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dirtyuncleron69 t1_ivaeida wrote

Reply to comment by theelous3 in What is the cause of the steep escarpment at the base of Olympus Mons? by Strong-Ball-1089

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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