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SayuriShigeko t1_iv9h4nh wrote

Nasa apparently has an article about their understanding of this actually: https://www.nasa.gov/mission_pages/MRO/multimedia/pia12992.html#:~:text=Most%20scientists%20think%20the%20the,rocks%20it%20is%20built%20of.

Tldr: it's not traditional erosion from water or wind, nor is it tectonic in nature. The edge collapsed in a landslide. As the volcano erupted over time it built up more and more depositted material in layers, and eventually the mass became too heavy for the bottom material layer to support so it crumbled and caused a land slide.

(Paraphrasing and a little filling in of the blanks here, I honestly only skimmed it out of curiosity, I would suggest reading the article if you really want more details)

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theelous3 t1_iv9vlbm wrote

Man, nasa is the coolest. What an incredible body of work in such a relatively short amount of time.

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dirtyuncleron69 t1_ivaeida wrote

Everyone I have worked with from nasa is absolutely top notch as well. A really good example is the Tin Whisker Symposium which diagnosed the failure of the toyota gas pedals in great detail.

They are the foremost experts in a ton of different fields at the same time.

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evranch t1_ivalv0z wrote

Great link, such detailed study into a niche problem with wide ranging effects.

I've always thought there was something behind the higher failure rate of electronics post-ROHS, and it's interesting to see that milspec still requires lead in coatings. Personally I still use lead solder and find a lot of failed modern electronics can be repaired for good by simply reflowing them with a touch of 60/40.

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[deleted] t1_ivbq1io wrote

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[deleted] t1_ivbruo9 wrote

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[deleted] t1_ivbwal2 wrote

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Cre8AccountJust4This t1_ivb90fp wrote

Hahaha one of those articles actually says: “Box could be reset through percussive maintenance (aka: hitting the front panel)”

‘Percussive maintenance’ 😂😂😂 I’m definitely going to be stealing that one!

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[deleted] t1_ivanxny wrote

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dirtyuncleron69 t1_ivar591 wrote

https://nepp.nasa.gov/whisker/reference/tech_papers/2011-NASA-GSFC-whisker-failure-app-sensor.pdf

here is the write up on the gas pedal specifically

A couple unique problems,

  1. mechanically dis-assembling the pedals broke the whiskers and fixed the problem

  2. Using a standard ohm meter also destroyed the whiskers via melting them from overcurrent without detecting them

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[deleted] t1_ivarzbt wrote

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SashimiX t1_ivatl42 wrote

Full quote:

– If the pedal is depressed quickly, then throttle is limited to 15 degrees
– If the pedal is depressed slowly, then throttle can jump to 15 degrees, and further pedal application can achieve wide open throttle
• In all cases, releasing the accelerator pedal closes the throttle, and brakes are fully operational
– Although the vehicle would operate, we did not consider it to be driveable

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Miss_Speller t1_ivdisgt wrote

This was a great writeup, but I especially enjoyed the Charybdis and Scylla illustration on p28. More whimsey than I was expecting in a NASA publication, which is wonderful!

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mrbombasticat t1_ivbbzqt wrote

e.g. in an Revisionist history podcast episode they concluded it was and is pedal confusion almost every time.

Even if the gas is stuck (which happened sometimes with after market floor mats according to the NHTSA) the brakes can easily overpower the engine in every car, which they tested in a 500hp car.

So for a car to get out of control without pedal confusion the gas has to get stuck and the brakes have to fail at the same time.

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KingZarkon t1_ivbs6ap wrote

From another comment I made, if your throttle is running wide open, then you lose engine vacuum. You have what's in the vacuum reservoir but that's it. Without regenerating it, you have enough to hit the brakes once, maybe twice with good power. After that, there's little chance a person could push the brake pedal hard enough to overcome the engine at full throttle. I suspect these tests have not taken that into consideration.

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akmacmac t1_ivd9edv wrote

I disagree. Not all cars have vacuum operated brake boosters. Also there was a time when no car had a brake booster or power steering. You can still stop without a working brake assist, it just requires more force on the pedal, just like you can still steer without power steering.

