Xionis

Jeb's last pic just as you're about to hit the runway = amazing. "LANDING? OMG SWEET, WE'VE NEVER DONE THIS BEFORE! FIRST!" *Bill in mission control quietly facepalms.*

If you use the symmetry option (One of the buttons under the parts list in VAB), the parts will all be EXACTLY the same height and spaced correctly (for the most part...complicated builds can get wonky). But say 4x symmetry and angle snap and you should be golden!

You are correct if negative mass is both inertial and gravitational. I was under the impression we were only calculating with inertial mass however. I don't think KSP models it this way (rockets do not have their own gravity, no matter how slight.) Pretty sure it uses simply inertial mass in it's calculations. And that would cause the rocket to fly away from the center of gravity that was affecting it.

Psh, Kerbals don't die, they just uh... experience a permanent reassignment to elsewhere.

@falofonos That point wasn't antigravity drive, it was "How does the game handle negative mass?" And the conclusion is "It dodges it's calls like a bitchy ex girlfriend and pretends it doesn't exist."

I'm guessing it's a safeguard in the physics engine against lots of very bad things that can happen w/ negative mass. Edit in reply to Temstar above me: The equation for gravitational attraction between two bodies is F = ( G * m1 * m2) / r^2 G is a constant, the m's are the bodies masses and r is the distance between them. There isn't a thing as "negative gravitational fields" except as would result from a very large negative mass. That force (when the masses are both positive) simply pulls the two objects towards each other. Reverse just 1 of the masses to negative, and the force pushes both object away from each other. Make BOTH masses negative and once again they get pulled together. Negative mass planets could totally exist by this math (ignoring all the other problems...) but would need to orbit negative mass stars and on and on etc etc. We're just experimenting with a tiny negative mass (relative to a planet) and what it should be doing in a gravity well (i.e. zoom off into space on it's own).

If both objects were negative mass, they would behave normally with each other (the -'s cancel out when you add 2 of them to the gravity equation). Making the mass negative means a normal equation of Force = mass * acceleration get's it's sign changed. Normally you get (Negative Force) = regular mass * (negative gravity). Make it negative mass and it becomes (Positive force) = (negative mass) * (negative gravity).

If the mass counts as negative inertial mass, than any force vector will cause it to behave the opposite regular mass would. Gravity causes a force vector towards the center of the gravity well (center of the planet in this case) causing normal matter to cling to it's surface. Negative mass would instead fly off away from the well, or, out into space, it's acceleration dropping the further it got from the planet.

Remember that if you are sitting in you computer chair "not moving" the only reason is the chair/floor/building/earth is pushing UP on you with the same force gravity is pulling DOWN. Take away the chair and you begin moving quite handily towards the floor thanks to gravity. F = ma is the equation the OP is trying to play with here, by making m negative, it reverses the normal direction of gravity (gravity being -9.8m/s2 assuming UP is positive and DOWN is negative). So an object with negative mass should fly AWAY from the gravity well at whatever appropriate acceleration, no initial movement necessary. UNLESS: 1) Physics engine is going "what, negative mass...that can't be right" and having it's brain blown/ignoring it for avoiding brain blowing. or 2) Your total ship mass is still positive. Are you testing only that 1 part with negative mass? Or did you add some regular, physics obeying bits too and they took the ship back into positive?

First kerbal to break orbit. Bill Kerman. Broke orbit so hard he left the solar system. (Technically not dead yet but seriously how much food could their be in that 1 man pod....)

Jesse Cox did a Fan Friday video of KSP. He killed some kerbals and exploded some rockets, I was sold.