Sol 90+, Extended mission Options

[HughFromAlice]

Stu - I've gotta say it - Your 3D work is spectacular. I could have almost reached through my screen into that trench and picked up that rock!

[Stu]

Thanks Hugh, appreciate that. Here's a colourised version...

[Phil Stooke]

Check this out:
http://mepag.jpl.nasa.gov/meeting/sep-08/index.html

Especially this presentation:

http://mepag.jpl.nasa.gov/meeting/sep-08/P...nix_results.ppt

Which is a nice summary of Phoenix including a very nice graph of power levels over the course of the mission so far. There's a nice topographic map of the site too.

Phil

[SolarSystemRubbl...]

NASA will hold a televised media briefing on Monday, Sept. 29, at 2 p.m. EDT (11 a.m. PDT). Briefing participants will provide an update of the Phoenix Mars Mission.

The briefing will be carried live by NASA TV and on the Internet at: NASA TV

[bgarlick]

Especially this presentation:

http://mepag.jpl.nasa.gov/meeting/sep-08/P...nix_results.ppt


Phil

Notice on the available power profile slide there is a mention of a "Lazarus Mode" which seems to imply they are going to put Phoenix into some sort
of state that 'might' allow them to 'resurrect' Phoenix in the martian spring.... The existence of such a mode implies they are not 100% convinced the
mission will end with the onset of winter.

[djellison]

The Lazarus mode has been discussed for a long time. I don't think anyone is expecting it to realistically come into play, but it's just common sense to put the code in there to give the vehicle a chance were that situation to arise.

Doug

[SolarSystemRubbl...]

Notice on the available power profile slide there is a mention of a "Lazarus Mode" which seems to imply they are going to put Phoenix into some sort
of state that 'might' allow them to 'resurrect' Phoenix in the martian spring.... The existence of such a mode implies they are not 100% convinced the
mission will end with the onset of winter.

I would say "they" are 99.999999% sure it will not survive winter. It never hurts to plan for the best possible outcome...

[helvick]

I'm pretty sure that the CO2 ice build up (which will kick in in earnest at around Sol 210 IIRC) will eventually lead to Phoenix being encased in many tens if not hundreds of kg of solid CO2. I may have been mistaken in the data I extracted from the Mars Climate Database in this post from earlier in the year but I think it is certain that the ice build up will break off the solar panels even if it is not sufficient to literally crush Phoenix. I certainly don't expect Phoenix to wake up but I'll happily eat my words if she does.

[ElkGroveDan]

The one thing that I wonder about, and we may never know, is the way they talk about the panels breaking off from the build up of CO2. My gut feeling is that the CO2 is going to accumulate from the ground up. Indeed the shadowed regions under the lander will likely see the first significant growth of solid CO2 and that area will likely always have more of it until the whole region is buried. That would mean that while the panels may wind up embedded in the ice, they probably won't ever be holding up a heavy load. My guess would be that any CO2 deposition on the panels will probably occur when the ground is already waist deep in the stuff.

[bgarlick]

Does anyone know if Phoenix has been imaged by an orbiter while its Lidar was turned on?
If the orbiter was directly overhead when the lidar was on, could the orbiter see the lidar beam or light from it?
I could imagine so since a laser being pointed straight into the camera sensor should be detectable!
If so, I wonder if toward the end of the mission when Phoenix does not have enough power to run its radio transmitters, could it
send a "I am still alive" signal to the orbiters by blinking its Lidar at them when they are scheduled to be overhead. (I presume operating
the laser takes a lot less energy than operating the UHV/VHF radios...)
Also, in general, I wonder if any atmospheric science could be done by imaging the lidar beam from orbit.

[stevesliva]

The one thing that I wonder about, and we may never know, is the way they talk about the panels breaking off from the build up of CO2. My gut feeling is that the CO2 is going to accumulate from the ground up.

I wondered the same thing, and have assumed that they expect CO2 frost to form on the panels because they'll be solid surfaces below the dewpoint, or whatever the CO2 equivalent is. I do wonder, though, why it would be assumed that one they're covered in a thin opaque layer of frost, that the deposition would still weigh them down enough before the surface frost rises up...

[Deimos]

If the orbiter was directly overhead when the lidar was on, could the orbiter see the lidar beam or light from it?
I could imagine so since a laser being pointed straight into the camera sensor should be detectable!

Good thought, but it doesn't work out. The orbiter must have a camera sensitive to 532 nm, which isn't too common And the beam has to not get swamped by the sensor being very broad band or the resolution being low. Good news is the Hirise blue-green channel sort of qualifies (its broad band). The possibility of detection, though, relies on the beam not spreading much. Assuming arbitrarily that the beam width is 1 m at orbital altitudes, the orbiter camera has to pass through that 1 m. There are 8000 km available to pass through in the Phoenix altitude circle. Unless I messed up my math, an orbiter would have one look directly into the laser beam every 900 years, give or take.

[James Sorenson]

How about HiRISE imaging the lidar beam at angle, and not directly over the beam?.

[ElkGroveDan]

There are 8000 km available to pass through in the Phoenix altitude circle. Unless I messed up my math, an orbiter would have one look directly into the laser beam every 900 years, give or take.

Sounds like a pretty tough request. Almost like asking them to image a craft during EDL.

[MahFL]

Can I just get confirmation from someone that the white stuff in this picture is CO2 frost ?
Thank you.

Frost ?