Scene Context: After the carabiner shatters, Sarah continues drifting away from the ship, even though the cover has disconnected from her.
Essence of the Phenomenon: Once a body has acquired velocity, disconnecting from the source of the jolt does not cancel the acquired momentum. In a vacuum, where there is no medium to dissipate it, the body continues moving due to inertia.
Scientific Basis: This is a direct consequence of the law of conservation of momentum. The carabiner shatters, the tether breaks its structural link with the hull, but the velocity gained at the moment of the jolt now belongs to the astronaut. From that point on, it can only be altered by their own maneuvering module or an external impulse.
Current Limitations: In open space, even a relatively minor separation velocity is critical if it exceeds the correction budget available to the emergency system.