Solar Warden — Peter Fuller

US Air Force combat pilot Colonel Steve Richardson suffers a severe head injury when his F-35 crashes in the mountains of northern Afghanistan. With help too far away, death appears imminent. When an unusual craft appears and rescues him, Richardson is convinced he's hallucinating. It conveys him to a massive spaceship in orbit, where he is treated for his wounds.
Once he recovers from his injury, Richardson is introduced to a covert space force called "Solar Warden." This secret space program utilizes futuristic technology to defend earth against a paranormal alien threat intent on destroying earth's inhabitants.
When Richardson joins the program, he learns that his new comrades are losing the conflict. Can he learn to operate technology half a century ahead of what he has been trained for in time to be an asset? Or will he become just another casualty in an interstellar war?