This topic is for posts concerning to any preparation of Phoenix Lander Mission to Mars programmed to launch on August 2007 (less than 2 years... but the time will fly)

http://marsprogram.jpl.nasa.gov/missions/future/phoenix.html

Overview

The Phoenix mission is the first chosen for NASA's Scout program, an initiative for smaller, lower-cost, competed spacecraft. Named for the resilient mythological bird, Phoenix uses a lander that was intended for use by 2001's Mars Surveyor lander prior to its cancellation. It also carries a complex suite of instruments that are improved variations of those that flew on the lost Mars Polar Lander.

Canada Will Land Instrument On Mars To Study Weather

http://www.spacedaily.com/news/mars-future-05t.html

Rodolfo

An article on Space.com where we can also "see" the real lander :
http://www.space.com/businesstechnology/06...oenix_tech.html

Principal Investigator Peter Smith has just answered perhaps the two biggest questions about Phoenix:

(1) The precision-landing test, using guided entry, has indeed been cancelled -- so MSL will be the first Mars lander to try that.

(2) Phoenix will, with luck, be able to detect methane in Mars' air at 10 parts per billion -- although "we will not know if this is doable until the first full TEGA test in May."

Where is this from, Bruce?

Phil

Smith E-mailed me personally, in response to my query last night. (We've talked before.)

Didn't see this elsewhere on the boards. The AO for Mars Scout '11/'12 went out on Monday.

http://www.marstoday.com/news/viewsr.html?pid=20314

Anyone have any info on the types of proposals we can expect?

At the 37th Lunar and Planetary Science Conference (LPSC), held March 13-17 in Houston, Texas, Phoenix team members presented both excitement and nervousness about the Phoenix Mars endeavor—specifically, addressing the dangers lurking at the spacecraft’s landing zone.

These worries are :

1) NASA wants to land down the Phoenix in a zone where does not have "egregious landforms" in terms of safety. Needs more pictures from MRO, MGS, MEX and Odyssey.

2) Additional uncertainties include air density, winds, lander attitude control…and just how well Phoenix will deal with slopes and rocks, Guinn explained. Fortunately, the northern plains of Mars are very flat and low.

3) The other trouble is that the Phoenix belly is so low, up to 35 cms of clearence above the surface. Depending the force of landing, the legs can lower even further. Hence, need a clean surface, no rocks bigger than 25 cms. So "If there is a pointy rock that you come down on, the belly pan [of the lander] could hit that rock…and that would be of serious concern," Golombek said. "So there is concern here. We will be looking at the MRO data with great interest," he concluded.

Up to now, not yet has determined the landing place for Phonix

Rodolfo

http://www.space.com/businesstechnology/06...oenix_tech.html

Several interesting new tidbits I've recently run across about this mission (in addition to the two I mentioned earlier):

(1) All its possible landing areas seem to have a very thin layer of dry soil over the underlying permafrost -- only 4-6 cm thick in most places. This presents problems for one desired science goal: using the MECA and TEGA to analyze chemical gradients with depth in the soil layer -- they may have to settle for only one or at most two scoops of soil before they get to the ice, instead of the hoped-for three.

For this reason, the planners are now placing greater emphasis on analyzing the permafrost itself on this mission -- but that, in turn, presents problems. Permafrost is very hard stuff, and Deborah Bass' blog ( http://phoenix.lpl.arizona.edu/features/we...eborah_bass.php , Nov. 13 and 21 entries) reports the problems they've been having designing the scoop to properly handle it. The robotic arm by itself, even with the digging tines fastened to its scoop, isn't nearly strong enough to rake up an adequate pile of the stuff without taking days -- during which any shreds of ice it manages to detach will probably sublimate away before enough can be accumulated for the scoop to pick them up. Thus the decision to add the Icy Soil Acquisition Device -- a rotating "ice shredder wheel"-- to the rear of the scoop to both quickly detach shreds and kick them straight into the scoop.

(2) The best description of the reasons for the choice of "Region B" as the overall landing region is at http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1328.pdf -- which can be summarized by saying that it's scientifically as good as the other two regions, and somewhat safer.

