Environmental testing at system level of complete spacecrafts requires several hundreds of sensors both for mechanical and thermal-vacuum testing. Wireless sensors provide a competitive solution to avoid buying, assembling, installing and in the end, withdrawing hundreds of cables. In the frame ESA’s Neosat Partnership Projects, Airbus Defence and Space has made significant progress with its wireless sensors roadmap.
Neosat was a good opportunity to federate in one programme, the development by Intesens, a French SME, of wireless sensors, with practical trials by Airbus Defence and Space on their telecommunications satellites.
Named T-Cube, the sensor is in fact a miniaturized data acquisition system for 4 thermocouples with a size of 31.50 x 16.50 x 20.19 mm (L x l x H). The network is using 2.4 GHz radio link and the Master is able to manage up to 600 T-Cubes (i.e. 2400 channels).
Several experiments have been carried-out by Airbus Defence and Space over the last years.
After a first equipment Thermal Vacuum test between -40 and +80°C in April 2015, 14 T-Cubes were installed in different areas during a month long telecommunications satellite Thermal Vacuum test in mid 2016 . To manage the network and collect the data, 2 RF antennas were installed inside the spacecraft. 8 T-Cubes were able to acquire data during 20 days of the test duration with one measurement per minute.
The correlation with standard TC gave satisfactory results with a gap of -1.1/+0.5°C maximum. The maximum difference was observed mainly during the temperature transitions.
The two following years were used to improve the reliability of the RF connection and data collection into the Airbus Defence and Space standard acquisition system, DynaWorks. Other tests have been performed on the level of outgassing and qualification of the product to space environment.
In summer 2019, a third real life trial has been performed by Airbus Defence and Space with 22 T-Cubes and the new “Master” generation during another telecommunications satellite TVAC giving again good results but also showing restrictions of the use and a few ways forward to improve the system.
The industrialization phase is now starting with the final qualification of the product. The first operational use is planned starting in mid 2020, during the first Eurostar Neo based application satellite TV test.
The objective of the Neosat Partnership Projects is to develop and qualify the next generation platforms allowing the two European satellite prime integrators, Airbus DS and Thales Alenia Space (TAS) to deliver competitive satellites for the commercial satellite market. The projects include development up to in-orbit validation of the new platform product lines for both Prime contractors, Eurostar Neo for Airbus DS and Spacebus Neo for Thales Alenia Space.
Ten (10) Neosat satellites have now been ordered, demonstrating the high economic impact achieved through ESA’s Partnership Projects. Neosat Partnership Projects are part of ESA’s Advanced Research in Telecommunications Systems (ARTES) and are based on a cooperation between ESA and CNES.