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Juramike
Or this:

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ustrax
The goodies are already at Lisbon airport waiting for me to pick them up... smile.gif
And Doug...are you ready for another Q'n'A? wink.gif
Stu
Not long to go now...


WHAT WILL I SEE..?

The first time I open my sleep-heavy eyes
what alien landscape will curve around me?
A Barsoomian Narnia, with petrified fields
of snow-capped rocks and lonely frost-cracked
boulders, standing boldly beneath the glaring arctic Sun
like shrunken Easter Island statues?
Or will there be no stones to see, just an endless plain
of pale polygons stretching like a crumpled quilt
to the horizon, each icy lily pad a stepping stone
leading my startled eyes to a sky higher and wider
than any ever seen on Mars before..?

I wonder… will that sky be white – a mirror of Old Earth’s
bright Antarctic heaven? – or will it shine with a polished
metal hue, a cathedral-ceiling dome of brittle silver-blue
dwarfing every ridge and rock and stone cupped
in Green Valley’s gentle hands? Perhaps the frigid land
chosen to be my frozen tomb will stand silent
beneath a sea of blushing, perfect pink? Whichever
colour wins, will I witness wind-teased, lacy clouds
racing overhead, chasing each other like children at play,
mocking me with their faerie grace and speed
while I stare up at them helplessly;
my clumsy, manhole cover feet rooted to the frozen ground
as if I were a tree and they were birds?

Around the shrunken Sun I imagine a ring
of hoarfrost-on-Holly fire;
a perfect circle of Mother of Pearl light,
the crowning glory of the first
arctic martian sunset ever seen by Man.
On either side: a soft-edged slice of rainbow;
known as “sundogs” on Old Earth
the first Barsoomians shall call them
“Deja” and “fair Thuvia” in tribute
to the martian maids who stole John
Carter’s heart with just a sigh. And close by,
perhaps, an azure spark – Earth,
glinting as a sapphire gleams
when held up to the Moon until, too soon,
she drops into the burning dusk,
her flickering flame snuffed out…

And when my metal monkey paw claws at the
ground beneath my feet, what sight will greet
me as its dust and dirt are wrenched
and torn apart? Within that long-awaited trench
will my eyes spy only lines of old Noachian ice
or layers of “Can it be..?” green? Will My Mars be
as dead as the burial plains of Sagan’s hero Vikings,
or will my graphs whisper “There is Life here…”?

Soon I will know; soon my eyes
will open on a breathtaking new world,
and though no flag will I unfurl
to flutter and fly o’er Green Valley’s
frigid floor, on Landing Day I’ll stake a claim for
All Mankind, declaring in bold Shakespearean tones:
“We shall know no rest ‘til we have found Life here!”
and slowly, but surely, I'll play my role in that great Quest.

© Stuart Atkinson 2008

ustrax
QUOTE (Stu @ Apr 21 2008, 04:18 PM) *
And when my metal monkey paw claws at the
ground beneath my feet, what sight will greet
me as its dust and dirt are wrenched
and torn apart?


Here you have it... tongue.gif


Great poem my friend...the palms of my hands are getting all sweaty...
Terrible...just terrible! smile.gif
antipode
Beautiful Stuart! I shivered while reading that - in a good way.

My aesthetic hopes for the mission

1) At least a little relief on the horizon (possible if it doesnt drill the landing ellipse?)
2) Atmospheric halo action (already mentioned)

and especially

3) The lander survives long enough to see the polar hood start to form and CO2 snow start to fall all around. Will it fall from a cloudy or clear sky? Will it only settle at night?

P
Stu
Not a million percent accurate, and I fear that the dawn sky there will actually be too bright to see anything in it, but in theory this is what Phoenix could see before sunrise during its mission...

Click to view attachment

Edit: "Jupiter" on the bottom image is actually VENUS. Just haven't got time to change the graphic now - due at work in 5 mins and it's a 10 min walk...
djellison
QUOTE (Stu @ Apr 22 2008, 03:43 PM) *
before sunrise


It wont be setting for some time after landing. We're north of the martian arctic circle here smile.gif

Doug
ElkGroveDan
QUOTE (Stu @ Apr 22 2008, 06:43 AM) *
due at work in 5 mins and it's a 10 min walk...


