Her astronaut husband, Mark Kelly, is the commander of the space shuttle.
This will be the first time Giffords has traveled since being flown from Tucson to Houston more than three months ago.
Giffords was shot in the head at point blank by a gunman during a public appearance in Tucson, Ariz., in January. Besides the congresswoman, six people were killed and 13 were wounded.
Giffords has undergone extensive therapy and is now cleared to travel.
"Medically, there is no reason she could not travel safely to Florida to participate in this incredible event with her husband," said Dr. Dong Kim, director of the Mischer Neuroscience Institute at TIRR Memorial Hermann.
She will be accompanied by staff from a rehabilitation center on her trip to the Kennedy Space Center, according to her doctors. Giffords' staff says she'll watch with other families out of public view, and then return to Houston to finish her rehabilitation.
Giffords' husband has been by her side from the beginning and has been hopeful for weeks that she would be able to attend.
President Barack Obama and the first family also are scheduled to watch the launch. It's unclear if Giffords' and the president will watch together.
The launch is scheduled for 3:47 p.m. ET Friday.
The Associated Press contributed to this report.