NASA's helicopter survives first freezing night on Mars(edition.cnn.com)
edition.cnn.com
NASA's helicopter survives first freezing night on Mars
https://edition.cnn.com/2021/04/05/world/mars-helicopter-ingenuity-nasa-rotorcraft-scn-trnd/index.html
81 comments
I've been trying to find out what communication protocols are being used between the rover and helicopter. I've seen on Wikipedia that it's supposedly Zigbee, but the source material referenced doesn't mention Zigbee. Does anyone know how this is working?
Wikipedia links to this (search for "Zig-Bee"): https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_A...
Just a reminder: that helicopter is running Linux.
Does anyone know if Perseverance is capable of recording video? I know it has several cameras but I can't figure out if it can actually record footage of Ingenuity taking flight.
Have they posted any videos yet? Somewhat disappointing that so far it's only been images with really poor UI/UX via the NASA site. That's not how you capture the public's imagination.
I also don't see why they are waiting so long to do the flight, why risk even waiting until nightfall for the batteries to get too cold or for dust to get into the electronics/mechanics?
I also don't see why they are waiting so long to do the flight, why risk even waiting until nightfall for the batteries to get too cold or for dust to get into the electronics/mechanics?
> Have they posted any videos yet?
An amazing one. Most of driving along at 1MPH on a barren landscape is incredibly boring, but...
https://youtu.be/4czjS9h4Fpg?t=10
> I also don't see why they are waiting so long to do the flight
Because there's a couple dozen steps that are each irrevocable involved in uncovering, unfolding, deploying, and then flying this thing... and that they want to make sure everything is perfect between each one and that comms still worked before cutting umbilicals, etc, because you can't just plug it back in.
An amazing one. Most of driving along at 1MPH on a barren landscape is incredibly boring, but...
https://youtu.be/4czjS9h4Fpg?t=10
> I also don't see why they are waiting so long to do the flight
Because there's a couple dozen steps that are each irrevocable involved in uncovering, unfolding, deploying, and then flying this thing... and that they want to make sure everything is perfect between each one and that comms still worked before cutting umbilicals, etc, because you can't just plug it back in.
Very cool video, thanks for sharing
There is a list of milestones on their site. They verify each step and don’t rush anything. Seems perfectly reasonable to me. The goal is not to launch the thing quickly but to verify that everything works as expected and if there is a problem to either fix it or at least being able to to learn from it.
>I also don't see
Maybe, just maybe, the domain experts involved know something you don't. Just a theory.
Maybe, just maybe, the domain experts involved know something you don't. Just a theory.
To be fair, maybe the OP was hoping they'd provide an explanation as to why. I have the same question too and I don't presume to be smarter than they are.
In that case, a question along the lines of I'm curious why... would have been perfectly appropriate. I don't see why just comes across as I know better. But perhaps English isn't their native language.
But perhaps English isn't their native language.
Or perhaps there are regional variants of English where this is a normal way to ask a question. There are probably lots of idioms that work in one area but would be offensive in another, and it's not always easy to predict.
Or perhaps there are regional variants of English where this is a normal way to ask a question. There are probably lots of idioms that work in one area but would be offensive in another, and it's not always easy to predict.
I am pretty sure that phrasing comes off as aggressively rude in all regional variants.
For what it's worth, that kind of surety that one knows every region comes off as rude in quite a few places as well.
For example, it was quite amusing and annoying watching a coworker insist that the rural area I originally came from isn't rural because it doesn't meet his personal definition, though he had never even been to the state.
"I don't see why" is a valid way of expressing a lack of understanding combined with a spirit of collaboration where I am from.
For example, it was quite amusing and annoying watching a coworker insist that the rural area I originally came from isn't rural because it doesn't meet his personal definition, though he had never even been to the state.
"I don't see why" is a valid way of expressing a lack of understanding combined with a spirit of collaboration where I am from.
I see where you're coming from. I'm used to hearing that kind of phrasing in-person so that's probably why I took it differently.
It’s probably a bandwidth problem and they probably have more important things to do transmit than videos. Although I think a little bit of Showbusiness is probably good for NASA.
