Propulsion system

A propulsion system is a device within a space station that produces a thrust to push the station through space. This system was used with both the BOTTLE SHIP and the Biologic Space Laboratories research station.

Metroid: Other M
As she is approaching Sector Zero, Samus Aran feels the BOTTLE SHIP rumble as its propulsion system is activated. This confuses her, as the ship was thought to be derelict. She continues on.

At the entrance, she is shot by Adam Malkovich, disabling her Power Suit and leaving her temporarily paralyzed. After he explains the unfreezable nature of the Metroids contained in Sector Zero, Adam gives Samus several missions. He remarks that the BOTTLE SHIP is on course to intercept Galactic Federation Headquarters, which he believes to be the catalyst for an attack by MB, the BOTTLE SHIP's rogue AI, against the Galactic Federation. He asks Samus to divert the ship off this course, as well as to save a survivor in Room MW and destroy Ridley.

Samus, deciding she still has time, focuses on securing the survivor. This survivor panics and releases a Queen Metroid to kill Samus. Halfway through the battle, the Bottle Ship P.A. Announcer states that the facility is to intercept GF orbit in 30 seconds. Samus, refusing to back down, continues to engage the Queen. As it begins to charge at her, the BOTTLE SHIP grinds to a halt. Samus uses the distraction to kill the Queen. Minutes later, she learns that her colleague Anthony Higgs, thought to have died in the earlier battle with Ridley, is alive. He reveals that he stopped the ship's engines.

Metroid Fusion
The Biologic Space Laboratories research station had a propulsion system as well. Near the end of the game, Samus learned that the Galactic Federation was coming to the BSL to secure the X Parasite for use as a bioweapon, and was ordered to leave. Knowing the danger that the X posed, Samus chose to disobey these orders and use the ship's self-destruct mechanism to destroy the X, the station, and if necessary, herself. The computerized Adam points out that the X on SR388, the planet the station was orbiting, would still be alive, and Samus would only succeed in destroying the "one obstacle to the galaxy's ruin"; herself. It suggests that she activate the propulsion sequence instead, so that the X Parasite would be completely eradicated. Samus does so and quickly escapes, confronting an Omega Metroid on the way back to her Gunship.