Now in fine pointing mode!

Testing pointing capability of the ADCS on a frictionless air bearing in the heliostat at LASP. This is how we had confidence the system would work on orbit.

MinXSS is now in fine pointing mode. That means that Blue Canyon Tech’s attitude determination and control system (ADCS) is using the star tracker, which provides high precision attitude knowledge. The particular target for MinXSS is the sun, so now we are pointing very precisely toward the sun. We’ll soon be able to characterize just how precisely. This change from coarse sun pointing to fine reference pointing was part of the commissioning plan and must be done by command. We first had to load the ephemeris, which tells the ADCS the orbital parameters of the spacecraft at a particular time. From there, the onboard software can propagate the orbit and use measurements of the earth’s magnetic field, star field, and inertial measurement unit to keep everything up to date. Then we just had to send the command to actually use that information for the control loop. The reaction wheels have been performing absolutely excellently for the past week and we expect they’ll continue to do so. It’s been a great day!