[HN Gopher] NASA's Europa Clipper: Miles Down, Instruments Deplo...
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       NASA's Europa Clipper: Miles Down, Instruments Deploying
        
       Author : rbanffy
       Score  : 147 points
       Date   : 2024-11-29 23:47 UTC (23 hours ago)
        
 (HTM) web link (www.nasa.gov)
 (TXT) w3m dump (www.nasa.gov)
        
       | rhcom2 wrote:
       | The extension mechanism for the magnetometer looks amazing.
       | Godspeed little probe.
        
         | Groxx wrote:
         | Holy cow, that 23 second video is _118 megabytes_
        
           | stavros wrote:
           | Modern technology truly is amazing.
        
           | qingcharles wrote:
           | You made me go back and fullscreen it. It is crispy as hell
           | on my 4K!
           | 
           | What a mechanism, though! Totally wild. I would have to have
           | tested that 100 times to believe it would actually work.
        
       | fn-mote wrote:
       | For once the article is more interesting than the HN discussion.
       | 
       | Note, though, that this is only about engineering. "The science
       | comes later." The probe is still months from Mars on its way to
       | Jupiter. Wait for 2030.
        
         | rkagerer wrote:
         | I wish it went into even more technical depth.
         | 
         | I've also been trying to find documents and movies about the
         | Apollo missions that are more about the engineering than the
         | people. (Nothing wrong with the latter, just feels like that's
         | all the existing, sometimes over-dramatized films are about).
        
           | dylan604 wrote:
           | > sometimes over-dramatized films are about)
           | 
           | For a film that's meant for entertaining, this is all you
           | well ever see. The drama is what the mass audience can
           | understand. The mass audience will not grasp the majority of
           | the science/engineering and will get bored.
           | 
           | There are some very science oriented content, but their
           | popularity is dwarfed by the dramatic stories of the people.
           | It's just like what true hacking in films is mostly just made
           | up stuff to look cool rather than just the boring work that
           | hacking truly is because nobody will watch it. They might as
           | well cut to a YouTube stream of someone live coding.
        
           | mulmen wrote:
           | I feel like Hidden Figures did a good job showing the impact
           | of innovation and the impact of hard work done on the ground.
           | There's drama too but it has a unique perspective. The "this
           | has to be calculated correctly or we miss the moon and people
           | die" moment was particularly impactful to me
        
             | ted_dunning wrote:
             | Sadly many of the situations depicted in the movie were
             | entirely fictional.
             | 
             | There were plenty of critical moments and plenty of drama.
             | Ironically, for all of the manufactured scenes about
             | discrimination and rejiggering of timelines by decades in
             | the movie, John Glenn apparently did ask for Johnson to
             | check some calculations ... he just didn't do it during
             | final launch prep.
             | 
             | The wikipedia page on the topic has a great list of "things
             | that didn't happen that way" in the movie:
             | 
             | https://en.wikipedia.org/wiki/Hidden_Figures#Historical_acc
             | u...
        
           | jessriedel wrote:
           | Scott Manley has some good videos focusing on various
           | engineering aspects of Apollo: https://www.youtube.com/result
           | s?search_query=apollo+scott+ma...
           | 
           | You could do worse than just reading all the Wikipedia
           | articles on all the various pieces of hardware, e.g., the
           | Lunar Landing Research Vehicle
           | 
           | https://en.wikipedia.org/wiki/Lunar_Landing_Research_Vehicle
        
           | ranger207 wrote:
           | Haynes, who is more well known for car repair manuals, puts
           | out a surprisingly good set of "owner's manuals" that are
           | highly technical. I loved the "Apollo 13 Owners' Workshop
           | Manual" since it went into exacting detail about how each
           | part of the spacecraft, including wiring diagrams and
           | plumbing charts. Their Saturn V manual was also very good
        
           | imemyself wrote:
           | I also find the "people" stories somewhat less interesting
           | than technical. I really enjoyed the "How Apollo Flew to
           | Moon" book. I also have "Stages to Saturn" on my list to read
           | sometime, sounded interesting but haven't read it yet.
        
