Also good for hard SF with pretty happy endings, try Julie Czerneda’s Species Imperative series, and it’s also written within the last 15 years.
Well, them, and members of future generations who aren’t dead or conquered, but see fit to second-guess the manner by which their liberty and their very lives were provided. 
Indeed.
Since we have now touched on Japanese light novels, might as well leap all the way to manga. Take a look at Uchuu Kyoudai/Space Brothers. Up to 325 chapters now.
The best stories (to me) punch your heart then give you a sweet ending.
You should read Forever War
I would recommend Poul Anderson’s The High Crusade. Medieval Englishmen take on an interstellar empire. There are some humorous bits and an upbeat ending. Anderson wrote some stories that are upbeat and/or pretty funny and some that were tragic. His short story “Day of Burning” gives Chee Lan some funny lines and is pretty good. That story uses FTL travel, but Tau Zero was firmly grounded in the hard science of the early 1970’s and has a great ending.
I recently read Connie Willis’ The Domesday Book, and while parts are grim, it does have an ending as upbeat as can be about the Black Death. Highly recommended.
Fritz Leiber’s novel The Silver Eggheads is hilarious and has a great ending.
Someone mentioned P.J. Farmer’s Riverworld series. Try The Maker of Universes, the first and best of the World of Tiers series.
I agree that Heinlein, Niven, and Asimov were generally upbeat. Pournelle and Niven’s Lucifer’s Hammer has an optimistic ending although much of the world gets destroyed. Someone mentioned Arthur C. Clarke and I would try Childhood’s End and The Sands of Mars.
Also recommended are Zelazy’s Lord of Light, Creatures of Light and Darkness, and “The Doors of his Eyes, the Lamps of his Mouth.”
Which version?
No, they clearly cheat. They work out with the traveler fithp that the Red Cross means ‘wounded, do not bomb’ then use that to disguise the Orion project. The fithp are outraged by that and promise - should they win - to bomb every place that ever used the red cross.
I inserted post #46 that was posted in a different thread my mistake.
[/moderating]
Since this is a thread specifically oriented toward new ideas for stuff to read… could I request that you guys take any extended exchange about plot points to a separate thread? There’s a discussion that appears to be half-spoilered - I can’t tell without actually reading the comments. At the moment I’m having to try to skim over certain posts without reading them.
I wouldn’t call it “hard” SF, but seconding the recommendation. If you want something that’s not depressing at ALL, try the comedic semi-sequel, “To Say Nothing Of The Dog”, which is set partly in Victorian England.
Ted Chiang’s short stories are “hard” in the sense that they take a fantastical idea to its logical conclusion, although on the SF-to-fantasy scale most of them are toward the ‘fantasy’ end. I’d especially recommend “Seventy-Two Letters” and “Tower of Babylon”. “The Lifecycle of Software Objects” is the closest of his works to hard SF, and is enjoyable.
I’ll second To Say Nothing of the Dog.
It probably looked pretty out of place in that discussion of all-time worst Hall of Fame quarterbacks, I bet. 
Yes, and you could also include Serpent’s Reach, about a human colony coexisting with large, intelligent ant-like aliens.
And for that matter, the whole Foreigner series.
Voyager in Night is highly recommended for people who are in favor of uploading copies of themselves to intelligent computers. It might make you think twice… 
No more than matter transmitters or FTL travel.
Oooh! I’ve read the print version but Wil Wheaton reading it would be epic!
Well, exactly. With all due respect to the good Doctor, nothing about the Foundation Trilogy is hard SF. Telepathic mutants? FTL?
That *is *hard SF.
FTL has been part of hard SF since day 1.
"At number two on our list of top hard science fiction books is Foundation by Issac Asimov. Why number two? Because we couldn’t have a joint number one, that’s why. Many of Asimov’s books would have fitted the bill, but given Foundation is part of the original foundation (sorry) of modern science fiction, we thought it the best starting point. With it’s sprawling, space-opera like setting, it’s focus on science and history and Asimov’s classic turn of phrase, it’s no wonder this novel has remained popular for decades after it was first published. Foundation takes the familiar starting point of the fall of an Empire, sets it in space and adds in that vital ingredient hope. Mixed together, we get a soaring epic that spans both space and time. Not only is the technology realistic, but so are the characters and society. Asimov is master of both story and science, and it’s evident throughout this. The best part is, this is the first in a series! So you can read even more!"
Disagree. FTL, telepathy and psychohistory are all impossible. If SF has no impossibilities in it then it is diamond hard - if it has one impossibility it is hardish, two impossibilities takes it towards softness and three impossibilities borders on fantasy.
I don’t suppose for a moment that Asimov thought he was writing hard SF. This is space opera at its finest.
And why do you say FTL is impossible?
That’s YOUR definition and I just cited a source that sez Foundation Trilogy ties for 1st as the best Hard SF ever.