Here's one Jeff Greason interview where he gives some details of their future orbital spacecraft.
- Fully reusable
- 2 stages
- Both stages return horizontally
So what comes to mind is a big Lynx which has a bit smaller Lynx (but still larger than the first Lynx) on its back, some questions remain:
- Can it take off horizontally?
- If previous is yes, will it have jet engines or rocket only?
- Is the first stage manned?
- Is it feasible?
Edit: corrected vertically to horizontally
Edit2: the orbital system talk is the last minute of the video