NASA should send many SMALL Mars rovers to survey

In article . com,
Alejandro Zuzek wrote:
Bear in mind that Sojourner relied on Pathfinder for communications, and
had a relatively short working life because of a lightweight short-lived
battery.

The short lived battery was on Pathfinder, not on the Sojourner rover.

Both.

Sojourner had a non-rechargeable battery, meant primarily to permit doing
APXS measurement runs at night (when instrument noise was much lower due
to it being colder), but also useful to keep the computer up and permit a
quick start in the mornings. It died at the beginning of September, about
two months after landing. A non-rechargeable battery was deemed perfectly
adequate, given that the length of the rover's primary mission was one
week! As it was, it died a little earlier than expected; possibly the
APXS was using more power than expected, there being little data on that
because most of the other rover electronics were shut down at night to
conserve battery power. Losing the battery messed up the APXS data and
generally hampered rover operations, but didn't quite kill it.

Mars Pathfinder had a rechargeable, but short-lived, silver-zinc battery
system. Again, with a short mission -- primary mission one month -- long
battery life was not a requirement, and a silver-zinc battery was lighter
than a longer-lived type. The battery died at the end of September, and
that shut things down for good, because while Sojourner had isotope
heaters, MP relied on battery power to keep its electronics warm at night.
Without the battery, the huge temperature swings quickly killed the
electronics. (The transmitter was heard faintly a couple of times in the
ensuing week or so, but full contact was never restored. In early
November JPL gave up.)
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On Wed, 7 Dec 2005 05:49:49 GMT, (Henry Spencer)
wrote:

The battery died at the end of September, and
that shut things down for good, because while Sojourner had isotope
heaters, MP relied on battery power to keep its electronics warm at night.

....Yeah, but as the CT Nutters still think Oswald wasn't alone, I'm
still going to cling to my vision of Sojourner having dug a dry moat
around Pathfinder when it went into "circle the wagons" mode after
Pathfinder died, and did so until it got below the surface level
enough to block off enough sunlight to keep it from powering up :-)

OM
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I think we should launch a dozen version 2s of spirit and opportunity.
since its a proven workhorse design all that would be needed are minor
tweaks.

with a bunch of rovers we could add much to the overall knoiwledge of
the planet, and some rovers could be sent to higher risk higher reward
areas with the knowledge they may be lost.

big returns for minimal costs

In article ,
OM wrote:
...still going to cling to my vision of Sojourner having dug a dry moat
around Pathfinder when it went into "circle the wagons" mode after
Pathfinder died, and did so until it got below the surface level
enough to block off enough sunlight to keep it from powering up :-)

Alas for the moat, the Sojourner operations crew expected that it probably
wouldn't even make one lap around Pathfinder before encountering a rock
big enough to make it stop and await further instructions.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On Wed, 7 Dec 2005 17:08:16 GMT, (Henry Spencer)
wrote:

In article ,
OM wrote:
...still going to cling to my vision of Sojourner having dug a dry moat
around Pathfinder when it went into "circle the wagons" mode after
Pathfinder died, and did so until it got below the surface level
enough to block off enough sunlight to keep it from powering up :-)

Alas for the moat, the Sojourner operations crew expected that it probably
wouldn't even make one lap around Pathfinder before encountering a rock
big enough to make it stop and await further instructions.

....Dammit, Henry, you are *not* going to spoil my dream. The rock will
turn out to be sentient, and simply moved out of the way :-P

OM
--
]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[

"OM" wrote in message
...
On Wed, 7 Dec 2005 17:08:16 GMT, (Henry Spencer)
wrote:

In article ,
OM wrote:
...still going to cling to my vision of Sojourner having dug a dry moat
around Pathfinder when it went into "circle the wagons" mode after
Pathfinder died, and did so until it got below the surface level
enough to block off enough sunlight to keep it from powering up :-)

Alas for the moat, the Sojourner operations crew expected that it probably
wouldn't even make one lap around Pathfinder before encountering a rock
big enough to make it stop and await further instructions.

...Dammit, Henry, you are *not* going to spoil my dream. The rock will
turn out to be sentient, and simply moved out of the way :-P

Didn't The Muppet Show cover that once? :-)