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Posted by: AlexBlackwell Oct 4 2006, 07:50 PM

http://www.nasa.gov/home/hqnews/2006/oct/HQ_M06154_Mars_meeting.html
MEDIA ADVISORY: M06-154
October 4, 2006

Posted by: gndonald Oct 5 2006, 01:30 AM

I see NASA is still afraid to show the RTG power supply on the MSL rover. Here's hoping that the Anti-Nuclear crowd don't 'smoke' them into chosing Solar Panels for this one.

Posted by: Mariner9 Oct 5 2006, 05:18 PM

Yes, I also noticed a mention of the mission using either an RTG or solar panel power. I have trouble imagining that JPL is still pondering that move this late into the design.... so have to wonder if that is also a political move on their part to give the impression that if they are indeed going with RTG, that the decision was carefully weighed from the engineering standpoint and they didn't just jump to that conclusion too quickly.

The sucess of the MERs might be playing a part in all this. The conventional engineering wisdom before the mission landed was that solar panels would loose effectiveness over time as the dust collected. At 2.5 years and going strong, MER is putting that concern to rest. So even if using an RTG is still a better choice for MSL, it gives ammunition to the anti-nuke crowd to point at MER and say that solar can do the job.

I hope they go with an RTG... because we all know that in spite of the improvement in solar cells over the last 20 years, many of the outer planets missions still need nuclear power. Loosing this one because of politics would bode ill for future missions.

Posted by: punkboi Oct 5 2006, 05:30 PM

They won't. They couldn't even 'smoke' NASA into not launching Galileo, Cassini and New Horizons

Posted by: helvick Oct 5 2006, 07:09 PM

I'm certain that they are being vague in order to avoid drawing unnecessary attention to it but the argument that the MER's have proven that solar panels are good enough doesn't hold water for MSL. Speaking as UMSF.com's #1 Solar power fan I have to say that I'd be disgusted if Solar power is being seriously considered for MSL.

The MER's have been lucky. There have been no really bad dust storms since they landed. A single dust storm on a par with either of the 1977 storms that the Vikings lived through would have killed both MER's. To survive such a storm any rover needs approximately 5x margin of solar power generating capacity.

They are were also extremely tightly constrained in where they could be targeted. Spirit is only 12deg further south than Opportunity yet it is at the extreme edge of the survival zone for a MER type rover - and that was the case in it's first year of operation. Had it been even a few degrees further south it could not have survived its first winter.

Solar Panels are physically awkward and impose mobility constraints. Roving in canyon type terrain or even close in to cliffs that are badly oriented (ie that would block the sun) is just not an option.

I could go on.

Posted by: lyford Oct 5 2006, 07:50 PM

From the release:

I would say that it would be an extremely alternate mission, and would be so constrained as to change MSL's abilities and mission. 75kg of science instruments, heavier rover with more mobility power draw, longer range... all would be at the mercy of an unpredictable power budget. I can almost imagine that MSL with solar would more resemble a crocodile having to bask in the sun just to get enough energy to make it through the day....

Posted by: mcaplinger Oct 6 2006, 12:19 AM

Did anybody read the EIS? In my quick skim, they really didn't make this case as strongly as I thought they would, focusing mostly on the latitude restrictions that would come with solar. Frankly, if I read the EIS in isolation I might well conclude that they hadn't really justified needing the RTG.

Posted by: lyford Oct 6 2006, 12:51 AM

I agree it's a rather bland presentation of the restrictions:

Touche!

Solar restricts the mission to 15 degrees N in the alternate- which is the only place on Mars giving the full power for a full Mars year. If you lower the power requirements, you can stretch that a bit, but they you have to give up some instruments or make the mission less than a Martian year...

I think they also should mention that the solar version looks like a house boat compared to the cool batmobile thermal regulators on the RTG model

(let me know if the inline images are too large to load for some with slow connections and i'll make them attachments)

Posted by: Mariner9 Oct 6 2006, 01:32 AM

I stand by my point that the anti-nuke crowd could easily use MER as an argument against going Nuclear.

