|Title||Exploration and Evaluation Corps|
|Affiliation||Federated Sentient Planets|
|Notable appearance||"The P.E.R.N. Survey"|
Castor was the leader of the Exploration and Evaluation Corps team that explored Pern. He was hurt during one planetary exploration, injuring his legs. When the team reached Pern, he was forced to remain on board ship, coordinating the landing team's reports.