Mass Properties

Use the SOLIS Mass Properties tab to specify the mass and the mass moment of inertia matrix for the simulated spacecraft. All parameters on this page are "dry", i.e., without propellant. The Mass Properties tab is broken into two sections:

Main UI

Spacecraft Mass Properties

The entries on this tab specify the mass properties used by the flight software for the simulated spacecraft. Select Use STK Values to use the STK Mass Property values. STK Mass Properties are located on the following STK property pages:

  • Satellite's Basic -> Mass properties
  • HPOP Propagator Properties -> Force Models -> More Options
  • Astrogator's properties -> Initial State Segment -> Spacecraft Parameters tab
ODySSy (Truth Model) Mass Properties

Select the Override these values for the ODySSy Model check box to specify other mass and/or mass moment of inertia values to be used in the ODySSy simulation than are assumed by the spacecraft flight software. Selecting this option allows mass property errors to be simulated.

To model errors in the mass property parameters, use the ODySSy Mass Properties tab.
Parameter/Control Description Units
Use STK Values Copies the mass properties from the STK spacecraft properties. (requires STK Pro License) N/A
Dry Inertia Matrix (BDY CM) This is a 3x3 matrix representing the mass moment of inertia tensor about the spacecraft CG in the BDY frame. Spacecraft mass moments of inertia are assumed constant during a SOLIS run unless modified using MISC_CONFIG_PARSE.

IYX, IZX, and IZY are dimmed and cannot be specified directly because the inertia tensor requires a symmetric matrix. If the IDEAS CAD package is being used to generate the values being entered into the Inertia Matrix dialog, the off-diagonal terms (IXY, IXZ, and IYZ) must be negated before they are entered. This is a known difference of convention between SOLIS and the IDEAS CAD package.		 kg*m2
Dry Spacecraft Mass This is a user-specified scalar value representing the total dry mass of the spacecraft. Dry spacecraft mass is assumed constant during a SOLIS run unless modified via MISC_CONFIG_PARSE. Mass must be positive and nonzero. kg
Dry Spacecraft CG (BDY) Location of the dry spacecraft's center of gravity relative to the body frame. m