Faulty hardware found on shuttle

"Jorge R. Frank" wrote:

Of course they can, if the *purpose* of the comparison is to show that even
a first-of-a-kind spacecraft like the shuttle isn't "two orders of
magnitude" (as one poster claimed) more complex than an nth-generation
airliner.

The comparison is mostly meaningless because there is no metric for
'complexity', only subjective judgement.

Again, don't confuse complexity of design *effort* with complexity of
design *solution*. Yes, the software took a lot of care to develop, but
the resulting solution was much simpler than that of a 777.

Complexity of design effort directly affects costs. Just because two
things are equally 'complex' in their end state, does not mean they
should cost the same to develop even though the development processes
were of wildly different 'complexity' levels.

D.
--
Touch-twice life. Eat. Drink. Laugh.

In article , derekl1963
@nospamyahoo.com says...
Marvin wrote:
Microsoft has a great sales department, second only to their legal staff.
But quality control is waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaay down on the
priority list.

No longer true. QC has had a real priority for about two years. That's
why Passport has pretty much been phased out and Hailstorm has vanished
-- they couldn't be made to work. Also note the record of Windows 2003
Server, which is orders of magnitude better than early Windows.


*Right*. That's why millions of people around the world use it on a
daily basis.

And smoking can't be bad for you, since so many people are smokers.


It's far from perfect, but it does work, people hold it
to an unrealistic standard and them complain when it fails to meet
that standard.

Fair enough -- we don't expect Shuttle to fly to the Moon.

Let's try a realistic standard: compare it to other contemporary
systems. While the Windows XP that is running on my laptop is waaaay
better than Windows 3.1, it still falls short of contemporary Linux
systems.

With a exception of a single machine that had its network interface
removed and its floppy drive expoxyed shut, no Windows machine has ever
received a non-lousy Orange Book security rating, yet various Unix
systems have received high evaluations.

There are legitimate arguments that Windows machines are not just a
hazard to their owners, but also endanger non-Windows systems since
Windows-born malware can seriously disrupt the shared resource of the
Internet. No other operating system has been singled out for this kind
of disruption.
(see http://www.newsforge.com/relocate.pl?id=
31a5092ddba1fec14d06b2e38a44232a for this argument)
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins

In article ,
says...
The advantage of a limited memory for a computer is that it forces the
programer to really sit down and work the problem on paper to simplify it
before starting to code.

Youch! In software engineering (heck, all forms of engineering), the
development cost is a strong, non-linear, function of the number of
constraints on the system. A computer that is almost too small provides
a number of constraints that make it *much* harder to build a good
system.

One of the hardest lessons learned in the past half-century of
programming, is that it is really, *really* hard to work the problem on
paper. So much so that the current flavor-of-the-month in programming
("extreme programing") flatly rejects that it is possible. The folks who
have learned to work the problem on paper (e.g., Dijkstra, who never
learned to use a word processor and eventually transended the
typewriter, composing his latter thoughts with pen and ink) are
exceeding rare.


If they hire microsoft weenies to code the next
shuttle, they'll just bloat the code up and not worry about limited
resources and that is when you start to have problems because you're not
careful with memory allocation, buffer sizes etc etc.

On the other hand, if you have a bit of margin in cpu-speed, real-time
requirements, and memory, it is valid engineering to consider not
forcing the programmers to be careful with memory allocations. Let the
machine keep track of memory usage (keyword: "garbage collection").

If you have significant margin, you often have the chance to consider
reusing some programs that already exist. Reuse can have a dramatic
effect on cost, time and reliability of a system.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins

In article , says...
But what users actually need (despite contrary propaganda from microsoft),
is a *stable* and *predictable* and *secure* system.

That's not sufficient. There are any number of stable, predictable and
secure systems that are unusable by all but a handful of specially
trained experts (VMS, Linux, VxWare, Multics, OS/390...).


There have been other operating systems that delivered this, but they didnt
have nearly the public-relations and legal-wrangling skills of microsoft,
thus they got gobbled up or trampled out of business.

While acquisitors are a curse to the software industry, you
misunderstand why Microsoft became dominate. Part of it was marketing --
they do this quite well. Part of this the code-bloat that annoys so many
people. There were any number of word-processors that let someone create
a newsletter, or a book, or a Wanted-Dead or Alive poster, but MS Word
was the first (and still only) word processor that let you do all of
these. In the corporate world, there is a real benefit to having all
your documents readable by everyone in the company. Microsoft
understands and exploits this.


