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[ShadowHammer]

Well, from my limited understanding of things, we can generate electricity from two sources. Either chemical energy as certain atoms/molecules react and electrons are shuffled around, or kinetic energy by spinning things through a magnetic field. I'm probably missing out on a couple alternative sources, but those are the two major ones. So converting thermal energy directly to electricity is (most likely) impossible. After all, thermal energy is just atoms/molecules being highly energetic but without any unified direction or force. So we can't convert it to electricity without going through another step using the two methods we have. To convert thermal energy directly, we'd need some kind of substance that shuffles around electrons when it heats up. Which I'm pretty sure is impossible, or we don't have a substance like that. Or it converts the thermal energy into chemical energy before turning it into electricity.

Am I kinda making sense here?

I may be understanding incorrectly, but don't thermocouples make electricity directly from heat?

[USEC_OFFICER]

...

Well you learn something new every day. I honestly did not know about thermocouples. Huh. Interesting.

[10ebbor10]

Thermocouples don't generate electricity directly from heat, they generate electricity from a temperature gradient.

Which is kind of a big thing really, because it means that heat is useless, as far as energy is concerned. Only a difference in heat can be transformed into power.

[MonkeyHead]

Certain forms of transfer are more feasible/efficient than others. This may be down to our knowledge of physics or level of technology, or simply a property of energy and the universe. Chemical energy readily changes into heat. It is trivial to turn kinetic into electrical. Heat into kinetic is also pretty straightforward via pressurised gas. The combination of 3 efficient(ish) processes is still more efficient/higher output yield than a single step, say heat directly into electrical (though solar furnace style power plants are getting there).

[kaian-a-coel]

Entropy.

[Sheb]

Well, we can convert heat directly into electricity, we do it all the time with Radioisotope Thermal Generators.

[10ebbor10]

Nope, that is a heat gradient which is being converted into power. You can not get any useful energy out of heat, solely out of differences in temperature.

A radioisotope thermoelectric generator (RTG, RITEG) is an electrical generator that uses an array of thermocouples to convert the heat released by the decay of a suitable radioactive material into electricity by the Seebeck effect.

In 1821, Thomas Johann Seebeck discovered that a thermal gradient formed between two dissimilar conductors produces a voltage.[1] At the heart of the thermoelectric effect is the fact that a temperature gradient in a conducting material results in heat flow; this results in the diffusion of charge carriers. The flow of charge carriers between the hot and cold regions in turn creates a voltage difference. In 1834, Jean Charles Athanase Peltier discovered the reverse effect, that running an electric current through the junction of two dissimilar conductors could, depending on the direction of the current, cause it to act as a heater or cooler

[Sheb]

Yeah, true that.

[Dutrius]

The KSP forums are a great place for space related stuff.

[alway]

Interesting bit in the latest spacex launch video: http://youtu.be/essrkMGlw5s?t=7m20s
At around 7:20 and a bit more later, there's a few seconds of video from inside a LOX tank. So they apparently have cameras inside their fuel tanks now.

Which I suppose makes sense, considering nearly all of their failures or partial failures, going back to the original Falcon 1 tests, were due to prop sloshing in the tanks.

[10ebbor10]

Meanwhile, the ESA actually has a probe in orbit around a comet.

Science

Landing is scheduled for the Eleventh of November.

[alway]

https://www.youtube.com/watch?v=uIlu7szab5I&list=UUtI0Hodo5o5dUb67FeUjDeA
Video from an aircraft of the Falcon 9 first stage soft landing on the ocean.

[alway]

And today, SpaceX tested their self destruct mechanisms.
http://www.kwtx.com/home/headlines/Rocket-Explodes-at-Space-X-272370541.html

Apparently the test went badly; rocket appeared to have been tipping/loss of control shortly before it was self destructed. Supposedly it was a 3-engine version of the F9R test vehicle; which is probably why a loss of control may have happened (it's normally a 9 engine rocket). Their statement up on twitter: https://twitter.com/SpaceX/status/502976401729798144/photo/1

[10ebbor10]

http://www.forbes.com/sites/alexknapp/2014/08/24/esa-galileo-satellites-were-placed-in-the-wrong-orbit/

Galileo sattelites accidentally in wrong orbit.

[PTTG??]

In KSP .23 eccentricity and 5 degrees off from target is what I call "within normal parameters."