Next message: Bill: "Re: Cel nav in space"
> Forty five minutes after the umbilical cord was disconnected, the IUS
> would "wake up". It would then start searching the sky looking for a
> star of a specified color and intensity. When it found a star with the
> right color and intensity, it would place that star in the center of the
> visible star field and then rotate around until it found a second star
> of specified color and intensity. With two, it would then look for a
> third. This would enable the onboard systems to determine its orbital
> position and orientation.
Fascinating. I was once told that Soviet ICBMs used a form of cel nav for
targeting, as they could not trust a potential enemy's GPS system ;-) I
quipped, "Big deal. So SA is on and you miss by 100 meters. What does that
matter with multiple warheads?
I was surprised to learn that the destination was locked in while the
missile was high above the Earth, so a few seconds of an arc off could make
a potentially significant difference on final destination.
Bill
