Hi Tom,

It occured to me after I crunched the numbers for my updated Gemini, that I should've used the HMX AAS vehicle as either a baseline or a reality check. So, thanks for the reality check!

Turns out that I was pretty much on the right track, as the XV compares quite closely with my 4-person vehicle numbers:

HMX XV
---------------
5.8 m^3 Volume
1814 kg payload
2604 kg wet weight
4418 kg Total Mass

4-Person Gemini Derivative
---------------
6.0 m^3
2232 kg payload
2634 kg wet weight
4866 kg Total Mass

So it still looks like a 4-person vehicle is what'll work for the initial Falcon V. I presume that the payload numbers quoted for the XV are all to ISS orbit -- which I'm convinced that no commercial tourist craft will ever go to -- so the payload could probably be increased quite a bit. However at 5.8 m^3 of volume, I don't think you'd want to put more than 4 people onboard, at least not for tourism purposes, where luggage and leg-room will be real issues.

It looks like the XV design would scale differently than the model I worked up, however, so I'm curious to see what it would do on the upgraded Falcon V. Assuming that the airframe, power, and thermal control masses scale with volume, that the avionics & docking-related systems are fixed masses, and that the propulsion, landing, and consumable masses scale with the rest of the system weight, here is what a scaled-up HMX XV might look like on a Falcon V Heavy:

11-Person XV Derivative
---------------
15.95 m^3 volume
4989 kg payload
2010 kg airframe, power, thermal control
508 kg avionics, docking
2417 kg propulsion, landing, consumables
9924 kg Total Mass

As far as prices go, the AAS presentation mentions a total mission price of $35M, but I can't find any way of separating the Titan-II costs from the XV costs. Do you know what the breakdown would be? And do you have any speculation on how far prices could fall while maintaining profitability?

Cheers,

Nathan.