
The book depicts the arrival of members of an alien species called the Fithp that have traveled to the Solar System from Alpha Centauri in a large spacecraft driven by a Bussard ramjet. Their intent is conquest of the planet Earth.
First Contract (Greg Costikyan) - a book about the economics of first contact
John Courtney Grimwood (author) - science fiction, generally cyberpunk, told from the point of view of characters who don't understand the tehcnology, which gives his work a kind of mystic vibe. (Eg, Nine-tail fox is about a detective trying to solve his own murder)
Footfall (Larry Niven/Jerry Pournelle) - was a big release back in the day, but not so well known these days. Hard SF alien invasion novel (Independence Day might have ripped this off a bit)
The NASA trilogy (Stephen Baxter) - dark alternative future books, with bleak endings but great science. I think not so well known these days because of the bleakness, but that's also part of what made them memorable when I read them.
I keep thinking this was a Larry Niven story, maybe someone here is familiar?
Edit; another classic story was the novel Footfall by Niven and Pournelle which featured launching the USS Missouri into orbit on an Orion style pusher to battle the invading aliens.
