Vector Engine

The KS-25 'Vector' engine brings real-life RS-25 heritage to Kerbal launch vehicles.

The Vector Engine is a specific in-game component within Kerbal Space Program that serves as a real-world analogue to the RS-25 engine. Identified by its designation as the KS-25, this engine represents the game's integration of authentic aerospace hardware into its pseudorealistic physics environment. Developed as part of the core experience, it allows players to construct vehicles capable of performing complex orbital maneuvers such as Hohmann transfers and rendezvous. While the game features a scaled-down solar system with high-density planets like Kerbin, the Vector Engine provides the necessary thrust to escape gravity wells using Newtonian dynamics.

Lore & Background

The development of the Vector Engine within the game's universe is tied directly to the broader history of the Kerbal space program. As players progress through technology trees, they unlock parts based on real-life hardware, including this specific engine. It stands alongside other historical analogues like the Probodobodyne Stayputnik (Sputnik 1) and the Mk1-3 Command Pod (Apollo command module). The inclusion of such parts allows for the implementation of historical missions, such as the Apollo Moon landing or the Artemis II manned moon mission, within the game's sandbox, science, or career modes. These components are not merely aesthetic; they function with real-world physics logic, requiring players to manage thrust and fuel carefully to avoid structural failure or lack of propulsion.

Reader's Guide

To effectively use the Vector Engine (KS-25), players should place it on the lower stages of their rockets where high thrust is needed to overcome Kerbin's gravity. The engine features gimbal capability, which allows for precise steering via the Stability Assist System (SAS) or manual control. Because the game uses patched conic approximation rather than n-body simulation, orbital mechanics are stable but lack perturbations; thus, precise node plotting is essential.

Players must ensure they have enough fuel to reach orbit, as running out of propellant before achieving sufficient altitude will result in a failed mission. Additionally, since joints have limited strength, stacking too many heavy components or applying excessive torque can lead to catastrophic structural failure. For interplanetary travel, the engine helps achieve escape velocity, after which players must time their transfers correctly using the map interface.

Did You Know?

Kerbin's radius in the game is only 600 kilometres, approximately one-tenth that of Earth.
To compensate for Kerbin's small size, its density is approximately 8.3 g/cm³, about 1.5 times that of Earth.
The game was released out of beta on 27 April 2015 after beginning in Steam Early Access on 20 March 2013.

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