An authorized sequel to Armageddon 2419, A.D. (the original "Buck" Rogers novel) by Philip Francis Nowlan. From an outline by Larry Niven & Jerry Pournelle.
From the back cover:
In the year 2419 A.D., American guerilla forces under the leadership of 20th-century American Anthony Rogers (the same Rogers who would become, with a new nickname, the greatest comic-strip hero of all time) overthrew the hideous Han invaders. Little did Rogers guess at the end of that momentous time that his adventures had only begun - that years later the Han would come ravening out of their underground hide-outs, and that once again only he would stand between America and total destruction!
YOU ARE ABOUT TO READ THE ONLY AUTHORIZED SEQUEL TO ARMAGEDDON 2419 A.D, THE BOOK PEOPLE MAGAZINE CALLS "A POP CULTURE MUST!"
Holmes has a heavy lift here. The book never trades on the "Buck Rogers" name--probably still in the possession of the television series license--and it clings to the original Armageddon 2419 A.D. with all of those warts, and it advances the timeline by decades in order to clean the slate a bit. And then due to Science Magic the character of Anthony Rogers gets a refresh to launch into a new book series that may or may not resemble the pew-pew antenna-helmet space opera of the comics.
The original was kind of weird, but was a product of its time, with all the weird science and future history and a...problematic...yellow-peril view of the Han enemies. Holmes can't quite shake the problems baked into concepts that have aged to obsolescence, nor can he inject joy into the military action and march of plot towards inevitable conclusion. He can texture the characters more, making Rogers a flawed protagonist in his early 80's who faces his own frailties as much as he faces the political wrangle of the human/American leadership as well as trying to fly around and zap bad guys.
The Han themselves become the interest, and they are kept a faceless menace until far too late. Their broken, decadent society squats in hidden underground cities, only to be burrowed out by the savage humans, and then to be overshadowed by a more politically correct and threatening enemy that is far less interesting. That the Han quite correctly call the humans genocidal and Rogers in particular a war criminal is, I think, the reversal that the story dearly needed, yet just sits there once on the table.
A clear victim of the Star Wars effect, but not the worst offender of the copycats. Of course Star Wars was busy stealing from Flash Gordon serials which had stolen a generous pile of ideas from Buck Rogers in the first place, so I guess there's a correctness to this particular part of the pop culture cycle. The soap opera elements aren't out of place here, but they aren't anything to write home about either.
Never has a book been so concerned with the details of excavation. Granted that it's also the basis for most of the weaponry, but geez we do spend an inordinate amount of time on digging furrows with lasers. The best sci fi is certainly interested in technology and its consequences, but this particular technology didn't come close to engaging the imagination.