Some of us don't need to hear that. mad.gif
Stu
QUOTE (djellison @ Apr 22 2008, 03:52 PM) *
It wont be setting for some time after landing. We're north of the martian arctic circle here smile.gif

Doug


Oh... ok... that's just what STARRY NIGHT showed me... maybe my co-ordinates were out.

I'll get me coat. tongue.gif
SpaceListener
Phoenix's Landing site

What direction will Phoenix be landing on , from South East (236 E) to North West (232 E) or viceversa? I seems that maybe, up to know, no one know until up to few days before landing. rolleyes.gif

According to the output of the space simulator, now Phoenix is about ahead of Mars from the Sun side. Now Phoenix will be approaching very slow to it until on May 25 by 10:25 UTC, Phoenix will start to approach to Mars in the opposite direction to its flight path from Earth to Mars. At that moment, the flight path will turn aheading from Mars at about 71,180 km/h at 10:20 UTC and forwarding to Mars at 9,986 kph at 10:25 UTC. That is a drastic reduction speed according to Earth as reference point. By then, Phoenix will slowly start to increase its speed toward Mars from South West to North East (same direction to the Mars's orbit). The planned touchtdown on Mars would be around 23:25 UTC.

I tought it as strange since Phoenix won't ignite an rocket engine to lower the speed before approaching to Mars. Maybe, Phoenix will be flying from lower Mars' orbit plane. Due to Mars' gravity, it will pull Phoenix to change its direction from below orbit plane toward to Mars.

However. I am not 100% sure of what Ihave interpreted images samples of every 5 minutes from the JPL's tool and also the input information to this tool is still valid? (http://space.jpl.nasa.gov). huh.gif
djellison
What would be the point in using fuel now? I'm not sure what you're proposing. The spacecraft will land from the left in that diagram.

This is one of the 'not obvious at first' things about flying to Mars. Current - Phoenix is nearly ahead, and flying slower than Mars. Using the Sun as a reference Atmospheric Entry will actually speed up Phoenix smile.gif

Doug
SpaceListener
Thanks Doug for the answer.
QUOTE (djellison @ Apr 24 2008, 01:59 PM) *
What would be the point in using fuel now? I'm not sure what you're proposing.

Previously I tought that Phoenix will throttle the engines to reduce its speed during its approach to Mars but it is discarded.

By the way, I have found the info which states:

QUOTE
Phoenix won't use any thrusters for breaking its speed toward Mars instead Phoenix will probably use the thrusters for short duration during two TCMs which are scheduled to be performed within the last three days. Just before entry, flight path data is sent to Phoenix that is used by the onboard computers during the descent and landing to guide the spacecraft to its landing site.


Hence, it is evident, up to now, the flight path for landing is still unconfirmed.
slinted
The latest MARCI Weather Report mentions a dust storm blowing around the north pole last week. It's somewhat hard to see in the rotating globe movie, but I think the edge of that system may have obscured the Phoenix landing site before moving on. I've been trying to get a sense of what the daily weather will be like once Phoenix lands. Is this what we might expect for this time of year? Localized dust storms? Pole wide storms? Clouds? I haven't seen much mention of this elsewhere.
elakdawalla
Thanks for the reminder about that site, slinted; it's an excellent idea to be checking the weekly weather reports to try and figure out what Phoenix is going to encounter on its way in. The penultimate report has some general information on what happens near the pole when spring arrives:
QUOTE
For those of us living in the Northern hemisphere here on the Earth, many of the telltale signs of spring have finally arrived. The northern spring on Mars officially began in December 2007, and over the past few months, we've observed many uniquely martian springtime weather phenomena. A few common springtime observations include dust storm activity and water ice clouds near the seasonal north polar cap edge, clouds and dust activity in the southern mid-latitudes, and the early development of the aphelion cloud belt. The weather this past week included all three of these springtime phenomena, with localized dust storm activity west of Argyre and in north Tempe near the seasonal north polar cap edge. Water ice clouds also persisted over the Tharsis volcanoes, with a notable "split" cloud at Ascraeus Mons, and mid-afternoon cloud formation centers apparent near the summits of Olympus and Arsia Mons.


