Samantha Carter (Continuum reality I)

Samantha Carter was a NASA astronaut and Mission Commander aboard the Instrepid space shuttle. She was an alternate version of Samantha Carter due to the alteration of the timeline initiated by Ba'al. She died on 2004 when she sacrificed herself to save her crew.

Biography
This alternate Carter was hired by NASA and became an astronaut and later Mission Commander of the space shuttle Intrepid. In 2004, following a computer failure aboard the ship, which shut off the main engines, Carter stayed behind to replace the failed autopilot while Intrepid crew were able to escape and be safe. Intrepid went down from orbit over the Atlantic Ocean and Carter's body was never found. She had a national memorial service on the front lawn of the White House where General Hank Landry was.

(2008, alternate timeline)
After Ba'al came in 1939, sank the Achilles and modified the timeline, Colonels Cameron Mitchell and Samantha Carter, and Dr. Daniel Jackson are trapped in the North Pole. When Colonel Jack O'Neill of the Special Forces retreives them, he is surprised to see Mitchell, walking in the middle of the Artic with a dead astronaut (Daniel was left behind because of a frozen leg). Aboard the submarine Alexandria, the Commander Officer asks O'Neill if Carter is the one. O'Neill replies if it isn't, it is her twin sister.

Later, in the Elmandorf Air Force base, Carter is interviewed by an employee who reveals to her the fate of "their" Samantha Carter. Later again, a retired General Landry comes and visits the three teammates and tells Carter he was present at her memorial service on the front lawn of the White House. He thinks Carter might be an extraordinary person whatever the timeline she might be in.