Phoenix Site Options

[remcook]

did it got mentioned that the site was launched last week or so?


http://phoenix.lpl.arizona.edu/

[tedstryk]

Thanks for the link! This is much better than the old Phoenix site!

[Guest_BruceMoomaw_*]

Indeed it is -- although the other previous one ( http://planetary.chem.tufts.edu/Phoenix/-- a copy of Phoenix's very first website ) still contains some stuff which isn't in this one.

However, there is some new news in this one. The science payload has been mildly augmented since I last heard about it, with the addition of a 1.2-meter mast for air temperature profiles, some more Danish magnets on the deck, and two chemical pellets which will be dropped into each of the four MECA Wet Chem cells to improve the search for carbonates, sulfates and oxidants. A few months ago, William Boynton told me that they were seriously considering adding a chemical filter to the mass spectrometer so it could distinguish atmospheric methane from atomic oxygen, but there's no mention of it here. Also, he told me that the landing hazard avoidance system had been cancelled -- but this site describes Phoenix as carrying one based on "a cruise missile system". I intend to inquire into both these points.

Finally, this site includes a good new description of the planned operating schedule of Phoenix's experiments on the surface.

[Guest_BruceMoomaw_*]

From Doug Lombardi:

"We have made a slight modification to the [mass spectrometer] instrument and we are carrying methane detection as a lower priority requirement. However, if during calibration and characterization, operating the instrument in the fashion required to obtain the methane measurement compromises any of the original science requirements or goals, we may need to descope the methane measurement. We do not foresee any reason this should happen. Also, atomic oxygen is still 'in.' " (I imagine this "modification" has something to do with varying the degree of ionization that the M.S. will inflict on the molecules entering it.)

He also confirms that the landing hazard avoidance system will not be carried on Phoenix -- the new website was wrong about that.

By the way -- although he seemed to be alone among the Mars Strategic Roadmap Committee members on this -- Steve Squyres is apprehensive that the near-polar ground ice mantle may actually be so patchy (below the resolution of any of the current Mars orbiters' instruments) that Phoenix may be unlucky enough to land on an iceless area. As he says, though, there's nothing to be done about this in any case.

[Gsnorgathon]

Bruce -

Do you know if there are any plans for flying an instrument capable of detecting isotopic fractionation in the methane, or any other organics that might be found? With three independent teams all reporting methane, it seems the logical next step, but I have no idea how hard it would be to do such a thing. (Where "do" might include designing such an instrument and getting it to Mars, or just getting the funding for it in the first place...)

[YesRushGen]

Regarding the patchyness of the ice mantle, they should either:

a. figure a way to mount some small wheels on the lander's legs, or...

b. scrap the lander itself, and move the scientific payload onto a MER chassis.

The thing doesn't lanch until 2007 - there's plenty of time.

[tedstryk]

The payload wouldn't survive a MER landing. And the legs would have to be majorly reconfigured for wheels, if that is even possible, certainly busting the budget cap.

[djellison]

The thing doesn't lanch until 2007 - there's plenty of time.

There's <2 years before final ATLO ops - there isnt time to fart, let alone bolt wheels on it.

Doug

[TheChemist]

I have much appreciated the MERs after reading the whole Martian Chronicles series
at : http://www.astrobio.net/news/article611.html :

"Martian Chronicles I
Mars Life Summary (Sep 29, 2003): The Martian Chronicles, a multipart series, show the inside story of what it is like to join in a four-year space mission, in preparation for the dramatic landing sequence planned for January 2004. From the science diaries of Cornell's Steve Squyres, the principal investigator for the Mars Exploration Rovers' science package, this first-hand account shows exactly what it takes to plan and build a mission to another planet."

[Guest_BruceMoomaw_*]

In reply to Gsnorgathon: I believe (although I'll double-check this) that the MS on Phoenix isn't sensitive enough to detect the extremely small amounts of trace-isotope methane that may exist in Mars' atmosphere. However, the "SAM" instrument on MSL -- which is that mission's central instrument -- definitely WILL look for them, both in the atmosphere and in the emissions from heated surface samples.

[Gsnorgathon]

Thanks, Bruce. Guess we'll just have to be patient and bide our time, then. :@)

[tedstryk]

Some Phoenix SSI info (courtesy the SSI team). This should produce one hell of a panorama. And, looking over Viking views, it will be neat to see a site change with time, although, given its solar power and northern location, Phoenix might not be much longer lived than Pathfinder.
____________________________________________
The MVACS SSI used a 23 micron/pixel CCD with a 23 mm EFL lens to
get the resolution of 1 mrad/pixel. The PHX SSI design uses a 12
micron/pixel CCD from the MER with a 50 mm EFL lens giving 0.24 mrad/pixel,
and almost the same FOV. The MER rovers use the same CCD with a shorter lens
giving about 0.27 mrad/pixel. So the PHX SSI will have slightly higher
resolution then the MER rovers from the same CCD's.
We kept the entrance windows, filters, and first fold mirrors from the MVACS
SSI design, everything after that was different. We almost managed to fit it
in to the same space. The PHX SSI will have some bumps on the top cover to
package everything in. Sort of like a hood bulge on a hot rod.

[RedSky]

I ran across this page of the Phoenix landing animation done by Maas Digital in the same great style of the MER animations. I may have missed it, but I haven't seen this mentioned here yet... and its certainly worth a viewing. Fantastic realism, again!

The entry looks similar to the MER animation, but clearly is aimed at high latitudes. Also, the chute opening shot is more dramatic. But what especially makes one almost gasp is when the cable is cut and the top shell/lander plummet toward the surface. When the shell is jettisoned and the lander's thrusters fire... it almost seems too real in that the lander appears to really struggle keeping itself oriented upright until it finally gets to the surface. After seeing this animation, I really worry about this landing a lot more than I did for the MER airbag method. Guess we didn't know how lucky we were with two successful thruster-style Viking landings almost 30 years ago.

http://phoenix.lpl.arizona.edu/multimedia/...x_animation.php

[helvick]

That link led me to dig around on the site a bit and I found that some of the team are posting news and updates in Weblogs

Very nice to see the folks putting stuff like this out there, I certainly appreciate the effort it takes.

[Redstone]

I ran across this page of the Phoenix landing animation done by Maas Digital in the same great style of the MER animations.  I may have missed it, but I haven't seen this mentioned here yet...  and its certainly worth a viewing.  Fantastic realism, again! 

Dan Maas did an animation for the 2001 Mars Lander for the APEX project (Athena Precursor EXperiment) with Steve Squyers as a "Technical Consultant". It was the first one Maas did I think. The 2001 animation went from launch, through EDL, to surface operations.

Naturally there's many similarities between the 2001 and 2007 versions, but some interesting differences too. Some are of course due to the changes to the spacecraft. The 2001 lander back then was supposed to carry a copy of Sojourner, which was to be lifted down from the lander deck to the surface by a robot arm. And the camera mast was like MER's, not like the simpler one on Phoenix.

Other differences include the latitude of arrival, so in the 2001 version we don't see the polar cap and there's less ice on the ground. And the landing kicks up more dust! And the 2001 animation had a soundtrack too!