Stranded Kerbals are a common, often humorous, challenge in Kerbal Space Program (KSP). Whether your Kerbals are adrift in orbit or marooned on the Mun’s surface, selecting the right engine for your rescue mission is crucial for success. The “Best Engines” aren’t always about brute force; efficiency and suitability to the specific scenario play vital roles. This guide will explore the top engine choices to bring your Kerbal astronauts home safely.
Top Engine Choices for Orbital Rescue
Orbital rescues are generally less demanding in terms of delta-V compared to surface missions. In space, efficiency is king, making engines with high specific impulse (ISP) ideal. For these scenarios, several engines stand out as the “best engines” due to their excellent vacuum performance.
The Terrier engine (1.25m) is a fantastic all-around vacuum engine. It provides a high ISP, making it fuel-efficient for orbital maneuvers. Its thrust is sufficient for smaller rescue vessels, and its compact size makes it versatile for various spacecraft designs.
Stepping up in size, the Poodle engine (2.5m) offers a significant thrust increase while maintaining a high ISP. It’s a robust choice for larger rescue ships or when you need more power for quicker burns. The Poodle is a reliable workhorse for interplanetary travel and large orbital maneuvers, making it one of the “best engines” for more ambitious rescue operations.
For players with the Making History DLC, the Cheetah engine (1.875m) presents an excellent mid-range option. It bridges the gap between the Terrier and Poodle in both size and performance. The Cheetah delivers a high ISP and a thrust level that’s more than the Terrier but less than the Poodle, offering a balanced performance profile that can be considered among the “best engines” for medium-sized rescue missions.
When designing your orbital rescue craft, consider using a Mk1-3 pod for crew capacity and heat protection during re-entry. Pairing it with a passenger cabin can accommodate more Kerbals. Including a probe core within a service bay allows for unmanned control, and a heat shield with ablator is essential for safe atmospheric re-entry.
Selecting Engines for Surface Rescue Missions
Rescuing Kerbals stranded on the surface, like on the Mun, presents additional challenges. Surface missions require significantly more delta-V to land and return, and the engine needs sufficient thrust-to-weight ratio (TWR) for landing. While pinpoint landings are ideal, they aren’t always guaranteed.
For Mun surface rescues, the engines mentioned for orbital rescue – Terrier, Cheetah, and Poodle – can still be effective, especially for the return trip from the surface to orbit. However, for the landing stage, thrust becomes more critical. You may need to augment these engines with additional stages or consider engines with higher thrust for landing if your rescue vessel is heavy.
A practical approach for surface rescues, especially if landing accuracy is a concern, is to send a small rover along with your rescue ship. This rover can retrieve the stranded Kerbals, eliminating the need for a precise landing directly at their location.
An alternative, albeit riskier, method for surface rescue involves using external command seats to transport Kerbals. This dramatically reduces the weight of the rescue craft, making it easier to lift off and maneuver. However, exposing Kerbals to the elements and re-entry heat is a significant risk. Enclosing external seats within a service bay might offer some protection, but caution is advised.
Considering Specialized Engines: NERV, Wolfhound, and Rhino
While Terrier, Poodle, and Cheetah are often the “best engines” for standard rescue scenarios, it’s worth briefly considering other specialized engines in KSP.
The NERV engine (Nuclear Engine for Rocketry, LV-N) boasts the highest ISP of any rocket engine in KSP. However, it is heavy and uses only liquid fuel, restricting fuel tank choices. For missions requiring extremely high delta-V, the NERV can be advantageous, but for typical rescue missions needing less than 4500m/s delta-V, the Terrier is usually a more efficient and lighter option.
The Wolfhound engine (from Making History DLC) is another high-ISP vacuum engine. It offers a good balance of ISP and thrust, making it a strong contender as one of the “best engines” for vacuum operations. However, it is heavier for its thrust compared to the Poodle. Use the Wolfhound judiciously when its higher ISP outweighs its heavier mass penalty.
Finally, the Rhino engine is a massive engine with immense thrust. While its ISP is respectable, its sheer size and weight make it overkill for most rescue missions. The Rhino is designed for launching very large payloads and is generally not among the “best engines” for efficient rescue operations.
Conclusion: Choosing the Right Engine for Rescue
Selecting the “best engines” for your Kerbal Space Program rescue missions depends heavily on the specific situation. For efficient orbital rescues, the Terrier, Poodle, and Cheetah engines provide excellent ISP and a range of thrust options. Surface rescues may require more thrust for landing, but these engines are still viable, especially when combined with smart mission design like rover deployment. Understanding the strengths and weaknesses of each engine allows you to effectively bring your stranded Kerbals home, showcasing that in KSP, the right engine choice is key to a successful rescue.