--Emily
dmuller
When Phoenix meets Mars, the spacecraft will have a lower orbital speed around the Sun than Mars. Why? because the Phoenix orbit would take it all the way back to where it came from ... Earth (though Earth wouldnt be there at that particular time). So, in theory, Phoenix would have to speed up to match Mars' orbital speed and "stay" with it.

BUT

Phoenix (or any other craft going there) will get very close to Mars, and you want to stay there (land or orbit). So you cant fly "along" Mars because it's gravity would pull you in if you just match its orbital speed at close distance. The issue now is that you are too fast for Mars to capture you in its orbit, or land at a decent speed, so you have to slow down your orbital speed around MARS (not the Sun). Close to Mars, the gravitational force of Mars exceeds that of the Sun anyway, so you dont really care whether your orbital speed around the Sun goes up and down as you enter an orbit around Mars or land on it (it's a whole different story though if you use Mars for a swing-by).

Phoenix will reach the point from where the gravitational force to Mars exceeds the one to the Sun on 25-May-2008 11:25am SCET UTC, 12 hours before landing, at a distance from Mars of about 139,000 km

Phoenix will slow down its orbital speed around Mars as follows:
1. friction (glowing as it streaks through the atmosphere)
2. parachute
3. retro rockets for the last 500m or so only
4. ground impact

The remaining engine firings, TCMs, are not meant to slow the craft down to Mars, only to make sure it hits the atmosphere where it is supposed to.

Phoenix landing times are as follows:
Entry interface expected on 25 May 2008 23:31:12 UTC, landing expected on 25 May 2008 23:38:32 UTC Spacecraft event time
Entry interface expected on 25 May 2008 23:46:32 UTC, landing expected on 25 May 2008 23:53:52 UTC Earth received time

Stu
We REALLY don't want to come down in the middle of this lot, do we..? blink.gif

Click to view attachment
ElkGroveDan
Unless we were to land just below that ridge right on top of that little crack that runs along the base of it. rolleyes.gif
SpaceListener
QUOTE (Stu @ Apr 26 2008, 07:42 AM) *
We REALLY don't want to come down in the middle of this lot, do we..? blink.gif

Click to view attachment

Stu, I don't have the idea about the sizes of the stones. It can be interpreted as 1 cm or 1 meter since this picture has no referential size.

It would be very pity if the spacecraft loose the balance after the touchdown. The case landing MER is safer than the ones of Phoenix / Viking way of landing. This is because the ball will most probably be stopped whenever the surface is on the flat. Hope that MSL won't take so much risks as Phoenix does since MSL will cost many times more than Phoenix.
nprev
Oh, good Lord, no!!!! blink.gif (SL, I'm gonna bet that those boulders are <1m each, since I think that the maximum resolution of HiRISE is 0.25m).

Sure looks like frost upheaval at work there, churning up the substrate; hopefully, it's very localized, and well away from the landing site. Scary as all hell, though.
dmuller
Someone asked whether Phoenix will land heading NW (diagonally up) or SE (diagonally down) on the landing ellipse. I assumed the formed but after some research seem to have been wrong! Here's the reasoning I figured out and gave that person, but did I miss something?:

Mars, on 25 May, is about 7.4 million km above the eclipitc. Phoenix, when it launched, was right on it (by definition). So at the moment it is approaching Mars from the South, will cross it's equator and head North. Mars' gravity will pull it back South just a little. So it will land from the North West and head South East (from higher to lower) in the landing elipse. Compare the following 3 images (load them, then use back / forward in your browser):

http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1
http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1
http://space.jpl.nasa.gov/cgi-bin/wspace?t...=1&showsc=1

