The provider of satellite-phone service and high-speed data delivery is planning to add five in-orbit satellites to its current constellation of 66 satellites.
A launch is scheduled for Friday, weather permitting. Iridium CEO Gino Picasso said in December that the new satellites would "continue providing quality service for years to come."
Iridium uses a group of satellites as its network. Because the network floats above Earth, there is little to block the path of radio waves that carry the phone call or Internet access.
Cell phone networks rely on antennas placed on buildings, light poles or other structures. Coverage can be spotty in areas where there are no antennas or the cell phone does not have a clear line of sight to an antenna. However, satellite phones are bulky and expensive compared with cell phones, making them less popular.
Iridium is the world's first satellite-phone service. It grabbed $5 billion in funding from Motorola and other investors to build its satellite system. But high costs, poor demand and debt payments, among other setbacks, doomed the company to bankruptcy.
Four companies bought the company's assets, including the satellite cache. Service from the new Iridium owners began in early November.