Testing satellites with friction-free spherical air bearings

By Rachael Pasini | August 22, 2024

Spherical air bearings are extensively used for testing satellites’ attitude control systems. They provide a zero-gravity environment by allowing frictionless motion in three degrees of freedom (DOF) to simulate pitch, roll, and yaw movements. This capability is vital for testing how satellites will behave in the weightlessness of space without expensive and complex simulations, such as drop tests or parabolic flights.

PI’s 3-DOF spherical air bearing systems are commonly used to test the attitude control systems of small satellites. The A-651 through A-657 series offer frictionless motion in three rotary degrees of freedom with unrestrained rotation about the vertical Z-axis and ±45° tilt motion about the horizontal X and Y axes. They are available with diameters from 50 to 300 mm and can carry payloads from less than 20 lb to up to 1,400 lb with compressed air at 80 psi.

PI’s frictionless, 3-DOF spherical bearings are often used for satellite attitude control testing. Image: PI

This variety in size provides solutions for nearly any small satellite, from 1U picosatellites to half-ton minisatellites. The moving element of the PIglide HB spherical air bearing is lightweight to reduce moving mass and moment of inertia, ensuring the test system closely simulates actual satellite behavior.

The number of active satellites in space keeps growing at an accelerated pace. In July 2024, Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, estimated that more than 10,000 active satellites orbit our planet already. Different estimations expect that number to grow to 100,000 by the decade’s end. With the advent of compact CubeSats and commercial spaceflight, the cost of building and transporting a satellite into space has dropped significantly, which makes using a global network of low earth orbit (LEO) satellites for free space optical communication via laser beams more feasible, promising affordable high-speed internet anywhere on the planet.

This emerging technology has a huge potential for rapid growth, and the increased demand for satellites drives the need for new test equipment. Commercial and academic institutions developing these satellites continuously work on improved test systems and methodologies to fully validate their hardware before launch. In addition to its spherical air bearings, PI provides other solutions for space applications, such as 6-DOF hexapod positioning systems that can be used in the validation of optical terminals, such as the OTVT at the MIT Lincoln Laboratory and fast steering mirrors for free space optical communication in LEO satellites.

PIpi-usa.us