Read my letter to Dr. Plait again. The original concern was about a launch that resulted in New Horizons burning up in the atmosphere (perhaps from friction of unanticipated reentry). What help would the RTG be? If this could never be a plausible failure mode, and only something less intense like a Challenger explosion is involved, then RTG might afford protection.

But suppose the RTG indeed survives with the plutonium intact. Now we have the problem of locating and recovering the RTG, and the possible political, if not technical, fallout of difficulty or failure to do so. This may open yet another can of worms.

No one has answered my questions in the closing paragraphs of my letter to Plait.

Correction: Anticipating one more formal nitpick objection to my letter, plutonium is considered to be one of the most toxic “elements”, not “materials”, known.

OK. I’ll let you off!

Irishman said:
“Perhaps it wasn’t intended as such, and is just the habitual signature?” Good point. I hadn’t thought of that.

Perhaps it wasn’t intended as such, and is just the habitual signature?

In support of what the BA has written, “black box” flight recorders contain significantly more moving parts than an RTG, and they are expected to survive some very harsh treatment. Aerospace engineers know how to design something small to withstand VERY rough treatment. Plus, the BA did mention the extensive testing (although without supplying any detail – perhaps he assumed you had the initiative to go and find out for yourself).

Also, “Marcosa J. Santiago, M.D.”. Why is the qualification relevant? An MD is not a science qualification. Either your argument can stand on its own, or not. Irrespective of any qualifications you may have, your argument will be assessed by the many critical thinkers and sceptics (or skeptics if you’re west of the Atlantic) who visit this site.

Having said that, BA, I have a bone to pick with you. You need to have words with your pal Dan Durda about his dramatic representation of the New Horizons probe in the vicinity of the Pluto-Charon system. The sun is a small bright object in the far distance, providing faint and oblique illumination over the two planets (moons, KBOs, whatever). So what is illuminating the probe from the foreground????? Bad astronomy. Bad, bad astronomy!

Either that, or it’s all been faked in a studio with 2 sources of light!!! Hah! I knew it was too hard to get a space probe through the asteroid belt!!:)

Yes, the page I wrote did talk about fission of plutonium, which was the thrust of the debunking. However, I linked to a couple of off-site pages (http://www.seds.org/spaceviews/cassini/rtg.html and http://www.seds.org/spaceviews/cassini/rtgpages.html) which discuss RTG safety. The point is that the RTGs are built like tanks, and will almost certainly remain intact if a rocket blows up. Take a look at the Challenger explosion– at that speed and with that violent an explosion, a lot of the pieces of debris were still in “good” shape; that is, the assembly didn’t vaporize or crumble. The military has tested RTGs out the wazoo and uses them fairly often from what I have read.

> I’m just kind of sad that the possibility of a proper probe visiting Europa in my lifetime is looking rather bleak. I can understand why researchers want to ‘check out’ Pluto, but with their limited budget, why not the more ‘fascinating’ (from a general public point of view) objects in our Solar System first?

?? Do you really think the public is as interested in one of Jupiter’s moons as it is in the one planet we haven’t visited yet?

(I realize Europa is an exciting place to study, but the general public isn’t really aware of it. I also realize Pluto’s standing as a planet is questionable, but again the general public probably doesn’t feel that way.)

First I must say we are long-time followers of BA, and appreciate 99.9% of what you have done to defend rationality about astronomical topics.

On the remaining 0.1%: we noted your 14DEC05 comment on plutonium, and looked at the link to your debunking pages. These seemed to deal with the possibility of fission during the mission, which is not at all the concern being voiced by most critics. And your remarks evidenced sloppy research on the subject (your retraction on possibility of Pu-238 fission).

The concern is that should something go wrong with the launch, and the mission burns up in the atmosphere, the plutonium could be released. It is my understanding that plutonium is one of the most toxic materials known, and this is aside from its better-known properties as atomic bomb component. What can you possibly predict about its scatter pattern after such an event?

I need hardly remind you that NASA launches and missions have had a far from flawless record. And that many decisions and judgments made in the past during the space program have been questionable, especially in hindsight after disasters which “no one could foresee”. And that political concerns have distorted NASA’s program to favor pointless, wasteful, and dangerous manned missions over scientifically rewarding unmanned projects. Have political concerns now favored gratuitous use of plutonium stockpiles in the unmanned projects that do get approved? A disaster involving even potential human harm in unmanned missions could spell the political death (or dismemberment) of NASA and government funded space research.

What is your risk/benefit assessment here? Why use plutonium in this New Horizons launch? Is there any alternative way of gaining valuable knowledge about Pluto? What are the penalties for postponing such a launch until a more comfortable substitute for plutonium can be arranged?

All indications are that the launch will take place, and that nothing will go wrong. Almost certainly this time, right?

With all due respect,

David Ecklein
Marcosa J. Santiago, M.D.

I do have some info about plutonium and RTGs on one of my older debunking pages.

Rob

Michio Kaku mentioned this on his radio show tonight, but it was in a less-than-positive light. Not from an actual research point of view, of course, but he stated that NASA is underplaying the possible environmental concerns regarding the amount of plutonium involved. That while there is a small chance of something going wrong (isn’t there always?), the general public should be made aware of the risk.

He continued along the lines of “there is no immediate or urgent necessity to visit Pluto right now – it’s not going anywhere” and that – this is getting in politics now – NASA should be spending more time and resources developing into alternate means of space transport and travel, particularly concentrating on the utilization of solar energy.

Normally, I wouldn’t mention this – I’m all for space exploration and basically nothing will stomp on my enthusiasm; but The Science Channel replayed it’s “Killer Asteroids” documentary last night. One of the scientists (sorry, I’m blanking on his name – he looks like Santa Claus) mentioned that individuals involved with nuclear defense/weapons industry attended a scientific conference regarding hypothetical methods of destroying asteroids, and basically ridiculed his ‘non-nuclear’ idea.

That disturbs me. The thought of business interests that have nothing to do with ‘good science’, or even public safety, using what must be near unlimited resources to silence and/or intimidate researchers. We are getting enough grief from the tinhats and the “Adam and Eve rode dinosaurs to church” zealots.

Anyway, all politics aside – I’m just kind of sad that the possibility of a proper probe visiting Europa in my lifetime is looking rather bleak. I can understand why researchers want to ‘check out’ Pluto, but with their limited budget, why not the more ‘fascinating’ (from a general public point of view) objects in our Solar System first?

I think it’s somewhere around 6 hours one way. I could be way off as I’m no astronomer and I’m using knowledge that’s probably way off. Last I remember it takes 8 minutes or thereabouts for light from Sol to reach Earth. Pluto is 39 times further from Sol than Earth or thereabouts. 8 minutes times 39 is 312 minutes divided by 60 = 5.2 hours. However, that’s for light moving at top speed. This doesn’t begin to take into account the vagaries of data compression, etc…

What is great about these long missions to the outer reaches of the Solar System is: Jeeezee, I can’t die yet, I have to stay alive to see the return pictures. Just how long does it take a radio signal to return to the Planet Earth from Pluto anyhow?

Rob