Sunday, December 18, 2011

Added complexity- Do we really need it?

Interesting article on complex electronics added to new cars. I have always felt this way about launch vehicles- most cell phones have more computing power than used for the moon landings.  Why have UNNECESSARY complexity that reduces reliability and degrades performance (gross system weight)?  Some of the launch vehicles I've worked on had avionics systems that were heavier than the propulsion!



soubriquet said...

Absolutely in agreement with you.
I recently got a new phone. Now, I do use the cellphone camera a lot, so I chose one with a good camera....
But, it's a Samsung GalaxyII, android device, touchscreen....
And I find I'm still carrying my old SonyEricsson C905 around, because its quicker and easier to use in almost every way. Yes, it lacks the much advertised paperback book sized super amoled screen of the samsung...
But overall its half the size.
The Samsung's better at the internet, but most of its much vaunted features are, to me, pointless. I'm sure that with its processing power it could manage a mars mission, but I wish it was as good at being a phone. With the Sony, most things require no more than two actions. With the android phone, everything requires six or more. Intuitive it's not.
I've long had arguments with my brother, who is a programmer. Going back to the eighties, over poor programming. He's a geek, and thinks in code, but he has the common tech expert's problem in relating to users.
To call the person who needed to ask the helpdesk to resolve what for the helpdesk guy was an easy problem, findable on page 972 of manual "B", an idiot, is to miss the greater point. That the goal of the programmer is to make all those manuals unneccessary.
Maybe what little brother should be asking, is why the product isn't intuitive enough that the helpdesk guy has no calls and just gets fat on coffee and doughnuts.

Um... The samsung's a better satnav than my dedicated garmin thing. I do use a few apps. Just hate it as a phone. And it's okay, no more than okay as a camera. And most of that's down to controls.. With the Sony, I snap the lens cover open and take a pic. crisp, sharp, even in low light.
With the samsung? by the time I've got it configured, the moment's gone. And it has no corkscrew.

I'll bet those phone designers are working on software corkscrews and high-torque socket-wrenches as we speak... Oh. and I want it to be able to jump-start my car on a cold morning too.

Stephanie Barr said...


Here on the ground, if one's computer hardware or software fails, you repair a component, wipe and reload, or toss it and get a new one. In most cases, we don't have extensive backup and redundancy because the repercussions are minimal. Just money.

When things are more critical (say flight control systems for air craft or nuclear reactor systems) we have redundancy, backup up uninterruptible power supplies, duplicate sensors/controllers, fail safe software (of a different design). They use high reliability components because the repercussions of failure are devastating.

Is it too much on launch vehicles, where weight is a big deal? Hard to say. Simplicity is inherently easier to debug (both hardware and software), analyze and optimize. But, single point failures can kill you and space travel, boys and girls, is not forgiving. Your first mistake is often your last.

Given the cheapness and lightness of today's electronics, however, it should be so weighty, but the space community still uses high reliability MIL spec parts wherever it can, adding weight and cost and frequently at the expense of capability. On the other hand, COTS parts are frequently unreliable on the notion that they can be replaced easily and tin plate parts are becoming the norm, allowing things like tin whiskers to devastate even redundant systems.

Note that I've worked space safety since 1994 so I'm opinionated. I want a system built so that one component can't kill me unless I know that component won't fail. I want it simple enough with non-menu driven software that a pilot could fly it but reliable and capable enough that he doesn't have to.

In fact, those are the human rating requirements.

Oh, and I fought against my touchscreen android phone for the largest. Got one and I LOVE it. Everything's as easy to use as my old phone, if not easier.

But, I hate menu GUI interfaces and always have. Even on computers.

rocketsciencesense said...

Great comments, thanks. I'll come back later when I have more time to respond.

Real quick on phones- I had the Samsung Galaxy and it was awful- I quickly upgraded to the Droid Bionic and it is larger and much better.

Excellent point of COTS parts when actually I have seen there use qualified by there "proven" reliability (as well as cost). However, when a system is used in a different environment that "proven" reliability is lost. I worked on the X-43a which used a Pegaus launching in a vastly different flight envelop. Yup, the first flight of the X-43A scramjet failed do to failure of the Pegaus launcher. As soon as you use a component in a new way its function will also change sometimes in unexpected ways. Thanks again, I'll add more later.