[HN Gopher] Mars Helicopter successfully completed its second fl...
___________________________________________________________________
Mars Helicopter successfully completed its second flight
Author : Sami_Lehtinen
Score : 255 points
Date : 2021-04-22 13:49 UTC (9 hours ago)
(HTM) web link (twitter.com)
(TXT) w3m dump (twitter.com)
| jffry wrote:
| If you're curious, a press release from yesterday had more
| details:
|
| "This time around, we plan to trying climbing to 16 feet (5
| meters) in this flight test. Then, after the helicopter hovers
| briefly, it will go into a slight tilt and move sideways for 7
| feet (2 meters). Then Ingenuity will come to a stop, hover in
| place, and make turns to point its color camera in different
| directions before heading back to the center of the airfield to
| land."
|
| via
| https://mars.nasa.gov/technology/helicopter/status/294/were-...
| me_me_me wrote:
| Could the drone also be used as a means to dedust the rover if it
| was using solar panels?
| ceejayoz wrote:
| I can't imagine the risk of flying in close proximity would be
| worth it. If you crash into the rover you could jam up the
| wheels or a piece of scientific equipment.
|
| We know from Spirit and Opportunity that dust on the panels
| isn't much of a concern; wind seems to clear them regularly.
| SamBorick wrote:
| A large constraint on Spirit and Opportunity was keeping the
| panels clear, that's why they lasted so long.
|
| From what I remember, during martian winter they had to take
| the grade and the prevailing wind direction into account to
| keep the dust and fines off.
|
| Currently the InSight lander is going into hibernation
| because the solar panels haven't really gotten cleaned in 3
| years: https://www.cnet.com/news/nasa-mars-insight-lander-
| limits-op...
| LunarRover wrote:
| It's already been three years? Feels like a few months ago.
| Wow.
|
| Still can't believe we've got proof of Marsquakes - that
| alone turned the consensus on planetary geology upside
| down.
| jffry wrote:
| The Perseverance rover is using a plutonium-powered
| radioisotope thermoeletric generator (RTG) this time that I
| think is rated to provide something like 100 watts for
| something like 15 years.
|
| For the solar panels on the Ingenuity helicopter, it's my
| understanding that the flights do already help keep them clean.
|
| Ingenuity is highly experimental, but even for a future Mars
| helicopter I doubt they would risk flying it in close proximity
| to the rover.
| cheschire wrote:
| > using a plutonium-powered radioisotope thermoeletric
| generator (RTG) this time that I think is rated to provide
| something like 100 watts for something like 15 years.
|
| Or provide enough heat to keep a stranded botanist warm for a
| brief cross country drive.
| aerophilic wrote:
| Just a note on this: you can't "increase" the power output
| of these things. Basically you can imagine these power
| sources as a "heat pack" that lasts a _very_ long time. So,
| while you can "store" the energy, and release it later...
| you can not "use it faster".
| ilyagr wrote:
| As it produces 100W of electricity, the RTG also produces
| way more energy as heat. According to Wikipedia, the
| efficiency of an RTG is usually around 3% to 7%, so you
| get kilowatts of heat.
|
| https://en.m.wikipedia.org/wiki/Radioisotope_thermoelectr
| ic_...
|
| So, it's same order of magnitude to my electric space-
| heater, if it was stuck to "on". I trust Andy Weir's
| calculations on whether it is about right to keep a
| botanist warm on Mars.
| fiftyfifty wrote:
| Couldn't you use something like a Stirling engine to
| create more electricity from the excess heat? You might
| have to have an external radiator to create a heat
| gradient with a closed loop of liquid but it certainly
| seems possible.
| LeifCarrotson wrote:
| Yes, you could, and you could do better with more moving
| parts and more stages, but they're optimizing for
| reliability not for power.
|
| In theory, the best you could do is (T_hot - T_cold) /
| T_hot, or (430 - 210) / 430 ~= 50% , using some
| approximate values for fin root temperature and Martian
| climate. To exceed 10% of the theoretical optimum with
| something that contains no moving parts is pretty
| impressive, IMO.
