No. Space aliens are Behe's and other Intelligent Designers' idea.
The Designer in Intelligent Design is not God according to Behe, because Intelligent Design is not about religion. That only leaves unknown extra-terrestrial intelligences that were here before any life existed on the planet.
In Behe's own words from his "Molecular Machines":
There is an elephant in the roomful of scientists who are trying to explain the development of life. The elephant is labeled "intelligent design." To a person who does not feel obliged to restrict his search to unintelligent causes, the straightforward conclusion is that many biochemical systems were designed. They were designed not by the laws of nature, not by chance and necessity. Rather, they were planned. The designer knew what the systems would look like when they were completed; the designer took steps to bring the systems about. Life on earth at its most fundamental level, in its most critical components, is the product of intelligent activity.
But I didn't bring them up.
I'm not particularly interested in your interpretation of who Behe was talking about in the passage you quoted. It could be aliens, or it could be God, but it's not particularly relevant to the basic question of whether something was designed, vs. occurred through an accumulation of random mutations.
Again, all I'm saying is that the idea of design is inherently plausible, because we're so very familiar with it.