I had the same thought, but this has no effect on necessary delta-V. In terms of risk, I suspect it's already baked in to his analysis at some level. The risk c

I had the same thought, but this has no effect on necessary delta-V. In terms of risk, I suspect it's already baked in to his analysis at some level. The risk comes from human-time-on-planet or time-in-space, which having a return vehicle doesn't change.