LISA Pathfinder. Data Management Unit

The Laser Interferometer Space Antenna (LISA) is a joint ESA/NASA mission to detect and observe gravitational waves in space and thus verify Einstein”s General Theory of Relativity.

The LISA core technologies are gravitational reference sensors, reactors that deliver micro-Newton thrust and laser interferometry. These technologies will be tested in space on the LISA Pathfinder Mission, which will comprise two instruments: the LISA Test Package (LTP) and the Disturbance Reduction System (DRS). Both of them will test the key “free-fall control” technology by means of test masses.

Sener performed the design, integration and verification of the LTP”s Data & Diagnostics Subsystem, which includes:

• The Data Management Unit (DMU) equipment with integrated software, tasked with:

• Controlling the interferometer”s stability.
• Acquiring the scientific data for monitoring.
• Diagnostic equipment:

• Diagnostic sensors for monitoring the LTP”s payload.
• Sensor and actuation control.

The DMU performs:

• The interface with the satellite”s on-board computer.
• The Data Processing Unit (DPU), the on-board computer that controls the LTP”s operations.
• Power Distribution Unit (PDU), responsible for the generation and distribution of voltages.
• Data Acquisition Unit, DAU, which acquires the LTP”s environmental parameters (temperature, magnetic fields, and radiation).

Characteristics:

• On-board computer based on a TSC695F CPU processor with 64 K x 8 bit PROM memories, 256 K x 32 bit EEPROM and 512 K x 40 bit SRAM, plus two MIL-STD-1553 interfaces and three asynchronous SBDL ports.
• Data acquisition system to take measurements on 12 temperature channels with noise better than 10 μºK/√Hz and 16 analogue channels with a noise better than 230 μV/√Hz at 1 mHz.