I don't think it is a good argument, and would ultimately loose for all the reasons everyone has stated, but it is not a completely crazy argument either. Who said the rover HAD to go farther south or north? And does it HAVE to last more than a year? And so on and so on. Clearly you could do the mission with solar power, it would just be a lot less capable.

Keep in mind, these same folk argued that NASA had failed to consider making Cassini solar powered .... although I never did see any indication that the protesters had bothered to make even a back of the envelope study of their own to show that Cassini could get enough power from solar panels, or just how large and heavy those panels would need to be. But hey, not their job, right? They just complain, and NASA should spend millions proving their wild complaints to be invalid.


I think the point was made that the presentation was made to avoid drawing unecessary attention to the whole issue. I agree... and I hope it works. I don't see the anti-nuke folk suceeding (especially with the current administration in office) but I also don't want a nasty battle which would make any future use of RTGs that much harder.

Posted by: dvandorn Oct 6 2006, 03:53 AM

The problem is, if you tell these people that you need the energy available from an RTG to accomplish the mission, they'll just use their circular logic to conclude that any mission which requires nuclear power isn't worth the risk. Period. End of story. Their argument becomes: If you can't do the mission without using plutonium, then the mission doesn't need to be flown. If you insist that it does, then you are knowingly exposing them to an almost certain death. They're looking for a reason to hate and fear you.

No amount of logic or reasoning will budge them from that position, because they are not operating from a rational position. They are irrational and driven entirely by fear -- fear engendered by people who want to use a mass of fearful people to further their own goals of acquiring and retaining some form of power.

Keeping people afraid in order to achieve power is the worst, most profoundly sick and perverted mindset in the entire panoply of the human psyche. It's also one of the most common perversions. If it were possible to alter human nature, this is the place I would start.

-the other Doug

Posted by: djellison Oct 6 2006, 07:23 AM

The Anti's couldn't stop Pioneer, Voyager, Viking, Cassini, Galileo or NH....they won't stop MSL either.

Doug

Posted by: Jeff7 Oct 6 2006, 03:28 PM

Though let us not forget, the MERs do have some radioisotope heaters in them. Even for them, solar still isn't technically enough. Otherwise I guess they'd need bigger batteries to provide power to electric heaters, which means either larger solar panels are needed, or less science gets done.
So the anti-nuke extremists could probably even say that the MERs shouldn't ever have flown in their current form.

Posted by: Rakhir Oct 6 2006, 04:57 PM

http://www.minutemanmedia.org/GROSSMAN%20100406.htm

Posted by: helvick Oct 6 2006, 05:53 PM

This is out of date, inaccurate and makes some claims that are unsubstantiated and improbable. If it were were worth picking apart I'd spend some time doing it but it's far too sloppy to warrant the effort.
But some quick points:
[1] This is old news - we debated this (Solar Power for probes beyond Jupiter) months back.
[2] The data referenced is grossly inaccurate, especially the damage caused by US launch failures that involved spacecraft with on board nuclear power.
[3] The implications that solar power was developed as a consequence of either those launch failures or some dudes speculative analysis of the effects of them is highly simplistic at best.
And I could go on.

Folks like the author of this piece really would be well advised to put their energy into having resources put towards the safe recovery and disposal of the RTG's used by the Former Soviet Union to power remote lighthouses. That stuff is much more likely to do bad things to people here on earth.

Harrumph.

Posted by: Jeff7 Oct 6 2006, 09:05 PM

The article cited something in “Aviation Week & Space Technology”:
"The U.S. space agency is already planning a solar-powered mission to study the atmosphere of Jupiter, and has looked at sending probes as deep into space as Neptune using only the Sun’s energy for spacecraft and instrument power…It is all but certain the next U.S. deep-space missions will be solar-powered."

To Neptune? Using solar power? To do what, run a 1MP digital camera and a transmitter?
If there are such efficient solar cells out there, where are they? Why are we in the consumer market stuck using cells that max out at around 13%?


Plutonium in space would be even less necessary if they'd get the Prometheus program going again.
Sure they'd use uranium, so some people would still complain, but it's not nearly as toxic, and it would allow for much more powerful spacecraft.

