[X] My Assistant

[vikingmars]

My dream would be the SSI seeing the built-up of heavy patches of frost around Phoenix during the autumn before her winter shut-off...
... with some gathering of meteorological data as well !
I was impressed to see how quick the energy available will drop before the autumn equinox
(see link : http://www.unmannedspaceflight.com/index.p...t&p=116809)

Knowing that the Robotic Arm (RA) is strong enough to lift the lander, why not using it as an Xtra leg to tilt her to gain Xtra sunlight on its solar panels and, thus, some Xtra weeks of imaging and meteo activities ?
Rationale :
- Anyway Phoenix will die from cold : no survability is expected after winter ;
- After an extensive use for trenching, the RA will thus no longer be useful, except from being parked ;
- could the RA be parked in any position ?
- Luckily the RA is almost facing north...
Then, why not using it to push firmly on the Martian surface to tilt the Lander towards the south, to help her solar panels receive Xtra weeks of sunlight ?

==> Tilting Phoenix with the RA for Xtra weeks of activities : a feasible dream ?
What are the opinions of our s/c hardware specialists ? Was it discussed before ?
(...and, please help, help MarsEngineer ! )

[helvick]

Interesting questions Ken.

The panels don't have heating elements - I'm almost certain of that. They are a very lightweight design that delivers approx 105W/kg at 1 AU (vs about 50W/kg for the MER type rigid panel), total mass of each wing is under 10kg.

The minimum night time surface temperatures will drop towards the CO2 frost point [-123 C] sometime between LS 180 and 210 , that's approximately Sols 205 - 260. Modelling either the effect of frost on the panels or the rate at which it would burn off is well beyond me I'm afraid but it seems probable that a southerly tilt would favourably change the micro climate on the panels\deck so as to add a couple of Sols of extra working time. Once the frost begins to fall in earnest though it's going to be lights out very rapidly I think, whatever gymnastics are tried.

As far as frost\CO2 deposition is concerned I've managed to extract the following from the Mars Climate Database. The basic data seems to only be available as averages across blocks of 30 Ls so I've only got a fairly crude values so far but what is there is interesting. At Phoenix's latitude a thin uniform layer ( <1mm) of frost will have begun to form by LS 210. After that the build up of CO2 proceeds at a rate of around 1cm for every 5 LS or thereabouts and it maxes out at 25cm of solid CO2. If that actually does build up on Phoenix itself there will be about 1.6 tons of CO2 ice on the solar panels (== detached solar panels) and about a ton of CO2 ice on the deck by the end of NH winter. I wouldn't be holding out much hope for a revival after that.

LS..MinTemp.MaxTemp..CO2Ice...PanelIce
Deg...Deg.C...Deg.C......cm......Kg
0......-124....-123......22....1470
30.....-120....-102......08.....529
60......-86.....-23......00.......0
90......-80.....-18......00.......0
120.....-91.....-23......00.......0
150....-108.....-49......00.......0
180....-123....-101......00.......3
210....-123....-123......02.....159
240....-123....-123......08.....508
270....-123....-123......14.....932
300....-123....-123......20....1365
330....-123....-123......25....1646