Limits

Limits

• Built and tested on KSP 1.12.5 for macOS with both expansions, in a stock install.
• Aiming in an atmosphere needs to start from orbit. With parachutes alone it predicts the drag and has been flown once, with a capsule on Kerbin (252 m off). Where the engine has to do the braking it has been flown on Duna with one lander (43 m); Eve and Laythe, heavier craft and weaker engines are untried.
• Thin-air landings are safe rather than frugal: about 730 m/s on Duna, aimed, for a lander a careful pilot could put down for less.
• Landing a big upper stage on its engine. With the stock Kerbal X in an 80 km orbit, land (aimed at the space centre, no stage) kept the whole upper stage, since it has landing legs, and planned to brake on its engine from 942 m/s to a stop 2.5 km up; it hit the ground at 384 m/s (Windows, 2026-10-10). With stage: true it dropped to the capsule and landed under the parachute. Why (found 2026-10-18): the stage's engine is a Poodle, 250 kN in a vacuum and 64 kN at sea level (its thrust goes with its Isp, 350 s and 90 s), under some 15 t; the braking was planned on the thrust the engine had high up, and near the ground it gave about a quarter of it, too little even to hold the stage up. Since then every braking decision (when to begin, how hard, whether the engine can land the craft at all) is planned on the thrust the engines will have at the landing site's air pressure, never more than they give now, while the throttle is still set on what they give now; where they could not hold the craft up there, the landing ends at once, before the burn, saying so and what to do (come down under parachutes with stage: true, or land where the air is thinner), and an entry with parachutes goes on under them. The re-entry's hand-over to the engine counts on the same. On airless worlds nothing changes. Tried in the game (2026-10-18, Mac): the Kerbal X's upper stage alone (15.2 t, the Poodle) put 20 km over the sea and told to land: refused at once, "the engines give 64.3 kN where the vessel would land (250 kN in a vacuum...)", 4.2 m/s² against the 9.8 that holding it up takes.
• Time warp on the ground now always runs on rails. Before that was fixed, a long 4x physics warp tipped the Duna lander over where it stood.
• The voice edition has been run on macOS and, since 2026-10-10, on Windows 11: its setup script (setup_voice.ps1) installed the speech models there; the ship said lines in the game with Windows' own voice and with Kokoro; and lines Kokoro spoke into a file were written down by Whisper word for word (about 0.7 s a line) and taken by the game as heard speech. On Windows the microphone was opened and read (levels only); nobody spoke to it. Nothing of it has run on Linux, where the fallback voice is written and was checked by reading. With the Claude Code command line as the brain for the terminal listener (ksp_voice.py listen --brain claude), two questions asked one after the other were each answered from the game in 3 to 5 seconds, the second as part of the same conversation. The wake word (--trigger open) was checked on a recording of the phrase, not through a microphone. Nobody has listened to it: that the game plays the lines and that a recogniser understands them was checked, how it sounds was not.
• The planner for small local models was tried with one model, qwen3:8b, on eleven requests in made-up situations, and flown in the game for one of them (see A model on your own computer). Other models and longer missions are untried.
• Aircraft means fixed wings and wheels: no helicopters, VTOL or seaplanes. The terrain watch looks about three minutes ahead along the track; it warns, but cannot help, when the ground rises faster than the aircraft can climb. Runway data for the KSC and the island airfield was measured in the game; other strips need their coordinates and heading.
• Rovers find their way round what they can see a few tens of metres ahead. There is no map, so a large enclosed area can still box one in; it then stops and reports.
• Docking was tested with small craft and Clamp-O-Tron ports. A target turning faster than about 12 degrees a second is refused.
• EVA: boarding on foot needs rungs all the way from the ground to the hatch (the test craft's first ladder stopped 0.9 m short, and the kerbal said so). Construction mode and repairs are not covered.
• The builder shapes fairings (a shell that follows its payload's outline, and interstages) but does not set up robotic parts. Parts a mod reshapes while the game runs (procedural parts, B9PartSwitch) are placed by the shape they come in: none is installed here but the plume switch StockWaterfallEffects adds to the Mammoth and the Vector through B9PartSwitch, which changes only the look of the exhaust.
• How long one tool call may run was measured with the tools attached to Claude Code in the Claude desktop app (the client names itself claude-code): single calls of 100, 300, 600 and 1200 seconds all ran to the end, so there is no limit there up to at least twenty minutes. Other clients have not been timed; the server assumes 45 seconds for a client it has not seen and measures the real figure on first use (ksp_call_limit shows it). Flight plans do not depend on it either way.