Picometer-stable scan mechanism

Detection and observation of gravitational waves requires extremely accurate displacement measurement in the frequency range of 0.03 mHz to 1 Hz. The Laser Interferometer Space Antenna (LISA) mission will attain this by creating a giant interferometer in space, based on free-floating proof masses in three spacecrafts. Due to orbit evolution and time delay in the interferometer arms, the direction of transmitted light changes. To solve this problem, a picometer-stable Point-Ahead Angle Mechanism (PAAM) was designed, realized and successfully tested.