I see, well CSS3 does have that option of using multiple backgrounds (it's just what you might think it is, google multiple backgrounds css3, there are plenty of easy tutorials).
But not all people have the latest browsers so, other options:
Maybe make starfield background image repeat and then make a div that has the width of the table(with the content stuff) + whatever you need for the bumpers with another background image with the ships and the gap/black area in the middle (if you want it to blend, use gif and make the edges on the left and right with transparency). Within that div place the table with the content, centered.
Or:
If you just want to make it really simple you could make just the ordinary background image which shows blank center area (or anything at all) + bumpers with ships + an area which has the stars that fade to black on the far left and far right side - just one big image.
Then make the background color of the body black and you basically get the baked background but you also get a bit of the starfield in it, even it's not tileable. Still should be an ok small size if the starfield is not overly complicated.
But not all people have the latest browsers so, other options:
Maybe make starfield background image repeat and then make a div that has the width of the table(with the content stuff) + whatever you need for the bumpers with another background image with the ships and the gap/black area in the middle (if you want it to blend, use gif and make the edges on the left and right with transparency). Within that div place the table with the content, centered.
Or:
If you just want to make it really simple you could make just the ordinary background image which shows blank center area (or anything at all) + bumpers with ships + an area which has the stars that fade to black on the far left and far right side - just one big image.
Then make the background color of the body black and you basically get the baked background but you also get a bit of the starfield in it, even it's not tileable. Still should be an ok small size if the starfield is not overly complicated.