[HN Gopher] Japan: Moon lander Slim comes back to life and resum...
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Japan: Moon lander Slim comes back to life and resumes mission
Author : neversaydie
Score : 287 points
Date : 2024-01-29 07:43 UTC (15 hours ago)
(HTM) web link (www.bbc.co.uk)
(TXT) w3m dump (www.bbc.co.uk)
| soco wrote:
| 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?
| echoangle wrote:
| 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.
| thrdbndndn wrote:
| 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?
| KineticLensman wrote:
| No actuators. It's basically a box
| dotancohen wrote:
| It has the exact same actuators to correct upside down
| position issues as does the Toyota Camry.
| bashauma wrote:
| 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.
| whycome wrote:
| > optical observations of the surrounding environment
|
| turn cam on. take pictures of rocks.
| bashauma wrote:
| I wish someday we could take our camera to the moon as
| easily as our replying ;)
| angiosperm wrote:
| Has attitude thrusters, but they might be worried about it
| ending up in a worse position.
| soco wrote:
| 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?
| InitialLastName wrote:
| 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.
| deelowe wrote:
| > 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.
| makeitdouble wrote:
| 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.
| firtoz wrote:
| You just send the commands upside down and it works
| nottorp wrote:
| Unicode already has a special case for this, right?
|
| "Upside down hiragana right yourself". "Mirrored upside down
| hiragana right yourself".
|
| And 31284 related emoji.
| jojojaf wrote:
| Basically the same as contacting Australia
| Etheryte wrote:
| 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.
| xattt wrote:
| The concept of endianness would like to have a word with
| you.
| _joel wrote:
| We need middle endian
| npongratz wrote:
| You got it:
| https://en.wikipedia.org/wiki/Endianness#Middle-endian
| p1mrx wrote:
| Down under they call it numboriginality.
| steelbrain wrote:
| Although I know you're poking fun, I just want to note here
| that HN is not reddit :)
| lukan wrote:
| 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)
| numpad0 wrote:
| 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.
| baggachipz wrote:
| So maybe we could move the moon then?
| petee wrote:
| But all the bits might spill out!
| 1970-01-01 wrote:
| Send them from Australia.
| resolutebat wrote:
| 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.
| nottorp wrote:
| > 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?
| yencabulator wrote:
| 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.
| HALtheWise wrote:
| This may be a silly question, but shouldn't the attitude
| thrusters still be restartable?
| adrian_b wrote:
| 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.
| jacquesm wrote:
| Maybe, just maybe they can use the rovers to push it over.
| yencabulator wrote:
| 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.
| jacquesm wrote:
| Ah, too bad.
| cubefox wrote:
| > 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".
| adrian_b wrote:
| 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".
| numpad0 wrote:
| 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.
| tetris11 wrote:
| Schematic |
| -*- | _X_X_X_ K
| | |=K |_______| K ---------------
| where: X is throttle K is solar panel
| * is the sun
| lawlessone wrote:
| I'm kind of amazed your diagram came out perfectly
| unmangled.
| shagie wrote:
| If you indent text four spaces, it becomes a <pre> block.
|
| So
|
| +-----+ +-----+ | | | | | +---->| | | | | | +-----+
| +-----+
|
| Becomes +-----+ +-----+ |
| | | | | +---->| | | |
| | | +-----+ +-----+
|
| Note the indent from the regular text and the change of
| font that is noticeable with the head of the arrow.
| rkagerer wrote:
| 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
| WilTimSon wrote:
| 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?
| gliptic wrote:
| It = JAXA.
| WilTimSon wrote:
| Ah, makes sense. Not sure why I didn't just assume that.
| beAbU wrote:
| 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.
| numpad0 wrote:
| 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.
| skywhopper wrote:
| "It" here refers to Jaxa, not the lander.
| kybernetikos wrote:
| https://interestingengineering.com/science/japans-moon-lande...
|
| The team assigned nicknames, I think we're talking about Jaxa
| rather than Slim.
| beAbU wrote:
| 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.
| jacquesm wrote:
| Payload...
| jpgvm wrote:
| Self righting combat bots are awesome!
| drtgh wrote:
| 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
| shagie wrote:
| 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.
| helpfulContrib wrote:
| >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?
| shagie wrote:
| 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://uploa
| d.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.
| shagie wrote:
| (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...
|
| https://www.science.org/content/blog-post/things-i-won-t-
| wor...
| infinet wrote:
| 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.
| pvaldes wrote:
| It's been a really, really, long journey, a quick nap and like
| new again.
| nanna wrote:
| > 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?
| enlyth wrote:
| 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
| tempestn wrote:
| 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.
| dotnet00 wrote:
| 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.
| tempestn wrote:
| 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.
| EliRivers wrote:
| 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.
| dghughes wrote:
| He had no choice since he had only 20 seconds before the
| fuel ran out.
| xeromal wrote:
| Are you saying there was only one spot for him to land?
| 20 seconds gave him time to make many adjustments.
| kitd wrote:
| > _80 years ago_
|
| Either this is wrong or I'm doing great for 84
| nanna wrote:
| I think you're doing better than me ;)
|
| Corrected.
| jansan wrote:
| 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.
