Europa Orbiter, Speculation, updates and discussion Options

[Decepticon]

And I've always wondered why the articles are so fricken short.

[mars loon]

As for the article, they told me from the start that 4 pages was the length.  The trouble is that whenever I attend one of these damn conferences, I get enough interesting material for SEVERAL articles, and then go through the torments of hell trying desperately to hack a 12 to 15-page article down to a few pages while the article bleeds and screams piteously.  As with my 2004 article on the MER-A landing for "Astronomy", I finally just had to throw myself on the mercy of the editors by submitting an oversized article and letting them do the dirty work.  (A far cry from those bright college days when I was straining desperately to inflate puny term papers.)

Bruce, what month in 2004 was that?

Also, hard to say if you used the best approach with the editors. Did you consider 2 versions? one short, one long.

In your opinion did they retain the best stuff? or would you have preferred alternate surgery?

I/we can sympathisize with your pain and torment.

[mike]

Editors are evil. They should be outlawed.

[Rob Pinnegar]

And I've always wondered why the articles are so fricken short.

I guess that, if they weren't short, there'd be no room for the pretty pictures. That was something that _did_ bother me about Astronomy when I was a kid. But I guess that full page images of Saturn are probably a big selling point to the general public.

[Bob Shaw]

Bruce:

I dunno what the copyright issues are (hopefully, you'd be paid *twice*), but perhaps the editors of Astronomy could be persuaded to do a web-only version of your articles, perhaps a month or two after the print version, and which would be somewhat longer? It'd be the sort of thing which might drive us guys to their website, thus giving them a double-whammy on the advertising...

There are publishing imperatives in print media which don't always suit in-depth articles, but there's no reason these days not to claim back the high ground on the WWW!

Bob Shaw

[dvandorn]

Editors are evil.  They should be outlawed.

Reminds me of an old Isaac Asimov short story in which a writer had been cursed by Satan such that he was incapable of writing anything except pact-with-the-devil stories. The upshot is that, after the writer died and went to Hell, the only thing he could end up submitting to the publishers in the Underworld were........


.....wait for it.....


.....pact with the Editor stories!

:::ducking:::

-the other Doug

[mike]

Heh. I dare say almost everything is a pact-with-the-editor story.. and I dare also say that almost everything is dulled down and bland-ized so that it won't 'confuse anyone'. Yeah, why make people think when they can just read pap that reinforces their already long-held beliefs.. WHERE'S MY PAYCHECK SO I CAN WATCH MORE 'FRIENDS'

But I digress...

[Guest_BruceMoomaw_*]

Bruce, what month in 2004 was that?

Also, hard to say if you used the best approach with the editors.  Did you consider 2 versions?  one short, one long. 

In your opinion did they retain the best stuff? or would you have preferred alternate surgery?   

I/we can sympathize with your pain and torment.

My MER story -- along with a 1-page piece on Stardust's comet flyby, during which I expressed my belief in a theory of the craters which I gather is still not proven, but still seems to me probable -- is in the April 2004 issue.

Both then and this time, from the very first they warned me that the final article wouldn't be allowed to go over about 2000 words. I never dreamed I'd have such trouble deciding what to cut out. I was somewhat disappointed that the finished product for MER-A simply didn't include any news you couldn't have gotten from other articles on the subject, but with that short length you just couldn't do much else. The only thing that made me really grind my teeth was that the editor took it on himself to insert a passage in which he listed a bunch of elements and described them as "minerals", thus leaving me holding the bag for looking like a scientific illiterate.

On the bright side, while I hung around JPL for the first 11 post-landing days, I finished the article just before Spirit's computer crisis, which would probably have led me to include a gloomy passage on how the mission was Certainly Doomed.

[Guest_Richard Trigaux_*]

Here
Russia Plans "Long-Lived" Venus Probe
was dicussed the idea of using unconventionnal electronics to sustain the high temperatures (460°C) at the surface of Venus.

There was mainly three methods proposed:
-unconventionnal semiconductors
-micro-sized vacuum tubes implemented witht he techniques of integrated circuits
-micro-sized electrostatic relays

I note that the two latest proposals are also suited to resist to high radioactivity levels, so that they will be a good solution for a Europa orbiter (and even a Io orbiter) by increasing reliability and removing the weigh of shielding.

