Accelerometers and Inertial Sensing

O.D.I.N., part of the nasa grattis mission

Optomechanical-Distributed instrument for Inertial Sensing and Navigation (O.D.I.N.) is a scientific instrument designed in partnership with the University of Arizona’s LASSO Group headed by Professor Felipe Guzman, IST Precision, and Ruda Optical. O.D.I.N. is part of an upcoming NASA Technology Demonstration Mission called GRATTIS, scheduled to launch in February 2027.

Ruda Optical has been responsible for designing the optomechanical package of O.D.I.N., comprising 12 sensor axes that are intricately aligned to measure linear accelerations, rotational accelerations, spacecraft centripetal accelerations, and the gravity gradient.

ruda is developing the next generation intertial Nagivation Sensor (INS)

Configuration: Same as O.D.I.N.

• Full 6-axis Inertial Navigation System (INS), 3 linear, 3 rotational

• Additional sensitivity to centripetal accelerations & gravity gradient.

• Zero-g inertial sensing; can operate in drag environments

• Fully integrated package: sensors & all readout electronics

Performance Expectations

• Linear Acceleration: better than 1 ng/√Hz above 1 mHz

• Angular Acceleration: better than 100 nrad/√Hz above 1 mHz

• Expected performance is orders of magnitude better than a typical INS

  • Sensitivity is ng/√Hz as compared to µg/√Hz for typical systems

SWaP: Size, Weight, and Power

• Mass Estimate: <16 kg

  • Core Sensor: 8.8 kg  |  Electronics: 3.5 kg  |  Framing: ~3.5 kg

• Volume Estimate: 400 mm side length cube

  • Single unit with fully embedded electronics.

• Power Consumption: ~30 W

  • During launch lock release (1 time): approx.  additional 7.5 W

Expected Performance

Core Sensing Technology

Sensor is a test mass suspended on monolithic flexures.

• Monolithic flexures provide high-Q (>200,000 typ.)

• Test mass size is tailored to application sensing region

• Dynamics exhibit near-perfect representation of a 2nd order spring-mass-damper system; readily characterizable.

• Flexures provide very linear sensing with high stiffness (noise rejection) in other degrees-of-freedom.

• Test mass motion is caused by input accelerations

Test mass motion measured by interferometry

• Current: Balanced, differential heterodyne architecture; first-order insensitive to thermal changes

• Exquisite sensitivity: Displacements <10 pm can be readily measured

• Extremely high dynamic range; can measure <10 pm at large test mass motion ranges and at high bandwidth.

• Other interferometry architectures can be used, depending on application, sensing range, SWaP, and test mass configuration.

Partnership