Defilement of Honour Space Hulks do not usually move under their own power, the winds and tides of warpspace usually determine the course of these derelict clusters of ships. The Defilement of Honour was different, being equipped with a functioning engine room of sorts, as well as an ancient navigational device in control of its course.

Defilement of Honour 
 
Space Hulks do not usually move under their own power, the winds and tides of warpspace usually determine the course of these derelict clusters of ships. The Defilement of Honour was different, being equipped with a functioning engine room of sorts, as well as an ancient navigational device in control of its course. The Blood Angels knew that the Defilement of Honour only represented a threat as long as it was under its own power. If the engines were shut down and its progress through the Warp would stop, the Space Hulk could then be examined and then destroyed. 
 
Further scans of the ship provided details of the internal configuration of the vessel and the number of Genestealers present. There appeared to be two separate groups of aliens, at different ends of the Space Hulk. 
 
Sergeant Avernus was charged with command of a small strike force, just two squads, sent to seal the passages between the computer area and the engines. He felt honoured to be chosen for such a vital mission and swore that he would be victorious or die trying.

Good Game Database

Space Hulk - Defilement of Honour Campaign Achievements