so was there anything else?

From the article:

> The Japan Aerospace Exploration Agency (Jaxa) said it re-established contact with the lander on Sunday, indicating that the glitch had been fixed.

Being pedantic, the passive voice there doesn't give credit to anyone; the sun moving into a valid position for the current configuration could indeed have caused the glitch to be fixed.

> The Japan Aerospace Exploration Agency (Jaxa) said it re-established contact with the lander on Sunday, indicating that the glitch had been fixed.

I think the question is what exactly was "fixed?" Waiting for the sun to change position isn't a fix. The situation is still the same.

They use "glitch" as a synonym for "non functional", and this was probably only about the solar panel not getting sunlight.

In that sense, it's fixed.

You just send the commands upside down and it works

Unicode already has a special case for this, right?

"Upside down hiragana right yourself". "Mirrored upside down hiragana right yourself".

And 31284 related emoji.

Basically the same as contacting Australia

Little known fact, but this is why binary was chosen to represent data in the digital age, 1-s and 0-s look more or less the same upside down.

The concept of endianness would like to have a word with you.

We need middle endian

You got it: https://en.wikipedia.org/wiki/Endianness#Middle-endian

Down under they call it numboriginality.

Although I know you're poking fun, I just want to note here that HN is not reddit :)

And humor is not forbidden here, only low effort comments/jokes. And I think this one passes the bar .. (close probably, but I thought it was funny)

They put all thrusters in now-spaceward direction, there is not a single RCS port not coupled less than 50% with that direction. With enough KSP flight hours you'll understand that that could do the job, except for this precise situation.

So maybe we could move the moon then?

But all the bits might spill out!

Send them from Australia.

The lander has no way to correct its orientation, and in any case was never designed to survive in the lunar night, which starts in a few days on February 1st.

> was never designed to survive in the lunar night

But does it mean it won't actually 'survive' ?

What's survival in this case, getting enough power from the solar panel to boot up and transmit again, when the next day comes?

Survival means not being destroyed by the coldness of the lunar night, something like -130 C to even -250 C, for two weeks.

Many spacecraft have a radioactive heat source to heat themselves through the cold stretches. It seems for this one, primarily aimed at developing landing methods, that wasn't thought to be worth it.

This may be a silly question, but shouldn't the attitude thrusters still be restartable?

Actually it has landed on one lateral side, not upside down.

The engine nozzles that are now directed upwards were intended to remain on one lateral side. The lander was supposed to rotate one quarter turn after landing, to bring the engine nozzles from downside to a lateral side. Instead of that, it has rotated a half of turn, bringing the nozzles upside, due to an excessive horizontal speed at contact.

The solar panels are now on one lateral side instead of on the upper side.

Initially that lateral side was opposite to the Sun. After the Moon has rotated, the Sun has begun to illuminate the panels, though it is likely that the generated power has remained much lower than intended.

If they can no longer move it, they will have to save power, because they will be able to recharge the battery only during a small part of the Lunar day.

Maybe, just maybe they can use the rovers to push it over.

The two rovers it launched are small, one is a rolling ball the size of a baseball, the other is a hopper a few times bigger. Not much pushing happening with them.

Ah, too bad.

> Actually it has landed on one lateral side, not upside down.

The description "lateral side" only makes sense if the engines are the "bottom" of the craft. Then it did in fact land upside down. Otherwise the engine side would count as a "lateral side".

During landing, before contact, the engines were the bottom of the craft.

However the side with engines was not intended to be the bottom of the craft after landing.

Another side has legs and it was intended to become the bottom side after landing, by a quarter turn rotation from the flight orientation.

That went wrong by making an extra quarter turn rotation.

I have used "lateral side" as corresponding to the intended orientation after landing, not corresponding to the orientation during flight.

The engine side was intended to be a lateral side after landing, but instead of that it has become the upper side.

What counts is that the lander has made only a quarter turn of additional rotation compared to the original plan, not an additional half turn, as implied by "landing upside down".

The scientists and engineers at JAXA ISAS branch came up with a novel landing scheme that uses cylindrical body as part of the landing leg structure, by strategically tripping over and settle sideways. This method saves significant amount of weight according to them.

In that sense, the probe on its head up in the sand is only sideways, not upside down. In the sense that the probe is oriented the way it supposed to while on the rocket(it's sitting on the edge of PAF attachment plane and two forward legs), it's right side up.

Nevertheless, IMO, "upside down" is a close-enough description of the situation.

Schematic

                      |
                     -*-
                      |
       _X_X_X_  K
      |       |=K
      |_______| K  
    ---------------

    where: X is throttle
           K is solar panel
           * is the sun

I'm kind of amazed your diagram came out perfectly unmangled.

If you indent text four spaces, it becomes a <pre> block.

