Air Force missions, such as persistent surveillance of large areas, require massive data analytics on supercomputers to deliver the critical capability of finding the proverbial ―needle in the haystack and thereby help humans avoid sensory overload. At another extreme, covert special operations forces have limited communications, limited time and limited battery capacity but need functionality from a portable computational capability that only a few years ago would have taken a supercomputer. Even more daunting, autonomous operation of bird-sized micro air vehicles demand high capacity computer operations be carried out in physical spaces equivalent to golf ball sized brains. This challenge is becomes even more difficult when vehicles are shrunk to bug-sized around 2020. The combination of massive data analytics on supercomputers and embedded high performance computing enables new mission capabilities for the Air Force.
As captured in Table 4.1, the first technical challenge that directly addresses all these mission needs is achieving energy efficiency at the system level and finding the technical means for another 700X improvement over the next 15 years. Energy efficiency needs to be a first order, if not the primary, design criterion driving system engineering tradeoffs. Technology advances such as three dimensional stacking can be game changers, but not if the stack overheats from power hungry chips.
The Air Force is considering science and technology areas that could ―change the game as regards cyber energy. Given the history of exponential advance of computing technology sustained across decades there is a reasonable expectation that game changers will continue to emerge and continue driving cyber quickly forward via innovations. Important technologies that have strong potential as game changers where the AF science and technology community is investing are quantum computing, nanotechnology, and superconducting materials.
Quantum computing can alter the inherent computational complexity of some of our most daunting computing tasks by realizing a completely different form of computation that explores many alternatives simultaneously using the attributes of quantum physics. For example, many worry that quantum computing could attack the assumed intractability of cracking our encryption algorithms and thereby put the whole cyber security infrastructure at risk.
What nanotechnology advances could mean to cyber energy goes far beyond ultracapacitors and 3D stacking of thinned chips. The astounding thermal conductivity of carbon nanotube structures could broker new solutions to thermal management challenges and overcome key issues limiting how closely chips can be situated. Nanotechnology can also deliver the materials connecting the cyber ―brain to the minute actuators to achieve bug-sized air vehicles with an energy efficiency to meet challenging weight, power, and energy constraints. Other innovations, such as the memristor can allow dense, non-volatile storage with learning capabilities that may provide the path to energy efficient computing architectures that can begin to mimic capabilities of the human brain.
Finally, superconducting materials change the game by reducing parasitic resistance to zero. Line resistance has become the major component of energy dissipation within chips as transistor sizes have continued to shrink. Attacking this key factor would have a game changing impact. But beyond circuit switching speed, an even larger impact of affordable, high temperature superconductors would be the delivery of energy, not only with and amongst chips, but around the world without parasitic losses. The cyber infrastructure will be challenged to ensure the security of the grid. This will require new technical approaches at the cyber-physical interface to ensure protection of critical infrastructure as the integration of renewable, loads, and intelligent controllers are required to optimize energy efficiency.
These technologies offer potential game changing components for the way we develop not only system components but also monitoring devices for ensuring the security of the cyber-physical infrastructure (e.g., national grid systems). This can also provide the required devices for intelligent controllers which can provide optimum energy efficiency as mission requirements and loading changes occur.
How future technology could come together
The merger of advancements in nanofabrication with new photonic materials has enormous potential for revolutionizing the energy technology landscape. Nanofabrication allows for the development of devices at the nanometer level, and photonics allows for the controlling of photons, or light, at similar length scales. The combination of these two fields promises new technologies to efficiently harvest and convert light into electricity. Research in light localization below the diffraction limit, using concepts of plasmon optics and photonic crystal nanophotonics, can lead to ultracompact integrated photonic systems. Recently, novel plasmon-based materials with feature sizes in the range of 1-50 nanometers have begun to emerge in which the optical electric field interacts directly with the material in ways reminiscent of electronics. These advances in photonic devices may ultimately result in lower energy consumption for future computers. Efficiently radiating antenna elements and very low-loss transmission devices would provide telecommunications devices with lower power requirements. Opportunities exist to investigate nanostructures to guide light that include ultracompact optically functional devices, light-harvesting elements for molecular and nanocrystalline-based photovoltaic devices, lithographic patterning at deep subwavelength dimensions, and aberration-free lenses that enable optical imaging with unprecedented resolution.
Though it is impossible to predict the specific discoveries that will lead to technology advancements, this is a broad area of research activity that will almost certainly have a profound impact on both the production and utilization of energy within tomorrow‘s AF. Early adopters of leading research activities that are emerging in today‘s nanotechnology include: lightweight, durable and efficient photovoltaics that can provide power for facilities as well as for air and space systems, next generation batteries and high energy density capacitors and superconducting energy storage.
Fractionated Systems 2021-2025
In the far-term, fractionated systems, in which functional subsystems combine to create a larger capability, can enable game-changing and potentially fuel-saving methods of airframe employment. As envisioned in Technology Horizons, these subsystems would be dispersed spatially, but through robust connectivity and communication could collaborate to affect a mission. A hallmark of such a fractionated system is mission survivability—as envisioned the loss of a few members would not necessarily be capability limiting because functions would be shared and replicated. Such a fractionated system may enjoy fuel efficiency benefits over a traditional integrated system, by eliminating the fuel currently expended in protecting high-value integrated platforms.
Hybrid Airships 2016-2020
A mid-term technology, the hybrid airship exploits both the buoyancy of gas (typically helium) in its envelope and aerodynamic lift produced by airflow over its large surface area. There remain daunting operational challenges, such as ground handling, bad weather avoidance, buoyancy control, and infrastructure, but the projected cost per pound of cargo moved is significantly less than traditional airlift. High altitude airships also have mobility and ISR applications. These unmanned systems promise aircraft coverage for days or longer on station and could augment an ISR or communications relay fleet.