Space craft question

I just saw a show on national geographic called "I didn't know that". (I think?)

Anyways, in the show was a segment about diamonds and what they use it for. One thing they show is a very thin plate of diamond, which is sanded transparent and glass-like. One of the hosts then explain that the diamond window is so strong and versatile that it was once used for a space craft traveling to Venus?

I then tried to find such a craft, because I was thinking "why the heck have windows if no one is inside looking out?". All I can find that has traveled to Venus from earth is probes and satellites. And their is obviously no windows in them. My only logical explanation would be a window where a camera was behind it, but it really didn't sound like that was what he meant when he said it. Besides, not that many pictures are taken from probes, they take samples and analyze data, and have radars. Do they need windows? I just don't understand why he wouldn't say traveling to space or the moon, to not arouse my excitement for one.
Why bring Venus in to the equation?

I hope some of you will help me answer these questions, thanks.

Joe

I hope this helps:

A diamond window was used in the Pioneer Venus I.R. radiometer. The paper suggests that diamond should be considered more widely as a possible optical component for windows and small lenses in space-optics and other optical applications. The cost is not high in relation to other costs involved in space research or for some land-based instruments.

www.ingentaconnect.com...

The Pioneer Venus Orbiter was inserted into an elliptical orbit around Venus on December 4, 1978. The Orbiter was a flat cylinder 2.5 m in diameter and 1.2 m high. All instruments and spacecraft subsystems were mounted on the forward end of the cylinder, except the magnetometer, which was at the end of a 4.7 m boom. A solar array extended around the circumference of the cylinder. A 1.09 m despun dish antenna provided S and X band communication with Earth.

nssdc.gsfc.nasa.gov...

[edit on 9-8-2008 by ziggystar60]

Yes, that clears things up for me.

I was thinking that it had to be for optics and stuff.
Many thanks to you

Joe