Not a word of what follows is mine, it is all quoted from John Walker and the source cited in the link ... I thought y'all just might find it interesting:
A Rocket a Day Keeps the High Costs Away
John Walker's classic 'modest proposal' to reduce launch costs.
by John Walker (September 27, 1993)
Consider the following mass-produced expendable rocket.
Number manufactured: 6,240
Number launched: 3,590
Successes: 2,890 (81%)
Failures: 700 (19%)
In inventory: 2,100
Work in progress: 250
Expended in development: 300
Development program cost: US$ 2 billion
Development cost per launcher: US$ 350,512
Total manufacturing cost per launcher: US$ 43,750
Marginal cost, launchers 5000+: US$ 13,000 (Yes, 13K!)
These are actual figures for the first mass-produced rocket vehicle, the V2 (A4)--fifty years ago. Prices are in US wartime dollars.
A Rocket a Day
Suppose we translate these figures, almost incomprehensible by modern standards (*three hundred* launch vehicles expended in the development program!) into quasi-modern terms. Consider an orbital launch vehicle two-stage, say, clean and green thanks to LH2/LOX propulsion in all stages. Engines: J2 or RL10s or follow-on uprated versions (we'll have plenty of opportunity to develop them and phase them in). A simple two stage cylindrical stack like Titan II, with GPS or ground-commanded navigation. Payload interface is a big ring with bolt-holes and a standard fairing with plenty of volume inside.
Sounds a lot like NLS/SpaceLifter, doesn't it? STMEs may have marginal advantages over sea-level-optimised derivatives of RL10 or J2, but otherwise what's the difference?
What if we launch one every day?
Three hundred and sixty-five a year.
That would be less than one twenty-fifth the production rate of the V2 under concentrated Allied bombardment in 1945.
How much would each one cost?
Assume we expense the development cost or amortise it over a sufficiently large number of vehicles that it can be ignored. Further, assume that our bigger, more complicated (two-stage), and higher tech (LH2/LOX instead of Ethanol/LOX), launcher costs ten times as much as the V2, and that 1945 wartime dollars convert into current dollars at 10 to 1. Then, starting with the US$13,000 marginal cost of a V2, we arrive at a cost of US$1.3 million per launch vehicle. If we launch one a day our total vehicle budget will be US$475 million per year--comparable to a single shuttle flight (no, I don't want to re-open *that* debate again; let's just say it's the same order of magnitude, OK?). If our mass produced LH2/LOX launcher equals the performance of the Delta 6925 by placing 3900 kg in LEO, the cost to LEO is US$333/kg; if we achieve better throw-weight, this figure goes down accordingly. If we build the thing so cheap, dumb, and heavy that its payload is only 1000 kg--one metric ton--the cost rises to US$1300/kg, which is still a factor of ten lower than the comparable cost to LEO for Ariane, Atlas, Delta, and Titan.
