Voyager 1 Communicating Intelligibly Again

[bilby]

C defined as exactly 299,792,458 m/s is an abstraction. It can not be exactly demonstrated.

No, it's a definition. It requires no demonstration; It is declared to be the truth.

The numerical value can be anything depending on the system.

No, it can't. The numerical value is, and only is, exactly 299,792,458ms^-1

You cannot test or demonstrate the speed of light; You can only try to obtain a more precise measurement of the length of the metre.

 

[steve_bank]

I suspect bacteria mutated by radiation in space into a conscious organism and is trying to communicate with us. Unfortunately they like to eat electronics.

Though we don't know specifically which processors are used in Falcon 9, we do know that they use Linux and dual-core x86 processors in their equipment. Crew Dragon uses three computers, with each processor checking the others for any redundancies or problems caused by radiation in-flight.Dec 29, 2021

Don't know about today, in the past space electronics were hardened against particle radiation. Special doping was used in the semiconductors. Parts were radiated and ones that worked were selected.

Back around the time of the space shuttle to save money NASA went to COTS commercial off the shelf equipment operating in a human environment.

 

[Jarhyn]

C defined as exactly 299,792,458 m/s is an abstraction. It can not be exactly demonstrated.

No, it's a definition. It requires no demonstration; It is declared to be the truth.

The numerical value can be anything depending on the system.

No, it can't. The numerical value is, and only is, exactly 299,792,458ms^-1

You cannot test or demonstrate the speed of light; You can only try to obtain a more precise measurement of the length of the metre.

This is why I prefer Hartree units.

In Hartree units, expression of the speed of light is exceedingly simple and relies absolutely not-at-all on the measured length of the meter, instead being a simple expression of the fine structure constant.

 

[Tigers!]

I doubt a memory chip made today would last 50 years in space. Not even that on earth.

Research radiation-hardened computer chips. They are used in spacecraft, and that's why spacecraft CPU chips may seem behind the times.

Who made its batteries or power supply?

This is not a typical laptop or desktop computer. This is a spacecraft. Tigers!, you are on the Internet, and you can easily find out about spacecraft design.

The main source of electric power for spacecraft is solar panels, but that obviously does not work well in the outer Solar System. So that is why outer-Solar-System spacecraft use radioisotope thermoelectric generators (RTG's).

I bow before the designers of such craft.

 

[Loren Pechtel]

Oops.
I foolishly converted 24b miles to KM

...OK NOW folks can hook into me about my reading/comprehension skills.

So you're a NASA employee?

 

[Loren Pechtel]

I doubt a memory chip made today would last 50 years in space. Not even that on earth.

I'm sure there are chips around that would. It's just that it's always a tradeoff between cost and durability. While NASA obviously cares very much about weight in other respects they build spacecraft like brick outhouses. The cost difference between the best and the worst is usually far less than the cost of simply getting the item there to do it's job.

 

[steve_bank]

Some electronics trivia. Looks lie my long term memory is still woking.


A major reliability issue is moisture. Through the 80s high reliability chi[s were packaged in expensive hermetic ceramic packages, sealed in a dry nitrogen environment. Cheaper plastic packages did not keep moisture out. The solution was called passivization, coating the chip in a glass layer.

US Patent Application for RELIABLE PASSIVATION FOR INTEGRATED CIRCUITS Patent Application (Application #20190312000 issued October 10, 2019) - Justia Patents Search

Device and method for forming a device are presented. A substrate having circuit component and a back-end-of-line (BEOL) dielectric layer with interconnects is provided. A pad dielectric layer is formed over the BEOL dielectric layer. The pad dielectric layer includes a pad via opening which...

patents.justia.com

An old chip reliability issue found in the 70s or 80s was called purple plague because it looked purple. It was fond dung long erm rel9ability tests.

https://ieeexplore.ieee.org/abstract/document/1445389

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Abstracturple plague is shown to be the development of a purple intermetallic compound AuAl 2 when gold wires are bonded to aluminum metallization regions in silicon transistors and integrated circuits. It is further shown that the rate of formation of purple plague is catalyzed by the presence and interaction of silicon, and that the catalyzed product is harmful to the device. Part of the ternary system is investigated to elucidate the mechanism of the ternary interaction. Various metallization-wire systems are reviewed which are currently in use or development. The use of aluminum wire to aluminum metallization is shown to be the simplest, most reliable method presently available for eliminating purple plague.