┌─────┐ ┌─────┐ │ │ │ │ │ ├────►│ │ │ │ │ │ └─────┘ └─────┘

Becomes

    ┌─────┐     ┌─────┐
    │     │     │     │
    │     ├────►│     │
    │     │     │     │
    └─────┘     └─────┘

Note the indent from the regular text and the change of font that is noticeable with the head of the arrow.

Here's how it was supposed to land (bear with the video through the boulder scanning discussion):

https://youtu.be/nvXLt3ET9mE?t=1384

Here's how I gather it actually landed:

https://static.euronews.com/articles/stories/08/19/58/62/120...

Scott Manley describes it in more detail (don't miss the hilarity around 4:48): https://youtu.be/7bFiJvbKyPs

> Statistically, it has proven very hard to land on the Moon. Only about half of all attempts have succeeded.

Why is this still the case given that NASA were able to land humans on the moon 55 years ago, not to mention do so in a way that could also bring them home?

I'm guessing having humans on board makes it easier, since they can tend to the landing instead of having to do it semi-autonomously all the way from Earth

That does make the most sense. Given the technological gap over more than 50 years, that's the one advantage those missions had, and with 6 successful landings (and none of the failures being in the moon landing phase) it couldn't just be luck.

To an extent, given how crewed spaceflight safety standards have improved since then, it was a combination of luck and only doing it 6 times that no crew was lost on the Moon.

Famously there were two versions of the president's speech prepared, one for the case that the astronauts would be unable to return.

Yes, agreed that there was some luck involved, certainly. I'm just saying that there were enough successes that it's statistically significant that their results were better than more recent ones. And agreeing with the parent that the manned component is the best explanation for that.

As I recall, Armstrong chose the landing site personally, using the awesome power of looking out of the window and judging a good descent speed for touchdown. He avoided big rocks and craters.

He had no choice since he had only 20 seconds before the fuel ran out.

Are you saying there was only one spot for him to land? 20 seconds gave him time to make many adjustments.

>80 years ago

Either this is wrong or I'm doing great for 84

I think you're doing better than me ;)

Corrected.

This is really interesting. They had a team of incredibly smart people and it seems that humans on board can handle difficult situations better than a computer. Apollo 11 would probably have crashed without a highly trained human on board.

Easily solvable in the design. Is a robot, it does not need a head and a tail, or to carry people that needs to have their heads up.

Just remove the up and down constrains and make any part able to be the upper part, or design it as a tumbler doll.

As a rule of thumb, solutions starting with "just..." get something wrong.

As a rule of thumb, nobody sane would propose to go to the moon. I would be very disappointed if this people would follow general rules instead to point to the excelence.

That's designing specifically for this failure case, when the typical case is that a sensor or engine encounters an overlooked edge case during the descent phase and smashes into the surface.

In such big projects as this, you just can't say "we didn't though about that, we will wait to see if we have luck".

Having B-plans for each specific case that you could reasonable obtain is a must. They were paid big sweet money for thinking about that.

The idea that the machine can be moved only if receives sun by some specific direction, is not logical when you play at this level.

This isn't a $20B project paid for by a corrupt government and poorly educated population like what NASA deals with, where indeed they cannot go without a measure for every contingency and without promising to burn billions of dollars buying votes, because otherwise they won't get funding at all. This had a total cost of $121M.

Like any sane engineering project, it did accept some risk and chance of failure as part of the tradeoffs. Part of that was potentially landing in a bad orientation.

> not a project paid for by a corrupt government and poorly educated population like what NASA deals with,

Was that part really necessary?

If nose landing is ok for the Japanese, is ok for me.

Also, this failure case was loss of engine 50 meters high. That'll ruin the day of just about any landing strategy.

That never happened. 54 years. I should know, I watched it happen and I'm 58.

What?

He's pedantically correcting the poster who said "NASA were able to land humans on the moon 55 years ago". The first moon landing was July 20, 1969, so 54 years and 193 days ago.

To be fair to jaquesm, it looks like nanna's comment used to say '80 years ago' and was edited, so the correction was more significant. See comment by kitd.

That depends on how you're rounding. Human age is always rounded downwards, but with general timeranges, it differs. 193 days is 52.8% of a year (52.7% of a leap year), so you can round that to 55.

It said '80'.

Budget is likely a large contributing factor.

Commonly thought - as well as intuitive, but 100% untrue. The entire Apollo program, from start to finish, cost $178 billion (in 2022 dollars), over 11 years. [1] That's a bit more than $16 billion a year. NASA's budget has been greater than $16 billion/year (in 2022 dollars) every year since 1963. [2]

And that was going from absolutely nothing - having never even put a man in orbit, to putting a man on the Moon, all in 8 years.

