Galileo Update - November 23, 1998
C. Cagle
<rcl...@op.net> wrote:
> Ron Baalke <baa...@kelvin.jpl.nasa.gov> wrote in article
> <23NOV199...@kelvin.jpl.nasa.gov>...
> | MEDIA RELATIONS OFFICE
> | JET PROPULSION LABORATORY
> | CALIFORNIA INSTITUTE OF TECHNOLOGY
> | NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
> | PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
> | http://www.jpl.nasa.gov
> |
> | Galileo Europa Mission Status
> | November 23, 1998
> |
> | Galileo project engineers expect the spacecraft to return to
> | normal operations today at about 5 p.m. Pacific Standard Time,
> | following a weekend in which the spacecraft entered safing mode
> | twice. The first of these events prevented Galileo from
> | gathering data on Europa as it flew by the icy moon early Sunday,
> | November 22.
> |.
> |.
> |.
> | These anomalies are somewhat similar to a reset that
> | occurred during a previous Europa flyby last June. However, in
> | the latest anomalies, the semi-redundant halves of the control
> | and data subsystems reset simultaneously, while in June they
> | reset one after the other.
>
>
> Huh? You mean that once again Galileo was unable to retrieve data on Europa
> on its closest approach? Shades of Arthur C. Clarke:
>
> "All these worlds are yours to explore except Europa. Attempt no landing
> there."
> _2010: Odyssey Two_, by Arthur C. Clarke.
>
> Perhaps some quotes from 2001 would be a propos here
>
> "Look Dave, I can see you're really upset about this...I honestly think you
> ought to sit down calmly, take a stress pill and think
things over."
> ftp://ftp.research.ryerson.ca/pub/elf/audio/2001/stresspill.au
[audio]
>
> "Well, I don't think there is any question about it. It can only be
> attributable to human error.
> This sort of thing has cropped up before and it has always been due
> to human error."
> http://www.palantir.net/2001/sfx/wav/error.wav [audio]
>
> More seriously (a little), have there been cases where Galileo entered safe
> mode on entering Jupiter's intense radiation fields when it wasn't close to
> Europa?
>
>
> _______________________________
>
> "In science, everything is significant."
> -- Bob Clark
> ________________________________
Well, now they ought to have this big clue that they ought to disable the
'safing' mode (if it is possible to do so) when they next make a close
approach to Europa.
Robert Clark
Robert Clark
Robert Clark <rcl...@op.net> wrote in article
<01be1754$7afc4f40$c0c6...@rclark.op.net>...| ...
| |
| | Galileo Europa Mission Status
| | November 23, 1998
| |
| | Galileo project engineers expect the spacecraft to return to
| | normal operations today at about 5 p.m. Pacific Standard Time,
| | following a weekend in which the spacecraft entered safing mode
| | twice. The first of these events prevented Galileo from
| | gathering data on Europa as it flew by the icy moon early Sunday,
| | November 22.
| |...
|
| on its closest approach? Shades of Arthur C. Clarke:
|
| "All these worlds are yours to explore except Europa. Attempt no
landing
| there."
| _2010: Odyssey Two_, by Arthur C. Clarke.
|
| Perhaps some quotes from 2001 would be a propos here
|
| "Look Dave, I can see you're really upset about this...I honestly think you
| ought to sit down calmly, take a stress pill and think things over."
| ftp://ftp.research.ryerson.ca/pub/elf/audio/2001/stresspill.au [audio]
|
| "Well, I don't think there is any question about it. It can only be
| attributable to human error.
| This sort of thing has cropped up before and it has always been due
| to human error."
| http://www.palantir.net/2001/sfx/wav/error.wav [audio]
|
| More seriously (a little), have there been cases where Galileo entered safe
| mode on entering Jupiter's intense radiation fields when it wasn't close to
| Europa?
The closest visit of Galileo to Europa was encounter E12 on December 15-16,
1997. I wanted to look up the data retrieved on this encounter and found this:
"THIS WEEK ON GALILEO
January 12-18, 1998
Flight team members will spend the upcoming week collecting and analyzing
engineering
data to better understand and correct anomalous behavior from the spacecraft's
attitude
control subsystem. A second anomalous behavior occurred while the spacecraft
was
performing an orbit trim maneuver in late December, a few days after the first
occurrence
during the Europa-Orbit 12 encounter. The behavior of the attitude control
subsystem, the
system responsible for controlling where the spacecraft is pointing, has left
Galileo's radio
antenna pointing in a direction that is about 10 degrees from the Earth. This
has reduced the
amount of science information that was scheduled for transmission to Earth.
Typically,
Galileo's antenna is maintained within 4 degrees of Earth to maximize the
amount of
information that can be transmitted to Earth."
http://www.jpl.nasa.gov/galileo/today980112.html
Hmmm........
________________________________