A Brief History of
NASA’s Mars Robotic
Exploration Rovers
Sojourner - Launched in 1996
with companion Pathfinder
orbital explorer. Rover landed
July 4, 1997. Sojourner
successfully captured images
of the Martian surface until
communications with the rover
were lost in September 1997.
Opportunity and Spirit - Both Mars Exploration Rovers were
launched within a month of each other in 2003 and landed successfully in 2004. As of the end of 2012, Opportunity continues
to function as a remote-controlled explorer, far surpassing its
original mission duration. Spirit, which also operated long after
its original mission end date had passed, became stuck in the
sand in 2010 and operated for a short time as a stationary science
platform before NASA lost communication with it in May 2010.
Curiosity - Launched in November 2011, Curiosity landed in August
2012. The automobile-sized rover is officially known as the “Mars
Science Laboratory” and is continuing its exploration of the Gale Crater.
in the area of improved fidelity in robotic control systems,
Norris points to advances in graphics performance through
faster video processing chips, a phenomenon driven for the
most part by the gaming community and gamers’ appetite
for more and more realistic video experiences. “We just ride
that wave and make use of their advances, and happily so,”
“The technologies and the
software that the video game
industry has developed
for rendering data, scenes,
terrain—many of the same
visualization techniques and
technologies are infiltrating into
the kinds of software that we
use for controlling spacecraft.”
— Jeff Norris, manager, Planning
and Execution Systems Section,
NASA Jet Propulsion Laboratory
(JPL), Pasadena, California.
he acknowledges. In addition, advances in graphics software
and video game engines, borrowed in part from the movie
industry, have resulted in highly realistic three-dimensional
displays that have also been borrowed by scientists designing robotic systems. “Games push the envelope on how
we’re going to render a landscape effectively so that it looks
right,” Norris explains.
When it comes to controlling NASA’s Mars Curiosity
robot—a car-sized science platform with six wheels and a
variety of cameras and sensors deployed on booms extend-
ing from the vehicle—the joysticks and keyboards found
in the JPL control room are very similar to what gamers
would use. Norris explains that NASA capitalized on the
“many, many millions of dollars that the companies making
these joysticks and other input devices have invested into
industrial design and user testing to build devices that are
comfortable to hold for long periods of time. We would be
foolish in my business to ignore all of that progress.”
Perhaps the most challenging part of operating NASA’s
Curiosity robot from Earth is compensating for both
the distance and the time separating the robot from its
human masters. Robotics experts condense this chal-
lenge into the word “latency,” described in engineering
terms as the time delay experienced by a system process-
ing data. It is something also faced by local police bomb
squads who use robots to disarm possible explosives,
scientists using ocean-going autonomous robots in mari-
time research, and pilots at U.S. military bases operating
unmanned aerial vehicles in Iraq and Afghanistan. Nor-
ris notes that a common complaint among gamers who
participate in massive multiplayer games on a server over
a network is that of latency, when the performance of the
game begins to deteriorate in relation to the performance
of the network, and the synchronization of the state of