[1] - https://en.wikipedia.org/wiki/Apollo_program

[2] - https://en.wikipedia.org/wiki/Budget_of_NASA

Never underestimate a good dick measuring contest.

That's comparing budget of a program to NASA's overall budget, ignoring that NASA hasn't been pouring its overall budget into a single lunar program since then (lack of political will), and ignoring that many of the recent landers are explicitly cheaper missions intended to have some risk of failure, either because the country attempting the landing has never done it before, or because they're trying to stimulate private competition in the industry.

Absolutely. But you're also not really considering that that was starting from literally nothing, and going at a hyper-accelerated rate. Now that we have that knowledge, to say nothing of a million other technological improvements, costs ought be dramatically lower. And indeed the Falcon Heavy's entire development cost about $500 million, over about 3 years of active development. [1]

The SLS, which is NASA's latest ship - being developed by Boeing/Lockheed, started 13 years ago and has, so far, cost more than $30 billion (the costs listed on Wiki are 5 years outdated). [2] If/when it is ever completed, its ideal goal will be to carry ~2x as much as a Falcon Heavy, at a launch cost about of well over 20x as much.

[1] - https://en.wikipedia.org/wiki/Falcon_Heavy#Conception_and_fu...

[2] - https://en.wikipedia.org/wiki/Space_Launch_System

I agree that costs should be lower, and they are indeed coming down. That's the intent of stimulating private competition, to replicate what Falcon did for rocketry.

We'd have gotten on this path sooner and the waste that is SLS wouldn't have existed, if Congress+MIC hadn't intentionally misaligned incentives to suppress progress in favor of profit for decades.

SLIM is a $100m project, including half of the launch(rideshare with XRISM x-ray telescope on H-IIA), not a billion dollar JPL project on a dedicated Atlas V, so budget likely is a factor.

Any source on the mission cost? I'm quite curious. The best Wiki has is a page from 8 years ago that gave an estimated 'cost of development' (which is unclear if it includes e.g. launch costs) of $121.5 million. [1]

[1] - https://en.wikipedia.org/wiki/Smart_Lander_for_Investigating...

The "Budgets" page in JAXA website([1], will quote below) indeed don't have a detailed breakdown:

| Small Lunar Lander Proving Craft(SLIM) | 180 oku-yen(~$121m) | 149 oku-yen(~$100.7m) | FY Reiwa 5 (FY2023) | Phase D (Production/testing phase) (snip) | March, Heisei 28: Project migration review at JAXA (...snip...) March, Heisei 30: At JAXA, changes of plan due to change in launch vehicle(Epsilon -> H-IIA rideshare), as well as change in launch dates. Incorporating the results, adjusted total development cost. (180 oku-yen -> 149 oku-yen) (...snip...) | (snip) |

There are few more media sources[2][3] that state 149 oku-yen[4] figure covers "part of the launch and initial operation". One of such articles[3] estimates Epsilon launch cost as 50 oku-yen or ~$35m, and theorizes change to H-IIA to be intending to save launch cost. Not sure if there are readily available English source, sorry for that - very few of us think in English and these deep topics rarely have English coverage.

1: https://www.jaxa.jp/about/transition/index_j.html

2: https://newswitch.jp/p/345

3: https://moonstation.jp/blog/lunarexp/slim/slim-launche-to-be...

4: 1 oku means 0.1 billion, 1 USD is ~150 yen, so 1 oku-yen is ~0.75 million dollar

Thanks for the links/translation! That's quite interesting. So is that to say it actually ended being done even substantially below budget?

On budget, but at quite a small one for what it is. Epsilon all-solid launcher had anomalies and changes in these years too, so that could also be a reason for LV change.

Inflation adjustments don’t really work well for projects like this across such different periods. Project Mercury spent $277 million (1965) or 2.6 billion (2022) to get 20 uncrewed developmental flights and 6 crewed orbital launches plus all associated R&D.

Which seems insane by modern standards, Mercury however wasn’t quite that efficient, manpower costs for example have risen faster than inflation. Which makes a huge difference for non automated tasks like building novel spacecraft.

Similarly a barrel of oil in 1969 was $3.09 or 25$ today vs the actual price of 82$ today.

You're conflating rockets. The rockets used during the Mercury program [1] were literally retrofitted ICBMs designed to deliver nukes. It offered a great proof of concept and kept prices extremely low, but is nowhere near what's need for things like a Moon mission. It had a payload capacity of ~3,000 pounds!

As for oil, its price is largely driven by geopolitics, not inflation. In April 2020 prices were all the way down to below $20 a barrel. [2]

[1] - https://en.wikipedia.org/wiki/Atlas_LV-3B

[2] - https://tradingeconomics.com/commodity/crude-oil

That doesn’t make as large a difference as you might think. The Falcon Heavy is dramatically cheaper than the Falcon 9 per kg even though it’s the same company and very similar hardware. Rockets just scale really well.