It's a technology demonstrator, and one of the technologies it is demonstrating is "survive the night". Does the heating, panel and charge management all work as expected? Repeat! Then fly once the daily charge-state is understood.
Thank you, for some reason I had a lot of trouble with Google when trying to find this answer. It kept returning results about the video taken by the skycrane, not the rover itself.
Note that most of that video is taken by the rover itself, watching the skycrane fly off etc.
Indeed, we don't have any video from the skycrane after touchdown, because I believe that data was fed over an umbilical to the rover before being sent to the low orbit (I'd typed LEO, but I guess I mean "LMO") satellites and back to Earth.
Indeed, we don't have any video from the skycrane after touchdown, because I believe that data was fed over an umbilical to the rover before being sent to the low orbit (I'd typed LEO, but I guess I mean "LMO") satellites and back to Earth.
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AFAIK it’s possible and will save to an on-rover disk.
The current limit to seeing that footage here on earth is the downlink bandwidth limit. So far it’s been used for more „interesting“ data and still images.
"Survives first freezing night" == Is this just sensationalism? Should NASA not have a good estimate of what the chances of survival are? Maybe it is the media, maybe it is the need to fill columns (like the old days) but I would probably make a list of milestones and track "time to first flight" or something similar.
It is literally a milestone on a list of milestones.
https://www.jpl.nasa.gov/news/press_kits/mars_2020/launch/mi...
https://www.jpl.nasa.gov/news/press_kits/mars_2020/launch/mi...
Wow, reading the first comment I would think that this was planned. It literally is the third thing on a list of "milestones."
I find the order of milestones a little surprising.
Why didn't they test the survival of the freezing cold after testing the rotor blades, lift-off and perhaps a short flight in the vicinity of the rover?
Why didn't they test the survival of the freezing cold after testing the rotor blades, lift-off and perhaps a short flight in the vicinity of the rover?
It's probably as simple as: they didn't have time. You have to move slowly and carefully on Mars. One rushed mistake and it's over.
Yes, but chances of getting useful data out of the helicopter are much greater if you test the thing before subjecting it to harsh conditions.
For example: if you know that lift-off works, then that's a huge datapoint.
For example: if you know that lift-off works, then that's a huge datapoint.
I bet they'd move faster if they could. I'm guessing for takeoff there's a good amount of analysis to do beforehand. Terrain, weather, system checks, whatever.
I don't know the actual list, but it's not hard to guess why they couldn't do everything, including ejecting it from the main rover and getting the main rover out of the way, in the ~12-14 hours a day that they have to do stuff.
I don't know the actual list, but it's not hard to guess why they couldn't do everything, including ejecting it from the main rover and getting the main rover out of the way, in the ~12-14 hours a day that they have to do stuff.
They don't want to fly it with the rover nearby. It needs to get to a safe distance before they can fly it.
They fully expect it to survive the night - it'll have survived identical conditions in pre-launch testing - and thus there's no need to rush through the other steps.
Identical except that the real one blasted off in a rocket.
Part of the testing procedure includes vibration and sound testing that effectively simulates launch conditions.
https://www.nasa.gov/centers/johnson/pdf/639713main_Vibratio...
NASA knows what they’re doing.
https://www.nasa.gov/centers/johnson/pdf/639713main_Vibratio...
NASA knows what they’re doing.
No it's not - firstly, you can go to JPL's version of the story here and see how they lead with the same headline:
https://www.jpl.nasa.gov/news/nasas-mars-helicopter-survives...
But I prefer to hear it directly from the engineers involved:
> "What was it like seeing that first image of Ingenuity on mars?"
> "Oh it was a dream come true. To see the culmination of the entire team's hard work really pay off. Being dropped - that's one huge milestone, but the massive one for us over the last few days has been realising not only did we drop, but we actually survived the first night. That is huge. That was one of the huge huge achievements that we've been looking forward to and now we can look forward to the rest of the mission. But being able to drop under our own energy, sustain ourselves, keep ourselves warm through the whole night and then wake up and talk with Perseverance and say "yep we're here alive and healthy" the team couldn't be happier."
https://youtu.be/PcpI8-S5ZE8?t=108
https://www.jpl.nasa.gov/news/nasas-mars-helicopter-survives...
