'Spirit' Communications Emergency

On Thu, 22 Jan 2004 17:46:51 GMT, "JimO"
wrote:

Problems -- give 'em a day or two to work them out...


Too bad there isn't a human there to repair it.

Bob

That second rover looks like a real good investment now.

lid (budbiss) writes:

Cardmanwrote:
On Thu, 22 Jan 2004 20:38:04 GMT, (Gary W.
Swearingen) wrote:

No, I didn't. Maybe Cardman did. Watch your quoting, please.

Someone please ask the "reset" question, when if it
can be made to
restart, then this may solve their problem.


I heard on the news this afternoon that they were going to attempt at
sending some type of RESET signal to the rover. I don't remember if
they said exactly when they plan to do it though. I believe it was
ABCnews that reported this.

I heard a guy on "The Newshour" say that RESET was an option that they
have no plans to use any time soon. They'll work with what they got
until they determine that won't be good enough. The next step is to
ask the rover to send back some diagnostic info over the low gain
antenna at the "safe mode" bit rate of about 8 bits per second. About
3 AM PST, IIRC.

"budbiss" wrote in message
...
Cardmanwrote:
On Thu, 22 Jan 2004 20:38:04 GMT, (Gary W.
Swearingen) wrote:

Someone please ask the "reset" question, when if it
can be made to
restart, then this may solve their problem.




I heard on the news this afternoon that they were going to attempt at
sending some type of RESET signal to the rover. I don't remember if
they said exactly when they plan to do it though. I believe it was
ABCnews that reported this.

Well that's a typical Microsoft Windows user talking there, hehe. The
computers on board spacecraft are designed specifically not to fail and they
won't. Besides, the computer resets itself automatically if a problem crops
up. Most likely the computer is still working but the data modulator (sits
between the computer and the radio transmitter) is faulty. But I would be
surprised if they didn't have a backup for the low-gain radio, but it seems
they don't.

It could also be a general computer failure, which leaves the radio sending
only beeps but the rover being essentially 'dead.'

On Fri, 23 Jan 2004 06:26:34 GMT, (Gary W.
Swearingen) wrote, in part:

I heard a guy on "The Newshour" say that RESET was an option that they
have no plans to use any time soon. They'll work with what they got
until they determine that won't be good enough. The next step is to
ask the rover to send back some diagnostic info over the low gain
antenna at the "safe mode" bit rate of about 8 bits per second. About
3 AM PST, IIRC.

This, of course, makes sense; they want to play things safe, and
ensure they aren't making things worse instead of better. (Although,
if there is no way to know just what the rover's program currently is,
and what it is doing, things could be getting worse; could a slip of
its robotic arm have led to it grinding itself open?)

John Savard
http://home.ecn.ab.ca/~jsavard/index.html

In article ,
"Dr. O" dr.o@xxxxx wrote:

"Schrodinger333" wrote in message
...
That second rover looks like a real good investment now.

Unless the cause is a design fault in which case it will fail in about the
same time. That would be a horror scenario!

Indeed!

A NASA TV documentary I was watching a night or so ago showed the techs
replacing the main circuitboards on the rovers at KSC shortly before
Spirit's launch due to a serious technical hitch that had been belatedly
discovered. The commentator pointed out in passing one danger of doing
such a thing at the last minute: that it might inadvertently introduce
*another* fault which there had not been time to test for.

--
Stephen Souter

http://www.edfac.usyd.edu.au/staff/souters/

baDBob wrote:

On Thu, 22 Jan 2004 17:46:51 GMT, "JimO"
wrote:

Problems -- give 'em a day or two to work them out...


Too bad there isn't a human there to repair it.

Something for all the unmanned spaceflight partisans to think about.
$400 million for maybe a couple dozen color photographs thus far.

Bob

Henry Spencer wrote:
In article ,
Gary W. Swearingen wrote:
jumble should have reset by now, right? What hardware issues could give the
symptoms we are experiencing now?

The dude at this morning's briefing mentioned "SAU" or "SUA" (?) and
something about cosmic rays, in the same breath.

Probably SEU, Single Event Upset, where a bit gets flipped by a particle
hit on a chip. If it's an important bit, a mess can result. :-)

The good news is that an SEU is a transient error, not a permanent failure,
assuming you have some way of resetting and restarting.

Umm... you mean somebody would seriously consider having a project measured
in millions of dollars and not include trivial small things like SECDED,
memory scrubbing and restarts? You know stuff that is slowly coming even
to low end servers? I would be really shocked...

--
Sander

+++ Out of cheese error +++

Sander Vesik wrote:
Henry Spencer wrote:

In article ,
Gary W. Swearingen wrote:

jumble should have reset by now, right? What hardware issues could give the
symptoms we are experiencing now?

The dude at this morning's briefing mentioned "SAU" or "SUA" (?) and
something about cosmic rays, in the same breath.

Probably SEU, Single Event Upset, where a bit gets flipped by a particle
hit on a chip. If it's an important bit, a mess can result. :-)

The good news is that an SEU is a transient error, not a permanent failure,
assuming you have some way of resetting and restarting.


Umm... you mean somebody would seriously consider having a project measured
in millions of dollars and not include trivial small things like SECDED,
memory scrubbing and restarts? You know stuff that is slowly coming even
to low end servers? I would be really shocked...



The ability of that stuff to work is usually overstated. Work
somewhere where they have thousands of Sun's and you will learn
that "ecache" is an evil word. There will be sections of the
cpu and ram that can't be scrubbed and then there is the question
of how effective a restart will be. Sun's, for instance, quite
often slag the filesystems during this type of shutdown and require
manual intervention to recover.

It is usually much more cost effective to just shutdown and
restart as Henry mentioned rather than exponentially increase the
software requirements by adding a lot of overhead. This hit a iwerd
boundry condition where hypothetically the bit-flip managed to
toggle something it should not have.

Sander Vesik writes:

Umm... you mean somebody would seriously consider having a project measured
in millions of dollars and not include trivial small things like SECDED,
memory scrubbing and restarts? You know stuff that is slowly coming even
to low end servers? I would be really shocked...

You shouldn't be; millions of dollars doesn't buy much custom
electronics, let alone all the big hardware, software, and people to
run the program. BTW, we don't know they don't they don't have the
features you mention (except we know they have restarts -- probably
more than 60 of them so far). Plus, they might have other ways of
keeping memory corruption risk low, like very good radiation hardening
or frequent checksumming of memory or something.

I did hear today that they have another copy of the main software
onboard which they can load up if they want to. But I suspect they
greatly suspect some real hardware failure and need to figure out what
that is before trying to work around it. They're even willing to let
the batteries go dead at night while waiting to gather more diagnostic
info, rather than just taking the Microsoft approach and reloading the
software.