MMS Spin Test

The four MMS observatories each undergo what's called a spin test, to learn how well the spacecraft is balanced. Italso provides information on how well the mass properties of an observatory can be measured and aligned. This movie shows Observatory #4 undergoing the test in May 2013 on the MRC Mark V spin balance machine. After launch, the MMS observatories will spin at approximately 3 revolutions per minute during normal operations.