[HN Gopher] NASA regains contact with mini-helicopter on Mars
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NASA regains contact with mini-helicopter on Mars
Author : Tommstein
Score : 267 points
Date : 2024-01-21 14:23 UTC (8 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| simion314 wrote:
| We will use more helicopters instead of rovers for new missions ?
| Or larger crafts would be much harder or riskier to use ?
|
| Or maybe have a helicopter that can move the rover with the
| equipment to different locations.
| wyldfire wrote:
| The existing helicopter is extremely small and light, IIRC.
| less than one kg. So it definitely won't be picking up a 900kg
| rover, even if you tried to scale it up somehow. The atmosphere
| is just too thin to support anything but a minimal payload.
|
| But yeah having more helicopters might be feasible - for
| surveying the surface.
| mmbop wrote:
| Is there a problem of scaling this up to say a 20kg payload?
|
| I'm not an aeronautical engineer, so I guess what I'm asking
| is if there is some problem scaling up flying machines in an
| extremely thin atmosphere?
| nortlov wrote:
| In a thin atmosphere, lifting a heavier payload needs
| bigger rotors or increased RPM, which increases power
| demands and structural stress. The challenge is to keep the
| vehicle light enough to fly while also making it sturdy
| enough to carry the payload and survive environments.
| mmbop wrote:
| Ok - this makes sense to me. Also taken into account the
| context that anything going to space needs to be light at
| this point in time. Hopefully we don't have that
| restriction forever :)
| D13Fd wrote:
| Why can't "more rotors" be another solution?
| swells34 wrote:
| This is what I'm thinking too. A number of posts above
| talked about physical limits based on speed of sound and
| rotor length. Cool, so add two rotors, or four.
| nortlov wrote:
| For sure, that's another way to decompose "bigger
| rotors". It would probably be appropriate to dive into a
| conversation about Ingenuity's design goals,
| requirements, and the trades performed to end up with
| what they got.
| Robotbeat wrote:
| It scales up to 20kg, yes.
| wongarsu wrote:
| One issue might be rotor span. Ingenuity has pretty big
| rotors to counter the thin atmosphere (about 4 feet top-to-
| tip).
|
| On earth rotor sizes are limited by the speed at the wing-
| tip. Once you make the rotor too long the tips start
| approaching supersonic speeds, giving you all kinds of
| weird mach effects. To make matters worse, the speed of
| sound is about 30% lower on Mars compared to near earth's
| surface.
| mmbop wrote:
| Oh interesting! I can see how that would be a harder
| problem (although not insurmountable since some planes on
| earth have supersonic propellers).
|
| Just a quick edit - wow, u didn't realize the span was
| already 4ft! Anything much larger could definitely be
| hard to pack inside a fairing!
| jessriedel wrote:
| Yea good point. Apparently the blade tip speed on
| Ingenuity is Mach 0.6-0.7!
| skovati wrote:
| Interesting note about this: the speed of sound on Mars
| is only ~70% of that on Earth, due to less atmospheric
| density. Might change your Mach numbers!
| Metacelsus wrote:
| It's not due to less density, but rather a different gas
| composition (CO2 vs. N2+O2).
| algas wrote:
| Let's run the numbers!
|
| The speed of sound in an ideal (calorically perfect) gas
| is given by a = sqrt( gamma * R * T )
|
| where gamma is the ratio of specific heats (thermodynamic
| property of a gas, which may vary with temperature), R is
| the individual gas constant, and T the temperature of the
| fluid. All of these are going to be different on Mars
| versus on Earth: Earth: R = R_atm =
| 287 J / (kg * K) gamma = 1.44 T = 293 K
| (taking room temperature as an average temperature)
| Mars: R = R_CO2 = 188 J / (kg * K) gamma =
| 1.37 T = 210 K (from a quick google, about -60 deg
| C)
|
| If the Martian and Earth atmospheres were at the same
| temperature, then the speed of sound on Mars would be 80%
| that of the speed of sound on Earth. Given the
| temperature difference, the speeds of sound are
| a_mars = 232 m/s a_earth = 347 m/s
|
| So yes, much of the difference is due to the composition:
| the Martian atmosphere has a higher atomic weight, which
| leads to a lower individual gas constant, and decreases
| the speed of sound. However, a substantial amount of the
| difference is simply due to the different temperatures on
| the surfaces of the two planets.
| jessriedel wrote:
| I included it
| AlexAndScripts wrote:
| What about multiple smaller rotors? Or would that cause
| weird turbulence effects? Could we use some kind of jet
| engine?
| jessriedel wrote:
| I don't know the answer to your question, but for context
| here are the weights of Mars rovers:
|
| Sojourner (1997): 11 kg
|
| Spirit & Opportunity (2004): 185 kg
|
| Curiosity (2011): 899 kg
|
| Perseverance (2020): 1,025 kg
| mmbop wrote:
| I know these are much larger - I'm just really curious
| about the dynamics of scaling up rotorcraft & why it is
| problematic. ie - do rotor physics become impracticality
| large or fast at some point for materials science, or is
| it purely a space problem for rocket launches.
| jessriedel wrote:
| Oh for sure, it's a great question.
| todd8 wrote:
| These must be the masses of the Mars rovers, the weights
| would be measured in newtons (or pounds in the USA) and
| would differ between mars and earth.
| jvanderbot wrote:
| Here's a paper that describes what the next gen
| could/should be. The lead author is the head of Mars heli,
| IIRC.
|
| https://ieeexplore.ieee.org/abstract/document/9843501
|
| In short: 30kg heli, 5kg payloads. Other designs by
| collaborators are closer to 20kg. It's probably possible to
| transport a few of these on the existing lander technology,
| which would be awesome.
|
| The scholar.google.com keywords you want are "Mars Science
| Helicopter" and a good touchpoint author is T. Tzanetos or
| S. Withrow-Maser
|
| Ames and JPL were still collaborating on this when I worked
| there.
| Firaxus wrote:
| I was surprised to learn that it's actually a fair bit
| heavier. I was lucky enough to get to attend a talk by the
| head of the Ingenuity program, and he mentioned how the mass
| ballooned a bit to something under 5 pounds.
|
| (Listed as 4 pounds on this official fact sheet) https://mars
| .nasa.gov/files/mars2020/MarsHelicopterIngenuity...
| surfpel wrote:
| That's the goal, yes. Depending on the destination, naturally.
| Here's what's planned for Titan:
| https://en.wikipedia.org/wiki/Dragonfly_(spacecraft)
| jvanderbot wrote:
| Was going to post this.
|
| Titan is such a wonderful place for a nuclear powered
| helicopter. Much better than rover/submarines/floaters, IMHO.
| A balloon would also have been excellent, but the extra
| mobility from helis is going to be amazing.
| wongarsu wrote:
| Ingenuity was just a technology demonstrator. I think it
| demonstrated the technology splendidly, so we are likely to see
| more helicopters on Mars in the future.
|
| Not sure if Nasa has said yet which roles they see for future
| Mars helicopters. The initial idea behind Ingenuity was to use
| them as scouting vehicles for rovers. Of course rovers improved
| a lot too, with better autonomous driving. But with a Mars
| rover driving about 100 meters/yards per day scouting
| helicopters are still useful.
|
| Maybe we will also see Helicopters carrying more instruments
| themselves. But I imagine in the beginning that's mostly better
| imaging instruments. Weight is still an issue for flying
| things, no matter the planet. But maybe we will see some future
| missions that instead of a car-sized rover and one tiny
| helicopter have a fleet of helicopters with a small support-
| rover for exploring wider areas.
| jessriedel wrote:
| I think the current plan is that helicopters will be very light
| with minimal instrumentation and will be used mostly to scout
| ahead for rovers. The rovers will be much heavier and include
| many instruments.
|
| (Of course, all of NASA's long-term plans for Mars would be
| completely disrupted if Starship lowers the cost-per-kg of
| delivering equipment by two orders of magnitude, which arguably
| is likely.)