That's Mars seen from above (in 1 minute intervals), and you can see Phoenix heading "down" again as it starts descending through the atmosphere
That's what I can figure out, at least
infocat13
[quote name='dmuller' date='Apr 26 2008, 04:44 PM' post='112865']
Someone asked whether Phoenix will land heading NW (diagonally up) or SE (diagonally down) on the landing ellipse. I assumed the formed but after some research seem to have been wrong! Here's the reasoning I figured out and gave that person, but did I miss something?:


what we need is a friendly JPL mission design or better yet aerodynamics folks to give us a glimpse of some of the AIAA aerodynamics papers on Phoenix.Unfortunately AIAA is very jealous about its copyright even through all of there papers are stamped
"paid by nasa grant number........"

This is a prelaunch astrodynamics/mission design paper for Phoenix scroll down to page 14 and are good images of approach and entry geometry.

http://trs-new.jpl.nasa.gov/dspace/bitstre...1/1/07-0267.pdf


Stu
QUOTE (SpaceListener @ Apr 26 2008, 04:34 PM) *
Stu, I don't have the idea about the sizes of the stones. It can be interpreted as 1 cm or 1 meter since this picture has no referential size.


Wow, if HiRISE can suddenly spot rocks 1cm across it's had a heck of an upgrade! tongue.gif

As HiRISE's best resolution is typically - correct me if I'm wrong, someone - "around a metre" then those rocks are each bigger than Phoenix. Again, I stand ready to be corrected here guys...

... but I'm going to have nightmares about "The Hump Of Horror" on PSP_002104_2485...!!! unsure.gif

Click to view attachment

Click to view attachment

Click to view attachment

ohmy.gif

Having said that, imagine the view if Phoenix lands smack bang in the middle of that Hump... so much for "few rocks and boulders visible..." wink.gif

Actually, being serious for a moment, why would these be so many rocks here and not elsewhere in this region? Why have they collected - or gathered - around the edge of this feature? There's another similar mound further "down" the strip, and it too has rocks arranged around its edge. What gives..?
dvandorn
QUOTE (Stu @ Apr 26 2008, 05:51 PM) *
As HiRISE's best resolution is typically - correct me if I'm wrong, someone - "around a metre" then those rocks are each bigger than Phoenix. Again, I stand ready to be corrected here guys...

HiRISE's best resolution is actually roughly 30cm (or very roughly one foot, for those of us who still use Imperial units). That said, though, I'd think you're still correct, each of those rocks is likely as larger as, or larger than, Phoenix itself.

-the other Doug
dmuller
QUOTE (infocat13 @ Apr 27 2008, 08:05 AM) *
This is a prelaunch astrodynamics/mission design paper for Phoenix scroll down to page 14 and are good images of approach and entry geometry.

Thanks infocat ... I used that document, and duly cited it, for some of the information used on my real-time Phoenix simulation script. Slipped my mind to look at it again to answer that question. Looks to me like we are going with "Page 14, Figure 13 EDL Communications Geometry, Open Launch" as shown in that document.

But yes it is a premission document, some things changed quite a bit. More information would definitively be a great plus. Emily mentioned the script on her Planetary Organization Blog, and I've had 250 site views on Saturday alone.

Daniel
edstrick
"...in the middle of this lot..."

It would be perfectly nice if it came down in the MIDDLE... between boulders.... ON TOP OF... that's different!

Another lower probability nightmare is if it came down nicely on a nice BIG flat-rock.... nice and level and undamaged... and with the sample scoop able to reach down to 1 centimeter ABOVE the ground below the edge of the rock. aaaAAAAUUURRGGGG!

djellison
It lands W to E because, looking at Mars, it flys left to right. Once you figure that Phoenix is ahead of Mars, then the geometry becomes self evident to be honest.

Doug
Stu
Hmmm... this could be interesting, or it might be nothing.

Was perusing the images listed in Emily's Blog posting re HiRISE images of the landing site, and whilst wandering over PSP_006785_2485 I found this...

