# What is gimbal lock Apollo 13?

## What is gimbal lock Apollo 13?

In gimbal lock, the outer gimbal moves with the spacecraft to a point where it is parallel to the inner gimbal (pi/2) and in such a case all gimbals will be in the same plane. So, will not be able to re-align itself to the basic plane in order to resume a normal orientation.

## Can you recover from gimbal lock?

It is in gimbal lock. To recover from gimbal lock the user has to go around the zenith – explicitly: reduce the elevation, change the azimuth to match the azimuth of the target, then change the elevation to match the target.

Thus if the gimbals “lock” together, you no longer have the ability to tell your orientation and thus your ability to navigate is ruined.

Why is it called gimbal lock?

The name “Gimbal lock” is the loss of one degree of freedom in a three-dimensional, three-gimbal mechanism. This happens when the axes of two of the three gimbals are driven into a parallel configuration, in other words, “locking” the system into rotation in a degenerate two-dimensional space.

### How do you read quaternions?

Quaternions are an alternate way to describe orientation or rotations in 3D space using an ordered set of four numbers. They have the ability to uniquely describe any three-dimensional rotation about an arbitrary axis and do not suffer from gimbal lock.

### Why do quaternions avoid gimbal locks?

Quaternion can uniquely identify a rotation, but when it is converted into euler rotation, it loses one degree of freedom information. Quaternions are easier to work with than matrices and using quaternions helps to avoid gimbal lock problem like in case of Euler angles usage.

How do Euler angles work?

The Euler angles are three angles introduced by Leonhard Euler to describe the orientation of a rigid body with respect to a fixed coordinate system. They can also represent the orientation of a mobile frame of reference in physics or the orientation of a general basis in 3-dimensional linear algebra.

How do you stop a gimbal lock?

The only way to avoid gimbal lock is to use quaternion instead of euler to represent rotations. In this specific situation, unless both rotate manip and direction manip use quaternion, the gimbal lock behavior can NOT be avoided.

#### Are quaternions a field?

The quaternions almost form a field. They have the basic operations of addition and multiplication, and these operations satisfy the associative laws, (p + q) + r = p + (q + r), (pq)r = p(qr). The only thing missing is the commutative law for the multiplication.

Why is quaternion used?

Unit quaternions, known as versors, provide a convenient mathematical notation for representing spatial orientations and rotations of elements in three dimensional space. Specifically, they encode information about an axis-angle rotation about an arbitrary axis.