It amazing what you find when you are trawling around the internet looking for something, and find something else just as, if not more interesting.
I was searching for books by Donald Gordon. I read one many years ago called
"Flight of the Bat" and another called
"Leap in the Dark" and I found that there was another book of his that I haven't read, called "Star Raker", but when I did a Google Search for this, I got something I didn't expect.
Star-raker
It certainly looks impressive.....
The American winged orbital launch vehicle, Rockwell International's Star-raker, was an enormous 1979 heavy-lift ramjet/rocket horizontal takeoff/horizontal landing single-stage-to-orbit (HTHL SSTO )concept capable of atmospheric cruise and powered landing for maximum operational flexibility.
Rockwell studies in the late 1960's indicated that Mach 6 turboramjets would provide significant advantages to horizontal takeoff/horizontal landing (HTHL) two-stage-to-orbit (TSTO) designs provided were only marginal benefits for single-stage-to-orbit (SSTO) vehicles. However by the late 1970's, Rockwell believed that new materials technologies, combined with a wet wing design, would make HTHL SSTO possible. The lower wing loading of the design would make surface temperatures during reentry several hundred degrees lower than the Space Shuttle. Rockwell asserted that the Star-raker, using advanced airbreathing engines, could carry double the payload for the same gross liftoff mass as Boeing's Reusable Aerodynamic Space Vehicle all-rocket HTHL SSTO concept. However Star-raker's dry mass would be 45% higher than the Boeing design and the vehicle would be exposed to a more severe aerodynamic heating environment.
Rockwell investigated the operational issues and requirements for launching 1600 tonnes of payload into low Earth orbit per day to support construction of solar power satellites. The baseline concepts were Boeing's rocket-powered VTVL TSTO (400t payload capability) and the Star-raker turbofan/air-turbo-exchanger/ramjet HTHL SSTO (100t payload). Although the airbreathing HTHL SSTO concept would require some advanced technologies, it appeared to be better suited for high flights rates (16/day) than the vertically-launched TSTO.
The VTVL vehicle would require ten launch pads requiring extensive refurbishment between missions, to meet the launch rate requirement of 4 flights per day from the Kennedy Space Center. Two high-bay Vertical Assembly Buildings would also be required as opposed to two aircraft maintenance type buildings for Star Raker. The turnaround time for the HTHL SSTO (1.8 days) would be one-third that for the VTVL TSTO (5.5 days), primarily because the latter would land at sea and the requirement for mating and stacking two extremely heavy stages. On the other hand the risk of recovery damage was considerably higher than for aircraft landing.
For the HTHL, a single-runway air base would support an entire fleet of 30 Star-rakers. The VTVL TSTO launch range would have to be 850 square km in area to accommodate a fleet of 22 vehicles and the launch noise they generated (120db at 13km, vs. <120db at 1km for the HTHL SSTO).
Payload Specifications
20 x 20 x 141.5 ft cargo bay (56,600 ft3) accessible via hinged nose
196,600 lbs to 300 nm.i at 28.5 deg inclination from Kennedy.
Deliver above payload at cost of $30-$45 US 2010 Dollars per pound*
Propulsion Specifications
Ten hydrogen fuelled high bypass supersonic turbofan/air-turbo-exchanger/ramjet engines, each with 140,000 lbf of thrust.
Three hydrogen fuelled shuttle SSME-type rocket engines, each with 1.06 million lbf of thrust and an ISP of 455 seconds.
Operate from runways 8,000 to 14,000 ft long (2,440 to 4,270 m).
Other specifications
LEO Payload: 100,000 kg (220,000 lb) to a 556 km orbit at 28.00 degrees.
Gross mass: 2,278,800 kg (5,023,800 lb).
Height: 94.50 m (310.00 ft).
Span: 110.00 m (360.00 ft).
Apogee: 556 km (345 mi).
A typical profile flown from Kennedy Space Center to a 300 n.mi orbit at 28.5 deg inclination was to be:
► Runway takeoff under high-pass turbofan/airturbo exchanger (ATE)/ramjet power, with the ramjets acting as supercharged afterburners.
► Climb to cruise altitude with turbofan.
► Cruise at altitude, Mach number, and direction vector to earth's equatorial plane, using turbofan.
► Execute a large-radius turn into the equatorial plane with turbofan power.
► Climb sub-sonically to optimum altitude, using high bypass turbofan/ATE/ramjet power.
► Perform pitch-over into a nearly constant-energy (shallow Y-angle) dive if necessary
► Accelerate through the transonic region to approximately Mach 1.2, using turbofan/ATE/ramjet.
► Execute a long-radius pitch-up to a supersonic climb flight path, using turbofan/ATE/ramjet.
► Climb to approximately 95,000 ft at 6200 fps using proportional fuel-flow throttling from turbofan/ATE/ramjet, or full ramjet, as required to maximize total energy acquired per unit mass of fuel consumed as function of velocity and altitude.
► Ignite rocket engines to full required thrust level at 6200 fps and parallel burn with ramjets to 7200 fps.
► Shut down ramjets and close ramjet intakes.
► Continue rocket power at full thrust.
► Insert into an equatorial elliptical orbit 91 x 556 km (50 x 300 nmi) along an optimum lift/drag/thrust flight profile.
► Shut down rocket engines and execute a Hohmann transfer to 556 km (300 nmi).
► Circularize Hohmann transfer.
► Release Payload or dock with Space Station at that orbit.
► Perform delta-v manoeuvre and insert into an equatorial elliptical orbit 91 x 556 km (50 x 300 nmi) in preparation for re-entry.
► Perform a low-gamma -high-alpha re-entry deceleration profile very similar to Space Shuttle to approximately Mach 6.
► Reduce alpha to appropriate angle for maximum lift/drag ratio for high speed glide and cross range maneuvers to subsonic velocity (Mach 0.85).
► Open inlets and start ramjet engines.
► Perform powered flight to landing field, land on runway, and taxi to jetway. Flyback fuel requirements include approximately 300 nmi subsonic cruise and two landing approach manoeuvres (first approach wave-off with go-round for second approach).
* = What? $30 - $45 per lb ($67 - $100 per kg) to orbit. No. That HAS to be a mistakeThis looks more like science fiction that science fact.
Was this even workable?
Have there been sufficient advances in aerospace for something like this to be feasible today?
Could it really have been a cheaper long-term option than STS?