           | PaulGaspardo wrote:
           | Maybe you're aware but NASA publishes lots of technical and
           | scientific documents to https://ntrs.nasa.gov/
           | 
           | Like this technical memo about Apollo data network systems
           | from 1966: https://ntrs.nasa.gov/citations/19670009662
           | 
           | JPL specifically has its own repository with similar content
           | at https://dataverse.jpl.nasa.gov/dataverse/jor
           | 
           | Like this paper about file transfers with the Europa Clipper
           | spacecraft: https://dataverse.jpl.nasa.gov/file.xhtml?fileId=
           | 72593&versi...
        
           | ThinkingGuy wrote:
           | The engineering-focused "Omega Tau" podcast had some some
           | good episodes on the Apollo program:
           | 
           | http://omegataupodcast.net/83-how-apollo-flew-to-the-moon/
           | 
           | http://omegataupodcast.net/97-how-apollo-explored-the-moon/
        
       | t1234s wrote:
       | Will starship make any difference in the speed of these probes or
       | will it just allow much heavier probes to be launched?
        
         | tekla wrote:
         | A little, but mostly insignificant. The real practical benefit
         | is that if Starship succeeds to be as reusable and rapidly
         | launchable as claimed, its easier to line up launches with
         | gravity assist windows as needed, and thats where you get the
         | huge velocity increases
        
         | JumpCrisscross wrote:
         | Yes and yes. Starship offers about twice the delta-v and triple
         | the mass capacity as Falcon Heavy. Capitalising on the former
         | for a deep-space mission, however, would require sacrificing
         | some reusable.
        
           | kevin_thibedeau wrote:
           | Given its relatively low cost, it would be entirely possible
           | to use a non-reentry starship as a bus for an interplanetary
           | probe with extra fuel capacity. They'd just have to strip
           | down their lunar starship and possibly add segments for
           | larger tankage.
        
         | jccooper wrote:
         | Starship itself will not be a great deep space delivery
         | vehicle, in the same way current disposable second stages are
         | used. Too big and too... reusable.
         | 
         | However, it'll make a great delivery system for some serious
         | high-energy escape velocity "third" stages, rather like the
         | Shuttle "Inertial Upper Stage" that delivered Magellan and
         | Galileo and Ulysses.
        
           | Laremere wrote:
           | Well, Starship is specifically designed to make it to Mars if
           | refueled in LEO. So it could deliver monstrously large Mars
           | rovers. If they're going for the outer planets, they could do
           | as you suggest after the first burn using a refueled
           | Starship. Either way you're sacrificing a Starship second
           | stage (old, or better yet reduced mass version) to the gods
           | of delta V.
        
           | jessriedel wrote:
           | A re-fueled Starship will be able to deliver ~100 tons to the
           | surface of Mars, to be compared with the heaviest existing
           | rover that was slightly over 1 ton. Yes, it will take ~10
           | Starship flights to fully refuel one Mars-bound Starship, but
           | the fully reusable design is supposed to ensure this can be
           | done for relative cheap.
        
         | jvanderbot wrote:
         | The vision I have for NASA missions is to avoid these tiny one
         | off probes and use starship to lift multiple boosters to orbit,
         | assemble a server rack and multiple imagers, a radio thermal
         | power source, and boost it to orbit around each outer planet
         | (except perhaps Jupiter, too much radiation).
         | 
         | It's just not the right business model to build "small" probes
         | like this that trickle back imagery when we can be downloading
         | the same imagery AND querying data that's sitting in situ to
         | run analysis on a planet -local server of TB of real time
         | signals.
         | 
         | Imagine you see something interesting in one image, and just
         | ask the server to find local similar things all over the planet
         | from the imagery in storage. Instant frequency and geospatial
         | analysis product without begging for observation time or
         | (worse) a new mission.
         | 
         | Oh and a kilometer scale telescope in orbit.
        
           | Teever wrote:
           | I think that there will always be a desire for small probes,
           | but you're right that one-offs aren't economical.
           | 
           | The advantages of Starship is that with such a massive
           | payload capacity it can carry many small probes and combined
           | with a low cost per kg it will justify setting up assembly
           | lines that churn out small probes by the thousands.
           | 
           | We'll pepper the solar system with these probes and they'll
           | act as nodes in a large interplanetary network relaying data
           | between each other and larger, more powerful nodes as you
           | describe.
           | 
           | The nodes in a network are important and more powerful nodes
           | are more desirable, but the network itself is a powerful
           | thing that it greater than the sum of its parts.
           | 
           | This combined with economies of scale will always justify
           | more smaller satellites.
        
