Well, needless to say perhaps, things got a little tense early on in MET Day 3 when the TSS tether broke at about MET 4:15. Our operations were not particularly affected, but everything was going a bit more carefully. At the beginning of MET Day 5, however, the USMP3 payload becomes the prime payload, and we then have greater control over Shuttle resources and hour-to-hour mission operations.

Nevertheless, Zeno has been opeating continuously. So far it apears that the instrument is performing quite nicely, doing just what we need it to do. When we become prime, the orbiter will go through far fewer attitude changes than it has up to now and we will be able to optimize thermal settings for our Optics Module, and expect an increase in instrument performance over it's already good levels.

From the time of activiation, we've been cooling the sample ever close to the critical temperature, always at controlled rates. For the first 2 days the changes were rather large and fast, so we got quickly to our official starting point of Tc+4K. Since then we've been moving more slowly, moving first to Tc+1K, then Tc+.5K, and finally Tc+.2K by the time day 3 ended.

Although it wasn't part of the original plan, we decided to use our planned dwell times at each of these temperature set points to collect some data, running the correlator to get scattering correlograms and averaged intensity data, which we will use to refine our knowledge of the location of the critical temperature.

So, to give you a hint of what the data will look like, we show here an average of the first set of correlograms that we collected, at Tc+500mK.

At this distance from Tc, the statistics are not very good and so the curves aren't so clearly defined, particularly in the backscattering direction. Nevertheless, these are useful data, and the first measurements of the mission. Later in the mission we'll get to compare these to correlograms much closer to Tc, and you'll see a marked difference.