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LIVE FROM MARS: lfm
Charles Whetsel
Spacecraft Systems Engineer
Jet Propulsion Laboratory, Pasadena, California
My Job
Our project is organized into three main groups: 1) the scientists who are conducting
the experiments and designing the cameras and other scientific instruments to survey the
planet Mars; 2) the mission designers, who work to define what trajectory we should take
to get to Mars, what orbit we will be in when we get there, and how we plan to operate
the spacecraft while there to maximize the scientific data return; and 3) the spacecraft
engineers, who design the spacecraft on which the instruments will be mounted so that it
will: supply the required power to the instruments and keep them pointed well enough to
collect the required data; provide the propulsion necessary to change or "trim-up" the
spacecraft orbit as required; provide the radio link required to locate the spacecraft
and send remote-control commands up to it; and return pictures, scientific data and
engineering telemetry back from the spacecraft.
We systems engineers work first with the mission planners and scientists to make sure
that we understand what they are expecting the spacecraft to be able to do, and then,
after we think we understand it, we communicate that downward to the specialized
engineers who are each responsible for building the specific parts (or "subsystems") of
our spacecraft (e.g., the computer specialists or the radio specialists). As systems
engineers we are also responsible for things that the spacecraft is expected to do and
that are split between more than one specialty (e.g., the number of pictures that we can
relay from the camera depends both on how much power the radio engineers drive their
radio with and also on how precisely the control engineers can point the large parabolic
[high gain] antenna).