Online From Jupiter 97

Marcia Segura

Science coordinator, Near Infrared Mapping Spectrometer

My Field Journals

Greetings. My name is Marcia Segura. I was born in Down East Maine and lived in a fishing village called Cutler for my first 18 years. At that point, I set out for parts afar and finally settled in Los Angeles California in 1978. I began my career in aerospace in 1979 but decided that the space program would be more exciting than the defense industry so I came to JPL in 1984. I became a member of the Voyager spacecraft team during the Uranus encounter. In October of 1988 I joined the Galileo project.

I am a science coordinator on the Galileo Near Infrared Mapping Spectrometer science team. Both the science team and the instrument are referred to affectionately as NIMS by people on the project. Can you imagine how tired your jaw would be if you had to say Near Infrared Mapping Spectrometer all the time?! Actually, there is a dictionary of "Galileo speak" because NO ONE on the project EVER says more than one sentence without using acronyms!!

NIMS, the instrument, has a very exciting and important task ahead during the Galileo mission. NIMS will study the chemical composition of Jupiter's atmosphere as well as the surface composition of its moons (including the four largest, Io, Europa, Ganymede, and Callisto). How can you tell if the surface is olivine, pyroxene, or green cheese? Or if there is methane in Jupiter's atmosphere? The instrument works like a prism EXCEPT NIMS has the capability to separate the "near infrared" portion of the spectrum (0.7 to 5.2 micrometers, which is just past the red light that our eyes can see) into as many as 408 wavelengths or colors. This spectral region provides information about composition and temperature. Each mineral and gas absorb different colors causing each to have a unique spectral signature much the same way each human has a different fingerprint. Using the spacecraft and scan platform to point NIMS in the right direction, the instrument can then "map" any object... asteroids, Callisto, Jupiter's Great Red Spot. The Near Infrared Mapping Spectrometer is a new type of instrument and Galileo is the first spacecraft to carry it.

NIMS, the team, is a group of scientists, science coordinators, programmers, an engineer, and support staff with a common goal in mind: "Galileo NIMS Science!" The team is based here at JPL but many members work and live in Hawaii, Arizona, England, and France. Distance sometimes makes the work harder, but we rely on E-Mail, FAX, and telephone to help with communication.

As a science coordinator on the NIMS team, I have varied work assignments. One of my favorite tasks has been the planning of every NIMS Callisto observation for the entire 2 year Galileo mission due to start in December 1995. I started this assignment over three years ago and it still continues. Can you imagine your teacher giving you homework in 5th grade to be due in 8th grade or planning what you are going to have for dinner 3 years in advance?

When Galileo's large antenna didn't open correctly, the spacecraft and NIMS needed new software. One task that currently has my attention is NIMS instrument software testing; I am trying to make the new spacecraft and NIMS software malfunction!!! Have you ever heard the words "Don't touch, you'll break it?" That doesn't apply to this part of my job! This assignment has been interesting and challenging because things don't always work as expected.... many surprises and mysteries unfold on Test days. The fun and frustration happens as we overcome the "surprises" and solve the "mysteries".

Another task I have is to create sequences. These are really computer programs. We use the sequences to tell the NIMS instrument and the spacecraft what to do next. This part of my job requires a LOT of time. Each sequence we create to do science observations will take about 7 days to execute on Galileo but about 14 weeks to get it ready for the spacecraft. Why does it take sooooo long? Each science team does its own sequence, which is then merged with all the others; problems arise and need to be ironed out. Although this assignment is often stressful and is NOT my favorite task; the end result has to be the most rewarding part of my job--the NIMS data!!! When I see the NIMS images and spectra after weeks and months of sequencing work, I feel a true sense of accomplishment. It was one of my sequences that led to the Galileo-NIMS discovery of asteroid Ida's satellite Dactyl.

When I am asked what I like about my job, the answer is always the same: the people I work with, who are extremely talented and creative. The variety of tasks: no two days of the week are the same. The excitement and wonder of discovery: we are going to find and see new things much like the explorers we're taught about in grade school social studies and history books.

I believe "life is something to experience," so I'm involved in many activities apart from work. Many of these include my two sons, Adrian and Matthew. Adrian is away at Emerson College attending classes and basketball practices. Matthew is a 5th grader who enjoys Cub Scouts and sports. He plays football, basketball, and baseball; I attend almost every game. Although, I don't follow college or professional sports avidly, there are certain teams that I take interest in. Want to guess? Most of them are East Coast teams..... Emerson Lions, Boston Celtics, Patriots, Red Sox. I enjoy early music, genealogy, painting and needlepoint. I play the bowed psaltery and recorder with a group of musicians. I also spend time camping with my Cub Scout Den (yep, I'm a Webelos Den Leader). Most summers I return to my home state, spend time with family, and go lobster fishing!!!