Snappy! - 2005-08-07 8:21 AM
Really?
... that explains alot!! ... so why are we paying NASA boys $billions of tax dollars??
It's not some great conspiracy, mate. It's physics. Here on the planetary surface, we can get away with shrinking the transistor sizes and circuit paths and running up the speeds. But above the atmosphere, you don't get any protection from cosmic rays, gamma ray bursts, high energy neutral particles, etc. Above the radiation belts, you don't even get any protection from the ions in the solar wind or worse, the ion storm from a solar flare or coronal mass ejection event.
The older processes used in the older chips are big. Say 1.35 micron technology, whereas we are now at 0.09 microns and shrinking even further. You can even get some things at 0.065 microns, and 0.045 is around the corner. But the smaller the process, the more susceptible it is to damage from high energy subatomic particles and careening atomic nuceli.
It's like legos. imagine you built a clock out of legos, but you used jumbo toddler blocks. The clock would be big, heavy, slow, and consume a lot of power to run. But you could likely shoot it several times with a .22 or 9mm and it would still work. The bullets just punch small holes but essentially goes right through. Now, build the same clock but with standard size lego blocks. The clock would be smaller, faster, consume less power.. But a single .22 varmint round would blow it away.
In space, size matters.
At least when one is talking microns and nanometres.
But it doesn't stop there, of course. Semiconductors come in commercial, military, and aerospace specifications. The latter have to work in vacuum, under extreme vibration and thermal shock, and operate in conditions from -100C to +250C. Special ceramic packaging, thick precious metal contacts, miniature faraday cage meshes built into the epoxy overcoat, surge isolation and swing dampers everywhere..
And before you know it, a $0.25 obsolete part becomes a $500 component of an umpteen-million-dollar satelite.
Of course, you could stick a top of the line modern processor into your expensive satelite, and have truly astounding performance. For a very, very short time. Then it becomes malfunctioning space junk.
