The TARDIS is then piloted to a Berthing Bay in the Dry Dimension Dockyard Cradles on Gallifrey and registered. Each Berthing Bay contains rows of Berthing Cradles, each capable of holding one TARDIS when it is not in use. There are hundreds of TARDISes on Gallifrey and it is possible for a Gallifreyan (with the Rassilon Imprimature) to purchase one. Even though all full Time Lords have a TARDIS assigned to them they must still obtain authorization before using it on a mission. Most TARDISes are designed to serve as mobile research laboratories and it takes a team of 6 researchers to make full use of TARDIS's capabilities. For this reason they rarely travel in groups. It is common for only a couple of TARDISes to be off Gallifrey at any given time.