Mars Rover longevity again limited by dust build-up

I was wondering why NASA accepts a shortened life for the Mars Rovers
due to "dust build-up on the solar panels".

Is cleaning them beyond their rocket scientists ?

Newsuser "groutch" wrote ...

I was wondering why NASA accepts a shortened life for the Mars Rovers
due to "dust build-up on the solar panels".

Is cleaning them beyond their rocket scientists ?

This is the most stupidity in space exploration when a ground probe's
lifetime
is limited to 2-3 months (making an assumption that a dust has no influence
on solar arrays)!
Why? Because plutonium Pu238 is bad?


A good science is to send a probe which is able to work all 5 years!
Look at Vikings.
Viking budget was about $2.5 billions (for both, recalculated) and ground
stations worked 5 years (average lifetime V1 & V2) so monthly cost is only
$35 millions!!!

--
(STS)

"Stanislaw Sidor" wrote:

I was wondering why NASA accepts a shortened life for the Mars
Rovers
due to "dust build-up on the solar panels".

I don't think cleaning them is "beyond" the engineers, but it may
be a case of diminishing returns (I was really hoping for someone with
direct knowledge to answer... Geoffery Landis?). Keep in mind a lot of
that "dust" is about the size of smoke particles, which you''ll have
trouble just "wiping off". Electrostatic solutions might be
troublesome on silicon cells.

This is the most stupidity in space exploration when a ground probe's
lifetime is limited to 2-3 months

Or, it's ecomonics. Viking, which did a wonderful job (well beyond
design specs), also was a lot more expensive than a MER-class mission,
involving things like Titan launch vehicles (not the less expensive
Delta). As another point, extending the mission to the year+ timespan
would involve a lot of hardware modification/certification, well
beyond just using a longer-term power source.

Why? Because plutonium Pu238 is bad?

Hardly. An RTG-powered rover is in the works for a future mission
with a life time of a year or so. But it will be a lot more expensive,
and will not use an airbag landing system (there are limits to that as
well).

A good science is to send a probe which is able to work all 5 years!

Sure. Good science would be to put hundreds of trained geologist on
the surface of Mars, with equipment to traverse the surface. But
economicly, there *might* be some constraints here.

--
Brian Davis

"Stanislaw Sidor" wrote in message ...
Newsuser "groutch" wrote ...

I was wondering why NASA accepts a shortened life for the Mars Rovers
due to "dust build-up on the solar panels".

Is cleaning them beyond their rocket scientists ?

This is the most stupidity in space exploration when a ground probe's
lifetime
is limited to 2-3 months (making an assumption that a dust has no influence
on solar arrays)!

They are well aware of the problem. It's a non-problem
problem. The real problem is the cold, that's going to
kill the rover stone dead with absolute certainty in a
few months. There isn't anyway around that, and it
just so happens that death by cold is going to come
at around the same time as dust buildup on the PV
arrays might become a concern. But by then it'll be
something to worry about after the rover's dead, which
is not something to worry about at all, especially not
something to spend tons of money trying to fix.


Why? Because plutonium Pu238 is bad?


A good science is to send a probe which is able to work all 5 years!
Look at Vikings.
Viking budget was about $2.5 billions (for both, recalculated) and ground
stations worked 5 years (average lifetime V1 & V2) so monthly cost is only
$35 millions!!!

Hey, go easy, it's not just that RTGs are kinda politically
hard to sell (though really they aren't), mostly it's the
cost and mass overhead. Solar panels are inexpensive and
easy, RTGs are expensive. I'd like to see an RTG powered
rover myself. Just imagining it blows my mind away with
the possibilities, it would be the single greatest thing
in space exploration since Apollo, easily. And it would
go on for years! But, it's gonna be expensive, so I can
wait. Interestingly, NASA has plans for such a thing,
and if they can get funding then it will happen.

groutch wrote:
I was wondering why NASA accepts a shortened life for the Mars Rovers
due to "dust build-up on the solar panels".

Is cleaning them beyond their rocket scientists ?

I wouldn't bother too much with dust...

In Mars the wind will clean the dust, so there will never be too much on
top of the panels.

Also if you get really in trouble they can allways put the rover in a
slope, by starting to climb a bigger rock, for example, and the wind
would clean the solar panels.