| kibwen wrote:
| Making it more economical to escape Earth's gravity well
| isn't going to alter the physics of the Martian atmosphere or
| the relative utility of copters vs rovers for Martian
| exploration. Which is to say, even if you stationed humans on
| Mars, they'd still be exploring remotely via copter/rover
| pairs, just no longer with a human-to-robot latency measured
| in tens of minutes.
| wongarsu wrote:
| However we might be willing to drive a lot more agressively
| if we know we can get a mechanic out to a stuck rover.
| Similarly, cheaper delivery might make a large number of
| smaller more disposable vehicles more appealing for many
| missions, just like what happened to satellites in the last
| decade.
| jessriedel wrote:
| If you increase the mass and/or number of vehicles by 100x,
| a bajillion things will change.
| jvanderbot wrote:
| A heli that can move a rover is basically worse than a heli
| that has rover instruments and a few wheels. You have extra
| weight and parts and complexity for hitching and carrying that
| you can just avoid by giving a small rover flying ability.
|
| Even the combo is probably too much complexity. A heli with
| good imagers, spectrometers, and the ability to cart soil
| samples would be _fantastic_.
| jvanderbot wrote:
| Surfacing a comment: Here's a paper that describes what the
| next gen could/should be. The lead author is the head of Mars
| heli, IIRC.
|
| https://ieeexplore.ieee.org/abstract/document/9843501
|
| In short, future designs target ~30kg heli, 5kg payloads. Other
| designs by collaborators are closer to 20kg. It's probably
| possible to transport a few of these on the existing lander
| technology, which would be awesome.
|
| The scholar.google.com keywords you want are "Mars Science
| Helicopter" and a good touchpoint author is T. Tzanetos or S.
| Withrow-Maser
| two_in_one wrote:
| > Other designs by collaborators are closer to 20kg. It's
| probably possible to transport a few of these on the existing
| lander technology, which would be awesome.
|
| Actually it could be like 50 of them. Plus some ground robots
| to put together solar farm. And wooh... we get the first
| extra terrestrial permanent base
| jvanderbot wrote:
| Well size is the limiting factor for fliers, since they
| like to have broad surfaces with low weight. But I think
| you're referring to some, ahem,
|
| untested possible landing vehicles ...
|
| in which case, yeah, you have a lot of robots.
|
| For the solar farm assembly case, It's actually a lot
| easier to have a teleoperated robot doing the work, a few
| astronauts in orbit doing the operation / construction. In
| the case of building things, you want as much space /
| weight landed to be the thing being built, not the
| builders, per se.
| deadbabe wrote:
| Why not some helium balloon type craft that could float along
| with low power for longer periods of times? Could cover vast
| distances? Descend into fertile plains looking for samples?
| Jabbles wrote:
| Helium's lifting capability is proportional to the density of
| the atmosphere, which is very low on Mars.
| bloopernova wrote:
| Is it viable to use vacuum instead of helium?
| nilsherzig wrote:
| Wouldn't you need something with some amount of pressure
| to stop the "shell" you plan to float from collapsing?
| somenameforme wrote:
| Minimizing moving parts, so much as possible, when dealing with
| hardware tens of millions of miles away, let alone with a 13
| minute delay in 1-way messaging, is generally smart. And Mars'
| atmosphere is so thin that these rovers will never be moving
| any meaningful payload, so their only real use case is as a
| scouting type system. But they also add very little value there
| given the existence of orbiting satellites. Even the Mars Recon
| Orbiter (from 2005) captures images in the < 1m resolution
| range.
|
| IMO NASA wanted to try to deal with the sort of 'oh boy...
| another rover' fatigue and saw the drone as a way to spice
| things up with some passable science arguments behind it, and a
| relatively minimal cost. Further supporting this is that the
| helicopter wasn't an initial part of the plan - it was strapped
| on at the 'last minute', speaking in government time. In any
| case, I would comfortably wager against us seeing more drones
| in future missions, at least to Mars.
