Mars 2007 - Phoenix Lander

With the success of Opportunity and Spirit, the planned 2007 Phoenix mission
to land a static lander on Mars seems almost to be a limited mission.
Clearly having mobility allows a significant amount of flexibility compared
to a stationary lander with a claw. How will the claw dig any better
trenches then that accomplished by the rover wheels ??...what happens if
something exciting and interesting rests just outside of the Phoenix
lander's reach....??... there is no option to move !!!

Jeff Lerner

On Sun, 29 Feb 2004 20:09:50 GMT, "Jeff Lerner"
wrote:

How will the claw dig any better trenches then that accomplished by the rover wheels ?

....The one thing that the wheels cannot do is a core sample or a
sample with a minimum amount of soil integrity disruption. Analyzing a
pile of soil is one thing, analyzing how it was layered over time is
another. The only problem is that the Rovers don't have any sort of
robotics along these lines. They have the arm with the microgrinder,
but nothing for deep - read: 1-2' at least - sampling straight down
with minimal disruption to the soil within the core.

....What would be interesting tho is to see, say, an M$ Project
timeline chart that shows where all the probes relate to one another
over time with regards to their respective developments. What I'm
suspecting with the Phoenix lander-only mission is that it was one of
the MPL-style landers that's already pretty much finished and NASA
simply doesn't want to waste the probe.

If only they'd felt that about Skylab B...

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

...What would be interesting tho is to see, say, an M$ Project
timeline chart that shows where all the probes relate to one another
over time with regards to their respective developments. What I'm
suspecting with the Phoenix lander-only mission is that it was one of
the MPL-style landers that's already pretty much finished and NASA
simply doesn't want to waste the probe.

If only they'd felt that about Skylab B...

OM



I suspect you're right about this lander being almost finished so you might
as well use it, but I guess I was thinking that Nasa might want to pull this
mission and come back with another rover. Of course, it's probably too far
along to redevelop into another rover and there is probably not enough time
to convert it into some sort of mobile vehicle.

Wasn't there an attempt to move a Surveyor moon lander by firing it's
thrusters briefly with left over fuel ??...maybe they can try the same trick
with Phoenix.

In article ,
OM om@our_blessed_lady_mary_of_the_holy_NASA_researc h_facility.org wrote:
...What would be interesting tho is to see, say, an M$ Project
timeline chart that shows where all the probes relate to one another
over time with regards to their respective developments.

Well, the fast answer is "loosely". :-) Despite more-or-less steady
funding, the Mars program did start out as somewhat of a grab-bag of
missions rather than an organized, systematic approach, and repeated
changes of plan haven't helped. (E.g., the MERs are a hasty improvisation,
combining a derivative of the MP landing system with a rover design
originally meant for a canceled lander mission but later removed from it.)
Originally, NASA was talking about a sample-return mission either last
year or next year...

What I'm
suspecting with the Phoenix lander-only mission is that it was one of
the MPL-style landers that's already pretty much finished and NASA
simply doesn't want to waste the probe.

Not quite. The Phoenix lander bus *is* the 2001 lander, the only other
MPL-design lander that was under construction when MPL was lost. But the
instrument payload and mission design have changed substantially; this is
a new mission using some leftover hardware, rather than a revival of the
canceled mission. Moreover, it's part of the Mars Scout program -- the
Mars equivalent of Discovery, based on competitive proposals from outside
groups -- not the main JPL mission sequence. The Mars Scout announcement
offered proposers the option of using the partly-built 2001 lander bus,
and some of them took it, including the Phoenix proposal.

Phoenix is actually rather closer to a reflight of MPL than of the 2001
lander mission. In particular, it's slated to go to a high-latitude site.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

On Sun, 29 Feb 2004 23:24:19 GMT, (Henry Spencer)
wrote:

[Henry's excellent points snipped]

Phoenix is actually rather closer to a reflight of MPL than of the 2001
lander mission. In particular, it's slated to go to a high-latitude site.

....Which begs the question as to why a second polar attempt hasn't
been considered.

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

...Which begs the question as to why a second polar attempt hasn't
been considered.

OM

Thats the HQ of the mars defense team and we already know landers there will be
destroyed

In article .rogers.com,
Jeff Lerner wrote:
Wasn't there an attempt to move a Surveyor moon lander by firing it's
thrusters briefly with left over fuel ??

Yes, that was done successfully. Didn't move it far, mind you.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

In article ,
OM om@our_blessed_lady_mary_of_the_holy_NASA_researc h_facility.org wrote:
Phoenix is actually rather closer to a reflight of MPL than of the 2001
lander mission. In particular, it's slated to go to a high-latitude site.

...Which begs the question as to why a second polar attempt hasn't
been considered.

Partly I think it's the remaining grab-bag aspect of the program: the
polar-landing enthusiasts "had their turn", so they don't get another one
soon. A systematic program would at least consider reflying failures, as
Surveyor in particular did (it took three attempts to land a Surveyor in
Sinus Medii). This program isn't generally that systematic, and its
priorities keep changing.

Partly, I suspect the timing just hasn't been right. Both for solar power
and for temperature, a polar lander wants to come down in polar midsummer.
That means you need a Mars launch window which gives you an arrival time
around then, at one pole or the other. And because Mars's year is about
686 Earth days, while Mars launch windows occur about ever 780 Earth days,
if you had a good shot at a polar summer in 1998, you don't get another
good one until 2007. (Probably. It's more complicated than those simple
numbers would indicate, and there's some room to play games, but not
enough to let you use any random Mars launch window.) And if you want
another shot at the *same* pole -- and the two polar regions are quite
different, and the scientists might prefer one over the other -- you get
to wait until 2013.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

The Mars Exploration Rovers have a rock focus - especially those rare
outcrops of in-place lithified material. This basically demands the
ability to move about, especially to get to craters.

The objective of PHOENIX (as well as 1999's MPL) is to sample the
extensive layered deposits that surround the poles, and directly
sample near-surface ice. As the distribution of these materials does
not appear to be patchy, mobility is not a priority. The arm of
PHOENIX will be able to dig down to a meter in depth, as opposed to
the centimeters of MER's wheels.

The 2001 spacecraft was originally slated to carry the engineering
twin of Mars Pathfinder's Sojourner rover, but that has been deleted
from the PHOENIX mission. A HGA has been added to the spacecraft
instead.

More info he http://phoenix.lpl.arizona.edu/

Ironically it will be run out of Tucson, not the other large Arizona
city.

Of course, all this depends on the nature of tomorrow's Astounding
Mars Science Announcement.

"Jeff Lerner" wrote in message ble.rogers.com...
[...]
the planned 2007 Phoenix mission
[...]

Is this a "pre-history" thread, since 2007 isn't *quite* here yet? ;-)

/dps