I made a hacked up ship and flew into several close, nearly circular orbits around the sun. (These were separate runs, because the kraken got me after each one.) Here's my raw data: <table><tr><td></td><td>Apoapsis</td><td>Periapsis</td><td>Velocity</td><td>Altitude @given velocity</td><td>Half-orbit time</td></tr> <tr><td>Orbit 1</td><td>1499999195 m</td><td>1499997471 m</td><td>25797.2 m/s</td><td>1499998333 m</td><td>214501 s</td></tr> <tr><td>Orbit 2</td><td>50110046 m</td><td>50109778 m</td><td>61326.8 m/s</td><td>50109912 m</td><td>15968 s</td></tr> <tr><td>Orbit 3</td><td>10090841 m</td><td>10090173 m</td><td>65688.35 m/s</td><td>10090438 m</td><td>12993 s</td></tr> </table> Running the numbers, Kerbol's radius has to be 261595+-10 km. I figured it's probably a round number, so I used 261600km in the rest of my calculations. I used velocity and semi-major axis for calculating the gravitational parameter, because there's much less error in those numbers than in the period. Based on that, I get mu = 1.172334+-.000001 * 10^18 m^3/s^2. I'm going to go update the wiki now.