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l337hackzor t1_ivbw9c7 wrote

What about the e-brake? It's still just a cable brake.

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KingZarkon t1_ivc2zbw wrote

It would stop the rear wheels but they would just lock up and end up dragging behind when you've got a fwd vehicle.

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l337hackzor t1_ivc4u3m wrote

I figure that would at least cause the engine to stall?

It was front wheel drive cars that had the "stuck accelerator" issue wasn't it?

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VertexBV t1_ivcptby wrote

I don't get the feeling the hand brake on my Civic is good for much more than parking. It takes quite a bit of force to achieve the same braking in motion you'd get with a light touch of the foot on the pedal.

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l337hackzor t1_ivcv7mn wrote

You might be surprised. I suppose if the engine is applying force it probably won't do much but you can stop a car with it otherwise.

We had to do it in driving school. You want to gradually apply the brakes while holding down the button otherwise you can throw yourself into a skid.

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smoozer t1_ivd5v1o wrote

It'll lock the wheels up if you activste it hard in any vehicle I've driven (up to ~2011)

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Drone30389 t1_ivdih2w wrote

emergency/parking brakes are extremely weak compared to the regular brakes.

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Tunafishsam t1_ivcm39e wrote

Seems like they found an unrelated manufacturing defect. Their summary seems to say that quickly depressing the throttle resulted only in 15 degrees of throttle. That's the opposite of the "stuck" accelerator problem.

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doug-fir t1_ivcifyx wrote

I remember back in the 1990s, NASA produced aerial photos showing the the liquidation of old growth forests in the Pacific NW was worse than the destruction of the Amazon. That opened a lot of eyes.

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redpat2061 t1_ivab8ko wrote

If they aren’t going to send people to space they gotta spend our money on something

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redballooon t1_ivbrqqd wrote

And they do. Unlike corrupt politicians who just pocket the money doing only smallish favors.

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eaglessoar t1_iva9btk wrote

I can't work out the orientation of that image, is it top down or a bit on profile?

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LordOverThis t1_ivabb35 wrote

It does kinda look like just a big ol’ mass wasting, so that checks out.

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Zoomalude t1_ivak7pt wrote

I don't understand why this would happen that "low" from the massive weight but not higher up where there's even MORE weight. Like, why wouldn't the whole thing have a massive collapse or like one big side of it at least?

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TheGrandExquisitor t1_ivaqyyi wrote

This is a very complex structure. And at this scale (which is MASSIVE...I mean the footprint of Olympus Mons is pretty much equal to the entire area of France. Oh, and it is 25km tall. There is a lot going on in there.

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willun t1_ivcort1 wrote

Isn’t it basically flat? 25km over the area of France should be so gentle a slope as to be unnoticeable

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TheGrandExquisitor t1_ivctrs6 wrote

As I recall that is true. It can basically be walked up with no special equipment (theoretically of course...I don't think it is that smooth, but the issue would be the local gradient, not the overall gradient.)

That is, after you get up the 7000 meter escarpment. That seems like it would be slightly more difficult.

But hey, after that the next 300km are easy!

I've always wondered if Olympus Mons wouldn't be an ideal place for a Mars based telescope. I think the top is almost out of the atmosphere.

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willun t1_ivddkdq wrote

Mars atmosphere is thin, almost a vacuum being about 1% of earth. Something those who are big on Mars colonies get upset if you remind them. So it may not make much difference.

A telescope on the moon would be easier than putting on Mars but i guess if you were going to do it on Mars than Olympic Mons would be a good place. We put them on volcanoes on Earth frequently so there is lots of precedence.

The moon has a lower rotation speed so probably has other benefits too.

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brokenaloeplant t1_ivb897f wrote

For the material in the middle, it's all surrounded by crystalline rock. It would have nowhere to collapse into, unlike the edges. If there was a ton of air captured inside or there was a hollow cavity like some kind of sink hole, then maybe.

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B0Boman t1_ivag5wh wrote

I wonder if the remaining material is stable or if walking on the edge of that cliff would cause it to collapse further.

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