Right, having a second chip functioning as a watchdog which doesn't share the same silicon substrate mitigates the latchup. If you can recover before both theoretically could get struck, statistically you'll be okay. For added safety, have an extra one that is not coplanar with the other two so a single heavy ion strike can't pass through all 3 chips.
I've taken a number of MCUs through radiation testing including testing watchdogs. I've generally found that latchups often take out the watchdogs, even something like the STm32 independent watchdogs, and shouldn't be relied on.
External hardware or a different system need to be deputized here.
What's so odd about this is that they add the flash ($), but skip the magnetics! It just has series capacitors and I don't think the jack has integrated magnetics since it's small and it wouldn't make sense to have a series cap as well.
I entirely agree that there is substantial tolerance for vehicle noise tolerance and this drives me crazy. Cities aren't loud, cars are!
I just want to make clear though that replacing the ICE part with electric engines solves the problem for low speeds only -- once they're going at a reasonable speed, engine noise doesn't dominate (if you exclude the antisocial behaviors of deliberately loud vehicles, most motorbikes).
I had a similar experience in a rental. The one feature I missed was a wireless key fob, which is not included in the base trim. I understand the relentless cost pressure in automotive mfg, but that seems like it would have been $2 worth spending.
Less than 5% of a full load. Any extra fuel you brought to the edge of space and back is lost performance, so substantial efforts are made to minimize this lost mass fraction.
I have been very interested in 802.11ah halow (wifi in 900mhz ism band) to solve the inconvenient distances where 2.4g wifi has insufficient range, but something like a LTE catM modem is overkill. I'd be very disappointed if this effectively takes over the band nationwide.
Can anyone comment on nextnav's intended duty cycle or just how much they'll occupy? They're asking for a lot of bandwidth, so perhaps it's in a short enough burst and infrequent enough to not cause real problems?
Alas there is no 'in general'. Acquisition is often the secret sauce due to, among other challenges, the extremely tight alignment requirement -- thermal shifts, satellite wobbling, etc, are all critical to manage.
On wavelengths, if you're trying to hit 100gbit+, you're probably having to use coherent optics, and there aren't many technology options or wavelengths on the market.
Take a look at the slides from the presentation, I think the geometry clearly shows cross-plane links in the mesh. Having worked on these types of systems, I've had more difficulty with the lookahead angles (rx from where the target was, tx to where it will be due to speed of light) than the tracking -- fine tracking performance was required for all modes, and it largely became a GNC and acquisition time issue (since they're ephemeral) for the cross-plane links.
There has been a lot of work developing standards for reliable ethernet for industrial and automotive applications, resolving most of the issues you mention which apply to 100/1000Base-T. Tesla isn't using your garden variety ethernet or abominations like ethercat.
100/1000Base-T1 is intended to be used with PoDL (802.3bg/cu) and TSN (various 802.1Q)to result in reliable links with guaranteed latency and bandwidth properties.
PHY power is a few hundred mw though, and star topologies are limiting to replace CAN/LIN nodes, that's what 10Base-T1S is for though (cheaper, bussed, lower power).
Came to upvote this. The station works unreasonably well. The needles are pointy enough that they deform solder/copper a little bit and stay put once placed (you can flex the arm to preload the needle).
You can buy it on the maker's website in the second link, with all the bits for ~50eur.
Naturally this is no good for high frequency, but it has saved me countless hours of soldering and removing fine wire in the lab.
Most panels shipped to space can't support themselves: Google "solar array deploy" and you'll see videos from lots of space missions where there are complex deployment jigs to hold the panels from collapsing under their weight during testing.
This isn't the entire story though - launch loads still meaningful contribute some to the weight. A certain amount of mechanical stiffness will still be required even for in-space builds for stability and controllability against slew, solar wind, drag, etc, putting a lower bound on mass. I'd like to see technologies that can avoid coverglass requirements (for atomic oxygen, solar wind), but that's a fundamental physics problem that looks tough to me.
I chose Trident because I wanted a fair(er) comparison of costs due to purchasing power. If you want to use North Korean ICBM pricing, it's $30M[1]. THAAD is very expensive, that you're right about...but it's also the only interceptor that has a chance of success against an ICBM. Please note as well, trident is typically deployed with far fewer warheads likely among other reasons because it doesn't need to be an interceptor sponge, per its role. If you're North Korea with a small arsenal, every one needs to count against an opponent with THAAD.
THAAD interceptors look to be ~$100M each from a google search. I remember seeing a leaked document that suggested up to 3 interceptors would be fired at each target to guarantee a kill, but I can't find the document now, sorry.
A Trident-D5 missile is $30M, and can carry up to 14 (small) warheads (which would likely be a mix of larger warheads and penetration aids). Trident is still in production, but note that it's an economical US missile.
So given this very approximate math, ~$2M on offense could soak up ~$300M on defense. The cost comparison would look worse for the defense if you don't assume the (high) cost of a US offensive missile for parity.
It's nothing like the 100x graphics card though, it's the 1.2x graphics card, and perhaps a few percent more for efficiency improvements. If it's down as far as 80% after 25 years, replacing it will net you such a small improvement for such a large amount of work to tear out and replace.
I dislike trash as much as the next person, but 50MT is 2% of global waste production (2000MT from my search). Is 50MT or (<1% of predicted 2050 waste) really that bad for generating most of the world's energy? This is before considering that solar panel lifetimes keep increasing; some solar panels are sold with 40 year warranties (88.3% @40years, SunPowerMaxeon), so that number could come down perhaps by half.
It's less unreasonable than you think. The Ranger 1 spacecraft attempted to land a payload with an impactor before the US had figured out how to land more carefully.
This probably isn't your issue, but I've had issues in the past, usually with a cell phone that sits in my pocket, that show up as cables no longer maintaining detent and falling out. The issue was actually accumulated dirt in the bottom of the female connector. Scraping it out with a toothpick fixed it for me. Just a FYI.
Can you tell me more about this? Are you unable to hit line rates, or are you just commenting about lackluster io options? I'm looking to add some M.2 storage via thunderbolt enclosure to my machine and would otherwise be expecting to be able to saturate the pcie lanes.
Can confirm this from my own experience.
Just elaborating on the availability requirements, the idea is that clouds aren't everywhere at the same time, so if you have enough in-space bandwidth, you can hop your traffic around the constellation until you reach a satellite that is above a cloud-free area.
Interesting perspective. Another view: solar panels on your roof, using your car battery for your house nighttime needs means that during doomsday your energy intensive lifestyle doesn't have to change at all.
You have to be very careful when talking about relative pollutant emissions. Yes, the average EV is heavier and results in more tire wear and tire dust, but note that these particles are much larger (pm10 or larger) than most ICE particulates (~pm2.5). Heavier particles fall out of the air much faster and don't get stuck in the bottom of lungs. Overall pm2.5 particles are far more harmful to human health once inhaled as well.
Regarding maintenance, road wear is a high order function with axle weight - so trucks and weathering contribute the vast majority of wear. So light duty cars getting a bit heavier won't make much difference, and regulations already bound axle weights, so it won't be increasing for EV heavy duty vehicles.
This all being said, the average American city and suburb suck and totally need to be reorganized around literally anything except the automobile. Visiting the Netherlands just made me sad...thinking this is how nice cities can be. I imagine the mental health benefits of such city planning could even outweigh the environmental ones.