Woodsat space mission - Sens4 A/S



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Rethink vacuum gauging

Sens4 A/S is participating in the WISA Woodsat space mission via the European Space Agency (ESA), which supplies a suite of novel sensors, including a MEMS SmartPirani™ vacuum pressure transducer.

One of the main objectives of the WISA Woodsat mission is to assess the use of wood materials in space structures.  This is done by gathering data from a nanosatellite about the behavior and durability of plywood over an extended period of exposure to harsh temperatures, vacuum conditions, and radiation.

The Woodsat space version of the MEMS SmartPirani™ transducer is a customized product that was designed and engineered according to requirements from ESA. The outcome is a compact version of a standard iVacSens™ SmartPirani™ transducer module for direct electrical and digital integration with the satellite’s main microcontroller.

WISA Woodsat space mission with Sens4 sensor technology

Measuring technology and functionality

The MEMS SmartPirani™ transducer measures the vacuum pressure indirectly by measurement of the heat-loss from a heated filament to the surrounding gas. The vacuum sensor will be used to monitor the internal pressure onboard the satellite in the hours and days after launch. Furthermore, the vacuum sensor has a critical function to ensure that the vacuum pressure level is low enough to safely turn on other electronic devices that require vacuum pressure to operate, including high-power systems and radio-frequency antennas.  

iVacSens vacuum transducer module

Why use MEMS Pirani sensors for spaceflight systems?

The MEMS SmartPirani™ technology has several advantages compared to traditional wire Pirani sensor technology. The technology is the obvious choice for space flight systems where vacuum needs to be measured.

The payload on the rocket will be exposed to significant vibrations and G-forces during the rocket launch, which the ultra-compact MEMS sensor technology can withstand for an extensive period by design.

The SmartPirani™ MEMS sensor technology also offers an extended measuring range of 1-2 orders of magnitude lower than competitive Pirani gauges, which is an important measurement performance parameter for the Woodsat application. Small mass and dimensions are critical parameters in space flight systems, and the SmartPirani™ technology offers the market’s most compact and lightweight wide-range vacuum sensor solutions.

Power consumption of the electronics is another critical parameter in spaceflight systems, where electronics are solar, or battery powered. The ultra-compact sensor element enables low sensor filament power and an overall low power consumption for the entire vacuum transducer electronics module.

The count-down is on

The nanosatellite is scheduled for launch already in 2021 onboard a Rocket Lab Electron launcher from the launch complex Mahia, New Zealand. When launched into space, the satellite will orbit at around 500-600 km altitude in a roughly polar Sun-synchronous orbit.

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