SDO Date 44: Spacecraft Jitter Tests
Thursday was spent testing the "jitter" of the observatory. Why do we care? SDO needs to keep its imaging telescopes pointed at the Sun with a steady hand. Our pixels image an area of the Sun that is about 0.5" across. While that's a patch the size of New Mexico on the Sun, it easier to think of it in terms of a quarter.

If you ran to the top of the Washington Monument in Washington, DC and held up a quarter, your friend would have to stand on the Wilson Bridge (6 miles away, waiting for the drawbridge to be lowered) to make the quarter look 0.5" across. Imagine how steady they would have to hold the camera to take a picture. SDO must keep the cameras pointed that accurately while moving around the Earth, keeping the high-gain antennas pointed at New Mexico, and with all the motors running to move filters and shutters in the instruments.

It's good to do jitter tests!