Tunstel also
advises the overall mission operations team about the mobility
and robotic arm software when the team commands the rovers
to place instruments on rocks and soil, and to drive and navigate
autonomously on the surface of Mars.
To accomplish this task—which is no small feat—Tunstel
has to understand what the scientists want the rovers to do,
how the rovers’ software works, and how the rovers’
mechanical components physically interact with the terrain.
Tunstel also assesses the terrain to determine where the rover
mobility system can perform its best.
“The software on the rovers is designed to keep the
rovers safe as they traverse and avoid obstacles on their
own in areas that we deem most traversable,” he says.
Typically, Tunstel’s day begins around 10 a.m. Local
Solar Time. (The time zone depends upon where Spirit or Opportunity
happen to be.) A Martian day is approximately 40 minutes longer
than an Earth day, so on each Earth day, his start time moves
forward about 40 minutes.
Each sol, he dons a headset and works at the Mobility/IDD
station in the mission support area or mission control, and
works alongside other SRET flight controllers responsible
for other rover subsystems. He reviews a number of reports
set forth for the sol, created by another part of the mission
operations team the night before.
“My shift starts shortly after a sequence of commands
that allows the rover to execute a whole sol’s worth
of planned activities,” Tunstel explains. “Later
in the sol, there are typically two times when we receive
communications from the rover, including results of how the
sol’s activities were performed. Before each communication,
I work with computer-based tools for viewing images, analyzing
engineering data, and visualizing rover simulations of the
planned activities in 3-D.”
After receiving the results of the rover’s activities,
Tunstel analyzes the data, reports his findings, and helps
plan the next sol’s drive or robotic arm activities
as requested by the science team. On occasion, this involves
experimenting on one of two operational rover models.
“From time to time,” says Tunstel, “I have
to remind myself that it is really happening, and it is not
business as usual.”
The complete version of this story will be published in the
Spring 2004 issue of Mirage,
coming out this April.
|
