I assumed both could be improved, but yes, the launch system is the most flawed thing. The Saturn Shuttle with flyback booster is my favorite approach given the circumstances. If we were to wank the project, besides the flyback first stage, incorporating the external tank into the orbiter would have made it 100% reusable/refurbishable, but it would have meant an enormous spacecraft.
Still, one can dream.
As EnzoLux points out making a fully reusable launch system while possible ("Right Side Up" after all
) meant a very large airframe which itself meant a larger up-front cost due to the scaling issues in aerospace. And cost was always going to be the biggest problem considering everything NASA wanted the Shuttle to do. So much flows from the decision to go with expendable external tankage that it's hard to over-state how much that effected the entire design.
The internal propellant Orbiter would have been lighter on re-entry and actually needed a lesser TPS system due to that but look again at the picture he posted. That orbiter is about half again if not twice the size of a Boeing 747 and despite it being mostly 'empty space' all that costs a lot to design and build, even if it likely costs less to service. And the Booster is even bigger and just about as complex. And all that's before you get into the politics and policies behind the Shuttle program. More than likely even if they had gone with an internal propellant Orbiter you still needed a 'cheap' way of getting it into flight and more than likely you still end up with something OTHER than a fully reusable Booster and more like the compromised SRB's for launch because costs have to be cut somewhere.
FWIW
I thought the picture in
@EnzoLux's post was an artist's impression of the Rockwell International Phase B shuttle. However, when I looked it up in my copy of Rockets & Missiles by Kenneth Gatland (First published 1975 by Blandford Press, London) the drawing on Page 239 was of a delta winged orbiter and a delta winged booster.
The text says the orbiter was about the size of medium-range airliner and the booster would be the size of a jumbo-jet.
These are the characteristics of the booster and orbiter from pages 237 and 238.
Booster
Powered by 12 Rocketdyne high-pressure, staged combustion cycle, liquid oxygen/liquid hydrogen rocked engines - total thrust 6,480,000 lb (2,939,388 kg).
Fly-back engines: 11 x Pratt & Whitney JTF-22 B-2 turbofans.
Length: 276 ft (84.1 m) (However, the drawing on Page 239 says 267 ft so one of them must be a typo.)
Maximum Diameter: 34 ft (10.4 m)
Wing Span: 151 ft (46 m)
Empty Weight: 621,400 lb (281,867 kg)
Propellants: 3,114,000 lb (141,251 kg)
Total Weight: 3,735,400 lb (423,118 kg) [Note: not in the book, I added this.]
Speed at Separation: Mach 10
Mission Duration: 90 minutes
Orbiter
Powered by 2 Rocketdyne high-pressure, staged combustion cycle, liquid oxygen/liquid hydrogen rocked engines - total thrust 1,240,000 lb (562,464 kg).
Fly-back engines: 4 x Pratt & Whitney JTF-22 low-bypass turbofans.
Length: 210ft (64 m)
Wing Span: 124 ft (37.8 m)
Cargo Bay: 15 ft x 60 ft (4.6 m x 18.3 m)
Payload: 65,000 lb (29,484 kg) maximum
Empty Weight: 243,900 lb (110,633 kg)
Propellants: 604,500 lb (274,201 kg)
Total Weight with Maximum Payload: 913,400 lb (414,318 kg) [Note: not in the book, I added this.]
Mission Duration: 7 days
The total launch weight was around 3,500,000 lb (1,587,600 kg) according to the book, but my calculation (empty weight + propellants + fuel) was 4,648,800 lb (837,436 kg).
The booster is actually somewhat larger than a jumbo-jet. According to the Wikipedia entry on the Boeing 747-400 its dimensions are.
Overall Length: 231 ft 10 in (70.66 m)
Wing Span: 211 ft 5 in (64.44 m)
Overall Height: 63 ft 8 in (19.41 m)
And the booster was a lot heavier. The booster's total weight was about 4 times the all-up weight of a Boeing 747-400.
My memory was that the estimated cost of the Rockwell International Phase B was 10 to 15 Billion Dollars, but the text says...
Preliminary estimates looked towards a 1977-78 operational date and a development budget of $6,000,000,000 spread over six years.
Which made me think
"WTF!" as the estimated R&D cost of the Space Shuttle that was actually built was $5.2B
"only" eight hundred million Dollars less. But the next paragraph said.
By any standards this was a formidable project and recognition that research and development costs could easily reach $10,000 to $14,000 million led NASA, in the face of a declining space budget, to re-examine the whole concept of the space shuttle.
The estimated cost of the OTL shuttle comes from The Observer's Book of Manned Space Flight by Reginald Turnhill, Third Edition, 1978. His exact words were...
...the Shuttle research, development, test and evaluation programme had risen in cost from $5.2B in 1971 dollars to $7.2B in 1978 dollars, largely as a result of inflation. This included 2 flight test vehicles. Originally estimated costs of $250M for each of the 3 additional orbiters with additional boosters at $50M each, were likely to rise proportionately.
It's also got a list of provisional shuttle missions to January 1982 (which was a few months before the Shuttle's actual first flight) that shows 23 launches with the first launch in June 1979 which include:
- Taking a TRS to Skylab on its second mission in July 1979;
- 5 Spacelab missions between December 1980 and November 1981, and:
- Launching a Jupiter Orbiter/Probe (with IUS) on the 23rd mission in January 1982. I assume that this is Galileo which was eventually launched in October 1989.
It also has a table of the projected shuttle missions for 1980 to 1992 which I think refers to US fiscal years commencing on 1st October 1979 and ending on 30th September 1992 which shows 358 launches from Cape Canaveral and 129 launches from Vandenberg for a Grand Total of 487 missions. However, the number of missions for 1980 doesn't match the number in the other list (which is on the same page) and in the Mission Planning section on Page 84 it says that 725 flights were originally planned for 1980-91 but this had been reduced to 570 because the US Defence Dept had reduced its 224 flights to 106.