(3) Bass' Aug. 27 entry talks about the measures being taken to keep chemical contamination of the site by the thrusters' hydrazine within acceptable bounds. (Note that the Vikings reported no problems from this.)

(4) The Dec. 8 entry talks about the fact that the lander will be swaying rapidly during its parachute descent, which may somewhat blur the descent images (as it might have on Polar Lander).

(5) Each MECA wet chemistry cell will finish its analysis by dropping two chemical pellets into the water: an acid one to reveal any carbonates, and another to reveal both sulfates and soil oxidants.

(6) Besides the meteorology measurements made by the lidar and temperature and pressure sensors on the MET experiment, and the periodic air analyses done by the mass spectrometer, the "TECP" probe on the arm scoop to measure soil electrical and thermal conductivity (which has a heated prong surrounded by temperature sensors) can double as a hot-wire anemometer, and an air humidity sensor is also built into the TECP. There are also strings dangling from the thin mast carrying the MET temperature sensors to serve as photographable wind sensors, like the windsocks on Pathfinder's mast.



ARES and MARVEL will be resubmitted, with only minor changes; but I haven't yet been able to find out whether SCIM will be. Bruce Campbell is also resubmitting his Mars Scout SAR orbiter, now christened "Eagle" ( http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2188.pdf ). Ames Research Center is trying to one-up Langley and its ARES with "MATADOR", another Mars airplane that might actually be able to survive its final landing ( http://www.aviationnow.com/avnow/news/chan...ATADOR11174.xml ) Bruce Banerdt is submitting some kind of single lander focusing on geophysics, and somebody else is submitting some kind of Phoenix-like lander with a mini-rover. Finally, besides ARES, the Langley center was planning to submit an atmospheric orbiter ("MARS": http://www.spaceref.com/news/viewsr.html?pid=18893 ) -- but the new plans for a big 2013 atmospheric orbiter may upset the chances for both that one and MARVEL.

Update: SCIM will be resubmitted in 2011 ( http://www.space.com/missionlaunches/06012...e_capsules.html ). I regard it as a major contender, especially given the new delay in the flat-out surface Mars sample return mission.

A Bit more on MATADOR at http://research.hq.nasa.gov/code_s/nra/cur...MT/winners.html :

"Lawrence Lemke / Ames Research Center
MATADOR: a Mars Advanced Technology Airplane for Deployment, Operations, and Recovery"

"Current Mars airplane missions typically begin by deploying the aiplane in a nose-down attitude, involve a dive below the cruise altitude in order to establish flight speed and end with an uncontrolled crash into the planet's surface. This proposal is to demonstrate technology which would improve this scenario by allowing controlled deployment of the folded wings at the beginning of flight without a negative altitude excursion and which would allow controlled impact of the aircraft into the planet's surface at the end of flight in a nose-high, low-energy approach which will leave the airframe in a condition to relay on-board data to an overhead spacecraft.

"The technology to accomplish this consists of a delta planform fuselage to contribute intrinsic pitch stability to the folded airplane at high angles of attack and a cold gas reaction control system under control of the autopilot to provide direct thrust vectors, independent of flight speed. This demonstration will be accomplished through a work plan to design, construct, and flight test an unpiloted aerial vehicle, named MATADOR.

"MATADOR is a blended wing-body rocket powered aircraft of 4m wingspan designed for steady-state flight on Mars at 4km above datum at 0.6 Mach and 0.6 Cl. The 3-year work plan calls for 2 high altitude flight test demonstrations of MATADOR to be conducted by carrying the airframe to approximately 30km altitude with a helium balloon and releasing it to begin flight. In addition, the plan calls for a series of ground impact tests in which the incidence angle and velocity and surface slope and roughness parameters will be experimentally investigated to determine their effect on the ability of the airplane to survive and function for the purposes of data communication."

A winged Mars lander which might survive after touchdown? What a good idea! I wonder if anyone has thought of it before?

