Thank you very much for posting this information. Im just posting for discussion not asking for a reply.



I agree that item P (which I believe for Spacex is a 30% reduction in mass to orbit penalty for reuse) is appropriate to consider if what is being transported something like propellant, in other words if Spacex is being paid $x for each kg to orbit. However this calculation is not currently applicable to Spacex from a business perspective in my opinion because that is not how they are paid.



For Spacex they already designed their launch system to launch payloads with enough propellant for reuse. So whether or not they expend their launch system they still launch the same payload and still generate the same revenue.



So from a spacex business perspective, given the launcher they have in service, the financial hit that spacex takes for reuse is not 30% of the revenue but only the additional propellant, in other words filling the tank full instead of mostly full. In other words I think $/kg is not the correct measure for the business case here.



In conclusion I think from a spacex business perspective the P value should be 1.02 not 1.42. (I think I have the units right, this is meant to represent the performance loss due to reuse?)



I also agree with Lar that K should likely be closer to .7 not .4, I think the cost of the 1st stage is closer to 70% of the launch costs, not 40% of the launch costs.



I also assume that while the .9 rate exponent may be appropriate for typical aerospace manufacturing, this number may not be the appropriate rate exponent for Spacex. Maybe someone could come up with another number for Spacex (considering the commonality of the upper stage, general manufacturing process and the fact Spacex might need the extra stages anyways for its small sat/mars projects) and then run all of these numbers and see how it looks.



I think the cost of recovery (drone ship ect.) and cost of refurbishment are unknown, it would nice to have that information but we don't have it.