| fiftyfifty wrote:
| Couldn't they use the heat to to drive the wheels
| directly, maybe they could go to more of a hybrid drive?
| Just seems like such a waste to produce that much heat
| for 15 years.
| simonh wrote:
| I'm not sure how heat would turn wheels directly. You
| need to convert the heat into either mechanical or
| electrical energy somehow. Any such system involves
| tradeoffs in efficiency (in terms of useful energy
| captured) against weight and reliability.
| Daniel_sk wrote:
| AFAIK NASA is already experimenting with Stirling engines
| + Plutonium for future missions. It's called ASRG https:/
| /en.m.wikipedia.org/wiki/Advanced_Stirling_radioisoto...
| jgeada wrote:
| well, unless you bring a number of the inner contents of
| several such packs into _very_ close proximity, at which
| point the reaction is going to be very much accelerated.
|
| Warranty probably not valid if you get anywhere near
| criticality ;-)
| LunarRover wrote:
| Just don't recreate the Demon Core... they're both
| plutonium, right?
| MengerSponge wrote:
| The dust is electrostatically charged, and the atmosphere is
| extremely thin. It probably wouldn't help.
|
| I imagine a tuned laser could ablate the dust, but that's a
| very expensive way to recover a solar panel!
| tppiotrowski wrote:
| Where are the shadows in the upper and lower right corners of the
| hover image coming from?
| tqkxzugoaupvwqr wrote:
| These aren't shadows but the helicopter's legs.
| herendin2 wrote:
| I guess they're not shadows. They're the tips of the
| helicopter's legs
|
| Edit: in case it isn't clear, this a photo of the helicopter's
| shadow on the surface, taken by a down-facing camera in the
| underside of the helicopter. It has a sort of fisheye lens, so
| there's some distortion at edges
| WJW wrote:
| Looks like the landing legs of the helicopter? Difficult to say
| from just this image though.
| the-dude wrote:
| Obviously, these are from the trusses in the studio. Must be.
| dylan604 wrote:
| Yeah, they had to choose the correct lens though. If too wide
| of a lens is used, you can still see the set with the moon
| lander from the 60s.
|
| Your response gave me a chuckle.
| 1970-01-01 wrote:
| For perspective, its not as easy as you would think. The air is
| extremely thin. Flying near the surface on Mars is like flying @
| 100,000 ft. on Earth.
| marricks wrote:
| If anyone was a stupid as me in thinking "wow that's not _that_
| high up! " the "death zone" for humans is 26k feet, where if
| exposed long enough we will die[1]
|
| [1] https://en.wikipedia.org/wiki/Death_zone
| alamortsubite wrote:
| Yes, and that altitude is right at the limit that helicopters
| on earth can achieve.
| [deleted]
| TrevorJ wrote:
| even 14k feet feels seriously noticeable and unsettling.
| throwawayboise wrote:
| Another point of reference, 10,000 feet is the limit in
| aircraft. If pressurization is lost above that altitude,
| oxygen masks will drop and the pilots will make a quick
| dive to below 10,000 feet.
| wongarsu wrote:
| Space starts at the Karman line at 330,000 feet, the ISS
| flies at about 1,300,000 ft (100km and 400km respectively).
| baq wrote:
| but the gravity is less, so it surely isn't that bad?
| outworlder wrote:
| 38% of Earth's. Still difficult as the atmosphere is too
| thin.
| nvilcins wrote:
| A great video explaining how the helicopter works (and why it
| is indeed a feat of _ingenuity_).
|
| https://www.youtube.com/watch?v=GhsZUZmJvaM
| jakemoshenko wrote:
| Thankfully gravity is also lower.
| hellbannedguy wrote:
| I was thinking a crash might be less damaging, but just
| looked up the gravity at 3.721 m/s2. That would hurt.
| mlindner wrote:
| Given the blades are spinning at not too far off from the
| local speed of sound, the blades would explode if they hit
| the ground I imagine, similar to helicoptor crashes on
| Earth.
