Their concept artwork (http://deepspaceindustries.com/expeditionstechnology/) seems to show ion propulsion. 1 engine on the Firefly, 4 on the DragonFly. The Firefly appears to be a 6U cubesat in a 1 x 2 x 3 configuration and the Dragonfly is a 12U (2 x 2 x 3 cubesat). Of course, these are just concepts images. For ion propulsion, you would need a pretty big solar panel system for power.
I hope they have funding. These sound like good ideas. But just generally speaking, Newspace startups still haven't figured out the key to credibility:1. Have funding before you publicly say or do anything else. 2. With the funding you already have, come up with something that can be done in that budget. 3. THEN announce that plan.
All NewSpace Global content is intended only for consumption by NewSpace Global subscribers; redistribution is prohibited and copyright is strictly enforced. All material is based on information obtained from sources believed to be reliable but no independent verification has been made, nor is its accuracy or completeness guaranteed. All material is published solely for informational purposes and is not to be construed as a solicitation or an offer to buy or sell any securities or related financial instruments.