- First Name:Ke Xun
- Last Name:Sun
- Working Group Presenter
- Title:LISA Gravitational Reference Sensors
- Presentation Type:Talk
- Presentation Work Group:Gravitational Waves
- Abstract:The Laser Interferometer Space Antenna (LISA) consists of three identical spacecraft placed at the corners of an equilateral triangle with a 5 million kilometer baseline. In the LISA design, the spacecraft at each corner will have two optical assemblies subtending an angle of 60 degree. A proof mass is housed in a gravitational reference sensor (GRS) located at the center of each assembly. LISA measures the distance variation between proof masses separated by 5 million kilometers to a precision of 40 pm. The GRS must shield the proof mass from external disturbances such as solar winds and functions as a drag-free sensor for spacecraft control. Significant progresses have been made in minimizing the disturbances and enhancing the sensitivity of the GRS.
Recently there have been proposals designed to simplify the LISA payloads by using a single proof mass and therefore only one GRS per spacecraft. Further a modular structure is proposed to reduce the complexity. Optical sensing and large gap size between the proof mass and GRS housing are proposed to lower the disturbance level. We will review progresses in both the GRS baseline, and the recently proposed modular GRS.