| walrus01 wrote:
| https://marsed.asu.edu/mep/atmosphere
|
| from the website:
|
| Relative to Earth, the air on Mars is extremely thin. Standard
| sea-level air pressure on Earth is 1,013 millibars. On Mars the
| surface pressure varies through the year, but it averages 6 to
| 7 millibars. That's less than one percent of sea level pressure
| here. To experience that pressure on Earth, you would need to
| go to an altitude of about 45 kilometers (28 miles). (Yes,
| you'll need a space suit to walk around on Mars.) The Martian
| surface pressure also varies due to elevation. For example, the
| lowest place on Mars lies in the Hellas impact basin, 7.2 km
| (4.4 mi) below "sea level." The pressure there averages about
| 14 millibars. But on top of Olympus Mons, 22 km (14 mi) high,
| the pressure is only 0.7 millibar.
| chrisshroba wrote:
| Wow! I just looked up the difference in pressure and found that
| the "air" pressure on the surface of Mars is 155 times less
| that of Earth (1013.25 mbar on Earth, 6.518 mbar on Mars).
| m4rtink wrote:
| Yeah, that was really not expected and only found via space
| probes. That's why you see gliders for landing in many of the
| early Mars mission concepts but not in the newer ones.
|
| Actually the atmosphere is too thin for full gliding or
| parashute landing but too thick to ignore it like we can on
| the Moon.
|
| Still twice the Moons gravity with no atmospheric breaking at
| all would also suck I guess.
| skykooler wrote:
| From what I remember of playing around with X-Plane's Mars
| atmosphere model, you can glide, but at very high speeds
| (for most planes close to the speed of sound), you can
| barely turn, and it's horribly easy to stall.
| jillesvangurp wrote:
| Basically means you need a lot more delta v too slow down.
| Which means burning a lot more fuel to first get below
| escape velocity (5km/s) and then slow down all the way to
| zero. Escape velocity for Earth is 11km/s. ISS flies at
| about 7.6 km/s. A typical Mars approach and landing starts
| at about 20km/s. Most of that is Atmospheric braking. So
| yes, that would suck.
| code4you wrote:
| What is NASA hoping to learn from this drone that they couldn't
| get from the rover? Is the point just to test if this type of
| flight is possible on Mars, or is the rover collecting some extra
| observations?
| KuiN wrote:
| As other have said, it's a tech demo. Partly just to show we
| can do powered flight on other celestial bodies, part of it is
| to test how well the off-the-shelf parts in Ingenuity work in
| that environment. Rotorcraft require more computing power than
| is available from typical rad-hardened processors. Ingenuity is
| using a Snapdragon mobile phone chip, will be interesting to
| see how long it survives up there.
|
| NASA have plans to use rotorcraft in many future missions,
| including the Dragonfly which will fly around Titan[0].
| Launches in 2027.
|
| [0] https://www.nasa.gov/press-release/nasas-dragonfly-will-
| fly-...
| NovemberWhiskey wrote:
| > _Rotorcraft require more computing power than is available
| from typical rad-hardened processors._
|
| Ingenuity uses a three-level control system for avionics[0] -
| the Linux part that runs on the Snapdragon 801 is at the top
| tier and does more the mission computer functions like
| navigation, computer-vision, telemetry, command processing
| and interfacing to the radio.
|
| The middle tier is a dual-path redundant microcontroller
| system based on the TMS570 architecture. This is an
| automotive-grade part qualified for safety-critical usage.
| This an ARM Cortex R5 design, so not exactly a speed demon.
|
| The bottom tier is a radiation tolerant, mil-spec FPGA
| (Microsemi ProASIC 3L) that actually runs the control loops
| at up to 500Hz, handles communication with the IMU, motor
| control interfaces etc; this part is actually supposed to be
| functionally identical to the space-qualified version.
|
| The "Linux running on a smartphone processor" aspect gets a
| lot of play but the stack as a whole uses a lot more
| traditional high-integrity design approaches. Most of the
| heavy-lifting of "fly the rotorcraft" is done away from the
| Snapdragon, and I'm not sure where the idea that "rotorcraft
| need a lot of CPU power" comes from.