| analog31 wrote:
| In the shorter term, I see the helicopter as making the rover
| more capable, by finding routes and destinations of interest.
| And the rover makes the helicopter more capable by providing a
| recharging station. So they're both at their best when working
| as a system. Maybe a rover can support multiple choppers.
| p1mrx wrote:
| > the rover makes the helicopter more capable by providing a
| recharging station
|
| Does it? I thought the helicopter was just solar powered.
| dotnet00 wrote:
| IIRC as a result of Ingenuity's success, one of the proposals
| for the Mars sample return mission architecture involved
| several helicopters to retrieve Perseverance's sample canisters
| (it drops them as it goes along, so that there's no worry about
| how to get the samples out of the rover in the future).
|
| I should add though that the prospects of the parasites in
| Congress properly funding such a complex mission seem pretty
| low for now.
| Kye wrote:
| Didn't this use mostly off the shelf parts? If so, I wonder how
| this will impact costs on future missions. If they can do more
| with consumer hardware, they can save budget to apply toward more
| science.
| artemonster wrote:
| Yes, it did. I like the sentiment but I wonder how much
| conflict of interest would undermine this idea. Imagine how
| many companies are involved in developing space grade one-off
| hardware! Also, why would a highly bureaucratic structure
| undercut the amount of money that they themselves are asking
| for (and receiving) out of a budget? Savings are not aligned
| with the interest of such structure. Its not that for the
| amount you have saved you can allocate rest of the funds for
| something else (usually this is how it works with publicly
| funded projects AFAIK)
| foota wrote:
| Well maybe they could start doing bigger and better missions,
| if they can reliably pull it off.
| augusto-moura wrote:
| This also drops the bar for other space agencies, from other
| countries and private alike. Getting cheaper hardware also
| means more launches and more testing. Instead of sendind a
| multi million project to space, you can send basically a
| smartphone (an epheumism, ofc) and some big antennas, and do
| it in bulk
| icegreentea2 wrote:
| Every bit of money and platform resources (rad hardened CPUs
| are giant, slow and power inefficient compared to even semi
| modern COTS) is money and resources that NASA can spend on
| scientific payload on the same platform.
|
| NASA absolutely does have some incentive to find savings in
| control hardware and software.
|
| Finally, while Ingenuity does use a non-hardened Snapdragon,
| many other of its critical electronics components are still
| rad-hardened. The FPGA and dual MCUs (that actually do the
| low level control and I/O I assume) are both rad hardened. In
| addition, the COTS components that were used where screened
| by NASA for their performance in radiation.
|
| The Snapdragon is really just there to control the radio, and
| do image processing. Critically, these are functions that
| have -some leeway- for timing, giving the option to just
| restart the Snapdragon if a watch dog detects a problem.
|
| All of this to say is that rad-hardening isn't going away,
| but will probably stick around in many critical niches. What
| Ingenuity absolutely do is validate that modern COTS
| processors have a role to play in radiation elevated
| environments, including in semi-critical applications.
| sho_hn wrote:
| This is a great and informative comment!
|
| HN is dominantly a web/SW crowd plus some mobile frontend,
| and "it uses a Snapdragon" gives many a wrong idea. In
| embedded device projects a lot of time is spent planning
| and designing around a heavy compute element running Linux
| like this, especially if the device has a safety concept or
| other mixed criticality concerns. It will have a
| substantial moat around it.
|
| On HN if you say "systems architecture" most folks go "Oh
| you mean like, whether we use microservices?". In embedded,
| while there is a lot of overlap and analogues, it's also
| all of the above, plus power state management and other
| aspects. It's not very shiny, but that profession makes all
| your cars, airplanes and alien planet multicopters.
| WWLink wrote:
| "It's not very shiny, but that profession makes all your
| cars, airplanes and alien planet multicopters."
|
| If you have a good head for it, it's a pretty darn good
| career. You might not make $500k/year like you would at
| google, but the money is still decent and reliable.
|
| Plus, working on spacecraft is cool as hell.