| pvaldes wrote:
| 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.
| soco wrote:
| As a rule of thumb, solutions starting with "just..." get
| something wrong.
| pvaldes wrote:
| 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.
| dotnet00 wrote:
| 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.
| pvaldes wrote:
| 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.
| dotnet00 wrote:
| 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.
| pvaldes wrote:
| > 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.
| yencabulator wrote:
| Also, this failure case was loss of engine 50 meters high.
| That'll ruin the day of just about any landing strategy.
| jacquesm wrote:
| That never happened. 54 years. I should know, I watched it
| happen and I'm 58.
| DelTaco wrote:
| What?
| lastofthemojito wrote:
| 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.
| z2h-a6n wrote:
| 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.
| wasmitnetzen wrote:
| 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.
| jacquesm wrote:
| It said '80'.
| hcrean wrote:
| Budget is likely a large contributing factor.
| somenameforme wrote:
| 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
| loopz wrote:
| Never underestimate a good dick measuring contest.
| dotnet00 wrote:
| 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.
| somenameforme wrote:
| 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#Concepti
| on_and_fu...
|
| [2] - https://en.wikipedia.org/wiki/Space_Launch_System
| dotnet00 wrote:
| 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.
| numpad0 wrote:
| 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.
| somenameforme wrote:
| 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_Inve
| stigating...
| numpad0 wrote:
| The "Budgets" page in JAXA website([1], will quote below)
| indeed don't have a detailed breakdown:
|
| | Project name | Total development cost(projected) |
| Total development cost(as of Jan, Reiwa 5) | Planned
| launch fiscal year | Project phase | State of Project
| (total dev. cost, launch FY changes, etc.) | References |
|
| | 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
| somenameforme wrote:
| Thanks for the links/translation! That's quite
| interesting. So is that to say it actually ended being
| done even substantially below budget?
| numpad0 wrote:
| 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.
| Retric wrote:
| 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.
| somenameforme wrote:
| 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 $20 a barrel. [2]
|
| [1] - https://en.wikipedia.org/wiki/Atlas_LV-3B
|
| [2] - https://tradingeconomics.com/commodity/crude-oil
| Retric wrote:
| That doesn't make as large a difference as you might
| think. The Falcon Heavy is dramatically cheaper than the
| Falcon 9 per kg even though it's the same company and
| very similar hardware. Rockets just scale really well.
|
| Also, those missions needed a capsule not just the rocket
| and more importantly a great deal of R&D.
|
| PS: April 2020 prices were due to drastic decreases in
| demand due to the pandemic not politics. Many current oil
| 'wells' ie oil sands lose money at even 60$/barrel
| therefore the market price needs to be higher than that
| or supply is reduced.
| somenameforme wrote:
| 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
| nolok wrote:
| 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.
| yencabulator wrote:
| 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.
| bookofjoe wrote:
| "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.
| Gravityloss wrote:
| 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.
| witx wrote:
| 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
| kerbs wrote:
| If you've played Kerbal, you feel for this.
| RetroTechie wrote:
| _" 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?
| szundi wrote:
| Not getting up but wait for the sun to get just above the
| horizon sometime and then turn on
| sp332 wrote:
| 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.
| pyinstallwoes wrote:
| The moon is rotating?
| Galaxeblaffer wrote:
| 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
| adolph wrote:
| 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...
| Terr_ wrote:
| 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
| jvm___ wrote:
| 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.
| RugnirViking wrote:
| It would only be once - the spacecraft is 90 degrees off from
| the orientation it is supposed to be.
| makeitdouble wrote:
| 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.
| stcredzero wrote:
| _Available solar power must be a big constraint in remainder of
| this mission, probably?_
|
| I guess Slim isn't all in the shady!
| HarHarVeryFunny wrote:
| Sounds like Monty Python and the Holy Grail.
|
| "I'm not dead yet!"
|
| "It's just a flesh wound!"
| szundi wrote:
| It is just like Kerbal
| kuschkufan wrote:
| The armchairism in this thread is something else. Happy the
| mission is not lost and kudos to JAXA.
| smashed wrote:
| 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.
| _xerces_ wrote:
| It didn't land upside down, it landed upside vertical - 90
| degrees off, not 180.
| angiosperm wrote:
| It landed upside-down relative to how it descended. it was
| _supposed_ to roll over 90 degrees, but turned 180 instead.
| stcredzero wrote:
| _The armchairism in this thread is something else._
|
| Right. Now we need more comments starting with, "What
| about...?"
| aa6ll wrote:
| Does someone has an idea for how the communication/fixing was
| done?
|
| Was it radio waves of flipping bits? Or how does that work?
| nothis wrote:
| >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.
| makeitdouble wrote:
| 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.
| m3kw9 wrote:
| I thought it landed upside down. If so they will just try to do
| stuff like that?
| t43562 wrote:
| 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.
| NotSammyHagar wrote:
| 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.
| Suzuran wrote:
| 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.
| NotSammyHagar wrote:
| 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.
| npteljes wrote:
| >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.
| stcredzero wrote:
| _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!
| LorenPechtel wrote:
| 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.)
| adolph wrote:
| 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.
| pavel_lishin wrote:
| 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!
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