|
| [0] https://rotorcraft.arc.nasa.gov/Publications/files/Balara
| m_A...
| walrus01 wrote:
| >Rotorcraft require more computing power than is available
| from typical rad-hardened processors.
|
| the CPU on a fairly advanced quad, hex or octocopter on
| earth can be a STM32F7 or STM32H7 family microcontroller,
| which is not very powerful in terms of raw computing power.
| That's more than fast enough (in an earth environment) to
| pull in sensor input at a high Hz refresh rate from dual
| IMUs, barometer, GPS, and control up to eight motor ESCs,
| along with running the UARTs for communication to a remote
| control link, and additional spi, i2c or UARTs to do things
| like run camera gimbals.
|
| https://docs.px4.io/master/en/flight_controller/cubepilot_c
| u...
| teraflop wrote:
| Yeah, I think the biggest factor preventing such a simple
| design from working well on Mars would be the (current)
| lack of anything equivalent to GPS.
|
| In order to navigate safely, especially during takeoff
| and landing, you need a reasonable idea of your absolute
| velocity relative to the ground. You can't get that from
| an IMU (except over very short timescales) because of
| integration errors. A barometer would work for the
| vertical axis, but getting the horizontal component is a
| lot trickier. GPS solves this nicely, especially since
| velocity can be derived from relative measurements, which
| are much more accurate than absolute ones.
|
| It looks like Ingenuity uses visual odometry from a
| downward-facing camera, which is likely to require a lot
| more processing than something like an STM32 could
| provide.
| NovemberWhiskey wrote:
| > _It looks like Ingenuity uses visual odometry from a
| downward-facing camera, which is likely to require a lot
| more processing than something like an STM32 could
| provide._
|
| I believe that for Ingenuity they are actually doing this
| in software; but at this point, you can just buy off-the-
| shelf an optical flow odometry ASIC with a built-in
| camera and lens system that draws <5mA, fits in a 4x5mm
| footprint and gives you delta-X and delta-Y.
|
| e.g. https://www.pixart.com/products-
| detail/108/PAA3905E1-Q
|
| Kinda mind-blowing.
| walrus01 wrote:
| At the relatively low heights ingenuity is flying at, a
| single point LIDAR rangefinder aimed straight down would
| also be well suited to maintaining a certain altitude.
| dylan604 wrote:
| >Launches in 2027.
|
| Hopes/Scheduled to launch in 2027 seems more accurate. Even
| when the rocket is fueled and on the pad, it can still get
| scrubbed.
| m4rtink wrote:
| Flying drones can open yet more places for exploration in the
| future - even with the new active precision landing feature
| introduces with Perserverance the landing elipse still needs
| to be relatively flat ground with limited ammount of
| obstacles.
|
| If we want to see and explore deep valleys or high mountains
| before some future the first setlers go there with gopros and
| do a Twich stream then flying drones are a good option.
| Denvercoder9 wrote:
| _> Quadcopters require more computing power than is available
| from typical rad-hardened processors._
|
| Ingenuity isn't a quadcopter though, it has two blades that
| counter-rotate around the same axis.
| lsaferite wrote:
| > two blades that counter-rotate around the same axis
|
| Which would make it a coaxial helicopter.
|
| https://en.wikipedia.org/wiki/Coaxial_rotors
| 0_____0 wrote:
| It's pretty funny to me that the processor on Ingenuity
| handily outperforms the one on Perseverance by several orders
| of magnitude.
| dylan604 wrote:
| That's the point of the demo. If Ingenuity's processor
| survives, then NASA can consider these more advanced
| processors. If it doesn't, then that means continued use of
| lesser capable but rad hardened processors will still need
| to be used. OR, it could mean a re-evaluation of mission
| lengths. if more science can be done using a more capable
| processor that is known to have a limited lifespan, then
| that will have to be evaluated against the benefits of
| longer missions with less processing requirements
| londons_explore wrote:
| They still have a sample size of 1...
|
| Surely a better test would be to get 1000 mobile phone
| processors and put them in a radiation chamber on earth
| and see how many fail? It would be far cheaper _and_ be
| better science.
