The Crossfield class USS Discovery NCC-1031 was a 23rd century starship operated by The United Federation of Plants' Starfleet. She was launched in the year 2256 under the command of Gabriel Lorca from the fleet shipyards on Earth. Discovery,along with her sister ship the USS Glenn were officially designated science vessels that had 15 decks and a crew of about 136. The Discovery was equipped with some of the most advanced technology in Starfleet at the time, allowing it to accommodate a record breaking (at the time) 300 discreet scientific experiments.
The most fascinating tech unique to the USS Discovery and it's sister ship, the USS Glenn was the " Displacement-Activated Spore Hub Drive." The spore drive in short was an experimental biologically based technology developed by Paul Stamets of the USS Discovery and Science Officer Straal of the USS Glenn that allowed starships to travel instantly across a mycelium network. (An intergalactic ecosystem, or an infinite number of roads leading everywhere. It spans the entire multiverse that includes the known universe and all other quantum realities.)
Stamets had intended his research to pursue purely theoretical knowledge and peaceful applications but, with the outbreak of the Klingon war in late 2256, Discovery was rapidly constructed to perfect the military applications of his research.
With much research and refinement still to be done with the spore drive, Discovery was only able to use it in short bursts while attempting to perfect it into a reliable drive system. Unfortunately, the crew of the Glenn took bolder risks to develop it more quickly, which resulted in an accident that killed the entire crew and crippled the ship. While a futile search of the Glenn for survivors and technology was being done, a tardigrade was found on board. Captain Lorca had the tardigrade brought on board the Discovery before destroying the Glenn and it's secret technology to prevent it from falling into Klingon hands.
Under increasing pressure to perfect the spore drive so that it could be utilized in the war, it was discovered that the tardigrade could be used as a conduit to navigate the Discovery through mycelial network. The spore drive was finally a success and turned the tide of the war for the Federation as the Discovery could "jump" anywhere in the universe in an instant. However, it was found after multiple uses of the spore drive that the tardigrade was being severely harmed. Unwilling to subject the tardigrade to further injury, Lieutenant Stamets injected himself with the creature's DNA becoming a human interface for the spore drive.
The spore drive with Lieutenant Stamets using it,became instrumental in turning the tide of the war for the Federation by obtaining the secret behind the Klingon's cloaking technology. However,before the war could be won, and carrying vital information about the Klingons ability to cloak their ships, Captain Lorca unexpectedly "jumped" the Discovery and her crew into the Mirror Universe. After a violent struggle with the ruling Terran Empire, the Discovery was able to return to it's own universe with the help of the spore drive. In her absence and still carrying the vital cloaking technology,the Federation was at the brink of defeat. Using the fact that the Federation now had a way to defeat the Klingon's cloaking tech and devising a plan to use the Discovery's spore drive to threaten the Klingon homeworld,the Klingon's agreed to an armistice to end the war.
Roughly a year later the Discovery was lost with all hands in a battle with a rogue Section 31 AI program. The records of the events leading up to and including the classified loss of the Discovery and it's crew can be found in video documentation found here.