             | gorgoiler wrote:
             | With economics, I think we have to be careful when
             | questioning the financial efficiency of organisations like
             | NASA, Universities, research, and the like. Some of these
             | things _should_ be societal cost centers.
             | 
             | The question for me therefore, based on your comment, is
             | whether Europa Clipper's expense can be justified because
             | it is funding the current generation of custom space
             | vehicle and mission experts, keeping alive their traditions
             | and skills for the next generation.
             | 
             | The alternative view is that it's a waste of money to
             | continuously support the careers of what are possibly the
             | spaceship equivalents of wheelwrights, stable masters, and
             | saddlers.
        
               | Teever wrote:
               | I believe that it absolutely can be justified for
               | precisely the reason you state -- it keeps the experts
               | trained so that they can as a minimum produce things like
               | Europa Clipper. But to me that's just keeping their
               | expertise and the potential that it offers on life
               | support.
               | 
               | Having the technology and infrastructure to produce the
               | things that they are experts at producing but in an
               | unprecedented scale is what we need if we want them to
               | reach their full potential.
               | 
               | It allows them to more rapidly iterate over design ideas
               | by seeing what works and what doesn't. It also allows
               | cheaper destructive testing to work out the bugs instead
               | of waiting a decade to find out if they just wasted
               | billions of dollars and centuries of man years with
               | intrinsically flawed designs.
               | 
               | And ultimately it allows us to build modular self-
               | assembling spacecraft on a scale that we've only dreamed
               | of allowing them to practice their trades in new ways
               | that will unlock new science and knowledge for the human
               | race.
        
               | pixl97 wrote:
               | With cheap and commonly launched rockets like starship
               | we'll also be able to launch many more cheap test
               | platforms that won't need billion dollar budgets. Take
               | the antenna on this thing, they get one chance to deply
               | it correctly. But now imagine launching a test antenna
               | project where for a few million you can make sure they
               | work before you put them on a more expensive probe.
        
             | jvanderbot wrote:
             | Well, sure, but how does "peppering the solar system" with
             | 100 probes at a time work when each insertion is wildly
             | different? Lifting 100 probes is great, but only if they
             | are going on same / similar boosts to their targets.
             | 
             | And how does it get the initial boost along its trajectory?
             | We could do solar electric and wait a year for it to pick
             | up enough delta-v to _start_ the journey ...
             | 
             | Fully disclosing my ignorance here: How does it work to
             | launch 100 probes to 10 planets from earth with one launch?
        
               | Teever wrote:
               | I'm not sure about that specifically, I've only taken an
               | intro to orbital mechanics class so esoteric orbital
               | maneuvers are a bit beyond me but I understand that in
               | some cases it is possible. I would imagine that one
               | technique that we have yet to try is putting fuel depots
               | in long distance places to facilitate the execution of
               | these manuevers.
               | 
               | With that said what I had in mind when I wrote my comment
               | wasn't using one rocket to launch a 100 probes to
               | different solar bodies but instead to launch 100 probes
               | to a single body in one go. I envision a time where we'll
               | deploy massive constellations of remote sensing
               | satellites, like mini-star link constellations for each
               | solar body be it a moon or planet so that we can get
               | real-time data across the whole body instead of having to
               | stitch together pieces of data from one probe. Like
               | Starlink these constellations will be able to relay data
               | between the nodes should they lose line of sight with
               | Earth and will be able to relay data to other
               | constellations orbiting other nearby solar bodies to get
               | the data to Earth if the whole constellation is
               | blocked.[0]
               | 
               | I could see a near future where we start sending these
               | Starlink like communications/remote sensing craft at the
               | same time we send craft designed to pepper the surface of
               | a body with multiple rovers and stationary probes to
               | survey the surface of planets and again relay the data
               | they collect between themselves and the constellations
               | above.
               | 
               | It would be cool to see terrestrial bodies explored with
               | some sort of RTG/solar powered stationary device that has
               | an automated lab for sample analysis and seismic
               | measurements paired with a dozen or so of these sandflea
               | type robots[0] that can roll and hop over the surface to
               | survey and collect samples to bring back to the
               | stationary labs for analysis.
               | 
               | You can even look at sample return missions where some of
               | these stationary devices have the means to send samples
               | into orbit around the solar body that they're located on
               | where the sample carrying craft rendevous with an
               | orbiting craft designed to return to Earth perhaps
               | refueling with fuel depots previously put in place along
               | the way.
               | 
               | [0] https://www.youtube.com/watch?v=XTmYm3gMYOQ
               | 
               | [1] https://www.youtube.com/watch?v=6b4ZZQkcNEo
        