| dylan604 wrote:
| But then we'd have no helicopter on mars right now
| SECProto wrote:
| In addition to the (very valid!) tech demo aspects of this,
| there's also the huge public interest/public relations
| aspect. I've seen more articles and comments on Ingenuity
| than on any other part of this Mars mission. (Personally, I'm
| excited for the MOXIE instrument[1] - tech that's all but
| mandatory before human missions)
|
| [1] https://mars.nasa.gov/news/8926/nasas-perseverance-mars-
| rove...
| 1970-01-01 wrote:
| A flight envelope.
|
| https://en.wikipedia.org/wiki/Flight_envelope
| jffry wrote:
| The NASA site contains a lot of info about Ingenuity:
| https://mars.nasa.gov/technology/helicopter/ , especially this
| fact sheet (PDF):
| https://mars.nasa.gov/files/mars2020/MarsHelicopterIngenuity...
|
| "Its performance during these experimental test flights will
| help inform decisions relating to considering small helicopters
| for future Mars missions, where they could perform in a support
| role as robotic scouts, surveying terrain from above, or as
| full standalone science craft carrying instrument payloads.
| Taking to the air would give scientists a new perspective on a
| region's geology and even allow them to peer into areas that
| are too steep or slippery to send a rover. In the distant
| future, they might even help astronauts explore Mars"
| justapassenger wrote:
| It's technology demonstration. It's not really used for
| science, other than learning how to fly there.
| ceejayoz wrote:
| This one's a technology demo.
|
| Future ones might be able to peek over a rock/ridge for
| planning purposes or access an inaccessible cliff or small
| crater that's dangerous to rove into.
| dylan604 wrote:
| Is the data collected by MRO not useful for this as well?
| Sure, the resolution would be increased, so I guess that
| would have some benefits.
|
| I tend to think of the rover and drone like one of those
| strategy games where you have to send out scouts to
| "discover" where to send the rest of the troops, and then
| plan out how many "moves" to do it in. But then I remember we
| have the MRO that has pretty much scouted the entire planet.
| It just takes us a lot of "moves" to get our troops there.
| LunarRover wrote:
| MRO has a max resolvable resolution of 1 meter - incredibly
| useful for planning, but not enough to keep a rover safe
| from harm, let alone do all possible science.
|
| The max resolution from a low-altitude helicopter is
| probably two-three orders of magnitude more detailed
| dylan604 wrote:
| The rover itself also has high resolution cameras, so it
| should be able to detect things hazardous/interesting.
| The drone might be useful to know if it is worth climbing
| over a dune or whatever, but I still think MRO data would
| be useful for mission control to plot routes. So maybe
| the drone+rover would be much more capable as an
| autonomous pair requiring less input from mission
| control?
| snypher wrote:
| It's main task is as a technology demonstration, after it's
| time or power budget is expended the rover will continue with
| it's scientific mission.
| temptemptemp111 wrote:
| HAHAHAHAH amazing that "engineers" believe this! Epic.
| fiftyacorn wrote:
| You wouldn't want to be the one who crashes this
| jpindar wrote:
| It's not like someone is controlling it live, I'm sure there
| are multiple people reviewing the commands.
| wongarsu wrote:
| The communication delay between earth and mars in 9 minutes at
| the lowest, 42 minutes when the planets are far apart. If
| something is crashing the helicopter then it's a software bug.
| LeifCarrotson wrote:
| As someone who writes software, the fact that it must be a
| bug is scant consolation when it crashes. It just means that
| you have no hope to prevent it by reflex, you had to fix it
| by thinking intentionally and carefully a long time ago when
| you wrote the software.
| jackallis wrote:
| what a time to be alive.
| sixothree wrote:
| I had pong as a kid. I know we dared mighty things back then
| too. But this is so much fun.
| MontagFTB wrote:
| In all the downward-facing images from Ingenuity, I find it
| surprising that the rotor blades have a lighter shadow than the
| rest of the helicopter. I asked about this on Twitter and was
| told the sensor for each pixel isn't fully shielded from light.
