Space Patrol Delta

Space Patrol Delta, often abbreviated to S.P.D., is a interplanetary Police force, It is an organization that oversees law enforcement over areas of space, and deploys advanced technology to maintain order and peace. S.P.D. also trains and delploys its own team of Power Rangers, who are quippped with the lastest technology.

History
The original Space Patrol Delta was founded on Sirius at an unknown time, training both Sirians and other alien races (such as Icthior's) (Badge) to be defenders of the galaxy. Prominent in its ranks was Anubis "Doggie" Cruger, who led the SPD forces in battle when Sirius was invaded by the Troobians under Emperor Gruumm and General Benaag. Despite days of constant fighting, Space Patrol Delta was defeated and every single Sirian except for Cruger was wiped out. Despite the fall of Sirius, SPD survived in the form of other planetary branches and a new central Galaxy Command under Commander Birdie Fowler.

One such branch, top secret and known only to a few, was the one on Earth in 2001, where scientist Kat Manx and several humans were performing experiments. The effects of the experiments became apparent when the scientist's children began displaying superhuman powers, and they were split up to avoid repercussions. (Sam) Doggie Cruger was reassigned to Earth and at some point founded the local SPD Academy, as well as watching over the scientists' children. Soon, SPD became a public organisation with its own group of Rangers with powers; only the original Red Ranger has been shown, wearing a uniform identical to the Time Force Red Ranger's. The original SPD Red Ranger would eventually fall in battle.

By 2025, SPD Earth had two sets of Rangers - the B-Squad Rangers reserve team and the A-Squad elite - and three of the children of the original scientists had joined the Academy and become part of B-Squad. Under the Rangers came the C-Squad and D-Squad cadets. The SPD organisation now spanned the galaxy with outposts on Zantor, KO-35, Gamma 4, Gamma Orion, Verinox 12 and the Theta Quadrant among others. Despite this, they were unable to stop the relentless march of the Troobian Empire. In Dismissed, Bridge Carson stated "Earth is the last place Gruumm hasn't conquered" (almost certainly an exaggeration).

When the Troobians came to Earth, the remaining children of the original SPD scientists were quickly drafted in to the B-Squad. They later became in charge of Earth's protection when A-Squad were Missing In Action after being sent to fight off a Troobian assault on the Helix Nebula Federation. Doggie himself joined B-Squad after an assault by General Benaag, becoming the S.P.D. Shadow Ranger, and an SPD Omega Ranger arrived from an alternate timeline. The Troobians soon became entrenched on Earth, though Gruumm was able to ensure the destruction of the Gamma 4 base despite this.

Eventually, Delta Base came under direct assault from the Krybot armies under Broodwing and many officers were taken down, with Delta Base's defences (specifically its ability to become the Delta Command Megazord) being offlined in the process in order to repel Broodwing out and the Delta Runners being destroyed by the A-Squad's Megazord. While the B-Squad took on the power of Omni direct, the remaining SPD personnel had to fight off a second invasion by Gruumm's full army - the sudden arrival by reinforcements from Galaxy Command turned the tide. Following victory, Doggie Cruger was promoted and the B-Squad were made highest-ranking team on Earth, with the A-Squad title being retired.

Afterwards, as revealed in Once a Ranger, Commander Birdie retired and Cruger has become Supreme Commander, with Sky Tate as head of the Earth base and Bridge Carson becoming the B-Squad Red Ranger. As Power Rangers SPD is set 20 years after the present day, the date of Birdie's retirement may have been 2027 as Operation Overdrive is set in 2007.

Each S.P.D. Ranger has a numerical designation written on their Ranger suit: S.P.D. Red is #1, S.P.D. Blue is #2, S.P.D. Green is #3, S.P.D. Yellow is #4, S.P.D. Pink is #5, S.P.D. Shadow is #100. Omega has VI on his suit, and Nova has M on her suit, presumably standing for 6 and 1000, respectively (So its possible in the future SPD will use Roman numerals). Each ranger (except Shadow Ranger probably because his number is "Too big") also has tick marks on their helmets above their visor corresponding with their numerical designation. S.P.D. Red has one mark, S.P.D. Blue has two, S.P.D. Green has three, S.P.D. Yellow has four, S.P.D. Pink has five, and S.P.D. Omega has six. Strangely enough, Nova Ranger has eight marks (Of course it would be hard to put 1000 marks on a helmet).

In an alternate timeline, July 11th 2025 was the day on which the Troobians wiped out most of S.P.D. Earth and conquered the planet. The remainders of S.P.D. developed the Omega Ranger technology and sent it back in time to avert the original defeat.