A great deal happened between Star Trek: Discovery seasons 3 and 4 that changed the face of Starfleet and the United Federation of Planets. Star Trek: Discovery will return with season 5, which promises a tonal shift for the serialized series taking place in the distant 32nd century. In Star Trek: Discovery season 5, Captain Michael Burnham (Sonequa Martin-Green) will embark on a hunt for the "greatest treasure in the galaxy," which could showcase a 32nd-century era that has markedly changed in the scant few years since Burnham permanently time-traveled from the mid-23nd century.
Michael Burnham and the USS Discovery solved the mystery of The Burn in Star Trek: Discovery season 3. They discovered the source of the galactic calamity that wiped out all dilithium and warp travel was a Kelpien named Su'Kal (Bill Irwin) who was orphaned in a nebula imbued with dilithium. A hundred years after The Burn, the United Federation of Planets collapsed, left with 38 far-flung member worlds from 350 at its peak. Burnham ending The Burn era of a broken Federation, and the Discovery's defeat of the criminal syndicate, the Emerald Chain, completely changed the course of the galaxy. Star Trek: Discovery season 4 picked up 5 months later and brought even further changes to the 32nd-century galaxy.
9 Discovery Brought Dilithium And Warp Drive Back To The Federation
The biggest change to the Federation in the interim 5 months between Star Trek: Discovery seasons 3 and 4 is that warp travel is back. Discovery, which can instantly jump thanks to its spore displacement hub drive, spearheaded a massive campaign to deliver dilithium to its member worlds. The Federation was up and running again thanks to Burnham and Discovery.
However, the Federation also recognized that its dependence on dilithium-powered warp drives was a mistake that can't be repeated, especially if another Burn could happen. The Federation began developing a next-generation spore drive, which was perfected by Dr. Ruon Tarka (Shawn Doyle). Unfortunately, the next-gen spore drive was destroyed by the end of Star Trek: Discovery season 4. Still, warp travel has reconnected the galaxy for the first time in over a century.
8 Most Of The USS Discovery's Crew Got Promoted
Star Trek: Discovery's first 3 seasons were Michael Burnham's journey to becoming Captain. But most of Burnham's crew also got promoted (without fanfare) in between Discovery seasons 3 and 4. For example, helmsman Kayla Detmer (Emily Coutts) and operations officer JoAnn Owosekun (Oyin Oladejo) became Lieutenant Commanders. Meanwhile, Paul Stamets (Anthony Rapp) in Engineering became a full Commander. The raised ranks are a reward for the Discovery crew's heroism but since it happened off-screen and was fleetingly mentioned in dialogue, it's understandable if many viewers missed this round of promotions.
7 Starfleet's Uniforms Changed Colors
Star Trek: Discovery's uniforms were a monochromatic blue in the first three seasons. When Burnham and her crew met the 32nd century Starfleet, they found the future uniforms were also a monochromatic gray, with colored stripes denoting rank. But in between Discovery seasons 3 and 4, Starfleet reconsidered their color schemes because uniforms returned to the color-coding from the Star Trek: The Next Generation era. Once again, Security and Operations uniforms are gold, blue is for Sciences, and red is the color of Command. The color shift perhaps denotes a brighter future for Starfleet.
6 Laira Rillak Was Elected President Of The Federation
Laira Rillak (Chelah Horsdal) became President of the United Federation in an election held during the five months between Star Trek: Discovery seasons 3 and 4. Rillak, a hybrid human/Bajoran/Cardassian, promised to restore the Federation to its pre-Burn status. Rillak's term in office was immediately faced with another galaxy-destroying crisis: the arrival of the Dark Matter Anomaly, which destroyed the planet Kwejian. Rillak also took a personal interest in Captain Burnham and the USS Discovery, which led the effort to discover the creators of the DMA, Species 10-C, in an adjacent galaxy.
5 Federation Membership Grew In Size
After the USS Discovery-A began delivering dilithium to the rest of the galaxy, faith in the United Federation of Planets began to be restored. The Federation's member worlds jumped from 38 to 59 in the five months between Star Trek: Discovery seasons 3 and 4. By the end of Discovery season 4, Ni'Var, home to the unified Vulcans and Romulans, and Earth were back in the Federation's fold, as well. In addition, the Federation no longer feared and hid from its enemies, and the cloaking device concealing Federation headquarters was dropped.
4 Starfleet Built The Archer Space Dock
The five months between Star Trek: Discovery seasons 3 and 4 saw Starfleet constructing the Archer Space Dock. Named for Captain Jonathan Archer (Scott Bakula) of Star Trek: Enterprise, who also served as the first Federation President in the 22nd century, the Archer Space Dock was meant to fully upgrade Starfleet's vessels. The Archer Space Dock retrofitting the fleet was also to fulfill President Rillak's promise that Starfleet would return to one of its core missions: scientific exploration.
3 Captain Saru Remained On Kaminar
After Su'Kal was freed from the Verubin Nebula, Captain Saru (Doug Jones) accompanied him home to Kaminar. Saru decided to remain on the Kelpien homeworld with Su'Kal so that they could reintegrate into their society together. Saru did not return to Starfleet during the five-month interim between Star Trek: Discovery seasons 3 and 4. Although he recommended Michael Burnham replace him as Captain of the Discovery, Saru turned down offers to Captain his own starship. Saru didn't return to the Discovery until after the DMA destroyed Kwejian, and he opted to serve as Burnham's First Officer in spite of his rank.
2 Starfleet Academy Reopened
The season 4 premiere of Star Trek: Discovery introduced the first new Starfleet Academy class of Cadets since The Burn a hundred years prior. Maintaining an influx of new Cadets was impossible in a disconnected galaxy without warp travel, which meant the Federation shuttered Starfleet Academy. The reopening of the Academy was the first step in Starfleet's rejuvenation. Star Trek: Discovery also moved Lt. Sylvia Tilly (Mary Wiseman) from her home starship and she became an instructor at the Academy.
1 Admiral Vance Was Reunited With His Family
On another happy note, Admiral Charles Vance (Oded Fehr) was reunited with his family. Vance was burdened with keeping Starfleet running and interfacing with the Federation during The Burn, and it was at the cost of seeing his wife and daughter, who were lightyears away. Captain Burnham bringing warp back to the Federation meant Admiral Vance could be with his family again, which is a personal reason for Vance's increased affection and admiration for Burnham when Star Trek: Discovery season 4 begins.
Star Trek: Discovery Season 5 is expected to premiere in 2023 on Paramount+.