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Mars Journal - Mars Exploration Rover Mission
February 17, 2004
An Hour in the Life of a Tactical Activity Planner #3
This entry continues my 'Hour in the Life of a Tactical Activity Planner' entries, and covers the time from 17:00-18:00 Mars Local Solar Time (LST), the third hour of my shift.
The clock in the control room reads 17:00 LST when I excuse myself from the Engineering Leads Tagup meeting. It's not a normal clock, but a complicated software program that is running on computers in almost every room of the operations facility. It can tell us what time it is anywhere on Earth or Mars, and shows a schedule full of colored bars indicating all of the important events and meetings for the sol. A pink vertical line indicating the current time creeps slowly from left to right. Right now it is creeping slowly towards a green bar labeled 'Science Operations Working Group Meeting," which begins at 18:00. I eye that pink line with some trepidation and jog across the building to the sequencing room.
Much of the Engineering Leads Tagup meeting is devoted to all of the problems and issues that came up over the past few sols, so it's a relief to step out and actually work on CORRECTING one of those issues. Sitting down at my workstation in the sequencing room, I start hopping between directories in search of the information I need.
Navigating the mission filesystem is a challenge in itself. The mission generates an amazing number of files (I personally generate over 150 every sol), and all of these files are stored in an incredibly complicated directory structure. Altogether, there are approximately fifteen thousand files in one thousand directories for each sol for each rover! That's almost a million files for every month that both Spirit and Opportunity are in operation. It can be so challenging to find what you're looking for that many of us have written our own utilities that make it easier to get to the data we're looking for.
After hunting for about 30 minutes, I find the solution I was looking for and return to the Engineering Leads Tagup meeting to report my success. It's now 17:30 and the meeting has concluded. The next 30 minutes are the calm before the storm. At 18:00, the Science Operations Working Group meeting will begin and the remaining five hours will be a nonstop sprint to the final plan. I grab my lunch from the fridge in the coffee room and call my wife. It's the closest thing to a break in my eleven hour day.
February 14, 2004
Science for Engineers
As a Tactical Activity Planner, I spend most of my time staring at a computer screen with hundreds of little colored bars on it that represent all of the things that the rover is going to do on the next sol. Sometimes it starts to look like some kind of demented Tetris game ' I keep packing little colored bars together until there isn't any room left. It's easy to forget that the little bars represent something that is going to be done on Mars!
Similarly, it's easy for an engineer like me to become completely focused on the mechanics of building plans for the rover and forget that this vehicle is doing science! The engineers who work the shift after mine feel even more disconnected from the science of the mission because almost all of the scientists have gone home by the time they show up for work. They work their whole day to finalize commands for the rover without really knowing WHY the rover is doing these things.
Recently, the late-shift engineers got so frustrated with this situation that they begged the only scientist still on shift, the Science Uplink Representative, to put together a short daily science lecture for us. It's only about 5 minutes long (we don't have much more time than that anyway), but I can't tell you how much of a difference it makes to hear a little about the 'why' behind what we're doing. Of course, many of the science team members are (or were) college professors, so they certainly know how to organize and deliver a good lecture. Lately we've heard a lot about the rippled soil that Spirit is parked near right now and the fascinating rock called 'Mimi' that appears to be layered.
The best part is that the scientists don't have answers for everything! Sometimes, they're as puzzled by the pictures as we are. This is truly science in the making, and it will take years of study by the world's scientists before we'll understand everything we've seen during this mission.
February 12, 2004
Keeping Rovers Safe
As I mentioned in a previous entry, I've been operating rovers since I came to JPL in 1999, but this is my first experience with operating a rover on Mars. Before we landed I participated in countless tests of the FIDO research rover in all sorts of settings. Some were in indoor laboratories like the JPL Planetary Robotics Laboratory, where the FIDO rover was developed. Others were in the JPL MarsYard, a sandbox not much larger than a swimming pool, or in the Arroyo that runs beside the laboratory. The largest field tests were in desert environments in California, Nevada, and New Mexico.
We performed these tests in order to test new technologies and learn more about how we could operate a rover like Spirit or Opportunity on Mars. In fact, most of the mission science team and some of the mission engineers learned the basics of this business during field tests of the FIDO rover. To make the tests as productive as possible, we did everything possible to pretend that the rover was really on Mars. Most of the operations team was 'blind' ' they were not told where on Earth the rover actually was, and every effort was made to operate the rover in a mission-like manner.
However, our desire to make these tests as mission-like as possible only went so far. The truth of the matter was that we were trying all sorts of on-the-edge experiments with an extremely expensive piece of hardware. To protect FIDO, we always made sure that there was an engineer standing just a few paces from the rover who was responsible for making sure the rover never did anything that would cause it to damage itself. This was quite often Terry Huntsberger, one of the principals on the FIDO project. When I look at the snapshots people took in the field, it seems like Terry was rarely more than a few feet from FIDO, always wearing a wide brimmed hat and sunglasses to ward off the desert sun. I think Terry had a strong paternal instinct towards FIDO ' he wasn't about to let us hurt his baby!
If Terry noticed something dangerous about to happen, he would hit a red button on the back of the rover that would cause the rover to immediately stop moving. This was called 'spanking' the rover, and it happened VERY rarely. Still, I must admit that it was comforting to me to know that Terry was always out there, watching every motion of the rover. If we made a mistake, we might feel pretty stupid about it, but Terry would stop us before it was too late.
It's hard to mentally adjust to the fact that there isn't anyone standing behind Spirit wearing a wide-brimmed hat and sunglasses, ready to spank the rover if we do anything wrong. Spirit and Opportunity are pretty smart about protecting themselves from harm, but there are still countless ways that we could seriously damage them. Whenever I wish we could drive just a bit further or take just a few more images I have to remind myself of that.