But I prefer to hear it directly from the engineers involved:
> "What was it like seeing that first image of Ingenuity on mars?"
> "Oh it was a dream come true. To see the culmination of the entire team's hard work really pay off. Being dropped - that's one huge milestone, but the massive one for us over the last few days has been realising not only did we drop, but we actually survived the first night. That is huge. That was one of the huge huge achievements that we've been looking forward to and now we can look forward to the rest of the mission. But being able to drop under our own energy, sustain ourselves, keep ourselves warm through the whole night and then wake up and talk with Perseverance and say "yep we're here alive and healthy" the team couldn't be happier."
https://youtu.be/PcpI8-S5ZE8?t=108
This is a technology demonstration of a novel robotics system build using many off-the-shelf parts, on a planet with night-time temperatures as low as -130F [1].
Ingenuity survived, literally, a first freezing night. That is an accomplishment by itself, and is hardly sensationalist.
[1] As linked in the article: https://mars.nasa.gov/technology/helicopter/status/288/its-c...
Ingenuity survived, literally, a first freezing night. That is an accomplishment by itself, and is hardly sensationalist.
[1] As linked in the article: https://mars.nasa.gov/technology/helicopter/status/288/its-c...
> on a planet with night-time temperatures as low as -130F
For anyone reading this: -130F is -90°C
For anyone reading this: -130F is -90°C
2/3rds of Ingenuity's stored energy goes towards keeping its batteries and critical components warm each night. Only 1/3rd is available for powered flight. It literally takes more energy for this helicopter to survive the night than it takes to fly on mars.
That's pretty interesting. Maybe the next rover needs an excavator tool so we can build an underground hidey-hole for storing sensitive equipment at night.
A little more efficient than a human then.
I'm not sure how to really internalize this.
Does it take a ton of power to heat. Or does it take very little power to fly?
I'd assume there is a ton of effort put into passive insulation? Since my non intuitive gut seem like it should be able to better insulate heat loss. I can't help but feel like there is probably a ton of effort and science to insulate. And this is even only possible because of that work. But is it just a much harder problem than I probably realize?
Does it take a ton of power to heat. Or does it take very little power to fly?
I'd assume there is a ton of effort put into passive insulation? Since my non intuitive gut seem like it should be able to better insulate heat loss. I can't help but feel like there is probably a ton of effort and science to insulate. And this is even only possible because of that work. But is it just a much harder problem than I probably realize?
-130F/-90C is VERY cold, and this system is VERY weight-sensitive. Presumably adding more insulation that always needed to be carried was more weight than adding power capacity that can serve a dual-use.
The power capacity metric isn't necessarily concurrent; one could imagine the chopper using its power to fly (which will generate heat as a byproduct) for a third of the sunlight time, and then using the rest of the day to charge for the night-time cold.
The power capacity metric isn't necessarily concurrent; one could imagine the chopper using its power to fly (which will generate heat as a byproduct) for a third of the sunlight time, and then using the rest of the day to charge for the night-time cold.
> one could imagine the chopper using its power to fly (which will generate heat as a byproduct) for a third of the sunlight time
This is impossible; the flight duration is ~ 90 seconds.
This is impossible; the flight duration is ~ 90 seconds.
It could still take a third of its total daily accumulated power for said 90-second flight, no?
Sure, but "fly for a third of the sunlight time" would mean flying for ~ 4 hours per day.
Mars is very cold, things like the battery can't handle these temperatures. It's been thoroughly analysed, here is a quote from the white paper [0]:
"""H. Thermal System
The helicopter must survive the cold of the night on Mars where temperatures can drop to -100 C or lower. The most critical component is the battery which is kept above -15 C through the night as it powers Kapton film heaters attached to the battery cells. The avionics boards in the ECM surround the battery and are also kept at an elevated temperature by virtue of their proximity to the warm battery assembly. Insulation around the avionics boards is provided by a carbon-dioxide gap of 3 cm width. Additional insulation can be provided by replacing the carbon-dioxide gas with an Aerogel formulation. The outermost fuselage thermal coating is from Sheldahl with Solar absorptivity α = 0.8 and infra-red (IR) emissivity = 0.1.
