Rollin' Rollin' Rollin'...Get That Rover Rollin' !!

"Diane Wilson" wrote in message
.net...
In article , "Greg D. Moore
\(Strider\)" says...

It actually has a power restriction based on available solar power.

Then it's pretty poor planning to have only one sun available.
I mean, what if it goes out?

Well, we just need to learn how to activate the other gas ball in the
system.:-)



Diane

Then it's pretty poor planning to have only one sun available.
I mean, what if it goes out?

Diane

Hey put a BIG inflatable reflector in orbit, and aim at the landing site. 24
hour daylight and warmth

The vehicle drivers would never rest

In article ,
Andrew Gray wrote:
...rather one of gradual degradation - over time, the solar panels are
expected to degrade [1], so you have a timeframe after which you can't
guarantee sufficient power...
[1] There may be incident-light issues here too, reduced solar flux...

There are. Given the fixed horizontal solar arrays, the choice of landing
sites was strongly constrained by a requirement to have the Sun pretty
much overhead at noon. And of course, that won't last.

The night-time cold is likely to kill the electronics before power
shortages become acute, though.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

On Wed, 07 Jan 2004 14:27:19 +0000, Greg D. Moore (Strider) wrote:

Then it's pretty poor planning to have only one sun available.
I mean, what if it goes out?

Well, we just need to learn how to activate the other gas ball in the
system.:-)

You mean usenet? The problem is that the sun is much more controllable!
G

"Dudhorse" wrote:
... all the Apollo astronauts were under severe time constraints due to
their very limited supplies of air/water/power; as far as I know Spirit has
no such restrictions.

Actually, both Spirit and Opportunity are under severe constraints.
They are solar powered, and can only be active during the day, (but
not too active lest they get too warm). Also, they only have a
limited lifetime before dust collecting on their solar panels will
kill them due to lack of power. (Some observations can take as much
as 12-24 hours, with a predicted life of 90 days that means they need
to get moving as soon as reasonably possible.)

All this, plus constraints on top speed and communications windows.

D.
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In article , Derek Lyons wrote:

kill them due to lack of power. (Some observations can take as much
as 12-24 hours, with a predicted life of 90 days that means they need
to get moving as soon as reasonably possible.)

Is that 90 days or 90 sols, BTW?

--
-Andrew Gray

"Henry Spencer" wrote in message
...
In article ,

There are. Given the fixed horizontal solar arrays, the choice of landing
sites was strongly constrained by a requirement to have the Sun pretty
much overhead at noon. And of course, that won't last.

The night-time cold is likely to kill the electronics before power
shortages become acute, though.

Stupid question, but what exactly in the electronics dies from being cold?


--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

"Diane Wilson" wrote in message
.net...
In article , "Greg D. Moore
\(Strider\)" says...

It actually has a power restriction based on available solar power.

Then it's pretty poor planning to have only one sun available.
I mean, what if it goes out?

If the spelling were worse, I'd have taken you for Bob Haller.
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"Hallerb" wrote in message
...
The vehicle drivers would never rest

Then there would be an accident, which would be NASA management's fault,
even though they took your advice.
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If you have had problems with Illinois Student Assistance Commission (ISAC),
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in the works.

In article ,
Greg D. Moore \(Strider\) wrote:
The night-time cold is likely to kill the electronics before power
shortages become acute, though.

Stupid question, but what exactly in the electronics dies from being cold?

The problem is not so much being cold, as going from a little bit cold to
a lot cold, and back again, over and over. Because different materials in
the electronics -- e.g., the circuit-board material and the copper
"wiring" lines plated onto it -- have different coefficients of thermal
expansion, this drastic thermal cycling stretches and strains them.
Sooner or later some of them start cracking.

This is almost certainly what killed Mars Pathfinder. It's unlikely to be
an accident that MP died soon after the demise of its battery, and thus of
its ability to heat its innards at night. (MP's specs called for a
relatively short surface life, so its designers chose a lightweight
battery that was good for only a limited number of cycles.)
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |