NEW YORK (CNNMoney) -- LightSquared's plan to become a fifth major nationwide wireless carrier hit a major snag this week, after government regulators said they would continue to bar the company from launching its network.

The National Telecommunications and Information Administration said late Tuesday that LightSquared's network could interfere with GPS signals, despite LightSquared's proposed engineering solutions. That interference has the potential to be extremely dangerous: In addition to powering consumer navigation devices, GPS is used by the military and the aviation industry to guide airplanes and missiles.

As a result of NTIA's decision, the Federal Communications Commission revoked a waiver that would have allowed LightSquared to turn on its network. The FCC on Wednesday plans to issue a public proposal that would bar LightSquared from launching its service "indefinitely.