Col. Alexi Vaselov personally requested a transfer to the SGC so that he could become an active member of the Stargate Program, in the episode, 8.03 "Lockdown".
Col. Alexi Vaselov was one of the most highly decorated men in Russian Air Force history, with over 20 years of flight experience. He had received decoration in the Russian's highest order of the Gold Star and recorded over 3,000 hours in 30 different aircraft or their prototypes.
He personally requested to serve at the SGC, and wanted very much to become the fourth member of SG-1 to fill the place left behind by Jack O'Neill's promotion to Brigadier General. Jack, however, did not feel that Vaselov's resume was enough to get him onto the flagship team, or any other team for that matter. He knew that Vaselov had no training to prepare him for stargate travel and he felt strongly that Vaselov go through that training before he put anyone's life at risk. After over 1000 missions through the stargate, it appears that the qualifications for being on an SG team have become more specific as to the type of training a team member receives.
Daniel Jackson befriended Vaselov and tried to make him feel more at home. He wanted the Russian to know that Jack didn't put him onto the team because of any personal dislike, but Vaselov sensed that Jack had a problem with Russians in general. They discussed the fact that Daniel had taken a part in the brokering of an agreement between the Russian and American governments concerning sharing the knowledge and technology gained through the use of the stargate.
When Vaselov became ill as a result of carrying the energy essence of the Goa'uld Anubis, he knew without the medical staff telling him that he was not going to recover. Dr. Brightman told Jack that she didn't give the Colonel more than two weeks to live because Anubis' possession of his body had completely shut down Vaselov's immune system. Because Vaselov knew he was about to die, he wrote a letter to his sister in Bryansk and he wanted Daniel to see to it that the letter was delivered.
After Anubis was successful at getting to the gate room through the use of Jack's body and starting the dialing out to his stronghold (possibly Tartarus), Vaselov decided that he'd offer his body as the host to Anubis so that Jack could live. He bravely sacrificed himself for the good of the many and his body is now frozen on the ice-age planet KS7-535 after Carter was able to divert Anubis' automated dialing sequence before the wormhole was established.
--DeeKayP 11:43, 24 Jul 2004 (PDT)