Wow, I loved the anime, and I loved the Manga, though the two certainly are different. Very different in fact, though with the same main characters (though very different side characters) and the story happens very differently. This Manga focuses on Hoshino from his days as a green astronaut, until he takes on a mission to Jupiter, and including meeting the young and idealistic Tanabe who he eventually marries. This Manga is in 4 volumes, though the last 2 are labeled 4 1 and 4 2, which means they must have been one large volume in Japan, still for any straight science fiction fan, and anime fan, they will love this manga.
I have to admit to being on a huge Masamune Shirow kick lately. After seeing the APPLESEED movie I broke out my old APPLESEED MANGA, re-read the original GHOST IN A SHELL MANGA, and have been looking at the 4 INTRON DEPOT Books, and I ordered this at the same time, not even believing it had come out, a reel sequel to GITS. I have had it for a while, but finally picked it up and read it. I did enjoy it greatly. I love his artwork, and it is a real pleasure seeing his artwork in full color in comic book form (some is in Black and White, but less than 1/3 I would say), and this looked great. I can honestly say I have no idea what happened. He seems to understand a good deal more about this than I do. Maybe I need to read it again, but right now I need to let my brain rest.