The Earth Cargo Service freighter on which Travis Mayweather was born and raised.
The ECS Horizon was an Earth Cargo Service Y-class freighter of the 2150s and the boyhood home of Travis Mayweather, who was born aboard. After his father died, Travis visited the ship in 2153 during the Xindi crisis.
He found the ship now commanded by his brother Paul, who resented Travis for leaving, and the Horizon soon came under attack by raiders. Travis helped rig the old freighter's defences to drive off the attackers, and he returned to Enterprise having made peace with his brother.