I would not assume that means the second stage therefore is about 30% of the remaining cost. 30% sounds like way too much for a second stage. Does not mean the second stage does not cost 30% of the first stage but.....
Also, did he mean 70% of the total hardware cost, or 70% of the launch cost? Because there is a lot associated with launch costs other than what the hardware costs are, the people, equipment, an so on.
Musk. Cagey.
I think what can be extracted out of that is that if the first stage could be reused forever with no maintenance, that after the first flight (if paid for in full) all the rest of the flights might cost about 30% (though first stage fuel costs also have to be factored in, and a few other things left danglng). But that is not realistic
Perhaps a reasonable guesstimate would be that after accounting for transport back, inspection, refurbishment, and so on, and maybe getting to reuse the first stages on average about 10 times or so (guessitmate) before the structure may not be able to safely fly anymore and/or engines too degraded, and random crashes, that the cost could be amortized down to about 50% of total expendable, maybe 40%. Still huge savings. If they can fly each stage for an average of 20 flights, much better. But nobody knows, not even Musk, because it is something that only lots of flights over time will show, not PowerPoint presentations or tweets.
Sometimes Musk talks as if these will be able to be reused and reflown over and over indefinitely like a Learjet, landing and taking off daily with almost no inspections or maintenance between flights, and that does not seem likely. And by that I'm not saying impossible, but they have to prove it, not talk it. Just like the reuseable second stage is something they are are talking about, but that will remain to be seen and proven for many years, for now it's talk.
So it won't be till they have made dozens of flights with the reused stages and established a record of how many flights per specific stage, and how much inspection they need, refurbishment, engine swaps, and likely loss of some due to accident and/or wearing out, before the picture becomes clear on just how reuseable they are and what the effective operational costs end up being.
- George Gassaway
Quite true...
One thing I've learned about "space accounting" is that you can justify ANYTHING or make it look any way you want to, depending on what you include in the costs and how you figure it up. Shuttle launches, for instance. NASA always said the costs of a shuttle launch were, depending on the time frame, on average, around $250-300 million or so. Most outsiders pegged it at $400 million + per flight based on known contracts and NASA program costs/funding. We now know, that the "final driveout price" for the shuttle flights were, when one divides total program costs (as best we can understand them, which will never be 100% due to "fuzzy math" and stuff paid for by shuttle program that wasn't shuttle related (like ISS development cost overruns, etc.) when the total costs were divided by the 135 flights of the program, it comes out to well over a BILLION per shuttle flight. Of course folks argue over "sunk costs" and "incremental costs" and "infrastructure costs" and argue til their blue in the face over what SHOULD be included in shuttle costings, and what SHOULDN'T be...
So yeah, you're absolutely right that a vague statement of "it's about 70% of the cost" certainly leaves a HUGE amount of doubt about what those costs actually include, how much would actually be saved, refurbishment costs, etc.
Propellant costs are actually 'down in the noise' when compared to hardware, infrastructure, incremental, support, and program costs for space launch vehicles. The main question to be seen with reuse of Falcon 9 first stages is, how much REFURBISHMENT, inspection, turnaround, etc. is required to SAFELY and SUCCESSFULLY reuse the first stage without having the rocket blow up or crash. How those flights are insured and what that costs for payload customers may blow a big hole in the savings too, until its proven with a flight record of numerous successes. Shuttle utterly failed as an AFFORDABLE reusable space vehicle because NASA *intentionally* VASTLY underestimated the costs to refurbish it and turn it around between flights, leading to totally unrealistic dreamland estimates of incremental launch costs of as little as $10 million per flight, with turnaround times and a supply chain and infrastructure capable of supporting up to 70 flights per year with a four orbiter fleet, according to early 70's projections, which was downgraded to more "realistic" numbers of around 40-50 flights PER YEAR by the later 70's. As we know now, these were totally la-la-land numbers... The flight rates could never approach the rates where the shuttle's design choices (like SRB's, which were cheaper for HIGH flight rates, but costlier for lower flight rates where the liquid rocket boosters would actually have been preferable and cost less, which shuttle of course could never achieve the flight rates to make SRB's cheaper) were made based on faulty assumptions as to flight rates, costs, turnaround time, refurbishment, touch-labor, etc. that all proved completely unrealistic, hence why shuttle never lived up to its promises, not by a longshot. That's what led shuttle manager John Shannon to reply to the Augustine Committee on the Constellation Program review board to testify "Reusability is a MYTH". (at least in terms of SHUTTLE reusability-- in fact it was proven that returning, refurbishing, retesting, and reusing SRB's and SSME's was MORE EXPENSIVE than if those elements had been designed for lowest cost to produce and EXPENDED after every flight and replaced with new ones used only once!)
That said, Falcon 9 is NOT shuttle! BUT, the question VERY MUCH remains to be seen exactly HOW much refurbishment of Falcon 9 first stages is required, what the overhead costs for recovery, refurbishment, and reuse actually is, and how much is actually saved, versus having a streamlined, sweet-spot hitting best-use-of-infrastructure economy-of-scale production methodology cranking out dependable, but EXPENDABLE, individual rocket stages and engines. There IS a cost for reusability; costs that are NOT THERE with expendables. The question is, is it more than the cost of an efficient expendable system, and how much is the savings for a reusable system over that?? Reusability also lowers your production rates, which lowers economies of scale, making the rockets you DO produce more expensive on a per-unit basis... after all, the overhead costs are the same (the light bill and stuff to keep the factory open and functioning, personnel paychecks, etc...) Fewer rockets produced for a given infrastructure cost means higher per-rocket costs compared to a higher production rate of rockets that are dropping in the drink after every launch. Add the reusability costs of recovery and refurbishment and relaunch on top of that...
It compounds...
Later! OL JR