| The fast-moving rotor blades allow for latent light to enter into
| the sensor during the image scan, causing the rotor blade itself
| to appear slightly lighter. [1]
|
| [1]: https://twitter.com/sdamico/status/1384205372668350465
| hanoz wrote:
| Then shouldn't the circle swept by the blades look slightly
| darker than the surround?
| Miraste wrote:
| > it's identical to the Google Project Tango SLAM camera module
|
| That's fascinating, I would've guessed it had a special
| radiation-hardened camera like the processor.
| meepmorp wrote:
| It's using an off the shelf Snspdragon CPU. The whole
| helicopter is made with COTS parts.
| Miraste wrote:
| Oh, I meant on the rover. From googling, it seems the
| helicopter's design lifetime is too short for radiation
| damage to matter, and the cameras actually on the rover are
| rad-hardened to some degree.
| kevin_thibedeau wrote:
| Rad hard cameras intended for long term operation use
| CCDs with the drivers and ADCs off chip, implemented in a
| hardened process.
| ixfo wrote:
| Generally cameras are reasonably rad-hard because the
| pixel size dictates a lot of the wiring size (and puts a
| lower bound on the process size). 3.5um pixels don't play
| well with 5nm features. Bigger features are generally
| more resistant to radiation fun.
| pkaye wrote:
| This paper discusses the design of the helicopter.
|
| https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_
| A...
| everybodyknows wrote:
| Thanks! Fascinating hints at the complexities of working
| around radiation hazards:
|
| >MCU processor units operate redundantly, receiving and
| processing identical sensor data to perform the flight-
| control functions necessary to keep the vehicle flying in
| the air. At any given time, one of the MCU is active with
| the other waiting to be hot-swapped in case of a fault.
|
| >Each subsystem has a current monitor to detect possible
| latch-up current and can be power cycled to clear a SEL.
| In addition, current limiting is added to prevent a
| destructive SEL event and most devices are switched off
| when not in use to minimize their exposure to SEL. For
| the critical FPGA which is always on for the duration of
| the mission, the radiation tolerant ProASIC3 is chosen
| with the military temperature grade (-55 C to 125 C) and
| -1 speed grade to mitigate the degradation in the
| propagation delay caused by the total dose radiation.
| meepmorp wrote:
| I'm always amazed by the crazy crap people deal with in
| space, and how much protection the Earth affords us.
| Extreme temperatures, radiation, small bits of material
| traveling fast enough to go through structural metals
| like a knife; it's a thrill a second.
| martin_balsam wrote:
| Don't forget vacuum welding
|
| https://en.m.wikipedia.org/wiki/Cold_welding
|
| https://en.m.wikipedia.org/wiki/Vacuum_cementing
|
| The first time it happened it must have been puzzling
| lisper wrote:
| This is an important and highly under-appreciated point.
| We humans evolved under some very particular
| environmental conditions, ones which are radically
| different from space in almost every conceivable way.
|
| When people talk about colonizing Mars, I ask them to do
| the following thought experiment: imagine you are going
| to move to the Atacama desert. You have to live there for
| the rest of your life. You get to take one standard
| twenty-foot shipping container with you. You can pack
| that container however you like, but you have to live
| inside the container along with whatever stuff you pack
| it with for nine months before you can go out for the
| first time.
|
| Figuring out how to make that work is about 100 times
| easier than colonizing Mars.
| mlindner wrote:
| I think that's a poor example.
|
| First off, doing such a moving experiment with only your
| own funds is a lot harder than if you had billions to
| millions of dollars to do it.
|
| Secondly, people won't be trapped inside on Mars and will
| make regular, if not daily trips outside on EVAs (we may
| need a new acronym as there's no "Vehicle" here.)
|
| Thirdly, a lot of hardware will be outside the
| "container" including the power generation from nuclear
| power or solar energy. (Likely nuclear powered sterling
| engines that have already been demonstrated in subscale
| versions.) (This contributes to the difference in funds
| point on my first point.)
