Lisa Pathfinder

Now operating in space: vH&S Command and Telemetry Interface card on-board Lisa Pathfinder!

On the 3 December 2015, a Vega rocket from Kourou, French Guiana was launched carrying ESA’s Lisa Pathfinder satellite. The satellite, a technology demonstrator for a future gravitational wave observatory mission, carries a Command & Telemetry Interface (CTI) card designed and built by vH&S to be part of the Charge Management System (CMS) for the Blackett Laboratory, Imperial College London. The satellite measures fluctuations of passing gravity waves by measuring the fine relative movements of two identical cubic test masses, which are “free-falling” within the satellite. Both masses must be isolated from any other forces generated by the environment or satellite: A significant component of this are electrostatic forces exerted by charge build-up on either mass as a result of the interaction of passing cosmic rays.

The CMS’s role is to purge any charge on the test masses by illuminating the test masses with light from one of its eight ultra-violet lamps. The state and operation of the CMS is controlled and monitored by the CTI card designed and built by vH&S.

The CTI cards features a MIL-STD-1553B standard interface and a dedicated FPGA which interprets commands and collects housekeeping data from all 8 UV lamps via a backplane within the same enclosure.

More information about Lisa Pathfinder can be found at