The relationship between the District and the Federal Transit Administration might be at a low point, but things in suburban Maryland couldn’t be rosier. This afternoon, Maryland Governor Martin O’Malley announced that the FTA had given its approval for the Purple Line light rail project to enter its preliminary engineering phase. The line — which was approved by the National Capital Region Transportation Planning Board in 2009 and will connect the Bethesda and New Carrollton Metrorail stations with 16 miles of track and 21 stations — will now undergo further environmental studies and detailed cost estimates.