Athena/MER Update Week Ending March 2, 2002

We had what looked like a pretty serious problem with our Mšssbauer Spectrometers this week. We’re now doing thermal testing, which means making sure that the instruments work properly at the temperatures that we’ll actually see on Mars. The Mšssbauers were behaving fine at room temperature, but when they got cold they started doing what we call “ringing”. Each Mšssbauer has a little drive system inside it that vibrates back and forth about 20 times a second. It’s supposed to vibrate in a controlled way, but when it “rings” it’s sort of like what happens when you put a microphone near a speaker and get feedback… it vibrates out of control. And if that happens, we don’t get Mšssbauer data.

At mid-week it looked like we might have a pretty bad problem, but the guys in Germany — Goestar and Bodo and Daniel — have really hunkered down and worked hard on it over the past few days and nights. They traced the problem to one part in the electronics, and with a change to that part one of the two instruments is now behaving itself down to temperatures as cold as -120 C. We still have to finish the testing and then fix the other one (once everybody catches up on some sleep!), but right now things are looking pretty good.