The E-Sail technology promises to provide a propellant-less propulsion that can obtain accelerations greater than 2 m/sec. This can lower trip times to any location in deep space with trips to 100 AU taking less than 10 years. This is less than half the time any current chemical, electric, or solar sail propulsion can do. The propulsion system can be scaled from CubeSats to full size exploration (Discovery Class) mission spacecraft. E-Sail propulsion repel the protons from the solar winds to push the vehicle. Much of the E-Sail technologies have been matured from recent NASA funded tests and studies. Parallel efforts in Europe are also maturing the concept. The highest risk element of the E-Sail are the tethers used to create the electrostatic field that repels the protons that propel the spacecraft. Deployment and control of these tethers presents a serious challenge. This effort will develop high fidelity simulations and demonstrate deployment of up to 16 km long tethers. This risk reduction effort will allow a technology demonstration of the E-Sail in the 2021 time frame. Technology demonstrations are required to move the propulsion system forward. Ground based testing will reduce much of the risk of the remaining technologies but the tether deployments which have been a challenge require innovated testing approaches to reduce the risk and to develop techniques and control strategies to reduce the deployment risks Potential NASA Applications The E-Sail technology is scalable from small CubeSats to Discovery class missions allowing the exploration of our solar system by large numbers of CubeSats. The E-Sail with a network of tethers could provide mining missions to the asteroid belts. Since the propulsion system is propellant-less the spacecraft can be re-directed at any time. Missions to one of Saturn moons could be redirected to another moon once the initial mission was complete. Potential Non-NASA Applications The resulting tether deployment system enables E-sail propelled systems to explore the asteroid belts in much shorter time frames than any other technology. The ability to survey and return to a particular asteroid allows commercial miners to narrow the potential targets for mining. The ability to redirect the spacecraft allows surveys to new potential mining sites on other asteroids. Development of higher fidelity tether models and knowledge will also benefit other low earth tether missions.