In addition to thermal losses through the gas gap (or aerogel), additional losses occur due to conduction in the mast as well as through the copper wiring that penetrate the ECM from the mast. To minimize the latter, the wire gauges are selected to be of the thinnest gauges that can still support the current draw during operations without overheating. Prior to flight, under the control of the FPGA, the thermal system powers on heaters in the motor control boards that have been exposed to the ambient temperatures. The internal battery temperature is brought up to 5 C to allow hi-power energy extraction from the cells. During operation the ECM and battery warm up as a result of avionics operations and battery self-heating. However, the thermal inertia of the elements is such that for the short flights of the helicopter, there is no overheating."""
[0] "Mars Helicopter Technology Demonstrator" https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_A...
EDIT: some detail on the battery capacity from section G:
"A de-rated end-of-life battery capacity of 35.75 Wh is available for use. Of this capacity, 10.73 Wh (30%) is kept as reserve, night-time survival energy usage is estimated at 21 Wh for typical operation in the northern latitudes in the spring season, and approximately 10 Wh is available for flight. Assuming that 20% of the power is at the peak load of 510 W and 80% is at a continuous load of 360 W, approximately 90 sec of flight is possible. These energy projections represent conservative worst-case end-of-mission battery performance at 0 C initial temperature. More moderate power loads will extend the flight time."
"""H. Thermal System
The helicopter must survive the cold of the night on Mars where temperatures can drop to -100 C or lower. The most critical component is the battery which is kept above -15 C through the night as it powers Kapton film heaters attached to the battery cells. The avionics boards in the ECM surround the battery and are also kept at an elevated temperature by virtue of their proximity to the warm battery assembly. Insulation around the avionics boards is provided by a carbon-dioxide gap of 3 cm width. Additional insulation can be provided by replacing the carbon-dioxide gas with an Aerogel formulation. The outermost fuselage thermal coating is from Sheldahl with Solar absorptivity α = 0.8 and infra-red (IR) emissivity = 0.1.
In addition to thermal losses through the gas gap (or aerogel), additional losses occur due to conduction in the mast as well as through the copper wiring that penetrate the ECM from the mast. To minimize the latter, the wire gauges are selected to be of the thinnest gauges that can still support the current draw during operations without overheating. Prior to flight, under the control of the FPGA, the thermal system powers on heaters in the motor control boards that have been exposed to the ambient temperatures. The internal battery temperature is brought up to 5 C to allow hi-power energy extraction from the cells. During operation the ECM and battery warm up as a result of avionics operations and battery self-heating. However, the thermal inertia of the elements is such that for the short flights of the helicopter, there is no overheating."""
[0] "Mars Helicopter Technology Demonstrator" https://rotorcraft.arc.nasa.gov/Publications/files/Balaram_A...
EDIT: some detail on the battery capacity from section G:
"A de-rated end-of-life battery capacity of 35.75 Wh is available for use. Of this capacity, 10.73 Wh (30%) is kept as reserve, night-time survival energy usage is estimated at 21 Wh for typical operation in the northern latitudes in the spring season, and approximately 10 Wh is available for flight. Assuming that 20% of the power is at the peak load of 510 W and 80% is at a continuous load of 360 W, approximately 90 sec of flight is possible. These energy projections represent conservative worst-case end-of-mission battery performance at 0 C initial temperature. More moderate power loads will extend the flight time."
On top of what others have said, we need advancement it batteries that can withstand low temperatures. Lithium ion batteries generally need to be kept above freezing temps. There have been some advances in capacitors that operate down to -100C, but their energy density makes them a non-ideal option for weight limited applications.
