The Solara 50 and 60 models can be launched at night using power from internal battery packs, then when the sun rises, they can store enough energy to ascend to 20KM above sea level where they can remain for five years without needing to land or refuel. Such capabilities make them ideal for regional Internet systems, like those that Internet.org would be focused on. (For those interested, Ars Technica took a more in-depth look at the technology and history behind Titan’s aircraft last August).