ESA GNC Conference Papers Repository
AQUILA and 3AA: design and test results of high-accuracy accelerometer sensor and equipment
InnaLabs Ltd, a privately held limited company incorporated in Ireland in 2011, is producing European ITAR-free Quartz Pendulous accelerometers since 2013, achieving top-end navigation performance with its AI-Q-2000 series of accelerometers. Thousands of those accelerometers have been since integrated into a wide range of land, marine, and aerospace platforms. These accelerometers have recently been successfully used in rocket launchers to support inertial navigation, demonstrating compatibility of the technology with space applications. AQUILA is a very high performance rad-hard accelerometer based on Innalabs quartz-pendulum accelerometer technology. It uses the same pendulum subassembly as the AI-Q-2000 family, but electronics have been developed to meet space PA/QA standards. A hybrid electronics component populated with thoroughly-selected high-reliability EEE parts has been designed for that purpose. Furthermore, performance is specified to meet the most demanding space navigation applications, in particular with the objective of supporting delta-v manoeuvres measurement. AQUILA was developed with the primary goal of qualifying an alternative to non-EU Navigation Grade Space accelerometers currently used on board ESA missions and other European Primes platforms (with similar fit, form and function). Performance specifications include, among others, very low noise, stringent bias and scale factor stability (i.e. 0.1µg short term stability, 2µg over 1 hour, 50µg over 1 month, and scale factor stability over 1 month of 100ppm) under full operating conditions (i.e. temperature, time, launch environment), including more than 15-years exposure to Space radiations (100krad goal). AQUILA is re-using the electro-mechanical cell used in the InnaLabs AI-Q-2000 series of COTS accelerometers which are proven insensitive to radiations and robust to stringent mechanical shock and vibration levels. 3 Axis Accelerometer (3AA) is a new equipment designed to provide acceleration and delta-v measurement on boards satellites and space systems. It includes 3 AQUILA accelerometers mounted in orthonormal orientation to provide measurement along 3 axes. 3AA is equipped with a standard 28V power interface and UART communication bus to easily interface with the main on board computer. The equipment allows for accelerometer compensation and calibration in flight (temperature, misalignment, etc.), providing the main on board computer with a high precision acceleration and delta-v measurement. This paper describes the specification and design of AQUILA Dry Pendulous Servo accelerometer and of the 3 Axis Accelerometer. The paper will also present testing results from AQUILA development models built so far, showing that the product meets the specified performance. Schedule of the development till completion of the qualification will be presented.