               | jvanderbot wrote:
               | This is a much better plan. One issue with 100 probes
               | around, say, Enceladus, is the downlink bandwidth. This
               | is why I suspect on site infra is going to be required.
               | 
               | But honestly let's do both. Infra and something like
               | Planet Labs for outer planets. We can.
        
               | Teever wrote:
               | There will absolutely be a place for super nodes in the
               | kind of networks that are going to be built out.
               | 
               | Their performance will likely be somewhat limited
               | compared to what you're looking for at this point due to
               | radiation and the excessive mass of the shielding
               | required to protect them from it.
               | 
               | That can be mitigated with in situ resource production.
               | Like burying a server rack scale processing node under
               | ground on mars and relaying data to it with the network I
               | described above or capturing water from comets and using
               | it fill compartments for radiation shielding in orbital
               | data centers.
        
         | mturmon wrote:
         | Related to your question, but not responsive to the "speed"
         | aspect: Here is a nice article from Ars [1] on the impact of
         | starship on large space telescopes. This is focused on Webb
         | successors (which in NASA fall under astrophysics, not
         | planetary, like Clipper) not "planetary probes" per se,
         | although a linked and more technical article [2] touches
         | briefly on that.
         | 
         | One coauthor of [2] is the chief scientist for astrophysics at
         | JPL, so it's not just idle speculation.
         | 
         | The ability to launch an 8m telescope definitely has space
         | mission designers interested. However, probe velocity itself is
         | not addressed.
         | 
         | [1] https://arstechnica.com/space/2023/10/astronomers-say-new-
         | te...
         | 
         | [2]
         | https://pubs.aip.org/physicstoday/article/76/2/40/2869438/Ac...
        
         | TrainedMonkey wrote:
         | Starship lets you trade money and mission complexity for time.
         | A fully refueled Starship in LEO should have around 5km/s in an
         | expendable configuration. A gravity assist from Earth or Mars
         | typically provides 2-5km/s. Looking at the
         | https://www.reddit.com/r/space/comments/1ktjfi/deltav_map_of...
         | 5km/s from LEO is barely enough to reach Jupiter. Looking at
         | the mission trajectory direct launch would shave off roughly 2
         | years from 5 year mission -
         | https://europa.nasa.gov/mission/timeline/
         | 
         | You could also launch much-much heavier probe with a dedicated
         | boost stage and / or electric propulsion...
        
           | ANewFormation wrote:
           | The largest probe ever launched afaik is Voyager 1, and it
           | was less than a ton. Even 'massive' things like the James
           | Webb telescope only weighs 7 tons.
           | 
           | Starship is aiming for being able to launch 200+ tons. So
           | stuff like this on a dedicated mission would have vastly more
           | delta-v available but also be kind of silly. There's no
           | reason we couldn't scale things up and just launch hundreds
           | of probes at once all through the Solar System. Alternatively
           | instead of launching probes we could look to start launching
           | modular observation stations that could one day even house
           | humans, or perhaps even grander ideas.
           | 
           | Launching one off probes, rovers, and satellites is really
           | something I think we should be aiming to move beyond, let
           | alone on the ridiculous time intervals we operate on at
           | present.
           | 
           | We shouldn't still be making basic, yet revolutionary,
           | discoveries on the Moon, more than half a century after we
           | set foot on it.
        
             | baq wrote:
             | Comms is the reason. DSN dish time is not a particularly
             | abundant resource even today.
        
               | rbanffy wrote:
               | The far side of the moon is prime real estate for
               | radiotelescopes. You can create a sizable expansion of
               | the DSN by sharing dish time with the antennas you can
               | build from local materials.
        