This video from Veritasium does a good job of covering the helicopter power system: https://www.youtube.com/watch?v=GhsZUZmJvaM&t=613s
This video from Veritasium does a good job of covering the helicopter power system: https://www.youtube.com/watch?v=GhsZUZmJvaM&t=613s
On the aerodynamic side, this aircraft has a mass of 1.8 kg / 4 lbs, which is an equivalent weight of 0.7 kg / 1.5 lbs on Mars. That is also the force required to maintain altitude. Imagine picking up four or five apples; that's what we're talking about as a minimum to stay in the air. For comparison, a DJI Phantom weighs 3 lbs, and a Mavic comes in at 2 lbs.
I can't find numbers on the power system or materials so I can't speak to the thermal side or how much flight time that affords.
EDIT: Apparently there's enough energy to fly for 90 seconds (!) per sol.
I can't find numbers on the power system or materials so I can't speak to the thermal side or how much flight time that affords.
EDIT: Apparently there's enough energy to fly for 90 seconds (!) per sol.
[deleted]
“130 degrees Fahrenheit” - seriously? What else, pounds and feet?
The article is written for an American audience. We use Fahrenheit here. That said, -130°F is so beyond what any American can relate to, I agree the article should use C and provide the -130°F in a parenthetical. Amusingly, the article does just that later on:
> During the first flight, the helicopter will attempt to rise about 10 feet (3 meters) in the air from the middle of its flat 33-by-33-foot (10-by-10-meter) airfield...
p.s. -90°C
> During the first flight, the helicopter will attempt to rise about 10 feet (3 meters) in the air from the middle of its flat 33-by-33-foot (10-by-10-meter) airfield...
p.s. -90°C
I think Americans would relate to -90C even less. Many Americans are used to thinking about sub-zero temperatures, it seems less of a burden to conceptualize a really low temperature on the scale you're used to than to conceptualize a really low temperature on a completely different measuring system. The first question most Americans would ask is "What's the equiv of -90 in F?".
Out of curiosity, what do Americans mean when they say "sub-zero"? 0°C or 0°F?
Generally they mean a refrigerator brand but sometimes a character from the Mortal Kombat franchise.
0°F.
0°F. "Below freezing" would be below 0°C/32°F.
I've never lived anywhere in the U.S. that gets that cold, but in my experience, I don't think Americans say that much, but rather "below freezing" to mean below 0°C/32°F.
I happen to easily remember that 20°C = 68°F and usually use that when mapping the temperatures back and forth which works for the usual ranges where I've had to do so by just adding/subtracting 5/9 on each side.
I once translated literally on the run (running the Boston marathon) for a foreigner who asked about the temperature and got a Fahrenheit response.
When I've been in other countries that use C, I've always had to translate from C back to F in my head to make sense of the temperature. The longest I've ever been any place outside the US is 10 days, and that hasn't been enough time for me to get a feel of what temps are in C.
I happen to easily remember that 20°C = 68°F and usually use that when mapping the temperatures back and forth which works for the usual ranges where I've had to do so by just adding/subtracting 5/9 on each side.
I once translated literally on the run (running the Boston marathon) for a foreigner who asked about the temperature and got a Fahrenheit response.
When I've been in other countries that use C, I've always had to translate from C back to F in my head to make sense of the temperature. The longest I've ever been any place outside the US is 10 days, and that hasn't been enough time for me to get a feel of what temps are in C.
> I've never lived anywhere in the US that gets that cold, but in my experience [which we've established is none], I don't think Americans say that much.
It's a thing in Northern climes where the temperatures can get that cold. Everyone living in such places will know the term and you'll hear it frequently when talking about the weather or listening to weather forcasts.
It's a thing in Northern climes where the temperatures can get that cold. Everyone living in such places will know the term and you'll hear it frequently when talking about the weather or listening to weather forcasts.
Where I come from, "It's fucking freezing!" colloquially means "under 10C". Because that's the lower edge of our "normal" climate here, so our houses are not insulated well for temps below that and central heating is rare because it's rarely needed. We also tend to not have a wardrobe with much that's suitable for temps down below 10C, unless you happen to have ski gear or winter motorcycling gear or whatever. (I've got one bike jacket which is too warm to wear at temps much above 10 or 15C - it gets very little use, in spite of me _really_ liking it...)
I'm the opposite way. I understand the world in C.
