The Isambard MMD is a fully automated mining vehicle found on the 3rd planet the player is sent to: Danopth. The player has to destroy it when it begins a collision course with the base by causing the oxygen storage tanks to explode as it passes by overloading them with methane.
This is the first Defense Assignment that the player undertakes.
On the final assignment on Danopth Joel orders the player to destroy the mining robot when he discovers that it is unable or unwilling to respond to the commands that he sends in an attempt to make it deactivate itself.
Planet Danopth, mission A Most Unfortunate Malfunction.