Bob Shaw

Here are 2 Phoenix model pictures I took at the Planetary's Society event called "Wild about Mars" on Spirit day landing. You can also see a Lego model of MER landers in the back ground. Note how big if Phoenix as compared to both MER and a person in front of it :
Click to view attachment Click to view attachment
Climber

Cool pictures - I guess those are spare Cosmos 1 'sails' behind?

Doug

[quote name='djellison' date='Apr 20 2006, 12:09 PM' post='51277']
Cool pictures - I guess those are spare Cosmos 1 'sails' behind?

Doug

You're right. As was amazed by both Phoenix (high & big arm) as well as Comos 1 'sails' size.
By the way, here is Pathfinder sitting nearby :
Click to view attachment

'Cool! Check out the *bling* on that, Victoria! Do you want a pair in Burberry?'

Bob Shaw

Pardon my newbie question, but are there any issues with "temperature contamination" from the lander? If we are trying to study pristine permafrost conditions, what affect would hot thrusters and the attendant gasses have? Would there be any delicate CO2 frost or ice melt that might change the local conditions? Or will the low temperature and pressure of Mars' atmosphere sufficiently dissipate any excess heat quickly enough?

Thanks Bruce for a very informative post.

I haven't heard anything about there being any problem with the temperature. Presumably the arm has a long enough reach to get beyond any places on the surface that might have been temperature-modified. (Nor did I ever hear anything about any such problem with Mars Polar Lander, which had similar engines and a similar arm.)

Bruce:

It's OK, for safety reasons they'll cut the engines at 30m above the surface.

Bob Shaw

Ho ho, yuk yuk, har de har har. While going through the report of MEPAG's "Mars Human Precursor Group" on the necessary safety measurements for Mars' atmosphere (more on that soon, down in the "MTO Cancelled" thread), I found the following little note: "Phoenix landing thruster system may erode 0.3 cubic meters of soil, which is a cloud containing a few hundred kg of loose soil and dust." Gaaack. However, they never made a fuss about this for Mars Polar Lander -- which had the same system using touchdown sensors on the foot pads themselves to shut down the engines.

So on one hand we've got reports of a terrain so hard they'll struggle to dig through it, and on the other reports that the engines will blow away 1/3rd of a ton of the stuff.

Doug

Upside down creme brulee?

um, i mean the hard permafrost UNDER the dust....

If the "blow zone" is four meters in diameter, the average amount of surface dust removed by the landing blast would be a couple centimeters. This is still a surprising amount to me.

What they're apprehensive about blowing away is the 5 cm or so of loose soil on top of that hard permafrost -- and what they're apprehensive about contaminating with hydrazine is both the soil and the surface of that permafrost. (As I said last night, however, Deborah Bass' August 27 blog entry suggests that they're not all that worried about it.)

It bears repeating that Deborah Bass' Blog contain's lots of excellent material and Suzanne Young's has a load of relevant info on the risks (or not) of Hydrazine contamination

Hydrazine contamination

Is this still a problem when you know exactely the contaminant and the quantity of it ? I mean, not talking about soil/ice disturbance, can we "remove" Hydrazine from the analysis ?

In order to be able to remove it from the analysis, you would need to be able to know what
it had reacted with. Since part of the reason for going is to find out what the geochemistry is,
I guess the answer is at very best "perhaps", and more likely "no".

From reading Suzanne Youg's blog, it seems that the engines are very efficient, so hydrazine
isn't a big worry. The ammonia produced by the breakdon of hydrazine may still be an issue though,
as approaching 80% of the exhaust gas is ammonia.

Chris

Since part of the reason for going is to find out what the geochemistry is,

Oh Yes! Exploration is. I kind of forget the reason we're doing this, didn't I ?

Given our struggles to get the power required for Spirit from solar panels, with the sun at about 50degrees up (midwinter midsol at Gusev), how well are the Phoenix panels going to manage? Is there any plan to tilt the panels and catch a few more rays? Or does Phoenix have another power source that I don't know about? (in which case why are the panels there??)