I've got a few references in my head -40C = -40F (because magic), 0C = 32F (water freezing), 37C = just under 99F which I'm mostly approximate to 100F (body temp). 92C ~= 198F (espresso brewing temp), and 100C ~= 212F (boiling).
I use those to interpolate other F temps to whatever precision I need.
Brewing espresso I care about maybe half a degree C precision. Deciding what clothes to wear I only need to be within maybe 5 degrees C (so to me, 60F is "about 20% under halfway between 100F/37C and 32F/0C, so ~20% less than 18.5C - call it 15 = cold enough to take a jacket). For cooking I don't need to care to much about anything better +-20 degrees.
I've got a few references in my head -40C = -40F (because magic), 0C = 32F (water freezing), 37C = just under 99F which I'm mostly approximate to 100F (body temp). 92C ~= 198F (espresso brewing temp), and 100C ~= 212F (boiling).
I use those to interpolate other F temps to whatever precision I need.
Brewing espresso I care about maybe half a degree C precision. Deciding what clothes to wear I only need to be within maybe 5 degrees C (so to me, 60F is "about 20% under halfway between 100F/37C and 32F/0C, so ~20% less than 18.5C - call it 15 = cold enough to take a jacket). For cooking I don't need to care to much about anything better +-20 degrees.
0F of course. We get pretty cold here.
When some youtuber is camping out in 'sub-zero' temps, I smile. We call it 'warm' in Iowa when it gets above freezing in winter.
When some youtuber is camping out in 'sub-zero' temps, I smile. We call it 'warm' in Iowa when it gets above freezing in winter.
I was hiking on the A.T. back in college mid-March and it was just a bit above freezing and rainy. My group (all from Florida) was bundled up inside a cabin to get out of the rain. In wandered some other college kids in shorts and tees, soaking wet. They were from Minnesota. I really don't know how they didn't have hypothermia, but I guess you can acclimate to quite a range of temperatures... for a while.
The Hunting reaction is, at least in my experience living in a cold climate the better part of my life, a real thing.
https://en.wikipedia.org/wiki/Hunting_reaction
https://en.wikipedia.org/wiki/Hunting_reaction
And when it goes off the rails: https://en.m.wikipedia.org/wiki/Raynaud_syndrome
Yeah at the top of Mt. Baldy we discovered a group of Georgian Scouts huddled shivering under their space blankets in a rock grotto. Meanwhile our Scouts (from Iowa) took off their coats and shirts and ran around like wild men. All about what you're used to!
On the other hand, I, as a year round motorcycle rider, consider anywhere that regularly drops below 0C/32F top be "unfit for human habitation"... :-)
New York city is fun to visit, but I'd never live there...
New York city is fun to visit, but I'd never live there...
Sub-zero in the United States means below 0F. Ambient freezing temp isn't really a "cold" benchmark to people in northern climes, but sub zero (-18C) is a milestone that communicates a cold day from an experiential perspective. For instance, if I tell you a place gets below zero for a couple months, you know it's committed to being frozen, and that circumstantial variations like radiant heat from sunlight aren't going to get you back above 32/0F. Incidentally, freezers are set at 0F/-18C. So being in subzero temps is like being in a freezer, whereas being at 32F/0F could be a completely different experience based on radiant heat from sun, warm winds, etc.
Ambient freezing is certainly a benchmark in Canada. If nothing else it's important as a warning of possible black ice.
"Below freezing" is when it goes below 32°F, "below zero" is when it goes below 0°F, and "ing cold eh" is when there's not a difference between C and F anymore.
Incidentally, –90°C/–130°F happens to be almost exactly the lowest natural temperature measured on Earth (–89.2°C, in Antarctica in 1982).
Protip: -40C == -40F
One way to relate to it is that -128.6F is the lowest recorded temperature ever on earth.
https://en.wikipedia.org/wiki/Lowest_temperature_recorded_on...
https://en.wikipedia.org/wiki/Lowest_temperature_recorded_on...
Making electronics work at a very high or low temperature is a challenge. You normally have to decide between custom-designing all components to work at the extreme temperature, or to figure out how to use off the shelf stuff, yet insulate them from the environmental temperature.
