The author worked on this project, and does remark that the only way to power the jet-borne laser at the time was to essentially pack a liquid rocket inside a 7

The author worked on this project, and does remark that the only way to power the jet-borne laser at the time was to essentially pack a liquid rocket inside a 747 - but advancements in laser tech over the last 20-30 years have created alternatives like solid state systems.