Posted by: gndonald Oct 7 2006, 02:50 PM

I don't think there were protests for missions from Viking to Ulysses/Galileo. I could be wrong but I don't think that they started until after some 'ding-dong' claimed that when Galileo entered Jupiters atmosphere the RTG were going to http://tinyurl.com/ngjj

I'd also like to add that I think NASA is only considering Solar Power for MSL because it's required to by the EPA, after all, the paperwork for the RTGs on Cassini reputedly cost as much as the Pathfinder rover.

Ditto for that mention of solar powered missions to Neptune. One wonders how much wasted design effort goes into pandering to the fears of the Anti's 'rent-a-crowd', who will no doubt be out in force at the hearings.

Posted by: lyford Oct 7 2006, 04:30 PM

I agree that much of the noise is maddening, but I do think we should not confuse the process with the hysterical responses of an emotional few. A publicly funded project should most certainly do impact reports; it's basically just describing what the scope of a project is, what the expected consequences would be, any ways to mitigate those consequences and any alternative ways to do the project. I shudder to mention there is a THIRD way described in the EIS - "No Action" -which means NASA won't do this mission to Mars at all! (Apparently this is a standard item in these statements, and I guess it's true - one could always choose not to do something.)

Anyway, the paperwork is a hassle, but it does serve the public interest to make known what potential impacts there are to a project before it is begun. Much better to plan for potential problems in the open than to have to do an impact statement http://www.atsdr.cdc.gov/HAC/PHA/santa/san_p1.html may have already leaked into the groundwater....

I think what really is at issue here is not so much a nuclear safety fear, but the general public's inability to deal rationally with large numbers and understand statistics.


(As someone who just moved to Carlsbad, I live a mile away from a "mitigated impact." When the plans were drawn for the http://www.dbc.uci.edu/~sustain/global/sensem/mineg197.html the trade off was the destruction of habitat in L.A. would be mitigated by the restoration of habitat elsewhere - the http://www.batiquitos.org/)

Posted by: MarkL Oct 10 2006, 01:36 PM

I greatly enjoyed this discussion. It seems to me that the real problem is allowing the making of a mountain from a molehill. The risk to people on the ground is utterly minute but has, with PR leverage and support of pliant media, been blown up (pun intended) into some potential catastrophic event. It's like a petri dish for wing nuts after that type of sensationalism. If you want to advance you just have to take the required steps forward and shake off these wing nuts. Send them back to their caves with their dogeared copies of Pandas and People tucked firmly somewhere in their anatomy.

Posted by: RNeuhaus Oct 16 2006, 09:18 PM

http://www.space.com/spacenews/businessmonday_061016.html

NASA expects to decide by the end of the year whether to use conventional solar arrays or a nuclear battery to power the 2009 Mars Science Laboratory rover.

Another important point is that NASA is waiting until one year prior to launch to make a final landing site selection, waiting for the latest information gathered by the planned MRO to identify a safe spot to land.

Rodolfo

Posted by: edstrick Oct 17 2006, 11:51 AM

You have to remember that one of the main methods the mass media use to increase reader/viewer/listenership and thus increase advertising revenue is CONTROVERSY MONGERING. Take a controversy, no matter how flimsy, pit an ACTIVIST against a CORPORATE PR FLACK or a government BUREAU-CRAP, give equal weight to their claims, ignore evidence.. and you have a wildfire controversy spreading like contagious hysteria.

Posted by: PhilCo126 Oct 17 2006, 05:17 PM

Well much a do about nothing ???

I believe the US space agency already launched over 25 missions using RTGs and nothing ‘major’ went wrong … Remember that RTGs are ruggedized = designed to withstand both impact on land/water and other forms of damage and destruction. Moreover the ‘radio-active’ fuel cell is well encased in some ceramic-shell.
Best of all, RTGs cannot explode because there’s no fusion nor fission process.

Posted by: MahFL Oct 17 2006, 05:26 PM

The general public don't know what a nuclear explosion is. I would not want to eat a pound of Pu though....I am heavy enough as it is lol !!!!