Phoenix is just arrays, they will be almost parallel to the ground - but it will get 24 hr sunlight early in the mission (check the website for an animation that shows this) so a tilt would be a bad idea as you would get from one side only what you would drop on the other.

Phoenix is going to be a short lived mission, the very long, very cold polar night will kill it.

Doug

Phoenix has a very well defined mission and there will be more than enough energy available for it during it's 3 month primary mission as it will occur during the late NH spring-summer season when insolation at high latitudes is high (higher than at the equator in fact because the sun will never set at all at the height of summer) and it may have enough energy to continue to do some science for up to 190 sols. Extending Phoenix's mission may be only of marginal value though since it has very specific objectives and extending the mission will only really make sense if scheduling difficulties mean that it can't complete it's planned tasks in the first three months or if some of the secondary instruments yield something really dramatic.

I've attached my estimate of the power that would be available from a 1M^2 panel, 26% efficiency cells with an 80% power subsystem efficiency for the Phoenix landing site (70degN) starting on the exected landing date of 10 May 2008. I've put in fairly aggressive dust loss parameters (0.2% per sol) and modelled Tau using the 1997 dust storm model from Viking (which was a medium scale global storm) which is fairly conservative. As you can see there's lots of power for 120 Sols or so but then it rapidly tails off as winter arrives and since it is above the martian arctic circle it will eventually get to a stage (around Sol 320) when it is dark 24.65979 hours of the Sol.

I've no idea what the actual solar panel area for Phoenix is or what the cell types are but 1m^2 seemed reasonable from the pictures I've seen online and 26% efficiency should be about right if they are using recent Triple Junction GaInP cells.
Click to view attachment

Thanks helvick, very attractive graphs.

I'm surprised at the idea that you can get more power near the poles than the equator even in summer, since you'll need many hours of 5º sun to equate to an hour of 90º sun. However the trig is too hard for me to do without some serious thought and lots of envelopes with plenty of space on the back, so I'll take your word for it (for now)!

And I guess the other thing is the limited mission, as you say. Once the analysis reagents are used, the most interesting part of the mission is done and the quiet slipping away of the Phoenix will be easier to bear.

This is an article from Space.com :
"Backhoe Ho-Down on Mars
The next robotic arm headed for the red planet is ready for final testing and installation onto NASA’s Mars Phoenix lander, due for liftoff in August of next year.The backhoe-like arm was built by Alliance Spacesystems, Inc. (ASI) of Pasadena, California. Once on Mars in May 2008, the arm is assigned a key duty of digging a two-foot deep trench in Mars’ north-polar region.
At the business end of the arm is a scoop about the size of a garden trowel that will do the digging down to an ice layer that is potentially rock-hard. The arm will deliver soil samples to a suite of devices on the lander’s deck for detailed analysis. A camera mounted on the arm will view layers in the freshly-dug trench wall.
The agile arm has a 7.5-foot reach (2.3 meters), with the aluminum and titanium device weighing less than 22 pounds (9.7 kilograms). The robotic arm – inherited from a shelved 2001 Mars mission to the equator – could not dig into hard icy soils at cold temperatures and had to be completely redesigned. Mars Phoenix is a three-month mission expected to yield new clues to the history of water on Mars and whether the environment was ever conducive to life."

I have actually seen and handled an engineering prototype of the completely redesigned scoop and have written an article that I'm trying to publish somewhere.

There was a full scale model of Phoenix at the 2005 JPL Open House. The mission may last up to 5 months and will likely end when the craft is buried under an accumulation of frozen carbon dioxide ice.

Interesting item on SpaceRef: NASA is going to procure laser-retroreflectors to install on the Phoenix lander so that it can be precisely lidar-bounced and located from orbit.

http://www.spaceref.com/news/viewsr.html?pid=20608

"NASA Stennis Solicitation: Phoenix Mars Scout Laser Retroreflector Arrays "
"NASA/GSFC intends to purchase an Engineering Model and two (2) Flight Laser Retroflector Arrays from ITE, Inc ..."
"GSFC intents to acquire a set of reflector arrays for the Phoenix Mars Scout mission due for launch in the summer of 2007. These arrays will enable the Phoenix lander to be located from Mars orbit"

A bit more on the new ice-sampling tool in Deborah Bass' lastest blog entry ( http://phoenix.lpl.arizona.edu/features/we...eborah_bass.php , Apr. 24 entry).

spacedaily

If you can't make it as a MER rover driver, this could be an interesting job vacancy: Mars arm operator.

reads much like the testbed they put together for Beagle 2 here in Leicester.