Microsoft is an incredible business success.

These days, one also has to admit that their monopoly position gives
them incredible leverage.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins

In article ,
says...
Thus, the free market in action. Nobody is forced to buy MS products.

Wrong. My brother is a Linux guru, hates Windows, so his new laptop was
purchased with, yes, Windows. The manufacturer can't sell him a laptop
without some version of Windows on it.

Several recent court actions have demonstrated that Microsoft has used
its monopoly position to do coerce the purchase of MS products.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins

In article , "Greg D. Moore
\(Strider\)" says...
"Kevin Willoughby" wrote in message
...
Several recent court actions have demonstrated that Microsoft has used
its monopoly position to do coerce the purchase of MS products.
This is true. But on the some token, some of the best examples I've seen
used of this in fact turn out to be weak.

The best example of this aren't weak, but might not be easy to explain
to a "jury of your peers". My favorite example: having written programs
that create web sites, I used to have a least a half dozen web browsers
on my office machine. Somehow, IE managed to find some way to reset the
file-associations/MIME types so that IE was always the preferred
browser, regardless of my efforts to the contrary.


Lotus 1-2-3 for Windows never made the transition partly because they bet
the farm on OS/2 and because when they did release their Windows product it
sucked.

I worked for startup where the CTO and VP/Engineering came from Lotus.
Apparently Microsoft sold them on OS/2, claiming that OS/2 was the
future and Windows-2.0 was the past. (Well, they were half-right.) 1-2-
3/OS2 was designed by Lotus' best architects, based on the 1-2-3/MS-DOS
code base. 1-2-3/Windows was a complete rewrite of everything by folks
who lacked experience -- second system effect?

Of course, to this day, they blame Microsoft, claiming the Excel team
had special access to the Windows team. Somehow, they never managed to
provide hard evidence to support this claim...


After that, IE became a faster, more stable product.

The flip side of this: once IE has significant market-share, the "Great
Browser Wars" insured that a web site that looked good in Netscape was
unreadable in IE. At that point, webmasters had to either design two web
sites (one for IE, one for Netscape), or add a "best viewed with IE" tag
at the bottom of page...


Price had nothing to do with it as many claimed

No, but for the "everyone can use the Internet" audience, being pre-
installed into the operating system and constantly resetting MIME-
type/file-type associations was a real advantage.


There's no doubt MS has taken advantage of their position. The
single-sourcing OS deal I think is one of the stronger examples.

These days, Windows Media Player is also a strong example. Witness the
recent E.U. ruling.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins

In article , says...
If you allocate some memory and the code that deallocates it doesn't always
get executed, it means that your logic is flawed and you haven't done the due
diligence to ensure your code reflects the intentions all the time.

Or it may mean a deliberate decision that 0.000001 seconds of CPU time
is less valuable than hours spent by a programmer, followed up by hours
and hours spent by program reviewers.

Which is cheaper: a microsecond of computer time, or 24+ hours of people
time?

(Oddly enough, this is on-topic for sci.space. Misplaced priorities
aren't limited to software engineering. Spacecraft engineers sometimes
focus on launch mass or GLOW to the exclusion of other important
parameters.)
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins

On Sat, 27 Mar 2004 23:58:59 GMT, Richard Lamb wrote:


But, just for a moment, everybody take a couple of steps back,
and take in the whole thing at once.

This really is one awesome machine.

Yeah, it would be damned hard to build one in your garage...

Dale

(Derek Lyons) wrote in
:

"Jorge R. Frank" wrote:

Of course they can, if the *purpose* of the comparison is to show that
even a first-of-a-kind spacecraft like the shuttle isn't "two orders
of magnitude" (as one poster claimed) more complex than an
nth-generation airliner.

The comparison is mostly meaningless because there is no metric for
'complexity', only subjective judgement.

And in my subjective judgment, development cost is a decent, though
certainly not perfect, metric for complexity of design effort.

Complexity of design effort directly affects costs.

Agreed.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

Richard Lamb wrote in
:

But, just for a moment, everybody take a couple of steps back,
and take in the whole thing at once.

This really is one awesome machine.

Oh, no doubt about it - I work with it every day. My point is not that the
orbiter *isn't* an astonishingly complex vehicle - it surely is. My point
is that airliners have *also* become astonishingly complex over the last
few decades.

--
JRF

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check "Organization" (I am not assimilated) and
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