Now they have stated in a new presentation that they will have an antimatter powered cubesat vehicles in 2016-2019. They will be able to keep a cubesat in low earth orbit for seven years instead of few days. Then they will enable high speed spacecraft to go the outer solar system and then to the stars at a significant fraction of the speed of light.
Mason Peck is an associate professor at Cornell University and former NASA Chief Technologist. Mason Peck is now on the Positron Dynamics team.
Peck has published in various aerospace sub-disciplines including; air-bearing spacecraft simulation, low-power space robotics, hopping rovers, and Lorentz-augmented orbits
Peck was awarded $75,000 in 2007 by NASA's Institute for Advanced Concepts (NIAC) to study how a large fleet of microchip-size space probes in Earth orbit might propel themselves into the Interplanetary Transport Network; and thence as far as Jupiter's moon Europa. This was to be achieved by exploiting the Lorentz Force, enabled by using photovoltaics to maintain an electrostatic charge while orbiting in Earth's magnetic field
SOURCE - Youtube, Positron Dynamics, Wikipedia