...I wonder how much refurbishment Grasshopper needs between flights?
Grasshopper is NOT a reusable Falcon 9 core. Not even close.
2) A v1.0 thrust structure (probably the qualification flight test thrust structure which would be sitting in storage at McGregor). This thrust structure would not need any modifications other than capping off the other 8 prop lines for the other 8 engines not being attached. The legs would be attached at the hold-down pin locations on the thrust structure. Also the add-on engine fairings and other engine compartment covers would not be installed.
I think it has more in common with the final RF9 than the oh so glorious Ares 1X had with the final Ares1 or the X33 would have had with the final Venture Star.That said, it is clearly a testbed for the technology needed to do a reusable first stage and NOT a reusable first stage. They can still gather a lot of experience with flight profiles and controls and control software. IIRC they are already working on the next version of grasshopper that will have a full Falcon 9 1.1 first stage tank instead of the F9 1.0 first stage tank and landing legs that are more representative of the final legs. I guess they will start testing that one soon after they (pretty much inevitably) will crash the first one into the ground during a (subsequently infamous) testflight that critics will doubtlessly use to ripp the whole project apart (since for some reason it has become unacceptable to loose a test vehicle these days).
So would SpaceX eventually build a "Grasshopper 2" based on a F9 v1.1 fuselage, possibly with a methane-burning Merlin engine, or go straight to a F9R 1st stage for use in actual launches? In their position I would certainly build a second, more advanced Grasshopper, but SpaceX may feel that the original Grasshopper flights provide adequate verification of the fly-back idea.
I think it has more in common with the final RF9 than the oh so glorious Ares 1X had with the final Ares1 or the X33 would have had with the final Venture Star.
The X-33 was as close to the Venturestar as the V1 is to V1.1