Developing such techniques will need only a series of small scale test, and then after a relatively short period of large scale development, in a total duration which is not uncompatible with the launching of the mission.

[JRehling]

Another description of the "Tour and Endgame" can be found on pg. 23-26 of the most detailed description of the original Europa Orbiter concept at http://outerplanets.larc.nasa.gov/outerpla.../Europa_MPD.pdf .  (One nice recent development: calculations now indicate that the total radiation dose that EO will get during this mission is less than half of the originally estimated 4 megarads....

It's seemed to me that if we found a way to transform the radiation from charged particles into energy, we'd solve two problems at once for Jupiter missions. Surely if the particles were segregated, this would be possible. I imagine the problem is that the net charge of any stream would be neutral and trying to segregate them would require more energy than you would get out of them... although I'm not *sure* that is so. If you could "split the beam" and get a net negative hitting a cathode and a net positive hitting an anode, you could run a current strong enough to power the beam splitter... in principle. Then you'd have a mission that would would *want* to fly, eg, near Io/Europa orbit. (And a generator that wouldn't much work anywhere else.)

[Guest_BruceMoomaw_*]

Uh-uh. Back when I was posting to the Europa Icepick website, I once did the actual calculations on the energy flux from Jupiter's radiation belts -- which turned out to be pathetically small: about five orders of magnitude less than you need to power a spacecraft! The belts are splendid at poisoning solid-state electronics (or biochemistry), but as a power source they stink.

However, running a long conductive tether from a spacecraft and letting it plow through Jupiter's intense magnetic field is a very different matter -- for an orbiter of Jupiter or one of the moons, that will work beautifully, if you're willing to put up with the tether.

[Guest_Richard Trigaux_*]

However, running a long conductive tether from a spacecraft and letting it plow through Jupiter's intense magnetic field is a very different matter -- for an orbiter of Jupiter or one of the moons, that will work beautifully, if you're willing to put up with the tether.

There was such an attempt by the NASA to fly a tethered satellite around Earth using this system, and it worked very well, providing a good power, except that the mechanical forces acting on the cable were stronger than expected, breaking the cable. Around Jupiter it would work well, and perhaps too around other giant planets. That will be safer than using a RTG, and potentially it could yeld more power. (RTGs too are good at poisoning electronics, although around Europa their action is smaller than the indigenous radiations)

[edstrick]

"except that the mechanical forces acting on the cable were stronger than expected, breaking the cable"

Actually, they had undetected flaws in the insulation on the conductive tether, possibly some grit in the insulation or between it and the wire (not sure working from memory). It electrally shorted through to one of the pulleys or guides on the deployment mechanism, and the considerably higher ELECTRIC CURRENT than expected burned through and severed the tether. That part of the experiment worked too well... oops!

[Guest_BruceMoomaw_*]

Yep. In fact, when I finally read about that incident in detail, I was startled to learn that it was due to a completely unexpected phenomenon that they still can't explain: they had an electrical arc run from the cable to the end of the deployment boom that -- amazingly -- continued to flow for several seconds after it had melted through the cable, while the end of the cable was drifting away from the boom. Apparently some kind of gas leaked out of the Shuttle to allow the arc, but they have never solved the mystery. This makes me a bit more inclined to forgive the Italians for having us fly that Shuttle mission twice and have it fail both times.

[Guest_Richard Trigaux_*]

Yep.  In fact, when I finally read about that incident in detail, I was startled to learn that it was due to a completely unexpected phenomenon that they still can't explain: they had an electrical arc run from the cable to the end of the deployment boom that -- amazingly -- continued to flow for several seconds after it had melted through the cable, while the end of the cable was drifting away from the boom.  Apparently some kind of gas leaked out of the Shuttle to allow the arc, but they have never solved the mystery.  This makes me a bit more inclined to forgive the Italians for having us fly that Shuttle mission twice and have it fail both times.

This is really odd, and cannot explained by the static charge of the shuttle: it had to receive current from somewhere else, to form a circuit with the cable. And the arc had to be pretty long, to be still sustained seconds after breaking.

There may have be some halo of gaz around the shuttle. Weren't emptying their toilets at that time? Letting some ice block stuck at the shuttle sending high flow of steam all around? This could be the origin of many "unexplained" phenomenon, water steam being especially conductive.

With my opinion this experiment should be made again, using two technological satellites, not the shuttle.