Spherical Air Bearings Aid Testing of Satellites | ASSEMBLY

The number of active satellites in space keeps growing. In July, Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, estimated that more than 10,000 satellites are now orbiting our planet. Different estimations expect that number could reach as high as 100,000 by the end of the decade.

With the advent of compact CubeSats and commercial spaceflight, the cost of building and transporting a satellite into space has dropped significantly, which has made feasible the use of a global network of low-Earth orbit (LEO) satellites for free space optical communication via laser beams.

The increased demand for satellites is driving demand for new test equipment. Commercial and academic institutions developing these satellites continuously work to improve test systems and methodologies to validate their hardware before launch.

Spherical air bearing systems are commonly used to test the attitude control systems of small satellites. The frictionless nature of the spherical air bearing makes it easy to simulate a zero-gravity environment, allowing the satellite’s pitch, roll, and yaw control systems to function as they would in space without cumbersome and expensive test simulations, such as traditional drop testing.

PI’s A-651 and A-657 series of spherical air bearings offer frictionless motion in three rotary degrees of freedom with unrestrained rotation about the vertical Z-axis and ±45-degree tilt motion about the horizontal X and Y axes. They are available with diameters from 50 to 300 millimeters and can carry payloads 20 to 1,400 pounds with compressed air at 80 psi.

These bearings can handle nearly any small satellite, from picosatellites to half-ton mini-satellites. 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.

In addition to the spherical air bearings, PI also provides other technology for space applications, such as six-degree-of-freedom 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.