The end of mars exploration

In an article today, the New York Times reports:
The mission is scheduled to come to a pragmatic end sometime this spring,
when the financing runs out

http://www.nytimes.com/2004/03/21/au...es/21MARS.html

In a similar article, space.com reports: (18 Mars)

To prepare for what is expected to be at least a few more months of Mars
exploration,
NASA officials plan to cut the 300 scientists and engineers on the mission
by more than
a third, according to one mission manager.
"We are going to be reducing the staff and slowing down as [the rovers] get
later into
their lifetimes," said Mark Adler, a mission manager for the Mars
Exploration Rover
(MER) mission during a press briefing today at NASA's Jet Propulsion
Laboratory (JPL)
in Pasadena, California

http://www.space.com/missionlaunches...ed_040318.html

The President's plan to Mars and beyond... :-)

To prepare for what is expected to be at least a few more months of Mars
exploration,
NASA officials plan to cut the 300 scientists and engineers on the mission
by more than
a third, according to one mission manager.
"We are going to be reducing the staff and slowing down as [the rovers] get
later into
their lifetimes," said Mark Adler, a mission manager for the Mars
Exploration Rover
(MER) mission during a press briefing today at NASA's Jet Propulsion
Laboratory (JPL)
in Pasadena, California

This seems like a very reasonable thing to do. I read where it is taking them
far less time and far fewer people to plan each day of activity for the rovers.
As the data flow slows from the rovers, I'm sure there will also be less need
for huge numbers of people to keep working on this project.

This will also help JPL gear up for the great science they hope to get from the
Cassini-Huygens mission to Saturn and Titan in the next year.

On Mon, 22 Mar 2004, jacob navia wrote:

In an article today, the New York Times reports:
The mission is scheduled to come to a pragmatic end sometime this spring,
when the financing runs out

Read sci.space.news, mission has been extended 7 months due to discovery
of evidence of ancient dried up lake or ocean


http://www.nytimes.com/2004/03/21/au...es/21MARS.html

In a similar article, space.com reports: (18 Mars)

To prepare for what is expected to be at least a few more months of Mars
exploration,
NASA officials plan to cut the 300 scientists and engineers on the mission
by more than
a third, according to one mission manager.
"We are going to be reducing the staff and slowing down as [the rovers] get
later into
their lifetimes," said Mark Adler, a mission manager for the Mars
Exploration Rover
(MER) mission during a press briefing today at NASA's Jet Propulsion
Laboratory (JPL)
in Pasadena, California

http://www.space.com/missionlaunches...ed_040318.html

The President's plan to Mars and beyond... :-)

"William Elliot" wrote in message
...
On Mon, 22 Mar 2004, jacob navia wrote:

In an article today, the New York Times reports:
The mission is scheduled to come to a pragmatic end sometime this
spring,
when the financing runs out

Read sci.space.news, mission has been extended 7 months due to discovery
of evidence of ancient dried up lake or ocean

Ah, that is still to be determined by battery life and the like.

On Wed, 24 Mar 2004 13:30:46 GMT, "Greg D. Moore \(Strider\)"
wrote:


Ah, that is still to be determined by battery life and the like.

Isn't it remarkable that the Rovers have such a short life span?
All that money for development and no one was able to figure out
a way for them to clean themselves that was worth the postage.
If the members of this list were to concentrate they would probably
come up with a dozen different techniques for getting dust off
the panels. You have to assume that the engineers at NASA
are just as capable, so it follows that all those techniques
have something wrong with them. But what? For instance, what's
wrong with erecting a brush at the right height and then running
back and forth under it? Something is, for sure, but what?

http://www.pobox.com/~hapgood

In article ,
Fred Hapgood wrote:
Ah, that is still to be determined by battery life and the like.

Isn't it remarkable that the Rovers have such a short life span?
All that money for development and no one was able to figure out
a way for them to clean themselves that was worth the postage.

You're making the mistake of believing news reports, which emphasized the
issue of dust accumulation and not the more fundamental problem of limited
battery life. (When the batteries die, there is no power to keep the
electronics warm at night, and the deep temperature cycling is almost
certain to kill the electronics rather quickly. Mars Pathfinder went
silent very shortly after its battery quit.)

If the members of this list were to concentrate they would probably
come up with a dozen different techniques for getting dust off
the panels. You have to assume that the engineers at NASA
are just as capable, so it follows that all those techniques
have something wrong with them. But what?

The answer is different for each technique. Also, a general thing wrong
with all of them is that this mission was put together in great haste from
mostly-existing hardware designs, and there was no time to do new
engineering development that wasn't absolutely necessary. (As it was, the
wind-correcting landing system in particular was considered high-risk.)

For instance, what's
wrong with erecting a brush at the right height and then running
back and forth under it? Something is, for sure, but what?

Brushes aren't good at removing fine, well-adhering particles, and there
is considerable suspicion that Mars dust would fit that description. And
if the dust is abrasive -- which lunar dust certainly is -- then attempts
to wipe it off or brush it off may do more harm than good.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

"Fred Hapgood" wrote in message
...
On Wed, 24 Mar 2004 13:30:46 GMT, "Greg D. Moore \(Strider\)"
wrote:


Ah, that is still to be determined by battery life and the like.

Isn't it remarkable that the Rovers have such a short life span?
All that money for development and no one was able to figure out
a way for them to clean themselves that was worth the postage.
If the members of this list were to concentrate they would probably
come up with a dozen different techniques for getting dust off
the panels. You have to assume that the engineers at NASA
are just as capable, so it follows that all those techniques
have something wrong with them. But what? For instance, what's
wrong with erecting a brush at the right height and then running
back and forth under it? Something is, for sure, but what?

Many things.

First, tell me which scientific instrument you're willing to sacrifice to
make up for the difference in mass?

Also... can you tell me the characteristics of the dust that's settling on
the panels? Will a brush work? If not, you just wasted your mass.

Perhaps something more like a squeegie? Ooops, you just scratch the surface
so badly that you've ruined the cells.

Or perhaps a rolling filter thing like on NASCAR cars? Ooops, turns out
that you've reduced your available solar power by 3%, which experiments due
you shut off now?

i.e. it's all about trade-offs.



http://www.pobox.com/~hapgood

Fred Hapgood wrote in message . ..
Isn't it remarkable that the Rovers have such a short life span?
All that money for development and no one was able to figure out
a way for them to clean themselves that was worth the postage.

Ok, here's how it works:

Step 1. Define the required lifetime to do a good science mission.
Pick a number. NASA picked 90 sols. (Turns out that that was a
pretty good pick, seeing what Opportunity has accomplished in 60
sols.)

Step 2. Figure out how to implement that requirement with the lowest
mass, cost, schedule, and mission risk.

For step 2 you can a) come up with some scheme for keeping the panels
clean through the 90 sols, increasing their power output at the end
by, say, 15%, or b) make the panels 15% larger. Guess which one had
the lowest risk.

mark

p.s. As you might expect, when you design to assure a 90-sol
lifetime, you can end up with more than that. Possibly a lot more
than that.

On Wed, 24 Mar 2004, Henry Spencer wrote:

Brushes aren't good at removing fine, well-adhering particles, and there
is considerable suspicion that Mars dust would fit that description. And
if the dust is abrasive -- which lunar dust certainly is -- then attempts
to wipe it off or brush it off may do more harm than good.

It has been notice that most, if not all of Mars dust is magnetic.
JPL news release 2004-079 notes how a magent on the explorers does
keep a small area dust free.