The Earthship is a very prominent landmark of West Sedona. The summit looks like a giant red doorknob when driving north on Dry Creek Road near the Devils Bridge turnoff. The whole thing is really more of a massif/cluster than an individual formation. In terms of climbing, the highest point (the doorknob) is technical on all sides, though it is flanked by subsidiary towers that can be scrambled/soloed (all FA'd by John Burcham). There is an unknown rappel route (?) down the lower west side of the formation, starting at the most prominent notch/chimney. 

The east face of the massif hosts a moderate slab route called Maiden Voyage (5.9) as well as the slightly more challenging Cholula Bottle (5.10). The west face hosts the longest all-bolted traverse in Arizona: Conveyor Belt to Conformity (5.10).

Park at the Long Canyon trailhead (a series of gravel/dirt pullouts on the west side of the road leading up to the Seven Canyons Golf Resort). Hike the Long Canyon Trail about 10 minutes until a left turn onto Deadman's Pass trail. Head west on Deadman's Pass trail for another 10 minutes until you can cut directly right (northwest) toward the base of the route. Reach the base via a dense network of social trails. The route Maiden Voyage is visible for nearly the entire approach, at times framed nicely above the trail.
Total approach time: about 30 minutes

Alternatively, one can approach from Boynton Canyon trailhead, coming in from the other direction (west) on Deadman's Pass trail. But this approach takes 5-10 minutes longer, and parking is quite a bit more difficult compared to the gravel pullouts for Long Canyon. No reason to do it this way.