From the National Journal: Energy and Commerce Committee Chairman Fred Upton (R-Mich.), Communications and Technology Subcommittee Chairman Greg Walden (R-Ore.), and Oversight and Investigations Subcommittee Chairman Cliff Stearns (R-Fla.) say the prolonged controversy over LightSquared's plans call the federal process into question.

In a letter to the FCC, the National Telecommunications and Information Administration, the interagency National Executive Committee for Space-Based Positioning, Navigation and Timing, and the Defense Department, the three lawmakers have asked for documentation of any communication with LightSquared, its corporate predecessors and financial backers, and GPS manufacturers.

On Tuesday the fallout from the FCC's decision continued as LightSquared CEO Sanjiv Ahuja announced his resignation. LightSquared says it will still try to overcome the interference problem.