The SQL Server Blog has since published a step-by-step tutorial on implementing the galaxy classifier in SQL Server (and the code is also available on GitHub). This updated version of the demo uses the new MicrosoftML package in Microsoft R Server 9, and specifically the
rxNeuralNetfunction for deep neural networks. The tutorial recommends using the Azure NC class of virtual machines, to take advantage of the GPU-accelerated capabilities of the function, and provides details on using the SQL Server interfaces to train the neural netowrk and run predictions (classifications) on the image database. For the details, follow the link below.
If you’re going to get into SQL Server R Services at any level of seriousness, I highly recommend R Tools for Visual Studio, as it will make building those external stored procedure calls much easier.