Even with the availability of the stardrive and network, early interstellar exploration efforts were hampered by a major problem: Generating sufficient energy to drive a starship across space at reasonable speeds or to power a mining settlement on an asteroid was difficult. Solar power required large and difficult-to-maintain solar arrays, and only worked in close proximity to a star; fission power generated dangerous amounts of radiation and was inefficient; and fusion power plants were temperamental beasts, prone to breakdowns and even catastrophic explosions on more than one occasion. In 2248, Bergstrom Systems announced the creation of the Planck Engine (pronounced "plahnk"), a device which extracts energy from the very fabric of spacetime itself. At the Planck level, the very smallest distances that occur in the universe, quantum reality consists of a seething "foam" of energies, both positive and negative, which are constantly canceling each other out. This is also known as a zero point field. (Editor's note: This is the same scale at which the quantum wormholes used by network are created.) The Planck Engine separates and harnesses these energies, converting them into usable energy. Since no energy input is required beyond that required to "jumpstart" it, the Planck Engine effectively creates a virtually unlimited amount of "free" energy. Because of the complexity of a Planck Engine, they are found only in large installations, such as Arks, planetside installations, and starships. The very largest Planck Engines are found inside the Arks, where they not only provide electrical power, but also heat and light. For those who dwell in the Arks, the "Sun" is a bright line of yellow light, stretching North to South within the Ark, dimmed only at "night". As with the stardrive and network, Aquila generates substantial annual licensing fees from the use of Planck Engines throughout the Colonial Sphere. It's estimated that roughly 4 trillion credits per annum are paid to Aquila for use of this technology.