Doug

Oh, gee -- that sounds like a really bad come-on line: "Hey, baby, wanna come back to my place and watch me operate my Mars arm???"



-the other Doug

Interesting interview with Chris Mckay about Phonix mission.

http://www.marsdaily.com/reports/Digging_D..._Mckay_999.html

The north pole is most desirable than the south pole because of the following factors:

1. The north is lower and smoother than the south. Easier to land
2. South is higher and heavily cratered terrain and harder to land.
3. South needs deep drill to get interesting data.
4. North needs less drilling to find liquid water (probably) at the surface in the more recent past.
5. In the north there might be more young ice.

He does not believe to find any organic materials...

Rodolfo

I believe this statement was in reference to MSL and Exomars which will land in areas where no ice is present to protect organics (if they ever existed) from oxidants. As far as Phoenix goes, he says that, if present, organics could be protected by the ice and detected. He doesn't say if he expects phoenix to find organics.

Public Invited to UA's Phoenix Mars Mission Open House Oct. 21
By University of Arizona Communications
October 11, 2006

Hi all

Not sure if this has been asked before, but here goes.

Assuming Phoenix outlasts its 90 day warranty - what will finally 'kill' it first - declining temperatures or oncoming polar darkness? I ask this because it seems that at this latitude, the winter frost/snowpack will be pretty deep - it would be wonderful (and sad) if the lander could document its own burial in snow! (until it WAS buried of course).

Is this likely, or will the lander be dead before any snowpack builds up around the vehicle? I always thought the Viking 2 frost pictures were evocative, and here we have a chance to go one better, and presumably catch all sorts of other polar weather processes (development of the polar cloud hood?) as well.

Phil

I don't know the creation process of martian frost/snow, but if some snow is able to build up on solar panels, even if the solar power and the temperature are still good enough, the death might be quick.

Without snow\frost degrading the panels power output will follow something like this:


My guess is that there can be no precipitation effects until insolation drops well below the levels we've seen at the MER sites ie 30% of the initial max. So frost/snow effects if any should only come into play after around Sol 210.

Looking at the MRO image of the region close to where Phoenix should make its landing,I would think JPl should be concerned about stone slabs littering the whole area.Has anyone given any consideration as this may be a serious hindrance to a safe landing.

Unlikely as it is, I think it would be really cool if Phoenix can be reawakend after the winter. Even if it can't do much. It would be neat to take a panorama for change detection, especially with regard to its trench, which will have experienced frost coming and going.

Julius: "Looking at the MRO image of the region close to where Phoenix should make its landing,I would think JPl should be concerned about stone slabs littering the whole area.Has anyone given any consideration as this may be a serious hindrance to a safe landing."

Yes. One of MRO's jobs is to look for areas without too many rocks.

Phil

Phoenix Home page show this as a future possible landing site : http://phoenix.lpl.arizona.edu/multimedia/...site_8_3_06.jpg
Can you provide us with the link of the MRO picture you're talking about ?
Thanks

After visiting the following Hiroc Web page. The closest ones are ones of polygonal terrain (TRA_000828_2495).
Specifically, around the Phoenix landing zone, up to now, MRO haven't yet posted any additional picture. Soon these pictures will come soon.

Rodolfo

Thats the MRO image I was talking about except you have to zoom in!The rocks are described as being part of the ejecta blanket from exhumed craters.

University of Arizona news article; Full-scale Mars Lander to be Unveiled at Phoenix Mission VIP Event: http://uanews.org/cgi-bin/WebObjects/UANew...ArticleID=13235

Hopefully I can make it down there on the 21st to check it out.