| iknowstuff wrote:
| The original Elon Musk biography describes how a legacy
| aerospace engineer joined spacex and was tasked with a part:
|
| > He got a quote back for $120,000. "Elon laughed," Davis said.
| "He said, 'That part is no more complicated than a garage door
| opener. Your budget is five thousand dollars. Go make it
| work.'"
| heavyset_go wrote:
| This is a terrifying anecdote.
| ThrowawayTestr wrote:
| You're talking about the $120k price tag right? Considering
| the reliability of Falcon 9.
| willis936 wrote:
| From some perspectives, yes. From others it's not so bad. I
| love having cover from the top to do engineering and
| qualification to have better solutions. Normally it's "we
| don't have time or resources to make it, get back to the
| spreadsheet mines".
|
| For LEO you can scoot by pretty easily with non-hardened
| solutions and better systems engineering and software. For
| deep space you'll need to be more clever.
| baq wrote:
| It is, but for different reasons to different people.
| tazjin wrote:
| Consider how many governments signed 8+ figure contracts to
| develop apps. Why would this kind of waste be any different
| in other industries? It's humans all the way down ;)
| heavyset_go wrote:
| It was a PoC, I assume mission critical hardware will go
| through the same vetting, hardening, etc processes that they
| currently do.
|
| It does bode well for sending cheaper "nice to have"
| experiments on missions, though.
| systems_glitch wrote:
| Applied Ion Systems is throwing these kind of rocks with small-
| scale electric space propulsion. It's interesting to see both
| the excitement and energy from eager researchers and hardcore
| hobbyists (cubesat folks), and the oftentimes rude and nasty
| pushback from industry.
| ijustlovemath wrote:
| "off the shelf" in aerospace means that you can buy it from an
| aerospace manufacturer, and don't have to build it in house.
| There's considerably more engineering behind these products
| than the equivalent consumer electronics
| Kye wrote:
| My understanding was they used actual consumer hardware for
| it. This was a big thing in the news when it landed.
|
| edit: from another comment:
| https://news.ycombinator.com/item?id=39081718
|
| It looks like it's just a couple of (important) components
| that can handle the quirks of not being radiation-hardened,
| but it's still significant.
| bloggie wrote:
| There is a lot of cost savings in taking COTS parts and
| qualifying them for space vs. designing new space-qualified
| parts, we will see more of this in the future especially with
| expensive niche technologies with a lot of crossover such as
| optical communications.
| xeromal wrote:
| I actually go to the gym with one of the guys who worked(s) on
| this copter/drone. Super cool guy
| daed wrote:
| How much can he bench?
| jvm___ wrote:
| On Earth or Mars?
| pimlottc wrote:
| I don't think you're supposed to hold your breathe when
| lifting...
| dylan604 wrote:
| Just like your not supposed to puff your cheeks when
| playing an instrument, but that never stopped Dizzy
| Gillespie. More of a suggestion than a rule
| analog31 wrote:
| Gillespie also exemplified why the rule against puffing
| your cheeks is more than just a suggestion.
| HPsquared wrote:
| It's the same if you measure in lb
| hackernewds wrote:
| is this a joke about America?
| xeromal wrote:
| He's an older dude. I see him working with like 135-155 but
| never seen him max
| csdreamer7 wrote:
| On Jupiter Broadcasting there was a lot of interviews on how this
| was a Linux powered device and could be the first of many new
| Linux devices on Mars by JPL. If I remembered correctly they used
| a space hardened Power cpu with an ancient version of Yocto since
| the newer versions of it did not have working drivers. When the
| rover had an issue they actually used the helicoptor's userspace
| command line GNU utilities to debug and get logs from the rover
| to send to Earth.
|
| Also, this makes Mars the second planet that uses Linux more than
| Windows as noted by the tweet in the linux below. :-)
|
| https://www.theverge.com/2021/2/19/22291324/linux-perseveran...
