Herbert Winthrop

Image credit: North American Rockwell

Image source: Numbers Station

Deploying a Space Tug

Image credit: North American Rockwell

Image source: Numbers Station

Assembly & Launch

Image credit: North American Rockwell

Image source: Numbers Station

Artist’s Rendering

Image credit: North American Rockwell

Image source: Numbers Station

S70-26310

Just to illustrate just how utterly massive the R-134B would have been, take a look at this illustration from a report written by Jack Swigert for The Society of Experimental Test Pilots:

Shuttle Program at Astronautix

Image credit: NASA

Image source(s):

Apollo4Ever

Massachusetts Institute of Technology

MDAC Orbiter

Image credit: McDonnell Douglas

Image source: n/a

532 Flyback Booster

Shuttle Program at Astronautix

Grumman & Boeing Phase B at PM View

Image credit: Grumman

Image source: NASA NTRS

MDAC Canard Booster

Shuttle Program at Astronautix

MDAC Phase B Shuttle at PM View

Imaged credit: NASA

Image source: NASA NTRS

NAR Booster Concept

Shuttle Program at Astronautix

Image credit: North American Rockwell

Image source: Numbers Station

518 Flyback Booster

Shuttle Program at Astronautix

Grumman & Boeing Phase B at PM View

Image credit: Grumman

Image source: NASA NTRS

619 by Craig Kavafes

Shuttle Program at Astronautix

Image credit: Grumman

Image source: n/a