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Did a search on "soviet secret space stations" because I remembered reading of them - my memory was refreshed about the Almaz program, in itself fascinating reading.

Further, if one reads the linked article and at the end clicks to the main page, there is a wealth of researched and referenced material on all manner of space efforts, manned and unmanned.

If you or anyone has interest, you may wish to check it out:

Space History Notes
http://www.svengrahn.pp.se/histind/histind1.htm

Kettering Grammar School were doing this in the 1960s. See the links in Wikipedia for more information.

Italian brothers Judica Cordiglia

There is also a marvellous documentary about these two guys.

You can cool the core with anything. Various schemes used both on earth and in space in the past have used water, helium, liquid sodium, liquid lead, etc. Also helium is already commonly used inside Stirling cycle engines as the working fluid for the generator. Organic rankine cycles actually use a refrigerent as the working fluid. The Russian Alfa class submarines used lead to cool the core and heat water for its turbine. It had to be kept hot and circulating at all times or it would solidify in the pipes. Over half of the submarines were "totaled" when for one reason or another they had to shut down.

For those that are interested, the Russians developed a lightweight fission reactor back in the 60's to power their Radar Ocean Reconnaissance satellite (RORSats) that they used to spy on our aircraft carriers. This was the type of satellite that caused a fluff back in the 70's when Kosmos-954 failed to boost to its disposal orbit and re-entered over Canada.

The reactor only weighed 130 kg and it generated 100 kW of thermal energy, but because it used low efficiency thermocouples to turn heat directly into electricity, it only generated 3 kW electrical. It was sodium cooled. This NASA reactor will use a thermodynamic cycle to spin a generator, and probably have an efficiency between 10 and 20%, so the core doesn't need to be much larger than the Russian version. I'm guessing it will probably be liquid metal cooled with a heat exchanger to expand helium for the generator.

And just to be clear, you can use water in a space reactor if you want. You just have to design for corrosion and used a closed loop so the water re-circulates.

Really? Considering that the US shot down a satellite over two decades ago, from a missile fired from an F15 of all things, I don't think the USA had a whole lot to prove. In fact, I think the military people are smart enough to not give any inkling of just what they are capable of (like the amazing fact the F-117A stealth fighter was kept secret for so long, until its unveiling during Desert Storm).

What irked me the most was China's whiny statements about the test, which was extremely benign in every regard, while China themselves produced a huge band of debris in a very useful polar orbit for no legitimate reason whatsoever.

> This story is complete horseshit. [blahblah] http://www.svengrahn.pp.se/histind/ASAT/F15ASAT.ht ml

Sure it is. Now. See also http://www.astronautix.com/lvs/asat.htm

22 years ago it wasn't. Solwind was still downlinking data when it poofed. http://www.patricksaviation.com/wiki/F-15_ASAT I got the story from Astronomy magazine at the time.

It was taking a lot of work to keep it synched, but USAF (its original owner) had not shut it down. http://franksblog.hoferfamily.org/2004/01/21/

Usually very complete with their data, Vought is rather mute about it, naming the sat only by its designator. http://www.voughtaircraft.com/heritage/products/ht ml/asat.html

Makes you wish they'd get their horse shit straight.

I was wrong about one thing. The debris from Solwind was tracked and the data made available. 250 pieces. One almost hit ISS 8 years ago. http://cns.miis.edu/pubs/week/070124.htm So if the US says pieces of the Chinese test might hit ISS, we can assume they're correct because they have experience in these things.

This story is complete horseshit. The target was known weeks in advance. I was actually in the printer room of the ops complex shortly before the test and the guys who ran the spacecraft were certainly well aware of the situation and had all gathered around to watch.

        Moreover, the spacecraft was barely functional enough to maintain despin and a telemetry downlink (which was iffy at best because antenna had degenerated years before). No one was getting much useful data due to multiple failures in the payloads and the tape recorder. It was certainly no accident and there was no comsat that was ever intended or claimed to be the target. In fact, special spacecraft were constructed to act as targets but were never used after the program was ended - due to orbital debris concerns by the USAF. All the debris wa/is cataloged and tracked like all the rest.

please see: http://www.svengrahn.pp.se/histind/ASAT/F15ASAT.ht ml for a correct, non-hysterical/paranoid story the way it really happened.

          Brett

If you are referring to Cosmos 954 crashing in the Northwest Territories, that wasn't a RTG. It was a nuclear reactor on a satellite. From Wikipedia, it is a BES-5 reactor fueled with U-235. According to one source (http://www.svengrahn.pp.se/trackind/RORSAT/RORSAT .html), there was 30 kg of 90+% enriched U-235 (as U-Mo alloy) in the core. Power output was 3kW, obtained by thermoelectric generators. The heat source is fission, not decay heat.

I've heard it described as a "Great Galactic Ghoul" that protects Mars. At every step on the way, Mars missions have tended to be frought with problems. The Soviet program fared even worse; only about one in five Mars probes that they launched went as planned.

Some people have suggested that having humans onboard would have helped. In most cases, this is not the case. Only the Phobos probes and perhaps one Viking mission would have had a chance for humans to help the situation, since their problems were computer related. Most accidents were explosions, bad trajectories, invalid atmospheric assumptions, etc - things you don't find out about until it's too late.

In fact, one mission that was a success could have killed humans if it were to happen: Mars Global Surveyor. A solar panel was damaged (its damper arm was sheared off on launch), and dipping down into the atmosphere to brake like it was supposed to, in order to brake, would have destroyed the probe. The damage wasn't known until the first atmospheric dip, making (on an equivalent manned craft) a spacewalk for repair quite difficult if it were even possible (doubtful, given the damage, unless they brought along entire extra solar panels). NASA solved the problem by suspending aerobraking and letting the orbit circularize much more slowly - delays that humans on board would not have been able to tolerate.

It seems that there is just so many opportunities for failure en route to Mars that even if chances for a single mistake are miniscule for any given system, the overall failure rate ends up uncomfortably high. We're not going to want to skimp corners when we send people to Mars, that's for sure.

Too bad there's not a -1 wrong moderation
Unless of course you don't believe that Soyuz 1 never happened....
Soyuz 1

At least no fatalities

Assuming that the antennae (note English spelling) are the expensive part, they why not buy up one or two from the Russians and stuff new signal processing equipment (aka computers) in them?

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