Rover 1 is the designation number of the 1st Ares Rover in every mission. Rover 1 is the first rover to be landed on Mars during the pre-supply missions before every Ares mission. The first pressurized rover to be landed on Mars was in 2029 with the Ares I mission.
The most famous pressurized Rover was the pressurized rover form Ares III. The Ares III Rover 1 was used as a trailer to carry all of Mark Watney's life support systems so he could use Rover 2 to drive, while on his way to the Ares IV landing site in Schiaparelli crater.