Click to view attachment

... and the colour version of a neighbouring area looks like this...

Click to view attachment

Anyone else think they look like the "geyser"-type features seen down near the south pole..? Could Phoenix land near... no, that would be too much to ask for, wouldn't it..? wink.gif
ElkGroveDan
Good eye Stu.

Imagine images of a geyser plume on the horizon. Maybe it's not too late to add one to Rui's contest...
djellison
I'd have thought they'd happen during the spring, when the place is warming up and the ice retreating. Phoenix is arriving when all the action, I'd have thought, would be over

Doug
Stu
QUOTE (djellison @ Apr 27 2008, 08:27 PM) *
I'd have thought they'd happen during the spring, when the place is warming up and the ice retreating. Phoenix is arriving when all the action, I'd have thought, would be over

Doug


I thought that too... but there could be some interesting material on the surface, and reachable with the instruments, if Phoenix were to land close to one of these vents, even if it's inactive...
ElkGroveDan
OK fine. No picture then. mad.gif I remember when folks around here had vision and imagination wink.gif

I may do the picture anyway.
nprev
Aah, c'mon. Dan...they do.

Speaking as one of the judges for Rui's contest, would love to see a geyser on the horizon in one of the entries (because, frankly, who the hell knows? We don't have a bleeding clue about the rate of thermal inertia for the terrain, fooling ourselves if we think so, even more so if we assume it's uniform...)
SpaceListener
Stu, 1 cm, impossible, then closer to 1 meter is the most likely. Thanks to Nep, Stu and The other Doug.

The other thing, about after interpreting the picture, what I was thinking that the surface must be somewhat wet (ending the spring and some water might have sublimated?? and the other part might have drought into the surface??). The surface aspect is smooth probably by the ice weight and by the water erosion and the surface have no white color, then no snow??. This contradicts to Planetary blog (Phoenix on Course for Mars Landing) which says that the zone landing surface will be covered by ice.
QUOTE
"Our landing area has the largest concentration of ice on Mars outside of the polar caps. If you want to search for a habitable zone in the arctic permafrost, then this is the place to go," said Peter Smith, principal investigator for the mission, at the University of Arizona, Tucson.

ohmy.gif

Finally, I am preoccupied about the success of landing since the ellipse landing is so big (the landing area is an ellipse about 100 kilometers (62 miles) by 19 kilometers (12 miles)). Indeed, according to the Phonix Web page says:
QUOTE
the sophisticated landing system on Phoenix allows the spacecraft to touch down within 10 km (6.2 miles) of the targeted landing area.

rolleyes.gif

On the other hand, I have heard that the intelligent discrimination among boulders was deactivated in order to avoid a major complication in deciding rightly the landing site. Although I have found a quote from Phoenix's Arizona's Web which says:
QUOTE
Besides, the Phoenix's navigation system is capable of detecting and avoiding hazards on the surface of Mars.

ohmy.gif
djellison
QUOTE (SpaceListener @ Apr 28 2008, 03:37 AM) *
I was thinking that the surface must be somewhat wet


What makes you think that? The temperatures and pressures involved render liquid water a very very transient phenomenon, with sublimation far and away the dominant process.

And the resolution is not a 'more likely' situation - it's not an interpretive issue. Each pixel IS 25cm.

The blog doesn't say it'll be covered with ice. It say there is ice there. Which there is - in the soil. Not on it. In it.

I think the two articles you've seen citing landing accuracy are out of date. An active, guided entry was an initial plan for Phoenix, but it was cancelled to save money.

Doug
ustrax
QUOTE (ElkGroveDan @ Apr 27 2008, 07:56 PM) *
Maybe it's not too late to add one to Rui's contest...


Well...there's only 20 days left...and I already have the prizes with me...
those signed posters are indeed a beauty... smile.gif
I'll try to post an image from one of them already in place at spacEurope's HQ wink.gif

EDITED: Signed posters, pretty t-shirts and 15 days to go...
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