An argument from authority that cites the father of "The Stick"
astronaut-osterizer, no offense, is a bit less convincing than it might
have been at the time...
Seriously, is that article available online? It could be interesting to
see how well the assumptions those conclusions were based on have stood
up. Times change, organizational and technological givens fade and give
way.
Henry
On 7/1/2019 1:12 PM, William Claybaugh wrote:
Anthony:
I think we both understand this to be a leading question....
Mike Griffin and I showed in a 1994 article in JBIS that reuse would eventually be lower cost than expending. But the trip from here to there is fraught: the breakeven between fully reusable and expendable space launch assets is typically north of 100 launches per year.
For partial reuse it depends on whether one is modifying an existing expendable to be a little bit reusable or building from scratch. The former—based on SpaceX’s example—might be as low as three to five uses if refurbishment is very low cost. The latter is calculably somewhere north of 20 launches (possibly well north) again depending largely on refurbishment costs.
So no, just because it is reusable does not mean—in the space launch business—that it will be cheaper. Until individual launch vehicles are flying more than 100 times per year, the calculation suggests that expending is more likely to be lower cost.
Bill
On Mon, Jul 1, 2019 at 1:29 PM Anthony Cesaroni <anthony@xxxxxxxxxxx <mailto:anthony@xxxxxxxxxxx>> wrote:
Bill,
Are you suggesting that because it’s reusable, doesn’t
automatically mean that it will cost less?
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
*From:* arocket-bounce@xxxxxxxxxxxxx
<mailto:arocket-bounce@xxxxxxxxxxxxx>
<arocket-bounce@xxxxxxxxxxxxx
<mailto:arocket-bounce@xxxxxxxxxxxxx>> *On Behalf Of *William
Claybaugh
*Sent:* Monday, July 1, 2019 2:33 PM
*To:* arocket@xxxxxxxxxxxxx <mailto:arocket@xxxxxxxxxxxxx>
*Subject:* [AR] Re: Human Rated Hydrogen Tanks (was Re: Re: tank
frost (was >
Henry:
As Philip has observed, others are addressing deep space
capabilities the investment in which does make economic sense
today. Let’s just agree that my requirements for return on
investments appear to be nearer term than yours.
The rest of your comments seem to me simply misleading. There is
no publicly available evidence known to me to suggest that
SpaceX’s reuse of first stages is either profitable to them or
lower cost. Indeed, the publicly available evidence is that the
cost per pound delivered to orbit on the Block 5 is higher than it
was on the FT; SpaceX’s customers would clearly be better off (by
several hundred dollars per pound) if they could choose the
expendable over the reusable.
I have no knowledge as to whether SpaceX is making money on reuse
and simply keeping the gain for itself or whether refurbishment
costs have proven to be so high that they are losing money on each
launch. The fact that they are looking to demonstrate five uses
of a stage could mean that profitable reuse is yet to be achieved
despite a two or so uses breakeven wrt the depreciation charge.
In any case, you have no basis for suggesting that my previous
analysis was in error unless you have knowledge of their
refurbishment cost of which I am not aware. Do you have such
knowledge?
Bill
