Re: RE: starship-design: Hull Materials

[KellySt@aol.com]

In a message dated 11/11/97 2:52:33 AM, lparker@cacaphony.net wrote:

>On Monday, November 10, 1997 10:37 AM, Antonio C T Rocha 
>[SMTP:arocha@bsb.nutecnet.com.br] wrote:
>> A few doubts regarding radiation shielding and fractional lightspeed.
>>   Would there be any considerable effect from doppler-shifting of
>>   impinging
>> radiation - taking into consideration relativistic effects?.
>>   Ditto for particles?
>
>I don't think Doppler shift is the problem, it is total energy in the 
>quanta rather than its frequency - a megajoule laser is more powerful than 
>a milliwatt x-ray, period. This the problem with particulate matter though, 
>a grain of sand impacting the ship at near c contains quite a bit of 
>energy, we don't even want to think about hitting anything larger. As 
>Timothy pointed out, dust alone is going to cause significant erosion and 
>thermal gain, "streamlining" may begin to make sense again.
>
>It should be possible to at least deflect charged particles with some sort 
>of magnetic field, but a lot of these particles are going to either be 
>neutral or simply to massive to deflect in time so the hull has to be 
>capable of absorbing quite a bit of impact for long durations. This means 
>high melting points, high thermal transmissivity or a least high 
>emissivity, extremely hard and yet ductile enough to remain "tough for 
>several years of use.


Oh, did I mention the dust shield idea?  You dump a cloud of fine dust or gas
ahead of you.  The debres slams into it and vaporizes, or at least ionizes.
 The resulting plasma is fairly easy to steer magnetically.

Kelly