Online From Jupiter 97

Louis D'Amario

Deputy Navigation Team Chief

My Field Journals

My name is Louis D'Amario. I am the Galileo Deputy Navigation Team Chief. That's a long title, but it doesn't really tell you what my job is. First I need to explain what the Navigation Team does, and then I can describe what my job is.

The most important task of the Navigation Team is to control Galileo's flight path (the trajectory). That means knowing the location of the spacecraft and where it is headed at all times and designing small course corrections to keep Galileo on the right trajectory for its next flyby of a planet or satellite. A course correction is just a small nudge given to the spacecraft by firing its rocket thrusters. These thruster firings change the velocity (the speed and direction of motion) of the spacecraft. A small velocity change can make a large difference to the trajectory if done early enough.

The Navigation Team has other responsibilities in addition to controlling Galileo's trajectory. Supplying trajectory information, such as distances and angles, to various Project teams is one very important activity. Science teams use trajectory information to find the most valuable science observations and calculate where to point the science instruments; the spacecraft team uses trajectory information for planning various spacecraft activities; and the Deep Space Network team uses trajectory information to point its large communications antennas in the right direction to transmit commands to Galileo and receive science and engineering data back from Galileo.

The Navigation Team is divided into three groups, and each group has a group leader who is responsible for the work of that group. The names of the groups are: Orbit Determination, Trajectory Design, and Maneuver Design. The Orbit Determination Group calculates Galileo's location in space and where it is headed. The Trajectory Group finds the best trajectory to get to the next flyby and produces trajectory data for use by other teams. The Maneuver Design Group computes what course correction is required to put Galileo on the right trajectory. The Navigation Team does all its navigation calculations on powerful high-speed computers.

I am personally responsible (along with the Team Chief) for supervising the day to day activities of the Galileo Navigation Team, which consists of about 20 people. This means figuring out what work needs to be done and how many people are required to do the work, making sure the work is done right and on time, and attending lots of meetings. Also, I need to make sure that the various products produced by the Navigation Team are communicated to the rest of the Galileo flight team through reports, presentations, and computer files. Most of the time I work with the three group leaders, but sometimes I work directly with specific members of the Navigation Team. Sometimes, I even get to do some of the work myself! One interesting job I worked on recently was figuring out the orbit of Dactyl, the tiny satellite that was discovered orbiting the asteroid Ida, which Galileo flew by in August 1993.

As far back as I can remember, I was always interested in science and anything to do with space travel and space exploration. As a youngster, I read lots of space comic books and science fiction novels, and I went to see every science fiction movie that came to the local theaters. I was 10 years old when Sputnik (the first Earth satellite) was put into orbit in 1957. I also remember staying up very late one night to listen to a radio broadcast of the first soft landing of a Surveyor spacecraft on the Moon in 1966 (I was a sophomore in college). I knew even before I started high school that I wanted to work in the space program and be an engineer. I used to draw pictures of rockets all the time, showing how the inside of the rocket was divided into engines, fuel tanks, crew compartments, etc.

To prepare for the career I wanted, I made sure I took all the advanced science and math courses that were offered in my high school. Then I picked a college to go to which offered an aeronautical engineering degree, and I took all the courses offered in orbital mechanics and navigation. I got a Bachelors degree from Rensselaer Polytechnic Institute in Aeronautical Engineering and a Masters and Ph.D. from MIT in Aeronautics and Astronautics. I was in graduate school when the first Apollo lunar landing took place in 1969. I started out working at the Draper Laboratory in Cambridge, Massachusetts (near MIT) and worked on the Space Shuttle program for about four years. Then I decided that what I really wanted to do was work in the planetary exploration program at JPL. So I came to JPL in 1977 and I've been working on the Galileo Project ever since. That's 18 years on the same Project!

What I like most about my job is that I am part of one of the most important and ambitious space exploration projects ever undertaken. Very few people can say that they directly contributed to the success of a mission that has made major new discoveries about our solar system. After 18 years working on Galileo, it's hard for me to believe that in just a few months Galileo will arrive at Jupiter. That, by itself, will be a major accomplishment. Then after we put Galileo into orbit about Jupiter, navigating through the close flybys of Jupiter's satellites will be even more exciting.

When I'm not at work, I try to relax at home. I still read lots of science fiction books. I also enjoy bicycling (mostly for exercise), hiking, gardening, and photography. My wife and I like to