Meet: Steven Stolper
Flight Software Engineer
Jet Propulsion Laboratory, Pasadena, California
What I Do
Robotic spacecraft, like Mars Pathfinder, are controlled by computers.
The computer onboard Mars Pathfinder controls thrusters, a sun sensor,
a star scanner, a radar altimeter, explosive charges, a parachute and
much, much more. Almost every activity performed by the spacecraft is
controlled by a central computer. The computer that controls our spacecraft
is just like the personal computers found in schools and in people's homes.
Like all computers, the computer controlling Mars Pathfinder follows
a set of instructions called a program. It is my job, along with several
others, to write the program that allows the computer to control the spacecraft.
This is very challenging because the computer must fly the spacecraft
during the seven-month cruise to Mars as well as control the atmospheric
entry, descent and landing on the surface of the planet.
I have worked at the Jet Propulsion Laboratory (JPL) for seven years
and have written flight control software for several planetary spacecraft.
The last spacecraft that I worked on was the Galileo Orbiter, which placed
a probe into the atmosphere of Jupiter in December 1995.
The programs that control spacecraft, or anything else that operates
in the "real world," are called real-time systems. The programs that control
the anti-lock brakes for a car, a microwave oven, or a jet airplane are
examples of real-time systems. These systems are especially exciting to
me because they have to operate in the "real world" where the amount of
time it takes the program to perform a task is very important. It is also
critical that these systems operate correctly, even when something goes
My Career Journey
I never expected to be taking part in an adventure to Mars!!! I grew
up in White Plains, New York, a suburb of New York City. When I was young,
I loved to read and was interested in space because my father was an astronomy
teacher at the local high school. I loved to watch old "Star Trek" episodes
on television and was captivated by the movie "Star Wars" when it appeared
When I was a high school student, I did not know what I wanted to do
when I got older. I believed that I would be a teacher, like my father.
I had never thought of programming computers because I had never seen
a computer! The personal computer had just been invented!!! Schools did
not have large numbers of computers and few people had computers in their
One summer, I took a computer programming course for kids offered by
a local college. I fell in love with computers!!! I especially liked computer
graphics and eventually learned to write my own video games. I soon found
that programming video games was more fun than playing them!
Since computers were so new, adults did not know how to use them! Many
businesses hired kids to teach adults how to use computers. I was hired
to teach both students and businessmen how to use computers. I became
a computer professional at age 14!
I decided go to college and study computer science at Rensselaer Polytechnic
Institute. While in college, I discovered that computers are used everywhere!!!
Computers are used for business, science, in industry, in consumer electronics
and in many other applications. I found that computers were even used
to control spacecraft! I decided to go to California to work at JPL and
program computers to fly spacecraft.
When I am not working, I enjoy hiking in the mountains of California.
I sometimes spend several days out in the wilderness. Once, I traveled
to the rain forests of Costa Rica. I had never seen a rain forest and
wanted to hike through one.
I also like to play the drums. I have been playing since I was in high
school. I enjoy playing all types of music. Right now I am playing in
a rock band in Los Angeles.
Every weekend, I play soccer with my soccer team, the Cosmics. We don't
win very often but we always have a great time.
I am very excited about the prospect of landing our spacecraft on Mars.
The Pathfinder team members have dedicated three years of our lives to
building the spacecraft and rover. We look forward to our landing on July