System for determining inertia properties of a rigid body, particularly the inertia tensor, the mass and/or the position of the center of mass, comprising: - a carrier, which is designed for suspending a rigid body from the carrier, such that the rigid body is able to perform movements along the six degrees of freedom of the rigid body corresponding to free vibrations along the six degrees of freedom, wherein the system comprises elastic elements (p), which are designed for suspending the rigid body from the carrier, wherein the rigid body is suspended from the carrier via said elastic elements (p), - as many sensors as degrees of freedom of the rigid body providing output signals for detecting the movement of the rigid body along said number of degrees of freedom of the rigid body,and - a measuring device cooperating with the sensors, wherein the measuring device is configured to measure said movement of the rigid body by means of said output signals ( š l (t k)), which correspond to the translation of the rigid body along the three orthogonal axes and the rotations about these axes as a function of time (t k), characterized by - an analysing means configured for determining from said output signals ( š l (t k)) said intertia properties ( r S) of the rigid body, wherein the analyzing means further uses the following parameters to determine said inertia properties of said rigid body: - the number (N p) of the elastic elements (p), - the stiffness value of the elastic elements (k p), - the lengths (l p) of the unloaded elastic elements (p), - the attachment locations ( ζ a,p) of the elastic elements (p) on the carrier, particularly in space-fixed coordinates, - the attachment locations ( ζ̃ b,p) of the elastic elements (p) on a platform or the rigid body, particularly in body-fixed coordinates, - the orientation of the field of gravity ( ñ g), and - particularly the inertia properties ( r p) of a platform comprised by the system, which platform is designed for suspending the rigid body, wherein the platform is suspended from the carrier via said elastic elements (p) in order to suspend the rigid body from the carrier. - a carrier, which is designed for suspending a rigid body from the carrier, such that the rigid body is able to perform movements along the six degrees of freedom of the rigid body corresponding to free vibrations along the six degrees of freedom, wherein the system comprises elastic elements (p), which are designed for suspending the rigid body from the carrier, wherein the rigid body is suspended from the carrier via said elastic elements (p), - as many sensors as degrees of freedom of the rigid body providing output signals for detecting the movement of the rigid body along said number of degrees of freedom of the rigid body,and - a measuring device cooperating with the sensors, wherein the measuring device is configured to measure said movement of the rigid body by means of said output signals ( š l (t k)), which correspond to the translation of the rigid body along the three orthogonal axes and the rotations about these axes as a function of time (t k), characterized by - an analysing means configured for determining from said output signals ( š l (t k)) said intertia properties ( r S) of the rigid body, wherein the analyzing means further uses the following parameters to determine said inertia properties of said rigid body: - the number (N p) of the elastic elements (p), - the stiffness value of the elastic elements (k p), - the lengths (l p) of the unloaded elastic elements (p), - the attachment locations ( ζ a,p) of the elastic elements (p) on the carrier, particularly in space-fixed coordinates, - the attachment locations ( ζ̃ b,p) of the elastic elements (p) on a platform or the rigid body, particularly in body-fixed coordinates, - the orientation of the field of gravity ( ñ g), and - particularly the inertia properties ( r p) of a platform comprised by the system, which platform is designed for suspending the rigid body, wherein the platform is suspended from the carrier via said elastic elements (p) in order to suspend the rigid body from the carrier. - the number (N p) of the elastic elements (p), - the stiffness value of the elastic elements (k p), - the lengths (l p) of the unloaded elastic elements (p), - the attachment locations ( ζ a,p) of the elastic elements (p) on the carrier, particularly in space-fixed coordinates, - the attachment locations ( ζ̃ b,p) of the elastic elements (p) on a platform or the rigid body, particularly in body-fixed coordinates, - the orientation of the field of gravity ( ñ g), and - particularly the inertia properties ( r p) of a platform comprised by the system, which platform is designed for suspending the rigid body, wherein the platform is suspended from the carrier via said elastic elements (p) in order to suspend the rigid body from the carrier.