This is the whole story to Gundam Wing. I'm not really going to put in the effort of summarizing every single part of the episodes (Some sites actually do that. Eek!), since I don't have the time and effort for it (in other words, I'm just too lazy!). But I can at least summarize the story.
In the year After Colony 175 (which is VERY far into the future), the leader of the colonies, Heero Yuy, was assasinated. The assasinator was unknown. His de-militarization and unification of the colonies had ended. 5 ex-OZ scientists; Doctor J, Professor G, Master O, Instructor H, and Doktor S; developed and built 5 very powerful suits called Gundams to take revenge for the loss of their leader. Gundam Wing, Gundam Deathscythe, Gundam Shenlong, Gundam Sandrock and Gundam Heavyarms were the end result. Each of them are made out of the rare metal called Gundanium alloy that can only be mined from the space colonies, but it's not the fact that it's rare is why it's so special. It's because it's basically indestructable.
Heero Yuy, Duo Maxwell, Wufei Chang, Quatre Raberba Winner, Trowa Barton. These are the pilots of the 5 Gundams. They are extremely skilled in what they do best, piloting mobile suits. The self-detonate button on their Gundams aren't big and red to them. It's almost like a basic button to them since they'd rather die than fail a mission (see Heero Yuy), but they have the looks of Magazine cover-boys that girls would die for to see in real life. Much like the other anime series called Ronin Warriors. But instead, the 5 Gundam pilots carry on their mission(s) like as they were instructed to do.
The Gundams and their pilots were to be sent to Earth, disguised as meteorites or shooting stars. This secret project dubbed "Operation Meteor" was shrouded in secrecy and denied by all people of the colonies. But OZ and the Earth Sphere Alliance were catching on to this "secret operation" and caught one of the Gundams falling to Earth; which was the Gundam Wing. Afterwards, the Gundams and their pilots were caught in the middle of a large crossfire. The Earth Sphere Alliance was on the brink of collapse, Peace was being established in the Colonies with OZ, Computers were piloting mobile suits which can replace human pilots, and the Gundams were slowly being isolated from the Colonies, having no place to return to. Sadly enough, this did happen. And when they returned to space, nothing was like it used to be.
The Gundams were in complete disarray. The Gundam Sandrock had to be self-detonated; Quatre's family was betrayed by their own colony, ending up in the death of Master Winner; The Gundam Deathscythe was captured by OZ; Duo Maxwell was captured as well; and the Gundam scientists were captured by OZ, making them build better mobile suits than the Gundams. Only the Gundam Shenlong, Heavyarms and Wing weren't captured or destroyed, but they didn't have much use at the time being. When Wufei returned to his home colony, everything was surprisingly okay. But later on OZ troops had to end up destroying the colony, making Wufei the only option of going it alone. Trowa Barton erased his earlier identity and joined OZ in an effort to cover up some data, and had to destroy the Gundam Deathscythe (*tears falling from eyes*). But in a later battle between him and Heero in the Vayeate and Mercurius against Quatre in the Wing Zero, he nearly killed himself and lost his memory. Heero was captured by OZ and was a test pilot of the Mercurius, also nearly getting himself killed as well in the same battle. And the split-personality Ladyune was "assasinated" (actually just knocked unconcious) by Tubarov, essentially ending the peace negotiations of OZ.
But a voice started to come up in the Colonies. Another revolution came up, the White Fang. Although it was a rebellion against OZ, the Gundams were completely let out of this, and were their enemies. With the Gundam team regrouped, they teamed up with Howard in his nearly mile-long ship the Peacemillion and their Gundams were rebuilt and/or modifications were completed. They were one force in the Solar System. The other was the White Fang with their hijacked battleship Libra; and OZ with their Space Fortress Barge.
All three of the Forces in the Solar System finally came together and duked it out. Treize Khushrenada lead the OZ force in his Tallgeese 2, Millardo Peacecraft/Zechs Merquise lead the White Fang with his Gundam Epyon and Quatre Raberba Winner in his faithful Sandrock lead the Gundam team. But with the Zero System programmed into a remote control system for the White Fang's Virgo2's, Quatre had to use the Zero system in his suit to get the Gundam team to hack through the hordes of Virgo's and to the Libra. But Zechs had different plans. He was planning to use the main cannon of Libra to render Earth uninhabitable. The cannon was fired, but it didn't have much effect on the little blue marble in space (Earth). So the battleship would now ram into Earth, hopefully being sucessful. The Gundam team and the newly appeared Maganac Corps attemped to destroy the innards of Libra. Zechs had a long-delayed battle to finish with Heero, and the two battled on and on. Ladyune broadcasted the meaningless battle to all the colony citizens, proving that battles are meaningless. With the failed attemps to get rid of the falling battleship, the Maganac Corps and the Gundams make a hasty retreat. Heero flies in to the reactor and sets the self-detonation for the Wing Zero. But Zechs intervenes and slices up the reactor, promising that they'll see each other again. Blowing up just about 85% of the ship, the leftover chunk was slowly falling to Earth. But, the Twin Buster Rifle of the Wing Zero still had some ammo in it and Heero used it to blast it to bits. It was successful, and the Wing Zero flew out of the blast, never stopping.