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Huygens A-channel images will never be seen??



 
 
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  #1  
Old January 16th 05, 02:44 AM
Ken
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Posts: n/a
Default Huygens A-channel images will never be seen??

from

http://www.spaceflightnow.com/cassin...15science.html

As it turned out, Cassini never listened to channel A because of a software
commanding error. The receiver on the orbiter was never commanded to turn
on, according to officials with the European Space Agency.

"We should remember we're human and we should learn lessons, so I will
institute an ESA inquiry on how the command came to be missing," David
Southwood, director of science for the European Space Agency, told reporters
today. "I'm not going to say any more about that, I'm not going to speculate
(about blame)."

In an obvious reference to NASA and earlier news reports, he did say "there
have been some erroneous messages implicating one of the other space
agencies involved. No. It's an ESA responsibility."

According to published reports, an ESA official said earlier that the
missing command was part of a software load developed by ESA for the Huygens
mission and that it was executed by Cassini as delivered.

"There isn't any doubt that the command was missing," Southwood said today.
"But I'm not going to say any more because the point of an inquiry is to
find out. We will certainly have NASA representation on the inquiry, but I
don't want to make a big thing about it."


  #2  
Old January 16th 05, 05:24 AM
Michael McCulloch
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Default

On Sat, 15 Jan 2005 19:44:34 -0600, "Ken" wrote:

from

http://www.spaceflightnow.com/cassin...15science.html

As it turned out, Cassini never listened to channel A because of a software
commanding error. The receiver on the orbiter was never commanded to turn
on, according to officials with the European Space Agency.


That's a inexcusable error. Sure, anyone can make a mistake, but with
the sums of money and man-hours spent on these missions is it not
resonable to hold to a higher standard?

Unknown conditions that cause unforeseen effects -- ok. But a software
error? C'mon.

---
Michael McCulloch
  #3  
Old January 16th 05, 11:46 PM
md
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Posts: n/a
Default


"Michael McCulloch" wrote in message
news
On Sat, 15 Jan 2005 19:44:34 -0600, "Ken" wrote:

from

http://www.spaceflightnow.com/cassin...15science.html

As it turned out, Cassini never listened to channel A because of a software
commanding error. The receiver on the orbiter was never commanded to turn
on, according to officials with the European Space Agency.


That's a inexcusable error. Sure, anyone can make a mistake, but with
the sums of money and man-hours spent on these missions is it not
resonable to hold to a higher standard?

Unknown conditions that cause unforeseen effects -- ok. But a software
error? C'mon.


why is it so unthinkable to software fails or contains an error? ever done a complex software
creation project?
--
md
10" LX200GPS-SMT
ETX105
www.xs4all.nl/~martlian


  #4  
Old January 17th 05, 12:12 AM
Tim Killian
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Posts: n/a
Default

The operative word is "complex" I would ask why the software for the
data transfer wasn't simplified. But ESA _only_ had seven years to run
simulations and debug the encounter code ;-)

A $250MM F-22 crashed last month because the flight software locked up
as the pilot rotated on takeoff. Fortunately, the pilot had a couple of
seconds before impact and was able to eject. It's a prime example of the
terrible state of software tools and processes used in modern systems.

md wrote:

"Michael McCulloch" wrote in message
news
On Sat, 15 Jan 2005 19:44:34 -0600, "Ken" wrote:


from

http://www.spaceflightnow.com/cassin...15science.html

As it turned out, Cassini never listened to channel A because of a software
commanding error. The receiver on the orbiter was never commanded to turn
on, according to officials with the European Space Agency.


That's a inexcusable error. Sure, anyone can make a mistake, but with
the sums of money and man-hours spent on these missions is it not
resonable to hold to a higher standard?

Unknown conditions that cause unforeseen effects -- ok. But a software
error? C'mon.



why is it so unthinkable to software fails or contains an error? ever done a complex software
creation project?


  #5  
Old January 17th 05, 01:08 AM
md
external usenet poster
 
Posts: n/a
Default


"Tim Killian" wrote in message
...
The operative word is "complex" I would ask why the software for the
data transfer wasn't simplified. But ESA _only_ had seven years to run
simulations and debug the encounter code ;-)


really? was ESA able to upload bugfixes during flight?

A $250MM F-22 crashed last month because the flight software locked up
as the pilot rotated on takeoff. Fortunately, the pilot had a couple of
seconds before impact and was able to eject. It's a prime example of the
terrible state of software tools and processes used in modern systems.


or: it shows how hard programming can be.
--
md
10" LX200GPS-SMT
ETX105
www.xs4all.nl/~martlian


  #6  
Old January 17th 05, 02:03 AM
Michael McCulloch
external usenet poster
 
Posts: n/a
Default

On Sun, 16 Jan 2005 23:46:25 +0100, "md" not given to avoid spam
wrote:

why is it so unthinkable to software fails or contains an error? ever done a complex software
creation project?


Yes, it is my daily job. With the resources they had there is no
excuse in my opinion if the error really turns out to be omission of a
command for Cassini to listen.

In the past I have been through the US government's idea of software
development (is the ESA similar?). The philosophy is basically to
produce a mountain of useless paperwork and rely on the "system" to
make things work. There's no replacement for individual
responsibility/ownership and exhaustive testing.

