During the 2150s, when transporter technology was still in its infancy, many people – including Starfleet officers – were hesitant to use the transporter despite the fact that it had been approved for bio-transport. According to Travis Mayweather, Captain Jonathan Archer himself even feared putting his dog through the transporter. (ENT: "Broken Bow") By 2155, the crew of Enterprise were getting more comfortable with the transporter and hence were not quite as reluctant to use the device. (ENT: "Demons")