|Out of universe information|
Mentioned in "The Prodigal"
Major Nelson was a Tau'ri and member of the Atlantis expedition. When Michael Kenmore invaded Atlantis in 2008, he used Major Nelson's IDC to gain access. It is not known if Major Nelson is alive or not. However, it would be possible that Michael could have converted both Nelson and his team into his hybrid soldiers to help him accomplish his mission. (ATL: "The Prodigal")