---
Michael McCulloch
  #7  
Old January 17th 05, 06:31 AM
Hsai Fu
external usenet poster
 
Posts: n/a
Default

well dont they ....ing test it!?
merci beau****s.









Ken wrote:

from

http://www.spaceflightnow.com/cassin...15science.html

As it turned out, Cassini never listened to channel A because of a software
commanding error. The receiver on the orbiter was never commanded to turn
on, according to officials with the European Space Agency.

"We should remember we're human and we should learn lessons, so I will
institute an ESA inquiry on how the command came to be missing," David
Southwood, director of science for the European Space Agency, told reporters
today. "I'm not going to say any more about that, I'm not going to speculate
(about blame)."

In an obvious reference to NASA and earlier news reports, he did say "there
have been some erroneous messages implicating one of the other space
agencies involved. No. It's an ESA responsibility."

According to published reports, an ESA official said earlier that the
missing command was part of a software load developed by ESA for the Huygens
mission and that it was executed by Cassini as delivered.

"There isn't any doubt that the command was missing," Southwood said today.
"But I'm not going to say any more because the point of an inquiry is to
find out. We will certainly have NASA representation on the inquiry, but I
don't want to make a big thing about it."


  #8  
Old January 17th 05, 06:32 AM
Hsai Fu
external usenet poster
 
Posts: n/a
Default

No. I just use the stuff. Dont you? (to test it?)



md wrote:

"Michael McCulloch" wrote in message
news
On Sat, 15 Jan 2005 19:44:34 -0600, "Ken" wrote:

from

http://www.spaceflightnow.com/cassin...15science.html

As it turned out, Cassini never listened to channel A because of a software
commanding error. The receiver on the orbiter was never commanded to turn
on, according to officials with the European Space Agency.


That's a inexcusable error. Sure, anyone can make a mistake, but with
the sums of money and man-hours spent on these missions is it not
resonable to hold to a higher standard?

Unknown conditions that cause unforeseen effects -- ok. But a software
error? C'mon.


why is it so unthinkable to software fails or contains an error? ever done a complex software
creation project?
--
md
10" LX200GPS-SMT
ETX105
www.xs4all.nl/~martlian


  #9  
Old January 17th 05, 09:48 AM
Martin Brown
external usenet poster
 
Posts: n/a
Default

md wrote:
"Tim Killian" wrote in message
...

The operative word is "complex" I would ask why the software for the
data transfer wasn't simplified. But ESA _only_ had seven years to run
simulations and debug the encounter code ;-)


really? was ESA able to upload bugfixes during flight?


Yes. And they did so to try and overcome an essentially fundamental
*hardware* design error that meant that the telemetry link between
Huygens and Cassini would not have been able to cope with the large
Doppler shift from their 21000km/hour relative motion.

See for example:
http://www.spacedaily.com/news/cassini-01g1.html

It had to be made signifcantly *more* complex and uploaded whilst the
mission was in progress to make the science telemetry stand any chance
of working.

What is sad is that the outcome after applying the fix seems to have
been similar to the original expectation (loss of half the data).

However, we should still celebrate that it returned real scientific data
from such a remote and hostile location.

A $250MM F-22 crashed last month because the flight software locked up
as the pilot rotated on takeoff. Fortunately, the pilot had a couple of
seconds before impact and was able to eject. It's a prime example of the
terrible state of software tools and processes used in modern systems.


or: it shows how hard programming can be.


As a software specialist I have to concede that the state of commercial
software is still pretty lamentable. Microsoft have copious buffer
overrun vulnerabilities in just about everything they have ever made

A cynic would say that in software development we are still at the stage
of mediaeval cathedral builders. After the event if it is still standing
five years on we can say it was a good design, but there are far too
many software projects delivered DOA. Consumer software has become
gothic - bloated with complex twiddly bits and immense "feature" lists
for salemen that convey no useful benefits to the purchaser.

But the embedded realtime code in aerospace, automotive, mission and
safety critical kit is generally much much better. But nothing is ever
perfect. Possibly the sole exception is Donald Kunth's Tex program.

Ultimately you are up against human error. The computer will follow it's
instructions to the letter. It cares nothing about whether they make any
sense. Fence post errors with boolean values are extremely disastrous
(and not as rare as they should be).

Regards,
Martin Brown
  #10  
Old January 17th 05, 04:41 PM
richard schumacher
external usenet poster
 
Posts: n/a
Default

In article ,
"md" not given to avoid spam wrote:

"Tim Killian" wrote in message
...
The operative word is "complex" I would ask why the software for the
data transfer wasn't simplified. But ESA _only_ had seven years to run
simulations and debug the encounter code ;-)


really? was ESA able to upload bugfixes during flight?

A $250MM F-22 crashed last month because the flight software locked up
as the pilot rotated on takeoff. Fortunately, the pilot had a couple of
seconds before impact and was able to eject. It's a prime example of the
terrible state of software tools and processes used in modern systems.


or: it shows how hard programming can be.


_Everything_ is hard, which is why realistic testing is important. A
few bytes of dummy data sent from Huygens to Cassini after separation
would have immediately shown the problem. The bug was in software in
Cassini (but which had been specified by the ESA) and could easily have
been fixed up to the last moment, if only the problem had been known.
 




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