In March 2017, SpaceX filed plans with the FCC to field a second orbital shell of more than 7,500 "V-band satellites in non-geosynchronous orbits to provide communications services" in an electromagnetic spectrum that has not previously been heavily employed for commercial communications services. Called the "Very-Low Earth Orbit (VLEO) constellation", it would comprise 7,518 satellites and would orbit at just 340 km (210 mi) altitude, while the smaller, originally - planned group of 4,425 satellites would operate in the Ka - and Ku-bands and orbit at 1,200 km (750 mi) altitude. SpaceX's plans were unusual in two areas: the company intended to utilize the little-used V-band of the communications spectrum, and they intended to use a new orbital regime, the very-low Earth orbit regime of ~340 km (210 mi) altitude, where atmospheric drag is quite high, which normally results in short orbital lifetimes. The March 2017 plan called for SpaceX to launch test satellites of the initial Ka/Ku-bands type in both 2017 and 2018, and begin launching the operational constellation in 2019. Full build-out of the approximately 1,200 km (750 mi) constellation of around 4,440 satellites was not then expected to be completed until 2024. The first two test satellites built were not flown but were used in ground testing. In the event, the planned launch of two revised test satellites was moved to 2018.