Also, those missions needed a capsule not just the rocket and more importantly a great deal of R&D.

PS: April 2020 prices were due to drastic decreases in demand due to the pandemic not politics. Many current oil ‘wells’ ie oil sands lose money at even 60$/barrel therefore the market price needs to be higher than that or supply is reduced.

If you haven't seen it, "The Right Stuff" is an absolutely awesome movie about this era. Of course it takes some dramatic liberties, but is overall also quite historically accurate. So one fun anecdote, that really happened, is that these capsules/suits were so barebones that there wasn't even urine collection. The pilot was expected to simply 'hold it.' In one launch, there was a delay of 4 hours and Alan Shepard ended up pissing his suit - resulting in short circuits among the telemetry. The solution on the next flights was for astronauts to wear rubber pants... seriously! [1]

Put another way, these guys were being treated like a glorified version of Laika [2], and they knew it. It was all about achieving the mission goal as quickly and cheaply as possible. Everything else was secondary. This sort of stuff wouldn't pass muster in a million years in modern times, which again gets back to the original topic.

[1] - https://en.wikipedia.org/wiki/Project_Mercury#Pilot_accommod...

[2] - https://en.wikipedia.org/wiki/Laika

The book is even better than the (great) movie. The Mercury astronauts had to fight to get a window in the capsule and some amount of control over the attitude jets. They didn't mind being expendable -- they were test pilots, after all -- but they didn't want NASA to forget that they were pilots, not passengers.

Because most of the time it's something small and "dumb" that cause the issue, but with no human there it's not possible to fix it instantly.

The difficulty is in planning for every contingency possible in advance, which you can't, and then hope that whichever one your mission encounters is in the list you planned for, essentially.

SLIM is a technology demonstrator for landing on slopes, with "pinpoint landing" accuracy (say, 10 meters).

Previous landings had to be made on limited large flat areas, deemed relatively safe for several kilometers around, and often the landing happened just in the rough vicinity of the target area, kilometers off the mark.

Sounds like Monty Python and the Holy Grail.

"I'm not dead yet!"

"It's just a flesh wound!"

It is just like Kerbal

"First Man" (2018)

https://youtu.be/PSoRx87OO6k?si=OPCRv2nLyhdvh9Lo

https://youtu.be/w4GtJB5WAlQ?si=ASRrv1K0akxJwj-I

Armstrong's coolness under pressure as the Eagle lander's fuel dwindled to within 30 seconds of "Empty" is depicted with gripping intensity in this film.

He survived a lot of close calls. He ejected in Korea, Gemini 8 spinning, the LLRV crash. And then the moon mission. He was exceptional under pressure. David Scott was flying with him on Gemini and gave kudos in his autobiography.

Yes! People usually only know him for the moon landing, but those who know a bit more are well aware of this (and and many others) man's courage and life before that. He went through so many life-ending events and still persevered. Gemini 8 alone is very very scary to think about

If you’ve played Kerbal, you feel for this.

I'm curious about this bit: "In a post on X, formerly Twitter, Jaxa shared a photograph taken by Slim of a nearby rock that it nicknamed a "toy poodle"."

What does nicknaming mean here? Is it the lander doing some sort of pattern recognition or how exactly does a machine generate a nickname?

It = JAXA.

Ah, makes sense. Not sure why I didn't just assume that.

Hard to say without an actual link to the twitter post, but I suspect they followed the Curiosity/Ingenuity playbook here, creating a twitter handle that personifies the robot. Posts are made as if it's the actual probe/bot making the updates, in which case the sentence "... that it nicknamed..." makes sense.

Their spectrometer team picked candidate rocks within view of the camera, rock A, B, C... then one of spacecraft manager crew said names might be useful, and few minutes later they were all puppies. Forgot the source, sorry.

"It" here refers to Jaxa, not the lander.

https://interestingengineering.com/science/japans-moon-lande...

The team assigned nicknames, I think we're talking about Jaxa rather than Slim.

It's been a really, really, long journey, a quick nap and like new again.

Does someone has an idea for how the communication/fixing was done?

Was it radio waves of flipping bits? Or how does that work?

>Its solar cells are working again after a shift in lighting conditions allowed it to catch sunlight, the agency said.

>It could not generate power when it landed on 20 January as the solar cells pointed away from the Sun.

Sounds like they were just lucky with the angle of sunlight.

Yes. I don't remember the details but they also adjusted the power management to basically make it sleep until the right conditions happen, once they could confirm the angle of the panels.

I thought it landed upside down. If so they will just try to do stuff like that?

Reply on news.ycombinator.com