question about drag

[White Wolf]

I'm a little curious/confused. I was taught back in school (perhaps incorrectly) that there is no drag in space. I remember reading a few years ago about Einstein's discovery that light has weight (don't remember where).

So i got to thinking: if light has weight and can be used to push objects, does it also create drag?

would the drag be significant enough to affect spacecraft or orbital bodies?

I'm probably way off on all accounts, but i just wanted to know.

 

[Hielor]

[ame="http://en.wikipedia.org/wiki/Solar_sail"]Solar sail - Wikipedia, the free encyclopedia[/ame]