<The crew carrying version is interesting. Was it meant to be a lifeboat or was it intended to be a two-way vehicle? One of those could carry emergency repair equipment to a Shuttle in distress. A couple of those could bring down the crew.

It was designed by us to be able to be adapted for both crew up and crew down missions, although we neglected to inform NASA of this. The abort motors were sized for launch pad escape capability, i.e. the ability to blow the capsule from a standstill on the pad and still get enough altitude for the chute to deploy properly. The abort motors worked by blowing out all the orbital maneuvering propellant in one high-pressure, high-thrust shot.

We had other ideas for propellants, but the standard storables seemed more comfortable to NASA.

It would take two to evacuate a full seven-person Station or Shuttle crew, but hey, they're cheap. You couldn't dock with the Shuttle, but could haul people around in spacesuits or rescue balls. We also had a version with standard APAS docking systems, and even one idea with an old-fashioned Russian probe-and-drogue. The CBM version (big door) gives you the best ability to haul large cargo.