A long term reliability issue is micro cracks. The dimensions are very small. Like any mechanical part long term vibrations and thermal cycling can increase the fr acre to a point of failure.

Then there are impurities in the chip. With temperature impurities can actually move around with temperature.


That leads to the Arrhenius Equation. Each defect in a sold state device has an activation energy number assigned to it. The equation predicts a failure at higher temperatures

Arrhenius Relationship - ReliaWiki

www.reliawiki.com

Another long term failure mode is the mechanical stress created by electric charges on very thin structures. A number I remember from the 80s is 300 years, estimated of course.

In the 80s reliability of plastic of commercial packaged chips became as good as high reliability parts. Don't know about today, high rel categories were replaced by industrial and automotive grade parts.

It is mostly temperature. Chips are screened at elevated premature and ones that work at higher temperature are but into the higher performance categories.

Temperature is the bane of solid state parts. Electronics reliability is generally modeled by the exponential distribution and the Weibul Distribution. The 'bath tub curve.

Human mortality used to follow a bath tub like curve. The infant mortality rate stars highand drops exponentially wiht time. Birth defects, disease. The curve generally flattens out to what is called the chance region, deaths by random events. Accidents, catching a disease. With increasing age the failure rate increases. Heart disease and so on.

In reliability the early stage fares are called infant failures. The middle range useful life. And the last stage wear out. Complex electronics ted to follow the bath tb curve.

For the mathematically inclined.

The Exponential Distribution - ReliaWiki

www.reliawiki.com

Weibull distribution in reliability analysis - Minitab

support.minitab.com

.

 

[thebeave]

Oops.
I foolishly converted 24b miles to KM

...OK NOW folks can hook into me about my reading/comprehension skills.

So you're a NASA employee?

Or a Lockheed Martin employee...

Mars Probe Lost Due to Simple Math Error

NASA lost its $125-million Mars Climate Orbiter because spacecraft engineers failed to convert from English to metric measurements when exchanging vital data before the craft was launched, space agency officials said Thursday.

A navigation team at the Jet Propulsion Laboratory used the metric system of millimeters and meters in its calculations, while Lockheed Martin Astronautics in Denver, which designed and built the spacecraft, provided crucial acceleration data in the English system of inches, feet and pounds.

As a result, JPL engineers mistook acceleration readings measured in English units of pound-seconds for a metric measure of force called newton-seconds.

 

[Loren Pechtel]

Oops.
I foolishly converted 24b miles to KM

...OK NOW folks can hook into me about my reading/comprehension skills.

So you're a NASA employee?

Or a Lockheed Martin employee...

Mars Probe Lost Due to Simple Math Error

NASA lost its $125-million Mars Climate Orbiter because spacecraft engineers failed to convert from English to metric measurements when exchanging vital data before the craft was launched, space agency officials said Thursday.

A navigation team at the Jet Propulsion Laboratory used the metric system of millimeters and meters in its calculations, while Lockheed Martin Astronautics in Denver, which designed and built the spacecraft, provided crucial acceleration data in the English system of inches, feet and pounds.

As a result, JPL engineers mistook acceleration readings measured in English units of pound-seconds for a metric measure of force called newton-seconds.

JPL engineers mistook.

That's NASA, not Lockheed Martin. NASA didn't RTFM.

 

[thebeave]

Oops.
I foolishly converted 24b miles to KM

...OK NOW folks can hook into me about my reading/comprehension skills.

So you're a NASA employee?

