Changing rotation of spacecratft or object

[jeff@nasaames]

I noticed that the Impactor (from Deep Impact) I have, rotates around an outside centerpoint versus rotating around its center.

I looked in the .ssc file for Deep Impact, but I don't know which variable controls the spin. I would appreciate any help I can get.

Cheers,
Jeff

[Chuft-Captain]

Jeff,

Generally this would be controlled by RotationPeriod (expressed in hours), however though I'm not familiar with the Deep Impact addon, from your description of an external centerpoint, I suspect it may have been implemented as an orbit around an invisible object.
Look for something like this in the SSC file:

Code: Select all

"Impactor" "<Name of Invisible Object>"
{
 ...
Period
.....
}

If that's the case, then the rotation speed is determined by the "Period" statement. (NOTE: units will be in years, not hours in this case)

[ElChristou]

..or perhaps the center should be reajusted with:

Code: Select all

MeshCenter [ 0 0 0 ]

(you will have to find out the coordinates)
In that case, the model should perhaps also be reoriented...

[Chuft-Captain]

BTW Jeff,

Is this suposed to be a realistic scenario? What I don't understand is how an object (presumedly in free space) can rotate around an external centerpoint which cannot possibly be it's center of mass.

[Vincent]

Jeff,

Jestr often builds his models into invisible spheres. I noticed that when I wrote the Deep Imapct Mission script. The impactor probably rotates around the sphere center instead of the impactor's center...