Kerbal Space Program

This is a bug that I really should have gotten around to reporting properly, I've known about it and have mentioned it on the forums many times since March 15th. I should have remembered the bug tracker!

• The actual Service Propulsion System (SPS) of the Apollo C/SM was a small low-efficiency hypergolic engine with 91 kN thrust and a specific impulse of 319 seconds.
• The J-2 rocket engine on the Saturn V was a high efficiency rocket engine with 421 seconds Isp, and 486 kN of thrust.
• The Wolfhound is the in-game SPS analogue. It has an Isp of 412 (which seems to be a typo--421 vs 412?) seconds and a thrust of 375 kN.
• The Skiff is the in-game J-2 analogue. It has an Isp of 330 seconds and a thrust of 300 kN--barely better than the LV-T30 Reliant. The in-game description describes it as having "high vacuum efficiency" and as being "powerful."

It seems obvious that a simple mistake has resulted in these engines having the wrong stats. This simple mistake means that building a physically correct Apollo/Saturn V rocket using the correct engine models is harder than it should be, and all ships built with these engines are unauthentic.