What is this Strange Tower on Columbia Pike (Rt 29)?

This building looks like a abandoned church, very tall tower structure with what looks like a room at the top. It is located on the east side of Rt 29 just north of Johns Hopkins Rd. and south of route 32. I have seen this place for years and wondered what the story on it is.

There has been a crane parked there for several years.

If you are not familiar with the structure, check it out on Bing Maps, the Birds Eye View of it puts it into perspective.