More and more designs are choosing the latter, although notable exceptions are LED light bulbs (which use special components rated to operate for years at ~150 Celcuis)
More and more designs are choosing the latter, although notable exceptions are LED light bulbs (which use special components rated to operate for years at ~150 Celcuis)
I haven't worked on anything related to Mars but have worked on the preliminary design of a camera system for the Artemis Moon mission.
Thermal design can be both surprisingly easy and surprisingly difficult. If the mission profile is cold-biased it's an "easy" matter of judiciously adding heating and insulation (to retain heat). Here "easy" is in quotes because nothing is trivial or truly easy in space.
If you have to deal with temperatures beyond the maximum thermal range of the design, sometimes the "easy" solution (again, in quotes) is to schedule shutdowns or duty cycle around thermal conditions. The power-down storage temperature of most devices is much higher than operating limits. Yes, you would need hardware that can deal with extremes in order to wake everything back up. That's where the rad-hard $300K microprocessors come into the fold.
At the same time, you'd be surprised how well some non-rad hard hardware can do in space. There are imaging satellites that basically use qualified COTS imaging sensors quite successfully.
The case is similar for dealing with radiation. Don't turn things on until you have to and, when you do, if you can, limit operating time to the absolute minimum.
There's a lot more to the art and science of making things for space, of course. Everything out there is actively trying to kill everything you send out there 100% of the time.
Thermal design can be both surprisingly easy and surprisingly difficult. If the mission profile is cold-biased it's an "easy" matter of judiciously adding heating and insulation (to retain heat). Here "easy" is in quotes because nothing is trivial or truly easy in space.
If you have to deal with temperatures beyond the maximum thermal range of the design, sometimes the "easy" solution (again, in quotes) is to schedule shutdowns or duty cycle around thermal conditions. The power-down storage temperature of most devices is much higher than operating limits. Yes, you would need hardware that can deal with extremes in order to wake everything back up. That's where the rad-hard $300K microprocessors come into the fold.
At the same time, you'd be surprised how well some non-rad hard hardware can do in space. There are imaging satellites that basically use qualified COTS imaging sensors quite successfully.
The case is similar for dealing with radiation. Don't turn things on until you have to and, when you do, if you can, limit operating time to the absolute minimum.
There's a lot more to the art and science of making things for space, of course. Everything out there is actively trying to kill everything you send out there 100% of the time.
Especially rechargeable batteries (that the helicopter uses), which not only discharge under extreme temperatures (especially cold), but also degrade in capacity over time.
Maybe JPL has overcome those with some new battery tech, but extreme temperatures have always been the vain of engineers who have to design technology for cold weather.
It'll be interesting to see if multiple cold-weather days or years eventually kill the batteries off. This helicopter only flies for 90 seconds at a time already. If the batteries degrade by 30%, we are talking about sub-minute flight times.
Maybe JPL has overcome those with some new battery tech, but extreme temperatures have always been the vain of engineers who have to design technology for cold weather.
It'll be interesting to see if multiple cold-weather days or years eventually kill the batteries off. This helicopter only flies for 90 seconds at a time already. If the batteries degrade by 30%, we are talking about sub-minute flight times.
A significant amount of energy in the battery is dedicated to keeping the electronics warm, which is why the flights are so short.
I thought I read somewhere that the length of the flight was dictated by over heating. That the thinness of the atmosphere required the rotors to move so fast that it was difficult to radiate the heat produced - radiating that was also made difficult because of the atmosphere.
Video from Veritasium about the helicopter that talk with the team about this. He mentions that 2/3rds of the daily energy gathered is used for the purpose[1]
Other information about the tech; camera & landing, energy use for heating, flight in low pressure atmosphere, the system to actually land the thing, is also really interesting.
https://www.youtube.com/watch?v=GhsZUZmJvaM
Other information about the tech; camera & landing, energy use for heating, flight in low pressure atmosphere, the system to actually land the thing, is also really interesting.
https://www.youtube.com/watch?v=GhsZUZmJvaM
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https://www.jpl.nasa.gov/news/nasas-mars-helicopter-survives...