| dylan604 wrote:
| > If I remembered correctly they used a space hardened Power
| cpu
|
| If you're remembering correctly, then I'm misremembering in
| that this has essentially a Snapdragon chip and _not_ a rad
| hardened CPU at all
| csdreamer7 wrote:
| Maybe I am misremembering the interview. Maybe the person
| said that they used to use a hardened IBM power chip?
| Denvercoder9 wrote:
| This information is pretty widely available, e.g. on
| Wikipedia [1], no need to go off memory. Flight control is
| done by an FPGA, the main CPU is a Snapdragon 801 running
| Linux, and it uses Zigbee to communicate with the rover.
|
| [1] https://en.wikipedia.org/wiki/Ingenuity_(helicopter)#Av
| ionic...
| eric__cartman wrote:
| They used the hardened PowerPC for the rover, similar to
| previous mars rovers and the Snapdragon chip for the
| helicopter.
| heavyset_go wrote:
| The space-hardened POWER CPU was in Perseverance.
|
| Some info from Wikipedia:
|
| > _The rover 's computer uses the BAE Systems RAD750 radiation-
| hardened single board computer based on a ruggedized PowerPC G3
| microprocessor (PowerPC 750). The computer contains 128
| megabytes of volatile DRAM, and runs at 133 MHz. The flight
| software runs on the VxWorks operating system, is written in C
| and is able to access 4 gigabytes of NAND non-volatile memory
| on a separate card._
| inamberclad wrote:
| Fun fact - the cameras that captures Perseverance's landing are
| also Linux based and vim is installed - at least on the later
| model that I worked with.
| kurts_mustache wrote:
| > When the rover had an issue they actually used the
| helicoptor's userspace command line GNU utilities to debug and
| get logs from the rover to send to Earth.
|
| Wow, such a great testament to The Unix Philosophy of building
| small, modular, focused tools that can be combined together to
| do all sorts of interesting and more complex tasks. I'm sure no
| one imagined using these utilities from a helicopter to
| retrieve rover logs to aid in diagnostics, but here we are.
| What a cool story.
| rigid wrote:
| now if we just teach those tools to kids instead of turning
| them into spreadsheet office robots, that would be great.
| rajamaka wrote:
| I imagine NASA is built and operated on a foundation of
| thousands of spreadsheets
| TeMPOraL wrote:
| Spreadsheets are the best thing in computing since a Lisp
| REPL. Half of the startups today would be much better (in
| terms of utility, simplicity and ergonomics) for users
| and customers if they were served in form of a
| downloadable Excel sheet.
| pimlottc wrote:
| It was probably just stuck in a tree.
| cubefox wrote:
| Or a Martian canal.
| wait_a_minute wrote:
| Yeah! Let's go NASA, Godspeed! USA, USA, USA!!! Not only has it
| already exceeded its objectives, but now it may generate even
| more useful data for new objectives...does anyone know if NASA
| maintains any kind of engineering blog or stream where we can
| learn more details about what went wrong and how they
| reconnected?
| patall wrote:
| For me, being listed as a contributor to Ingenuity is one of the
| highlights of my career in software development. I mean, I just
| fixed a bug in some python library, but that was enough to get
| the GitHub Ingenuity badge. And when ever I am asked for a fun
| fact about myself, I can answer: some of my code is flying on
| Mars :)
| mlsu wrote:
| Ingenuity is running Python?
| Rebelgecko wrote:
| The vehicle itself is mostly C++ but there's lots of python
| in the ground station and data processing
| foobarbecue wrote:
| We did recently (2 months ago...?) add a couple of Python
| scripts to the heli for the first time.
| latchkey wrote:
| I contributed to `twbs/bootstrap` and got the badge too, lol.
| hackernewds wrote:
| This has "University: Stanford" and "Company: Apple, Role:
| Individual Investor" energy
|
| (I'm kidding, the badging system is funny)
| bitwize wrote:
| Speaking as someone some of whose code probably helped search
| for the fallen Malaysian Airlines Flight 370 a decade back, I
| gotta say, you have me beat by a country mile and deserve to be
| chuffed.
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