Term
| Key advantages of minimizing J |
|
Definition
| Key advantages: you do not need all eigenvalues/eigenvectors, only need the maximum eigenvalue and its eigenvector, easy and fast methods for finding that eigen pair. |
|
|
Term
| What are the axes of rotation? What does energy dissipation do to the axes? |
|
Definition
| Major axis (x) stable, intermediate axis (y) unstable, minor axis (z) stable. Makes the minor axis unstable. |
|
|
Term
|
Definition
| The reason for the failure of this satellite was it spun about its minor axis. |
|
|
Term
| What is G2 stabilization? |
|
Definition
| This method is a way of stabilizing a satellite’s orbit by using only the satellite’s mass distribution and the Earth’s gravitational field. |
|
|
Term
| Is G2 stabilization accurate? Why or why not. |
|
Definition
| This stabilization method is not accurate because spacecraft can flip over, and needs extra payload mass due to the “boom” mass. |
|
|
Term
| Is the moon G2 stabilized? |
|
Definition
|
|
Term
| What is dual-spin stabilization? |
|
Definition
| stabilization method of having the spacecraft contain two parts: one that spins relatively fast, and the other spins slow or not at all. It allows satellites to spin stably about its minor axis. |
|
|
Term
| The name of the first satellite to be dual-spin stabilized. |
|
Definition
|
|
Term
| What happened to Polar BEAR? |
|
Definition
| It inverted its stabilization because of solar heating on the boom mass. |
|
|
Term
| What was the first spin-stabilized satellite? |
|
Definition
|
|
Term
| What is 3 axis stabilization? |
|
Definition
| Three-axis stabilization is a method of keeping all 3 axes pointed in specific directions. |
|
|
Term
| What is magnetic stabilization? |
|
Definition
| Magnetic Stabilization is a method of creating a torque due to the movement through the Earth’s magnetic field to increase or decrease the spin of a satellite. |
|
|
Term
| In particle model analysis, what motion(s) is/are of interest? |
|
Definition
|
|
Term
| In rigid body analysis, what motion(s) is/are of interest? |
|
Definition
| translational and rotational |
|
|
Term
| Inertia matrices are always... |
|
Definition
|
|
Term
| All eigenvalues of real symmetric matrices are ____ and all eigenvectors of real symmetric matrices are _____. |
|
Definition
| real;real and mutually orthogonal |
|
|
Term
| What is the significance of inertia matrices being diagonal? |
|
Definition
| the axes in which it is expressed are principal axes. |
|
|
Term
| (T/F) If a rigid body has 3 axes of symmetry, then those are the principal axes. |
|
Definition
|
|
Term
| (T/F) A rigid body's principal axes are always its axes of symmetry. |
|
Definition
|
|
Term
| Normalizing eigenvectors makes them... |
|
Definition
|
|
Term
| What is the Change of Basis Theorem? |
|
Definition
| It can be used to verify that for principal axes the inertia matrix is diagonal. |
|
|
Term
| (T/F) Angular momentum and energy are constant for asymmetric torque free rigid body. |
|
Definition
|
|
Term
| (T/F) Longest axis corresponds to SMALLEST PMOI (principal moment of inertia). |
|
Definition
|
|
Term
| What do the directions of the orbital frame correspond to? |
|
Definition
| o3 axis is nadir direction, o2 axis is negative orbit normal direction, o1 axis completes frame. |
|
|
Term
| The motion of the satellite’s center of mass motion around Earth’s center applies to... |
|
Definition
| Translational equation (Newton's Equation). |
|
|
Term
| satellite’s rotation around satellite’s center of mass applies to... |
|
Definition
| Rotational equation (Euler's equation). |
|
|
Term
| What is required for G2 stabilization? |
|
Definition
| A body fixed ref. frame, and a long boom. |
|
|
Term
| Why are the equilibrium solutions for Euler's equations hard to solve? |
|
Definition
| angular velocity is of the body frame with respect to the inertia frame, o3 is a column vector made by projecting o3hat onto body axes, and these equations are nonlinear. |
|
|
Term
| (T/F) You need small angle assumptions to find equilibrium solutions. |
|
Definition
|
|
Term
| (T/F) You do not need small angle assumptions to find equilibrium solutions. |
|
Definition
|
|
Term
| You do not need all eigenvalues/eigenvectors, only need the maximum eigenvalue and its eigenvector, easy and fast methods for finding that eigen pair are key advantages of what? |
|
Definition
|
|
Term
| Minor axis becoming unstable is due to... |
|
Definition
|
|
Term
| This satellite failed due to spinning about its minor axis. |
|
Definition
|
|
Term
| This stabilization method is a way of stabilizing a satellite’s orbit by using only the satellite’s mass distribution and the Earth’s gravitational field. |
|
Definition
|
|
Term
| This stabilization method is not accurate because spacecraft can flip over, and needs extra payload mass due to the “boom” mass. |
|
Definition
|
|
Term
| This stabilization method has the spacecraft contain two parts: one that spins relatively fast, and the other spins slow or not at all. It allows satellites to spin stably about its minor axis. |
|
Definition
|
|
Term
| What is the significance of TACSAT I? |
|
Definition
| The first satellite to be dual-spin stabilized. |
|
|
Term
| What is the name of the satellite that inverted its stabilization because of solar heating on the boom mass? |
|
Definition
|
|
Term
| What is the significance of Syncom 3? |
|
Definition
| It was the first spin-stabilized satellite. |
|
|
Term
| What is the name of the stabilization method of keeping all 3 axes pointed in specific directions? |
|
Definition
|
|
Term
| What is the name of the stabilization method of creating a torque due to the movement through the Earth’s magnetic field to increase or decrease the spin of a satellite. |
|
Definition
|
|
Term
| (T/F) If a rigid body has 3 axes of symmetry, then those are NOT the principal axes. |
|
Definition
|
|
Term
| (T/F) A rigid body's principal axes are NOT always its axes of symmetry. |
|
Definition
|
|
Term
| How do you create orthonormal eigenvectors? |
|
Definition
|
|
Term
| (T/F) Angular momentum and energy are NOT constant for asymmetric torque free rigid body. |
|
Definition
|
|
Term
| (T/F) Longest axis corresponds to LARGEST PMOI (principal moment of inertia). |
|
Definition
|
|
