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Meet: Jeff Theall
Orbital Debris Scientist
NASA Johnson Space Center
Who I Am and What I Do
I work in the Earth Science and Solar System Exploration Division,
which is a hodgepodge of many different areas. The best publicized is the Mars
meteorites discovery. Every year people go to Antarctica to look for meteorites
because they are easily found there sitting on the surface of the snow. Lunar
Rock Curration is part of this division, also. Sample Return Missions -- right
now they are working on the Genesis mission, which will bring back samples from
a comet -- are handled by this division. The field I work in is Orbital Debris.
The atmosphere in this division is very college like; most people here are involved
in research -- some of it long term.
There are two main areas I am working right now -- one
is mathematically modeling orbital debris. Orbital debris is all the bits of space
junk in orbit. I put together models, using numbers and math, to describe the
debris -- how much, where, how big, how high, how heavy, etc. This is done on
computers using data collected from many different sources. One of our sources
is the U.S. Space Command Catalog. This catalog has a record of everything found
in space that can be tracked on ground radar. This includes everything 10 centimeters,
or about 4 inches, in size. (Of course, space debris we can see is much bigger
than the things that can penetrate a spacecraft. Something as small as a marble
could penetrate the shuttle.) Because we can track it on radar, we can develop
an orbit pattern for it. Over 9,500 pieces of orbital debris are tracked at this
time. Another source for our data is the Haystack Radar in Massachusetts. This
measures space debris as small as five millimeters, though no orbital pattern
can be established. In California, there's GoldStone radar which can sample (pick
up on radar) down to a few millimeters. We also get data from the Long Duration Exposure Facility (LDEF), which was a spacecraft
kind of shaped like a school bus. All the little pits and craters that LDEF brought
home on its body were measured and analyzed. All of the data, from all of these
sources, is put together and used to build one big computer model. This model
shows how much orbital debris is where, its altitude and inclination, and how
it grows in time. This information is used to design shields for spacecraft, including
the International Space Station (ISS). NOTE: More advanced
students may enjoy this link to ORDEM96.
I am also working on Space Station Contamination issues.
When people are in space, they go to the bathroom, they breath, they drink water,
experiments are being run, etc. There must be a way to dispose of the waste products
from these activities. Sometimes things are released into the vacuum of space,
but we must understand what happens to these things. The overall responsibility
is to make sure that none of the contamination, from the various sources, interferes
with the work of the ISS.
Before working for NASA, I spent two years in West Texas,
teaching high school math. Then I came back to Houston and worked in the oil field
industry for a few years as a technical instructor. This involved traveling a
lot, all over the world. Then I taught school for a few years in Houston at my
old high school, Strake Jesuit High School.
Education
I attended college at the University of Houston's
main campus, earning a bachelor's degrees in math teacher education, with physics
as my second teaching field. Six years later, I returned to graduate school earning
my doctorate degree in space physics. I went to Antarctica twice while I was doing
my graduate work.
Family
I live in Friendswood with my family. My wife's
name is Anne, and our sons' names are Daniel (age 2) and Mark (age 1). We have
two pets -- a calico cat named Holly, and a dog named Jena who is a German Shepherd
Rottweiller mix. We enjoy spending some of the summers in New England when we
can. We all love to go to the zoo together, too.
My mom is from Oahu, Hawaii, and is Portuguese. She was
nine or ten years old when Pearl Harbor was bombed. My dad was in the service,
and they met when he was stationed at Pearl Harbor for the U.S. Navy in the 1950s.
My dad was a Houston, Texas native and unfortunately passed away in 1991 after
a battle with cancer.
Growing Up
I grew up in Houston,
Texas. Until I was about six years old, my family went back and forth from Houston
to Honolulu to Central Texas. In 1962, we stayed in Houston for good, and I have
been here now for 37 years. When I was in elementary school, I wanted to be a
pilot. That is until I had to get glasses to help correct my eyesight. I never
enjoyed elementary school. I liked junior high even less. It had to be one of
the most miserable experiences of my life. I liked school, the learning and the
classes, but I remember the kids could be mean.
As a kid, I was always interested in space, though I never
thought I'd work here, at NASA. I never imagined I had what it took to work at
NASA, especially the way I struggled through math. I have always been old enough
to have memories of the manned space program.
One of my greatest memories/experiences as a kid were my
visits to Louisiana. I so enjoyed these. I stayed in Louisiana a couple of summers
with my friend, Roy, and his family. They lived on the west bank of the Mississippi
River in a town called St. James, which is halfway between New Orleans and Baton
Rouge. I found it to be a fascinating place and the people were so interesting
with their deep Cajun accents, like Justin Wilson the chef.
I loved to read, especially the Hardy Boys Mysteries. I
got to where I could read one in a day during the summer. I really enjoyed reading
encyclopedias, too. Just open one up and who knows what you might read about.
Personal
I like all things
mechanical, especially cars and motorcycles. I like woodworking and creating things
with my hands. I love to watch movies. My all time favorite is Casa Blanca,
and my recent favorite is The Matrix. I love "munchie crunch" - soy-covered
rice crackers from Hawaii - which is sort of unusual. They are made in Japan,
and they became a favorite of mine when I lived in Hawaii.
Something I'd like you to remember about me is that I'm
a late bloomer. This is something I have come to find out about myself. My schedule
isn't everybody else's schedule.
A goal I have is to write a novel - a fictionalized account
of the people who work at NASA. I try to write everyday.
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