Find out more about the Ultra-Mech is a mission in Ratchet & Clank. Ratchet bought an Infobot containing an advertisement for the Ultra-Mech Unlimited on planet Quartu, as well as coordinates, which prompted Ratchet to decide to find out more.
Go down the nearby slope from the landing pad, ignoring the entrance to the robot factory that a Sentry-bot is guarding, as you cannot enter yet. Get rid of any Chompers nearby and turn left to deal with two plasmabots guarding an unfinished bridge. Use the Swingshot to get across, turning right while destroying more Chompers and plasmabots. Use the various structures along this curving path to your advantage by using them as cover from the plasmabots' attacks. Enter a building at the end of the path, turning right to talk to an Ultra-Mech Scientist, ending the mission and continuing straight into "Destroy the Ultra-Mechs".