Presuming no other major failures occur I predict the rovers will never
fail dues to dust and will work for years.

I don't think cleaning them is "beyond" the engineers, but it may
be a case of diminishing returns (I was really hoping for someone with
direct knowledge to answer... Geoffery Landis?). Keep in mind a lot of
that "dust" is about the size of smoke particles, which you''ll have
trouble just "wiping off". Electrostatic solutions might be
troublesome on silicon cells.

From watching all NASA webcast lectures (tens of them), the message has
been (questions answered by the main scientists themselves) that there is
no way currently to prolong the solar panel longevity with any cleaning
methods. Of course you can clean your summer shack solar panels because
you do not have the absolute and strict limitations of distant space
rover. Simply dry wiping the panels you would prolly do more damage to
them than good.

There is lots of other things that lessen the lifespan of rover, one of
the absolutely unpassable (with solar panels that is) obstacle is the
Mars winter, no sun no power. The electronics will break up when they
cannot be kept in stable warmth with electricity.

But, from what ive seen in those lectures, they are now starting to
really develope rovers that utilize plutonium power. Seems like atomic
hysteria is somewhat over. But even those do not last for years, theyre
just too small and filled with super high tech components that cannot be
eventually protected by the temperature changes which will be very
dramatic on winter. You just can begin to compare Viking landers and
these things, its like saying that why does paper burn when rock doesent.

Or, it's ecomonics. Viking, which did a wonderful job (well beyond
design specs), also was a lot more expensive than a MER-class mission,

Plutonium power, i think, will be a lot cheaper than the high tech solar
panel arrays. Its because the Pu - electricity is very simple design (by
space tech standards).

Hardly. An RTG-powered rover is in the works for a future mission
with a life time of a year or so. But it will be a lot more expensive,
and will not use an airbag landing system (there are limits to that as
well).

I remember them saying something like 9 months of operation. One big
benefit, besides the lifespan is that such rover can move much much
faster (more amps available) and thus move farther, even hundreds of
kilometers.

It will be helluva bigger machine (size of small car), i think that
restricts the landing to rocket propelled lander. Which means lots of
additional fuel kg:s - lots of $$.

Sure. Good science would be to put hundreds of trained geologist on
the surface of Mars, with equipment to traverse the surface. But
economicly, there *might* be some constraints here.

I dont believe that Mars surface will ever be accessed by humans, robots
can stand the super harsh evinroment (solar winds etc.) better. In 2050
the robots will prolly be better geologists than humans.. If there is
anything worthwhile of sending more robots in the distant future.

Op Wed, 7 Jan 2004 16:11:22 +0000 (UTC) schreef Poliisi
:

There is lots of other things that lessen the lifespan of rover, one of
the absolutely unpassable (with solar panels that is) obstacle is the
Mars winter, no sun no power. The electronics will break up when they
cannot be kept in stable warmth with electricity.

What winter, al the rovers are near the equator. Mars isn't tilted so
badly like Uranus.

--
Coos

On Wed, 7 Jan 2004 16:11:22 +0000 (UTC), Poliisi wrote:

From watching all NASA webcast lectures (tens of them), the message has
been (questions answered by the main scientists themselves) that there is
no way currently to prolong the solar panel longevity with any cleaning
methods. Of course you can clean your summer shack solar panels because
you do not have the absolute and strict limitations of distant space
rover. Simply dry wiping the panels you would prolly do more damage to
them than good.

Mount a pump with a rotating nozzle and hit them with a jet of air.
Would also be handy to stir up ground dust for analysis.

Rodrigo Cunha wrote:
groutch wrote:
I was wondering why NASA accepts a shortened life for the Mars Rovers
due to "dust build-up on the solar panels".

Is cleaning them beyond their rocket scientists ?

I wouldn't bother too much with dust...

In Mars the wind will clean the dust, so there will never be too much on
snip
Presuming no other major failures occur I predict the rovers will never
fail dues to dust and will work for years.

Unfortunately, you seem unlikely to be right.
Look at the data from Mars Pathfinder.
The dust accumulates, and does not blow off.

Presuming no other major failures occur I predict the rovers will never
fail dues to dust and will work for years.

Sojuner didn't.