               | philistine wrote:
               | Well I fully assume that the DSN itself will move to
               | space, courtesy of Starship's large tonnage to orbit.
        
               | Melatonic wrote:
               | I've been thinking for years we should built a space
               | network of probe and satellite like objects - imagine if
               | we landed a small relay on every asteroid passing
               | anywhere near earth - could be highly useful for
               | communication and possibly also give us a GPS like
               | location assist for additional spacecraft
        
           | AlessandroF6587 wrote:
           | Starship can be used to release a probe with gigantic fuel
           | reserve and a bigger than usual energy source (solar or
           | nuclear). Then the probe can use a VASMIR or other electric
           | propulsion to gradually accumulate a vast amount of delta-v
        
           | sandworm101 wrote:
           | A fully refueled starship in leo is a big _big_ ask, akin to
           | getting a full shuttle stack into orbit. On-orbit refueling
           | at such a scale has not been done yet and is difficult to
           | even think about doing. It isnt like KSP. The more efficient
           | route would be to scrap starship and design a high-energy
           | upper stage to be launched by the BFR instead, a purpose-
           | built probe thrower. Starship is way to heavy to be a
           | practical final stage for probes.
        
             | Alex-Programs wrote:
             | On-orbit refuelling at such a scale does sound rather
             | difficult, but they also fully intend to do it in the near
             | future. They're certainly going to give it a good try.
             | 
             | Also, if you don't want to make an entirely different
             | second stage to put on top of superheavy, you should be
             | able to fit a pretty substantial third stage in Starship's
             | payload bay.
             | 
             | Right now the payload bay doesn't open anywhere near enough
             | for that, but hopefully in the future that'll be an option.
             | 
             | And if you really want to make something go fast, you could
             | refuel in orbit, give it a push from Starship, then deploy
             | the third stage for another kick.
        
               | rbanffy wrote:
               | > Right now the payload bay doesn't open anywhere near
               | enough for that
               | 
               | Shouldn't be too hard to design a starship with a blunt
               | nose and place it under an expendable fairing.
               | 
               | With a 1-ton probe the budget is 99 tons for a kick
               | stage. That's a lot of delta-v. With some creative
               | propulsion options, maybe even interstellar probes can be
               | done.
        
             | sneak wrote:
             | Everything you said is right, but on-orbit refueling is of
             | course theoretically possible, and isn't THAT huge of a
             | leap given what SpaceX has already accomplished. Let's not
             | forget the space lasers, or the chopstick catch, or
             | Starlink-live-streamed 4K views from the plasma shadow
             | during reentry, or autonomous Dragon docking, etc.
             | 
             | Sure, it's hard, but that is perhaps the best engineering
             | team in the history of humankind, and I think they're up to
             | the task.
             | 
             | Additionally, people much smarter than me ALSO think they
             | are up to the task, and they have more and higher-
             | resolution data about the problem space, too.
             | 
             | My money's on they get it working. Maybe it takes five
             | years or a dozen failures, but I'm confident that they will
             | succeed eventually and there will be orbiting methane and
             | lox fuel stations sooner rather than later.
        
               | sandworm101 wrote:
               | Those things were never seen as impossible, just
               | difficult. Nobody has even a theoretical concept of how
               | to move tons of liquid oxygen between rockets in orbit.
               | And there is some talk of banning it as too dangerous.
               | Remember all those pad explosions related to fuel issues?
               | We cannot risk that much space debris as spaceX goes
               | through a learning process.
        
               | kolinko wrote:
               | If I'm not mistaken, SpaceX is already contracted by NASA
               | to do on orbit refuelling, and one of the recent
               | starships did initial trials of fuel transmission
               | (internal for now).
               | 
               | Update: - source article - $58M contract to do that -
               | https://www.teslarati.com/spacex-starship-nasa-contract-
               | orbi...
               | 
               | - chatgpt confirmation + links to more sources - https://
               | chatgpt.com/share/e/674b5c1b-d318-8004-b79d-c0eefc59...
        
           | perihelions wrote:
           | - _" A fully refueled Starship in LEO should have around
           | 5km/s in an expendable configuration."_
           | 
           | That can't be right; a naive application of the rocket
           | equation gives (3.72 km/s) * ln(1,300 mT / 100 mT) = 9.55
           | km/s.
        
             | TrainedMonkey wrote:
             | It's definitely higher than 5km/s, but I would not go up to
             | 9.5km/s. My napkin math was - booster provides 2km/s and
             | the LEO is 7.2km/s, so if the ship arrives nearly empty LEO
             | it must provide a minimum 5.2km/s. I did not account for
             | gravity + friction losses which could be guesstimated to
             | 2km/s. If we assume that ship handles all of them (which is
             | not true booster does some) we come up to 5 + 2 = 7.2km/s.
             | 
             | The equation you have uses block 1 prop + dry mass numbers.
             | Block 1 does not have significant payload capability and
             | the last one just flow on OFT 6. As such let's use Block 2
             | numbers, first one should fly early next year. Dry mass
             | target 100t, payload 100t, prop mass 1,500t. So (3.72 km/s)
             | * ln(1700 / 200) = 7.96 km /s. This is with using min
             | advertised payload of 100t and Elon's forward looking 100t
             | number for dry mass. Way above 5km/s, but reaching 9.5km/s
             | with 100t of payload will be challenging.
             | 
             | I've pulled stats from
             | https://en.wikipedia.org/wiki/SpaceX_Starship .
        
               | perihelions wrote:
               | You're mixing up unrelated concepts. In particular, the
               | payload capacity to LEO of 100 tonnes has nothing to do
               | with this calculation.
               | 
               |  _Europa Clipper_ isn 't a 100 tonne payload; it's about
               | 6.
        
         | creer wrote:
         | Speed is not necessarily the correct lever it might affect. A
         | probe with much larger antenna, with much larger or multiple
         | radioactive power sources, with much more solar panels, with
         | much more onboard fuel, etc could be much more useful with the
         | same speed.
        
           | ragebol wrote:
           | More mass means more fuel means more speed?
        
             | ben_w wrote:
             | More fuel may mean longer duration missions rather than
             | getting to the destination faster.
             | 
             | Or the same duration mission with a more massive payload
             | that can both do more and report more.
        
       | sph wrote:
       | _> On March 1, 2025, Europa Clipper will reach Mars' orbit and
       | begin to loop around the Red Planet, using the planet's gravity
       | to gain speed. [...]
       | 
       | > At Mars, scientists plan to turn on the spacecraft's thermal
       | imager to capture multicolored images of Mars as a test
       | operation._
       | 
       | The positive thing about space being so large is that the further
       | we go, the more of the neighbourhood we visit to take pictures of
       | (as we need their gravitational assistance in our travels)
        
       | Agraillo wrote:
       | Nice engineering achievement. According to Wikipedia the biggest
       | NASA interplanetary vehicle to date is powered by 600W solar
       | panels. Will your personal gaming PC work with 600W power supply
       | or is it doomed to "de-orbit"?
        
       | braden-lk wrote:
       | So cool! I worked on this project during my internship at JPL.
       | I'm sure they hucked all my code in the trash as soon as I left,
       | but it was a fun summer. :)
        
         | euroderf wrote:
         | Quick question: Does JPL use PowerPoint a lot ?
        
       | standardUser wrote:
       | I was just browsing these Wikipedia pages to get an idea of the
       | extent of interplanetary exploration:
       | 
       | List of Solar System Probes:
       | https://en.wikipedia.org/wiki/List_of_Solar_System_probes
       | 
       | Exploration of the Solar System:
       | https://en.wikipedia.org/wiki/Discovery_and_exploration_of_t...
       | 
       | The Russian space program, despite having many firsts and many
       | successes, had a huge number of failures early on with
       | interplanetary probes and fell off almost completely by the
       | mid-70's. Meanwhile Europe and Japan, both often viewed as
       | lackluster space powers due to their lack of manned space
       | programs, have contributed massively to solar system exploration.
        
         | Melatonic wrote:
         | They did land a probe on Venus however!
        
       | euroderf wrote:
       | > already 13 million miles (20 million kilometers) from Earth.
       | 
       | Please, just call it a "light-minute", and remind ppl that the
       | moon is one and a quarter light-seconds away.
        
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       (page generated 2024-11-30 23:01 UTC)