Sun Sensors (Medium)

Overview
• Product description:

• Recent deliveries include:
  
  • University of Hawaii
  • MSCI
  • MSI
  • Naval Research Lab
  • NTU
• Key Technical Performance:
  
  • Passively operated device (requires no bus power)
  • Better than 1 degree, 2-axis pointing accuracy
  • Weighs less than 35 grams
• Recent & Upcoming launches:
  
  • FASTSAT onboard S26 Minotaur IV

Comtech AeroAstro’s Medium Sun Sensor is a low-cost, two-axis, medium-resolution sun sensor with years of flight heritage. The sun sensor is comprised of a small housing containing a set of four photodiodes. Calibration data is provided with the sensor, to be stored on the satellite computer for computing sun angle from the four signal outputs. The sensor housing also serves as the aperture, reducing mechanical complexity and precisely masking solar light.

The Comtech AeroAstro Medium Sun Sensor provides attitude determination in two axes. Two baffle sizes are available—a short barrel (~1/2 in.) and long barrel (1 in.) providing 120-degree and 48-degree full-angle field of views, respectively. Both solutions are accurate to ±1 degree. The tall barrel unit is adapted to high-glint and other reflective environments, providing a sharp analog cutoff response.

Comtech AeroAstro also provides an array configuration of 5 medium sun sensors integrated into a common mounting bracket. In this form, a sun vector to within 2 degrees may be resolved within hemispherical 150-degree field of view. Calibration data is also provided and assistance with sensor response mapping is included.

Sun Sensors (Medium) History

Comtech AeroAstro’s Medium Sun Sensors were originally designed and built for the ALEXIS space program for the Los Alamos National Laboratory.

The sensor design has proven itself on multiple flight missions, having changed very little in its near two-decade life. The original design, the long barrel solution, provided the necessary response for early microsat programs. As mission designs demanded smaller and more flexible solutions with higher computing capabilities, the short barrel solution was devised to provide the same post-calibration accuracies. We continue to fine tune our calibration sensor response curves providing even better accuracies and performance without change to hardware.

Comtech AeroAstro's Medium Sun Sensors have flown successfully on several different spacecraft, including ALEXIS, HETE, TERRIERS, and FASTSAT.