Or a Lockheed Martin employee...

Mars Probe Lost Due to Simple Math Error

NASA lost its $125-million Mars Climate Orbiter because spacecraft engineers failed to convert from English to metric measurements when exchanging vital data before the craft was launched, space agency officials said Thursday.

A navigation team at the Jet Propulsion Laboratory used the metric system of millimeters and meters in its calculations, while Lockheed Martin Astronautics in Denver, which designed and built the spacecraft, provided crucial acceleration data in the English system of inches, feet and pounds.

As a result, JPL engineers mistook acceleration readings measured in English units of pound-seconds for a metric measure of force called newton-seconds.

JPL engineers mistook.

That's NASA, not Lockheed Martin. NASA didn't RTFM.

Its Lockheed Martin too. Here's another, more detailed article. The one I posted above is a little vague on how the error originated:

Mystery of Orbiter Crash Solved

The initial error was made by contractor Lockheed Martin Astronautics in Colorado, which, like the rest of the U.S. launch industry, traditionally uses English measurements. The JPL navigation team, on the other hand, uses metric measurements in the complex business of figuring out a spacecraft's position relative to moving planets and keeping it on course. The contractor, by agreement, is supposed to convert its measurements to metrics.

 

[steve_bank]

A guy fueling a commercial jet in Canada colluded pounds and kilograms. The jet ran out fuel in flight and mnaged to gllide to a safe landing at a closed runway.

 

[thebeave]

A guy fueling a commercial jet in Canada colluded pounds and kilograms. The jet ran out fuel in flight and mnaged to gllide to a safe landing at a closed runway.

I think that is referred to as the Glimly glider (or something like that). There was some sort of event or festival taking place at the abandoned airstrip, when this huge jet came gliding it. Kids on bicycles pedaling furiously to get out of the way. It must have been pretty surreal to have this plane came out of nowhere and interrupt your event like that.

 

[steve_bank]

I saw the movie....

From a show that looks at air disasters the first 3 or 4 crews who tried the scenario in a a simulator crashed.

 

[bilby]

Gimli Glider.

Don't you folks have Internet access??

 

[thebeave]

Gimli Glider.

Don't you folks have Internet access??

Yes, but its much more fun using foggy memories, rumors and innuendo to reconstruct a story from 40 years ago.

 

[steve_bank]

I watched a show on the failure analysis.

There were multiple issue including electronics.

It began with the guy fueling the plane not sure whether to report kg or pounds and made mistakes. His original paperwork was shown with his calculations.

The plane was a new model at the time and the fuel system used kg instead of pounds. It turned out the pilots had received insufficient no training on the new systems which added to the confusion. On older planes the flight engineer was directly responsible for overseeing fueling.

If you actually read the page it was both pilot and ground crew error.

Commercial jets can and do fly with electronics failures as long as there is an approved written backup plan in the plane's documentation.

What it shows is that there will be a catastrophic commercial space flight failure where commercial p[passengers will die.


I worked in a group that made true mass flow rate meters for commercial jets. Meters that give the true mass of fuel consumption regardless of density.

'Pilot error' as a metaphor is common, we don't usually hear about it unless it is public or catastrophic. The defect in the Hubble mirror. The decision to launch the shuttle Challenger in cold weather.

 

[Loren Pechtel]

A guy fueling a commercial jet in Canada colluded pounds and kilograms. The jet ran out fuel in flight and mnaged to gllide to a safe landing at a closed runway.

It never should have been in the air in the first place. All fuel gauges inoperative put it below the minimum equipment list to operate. They used dipsticks to measure the fuel, didn't realize the units.

And it's survival was due to the fact the pilot had glider experience. The energy didn't come out right for the approach, in the powered aircraft world you reject the landing and go around. Glider pilots do not have that option and are experienced with things like crabbing the plane (wing controls pushing one way, tail controls the other--the plane flies slightly off center and burns up a bunch of extra energy) that is what saved the Gimli glider.