|
| Fourth, even though you didn't mention it, I'll add it
| here to preempt a counter argument. The radiation risks
| are overstated. Radiation on Mars is at least half that
| of being in space because you have radiation from one
| half of the "sky" blocked by the planet itself. Also
| while the radiation levels are certainly elevated,
| they're likely not going to kill you. Any long term
| colonies are going to be mostly underground anyway. (Or
| more likely simply buried by shoveling dirt on top.)
| lisper wrote:
| > doing such a moving experiment with only your own funds
|
| I didn't say that you had to do it with your own funds.
| But how exactly do you think that extra money would help?
| Getting to the Altacama desert is not difficult or
| expensive. That's the reason that the fact that no one
| has bothered to even attempt it is so damning.
|
| > people won't be trapped inside on Mars
|
| I didn't say they would be. In fact, I specifically said
| that you would only have to spend nine months (the travel
| time to Mars) inside the container. After that you can go
| out as much as you like. You don't even have to wear a
| space suit.
|
| > a lot of hardware will be outside the "container"
| including the power generation from nuclear power or
| solar energy
|
| That's why I gave you a full 20-foot container. But fine,
| take three containers, which is about what will fit in a
| Falcon Heavy. Or six. It doesn't really matter. The point
| is, take some number of containers that you think is a
| plausible payload for a Mars colony -- _and nothing
| else_.
|
| > The radiation risks are overstated
|
| I never claimed otherwise. There are a zillion other
| things that will get you before the radiation does.
| zabzonk wrote:
| > Radiation on Mars is at least half that of being in
| space because you have radiation from one half of the
| "sky" blocked by the planet itself
|
| You have to get there, which exposes you to a lot of
| radiation. And then you have to live there which exposes
| you to a lot more, no matter if it is "half" that you
| would get if Mars was a one-faced world WRT the sun.
|
| Also, how are you going to get these diggers, their fuel,
| their support systems, etc, etc, to Mars that will
| excavate holes (lovely to live in) or cover things
| (ditto)? Why would anyone want to live like that, or
| worse, condemn their children to do so?
|
| I used (in the 1960/70s) to believe in the colonisation
| of space. But now not at all - it is simply too
| difficult. And that's the answer to the Fermi Paradox.
| extrapickles wrote:
| If you at least sleep underground (1-2m), it keeps the
| total lifetime radiation dose manageable.
|
| For most of the machinery, you would bring the tricky to
| manufacture bits (tight tolerance mechanical,
| electronics, non-basic chemicals) with you, and build the
| bulk structural parts on site. Even for something like a
| 10,000kg machine tool, only about ~500-2000kgs of
| materials need to be sent (see granite+epoxy CNC
| machines[0]). Other machines, such as diggers, they would
| have to be electric powered. This is not too difficult as
| most heavy machines are diesel->hydraulic, with
| electric->hydraulic conversion not too hard (run-time
| will suffer though).
|
| If you wanted to start a colony, its easy if you can get
| 10,000 people to go as everyone doesn't have to wear a
| dozen different hats to keep things going. With current
| in-use launch tech, its unlikely that enough people can
| afford to go (or can get a loan to do so). If launch
| costs get down to ~$500k/ton to Mars, then it would be
| possible. The biggest issue at first would likely be
| getting enough electrical power from solar to refine
| metals and chemicals as that takes a lot of electricity
| and the likely first sources or raw materials will be
| sub-optimal as you would be prioritizing ease of access
| over efficiency.
|
| [0]: https://www.cnccookbook.com/epoxy-granite-cnc-
| machine-fill/
| sixothree wrote:
| It's endearing to think of a rover having a companion helper.
|
| I know the whole thing is impressive. But it's really hard for me
| to get past the awesomeness of rocket crane landing a rover on
| another planet. That stuff is crazy awesome.
| [deleted]
| throwaway6734 wrote:
| I can't wait until we have the technical skills to land more
| autonomous bots to build landing pads/human liveable structures
| chasd00 wrote:
| that never dawned on me, you know it could be a way to start
| producing fuel for a return trip home too.
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(page generated 2021-04-22 23:00 UTC)