Anne McCaffrey's Brainships Series

The Brain & Brawn Ship series

The Brain & Brawn Ship series comprises seven novels, only the first of which (a fix-up of five previously published stories) was written by McCaffrey alone.[49] The stories in this series deal with the adventures of "shell-people" or "Brains", who as infants (due to illness or birth defects) have had to be hard-wired into a life-support system. With sensory input and motor nerves tied into a computer they serve as starship pilots (or colony administrators), seeing and feeling the colony or ship as an extension of their own body. They perform this job to pay off their debt for education and hardware, and continue as free agents once the debt is paid. To compensate for the Brains' inability to move within human habitats they are paired with partners known as "Brawns", who are trained in a wide array of skills (including the protection of their Brain counterparts). It was considered impossible for a person to adjust to being a shell after the age of two or three. An exception, in The Ship Who Searched, was a shell-person who was seven when she became quadriplegic.
The Ship books are set in the same universe as the Crystal Singer books; Brainship-Brawn pairings were also characters in the second and third volumes of that series.

The Ship Who Sang (1969) (fix-up of stories from 1961, 1966, and 1969) ISBN 978-0-345-33431-2
PartnerShip (1992) with Margaret Ball, ISBN 978-0-671-72109-1
The Ship Who Searched (1992) with Mercedes Lackey, ISBN 978-0-671-72129-9
The City Who Fought (1993) with S.M. Stirling, ISBN 978-0-671-87599-2
The Ship Who Won (1994) with Jody Lynn Nye, ISBN 978-0-671-87657-9
This series also includes solo entries by Stirling and Nye:
The Ship Errant (1996) by Jody Lynn Nye, ISBN 978-0-671-87854-2
The Ship Avenged (1997) by S.M. Stirling, ISBN 978-0-671-87861-0

Wikipedia Link