RE: satellites carrying atomic reactors

From: Robert Oler (
Date: Fri Aug 24 2001 - 10:48:07 PDT

  • Next message: Vitek, Antonin: "Re: satellites carrying atomic reactors"

    I had the great fortune at one point to talk to one of the pilots of the 
    modified B-36.  His remark was that it was one of the quietest airplanes 
    that he had ever flown.  I imagine so...
    Apparantly whereever it went so did a radiation team AND armed troops...
    Robert Oler WB5MZO Houston TX
    >From: Joe <>
    >Subject: RE: satellites carrying atomic reactors
    >Date: Fri, 24 Aug 2001 08:12:32 -0700 (PDT)
    > >>After this observation we continued to discuss about
    > >>different satellite topics and somehow it came up that
    > >>there are satellites with atomic reactors "up there" which
    > >>will decay in the atmosphere for sure.
    >An experimental nuclear reactor power system, the SNAP 10A which used
    >thermoelectric power conversion, was launched by the United States in 1965 
    >worked satisfactorily for 43 days until shut down.  It is now in a very 
    >orbit where it will remain for hundreds of years. Except for that one case, 
    >use of nuclear sources for powering spacecraft built and launched by the 
    >States been limited to very low power (less than 1/2 kW) systems called
    >radioisotope thermoelectric generators (RTG). They do not use nuclear 
    >heat sources. RTGs convert the heat generated by the decay of radioisotopes 
    >electricity by using an array of thermocouples. Compared to a 1000-kilowatt
    >reactor RTG's are extremely small,simple and safe. The fuel source in all 
    >RTGs has been plutonium-238.
    > >>Who knows, how many reactors are up there?
    >I'm not certain, but at last count I think it was about 48 RTG's.
    > >>Embedded in what satellites?
    >not sure of them all, I'll have to look it up later.
    > >>Any plans to bring them back safely? :-)
    >Of the RTGs launched by the US, there have been three mission malfunctions 
    >I know of involving spacecraft which carried a total of four RTGs. One of 
    >occurred in 1964 before the full fuel containment policy was initiated. 
    >was the SNAP 9A RTG aboard a malfunctioning Navy spacecraft and it burned 
    >up in
    >the upper atmosphere as designed. Since 1964, the design philosophy of full
    >fuel containment has performed flawlessly in two mission failures involving
    >RTGs. One landed intact in the Pacific Ocean in 1968 after a Nimbus B 
    >satellite failed to reach orbit.  The two generators were recovered and 
    >fuel used in a subsequent mission.  In 1970, the Apollo 13 lunar module
    >reentered the atmosphere and its RTG was jettisoned and fell intact into 
    >Tonga Trench of the Pacific Ocean. In each case air and water samples taken 
    >the reentry area indicate there was no release of radioactive material.
    > >>How, in general, it was possible to solve the
    > >>(veeery heavy) radiation shielding which made
    > >>reactor driven aircrafts obsolete
    > >>(because they where too heavy to lift off...)?
    >No country was ever able to develop a true atomic-powered aircraft. But a
    >nuclear plane of sorts did manage to fly, the NB-36H test airplane. Its
    >original B-36H airframe had been extensively modified, most notably with a
    >12-ton shielded crew capsule in the nose, a 4-ton lead disc shield in the
    >middle and a number of large air intake and exhaust holes to cool the 
    >in the aft section. The reactor was a 1000-kilowatt design weighing 35,000
    >pounds. Its operation was observed from the crew capsule by closed circuit
    >television. NB-36H flew with its radioactive cargo 47 times between 1955 
    >1957, and, although it did not power the airplane, the reactor provided
    >considerable data on the effects of radiation emitted during flight. The 
    >plane was eventually decommissioned at Fort Worth in late 1957.
    >Joe Hurley
    >42.669575 -073.685737
    >(Don't spam me, these are just the coordinates geocode spit out at me.)
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