10:30 AM (PDT) -- Well, it has been a very busy week! We're approaching the end of what we call an ORT, an Operational Readiness Test. This is the seventh and most realistic ORT that we've had so far in the mission. It is our dress rehearsal for the actual landing that will take place on July 4. (What do you wear to a martian landing? Green?)

During the test we don't use the actual spacecraft, but instead we use very accurate simulators. In preparation for the test, some of our engineers locked themselves in our "sand-box" (this is the area where we have martian-like sand and working simulators for both the lander and rover), and rearranged the rocks and sand so that we would be "surprised" by what we discovered when we "landed" on Mars. No one else is allowed to see the sand-box during the test. Just like school! No peeking!

On our first test day on Mars, we were able to accomplish everything that we had planned. We drove the rover off the lander and onto the surrounding sand, deployed our camera and took many pictures, and released our weather mast to take wind and temperature measurements. The rover was able to take its first 10-hour measurement of the composition of our test material.

My job during the test was to plan the activities that are to take place on the day after we land, our second day on Mars. Actually, we've already planned what's going to happen for the first several days, but once we land on Mars, we'll probably have to change a few of our scheduled activities. Since just about everything went properly on the first day, there wasn't that much to replan for the second day. Still, there was a lot to do.

My mission planning shift started on Wednesday at 9:30 PM. I didn't get to leave until about 12 hours later! During that time we moved around some science observations, adding some and removing others. Since the mission planners work when it's nighttime on Mars, we don't get to stay around and watch the activities take place during the Martian day. We have to sleep sometime!

Since I'm also one of six Mars Pathfinder flight controllers, I have to worry about the real spacecraft, not just the test lander and rover in our sand-box. We are now monitoring the spacecraft around-the-clock as it approaches Mars; landing is just 20 days and 22 hours away! This week I've had five flight control shifts, each from about 7:00 PM to 11:00 PM. In fact, the only night that I didn't have a flight control shift was Wednesday night, and you know what I was doing then!

It has been a very busy week on "Mars" as well as in space!