Page 93 - Modern Robotics Building Versatile Macines

ROBOT EXPLORERS 73

TRENDS: MILESTONES IN NASA’S MARS EXPLORATION

Humanity has explored Mars for more than four decades. The follow-
ing chart summarizes the most significant successful missions.

Year Spacecraft Mission
Small space probe sent on long trajectories to
1964 Mariner 4 Venus, Mars, and Mercury. Collected first close-up
photos of Mars

Mariner 6 Mars flyby missions returned many pictures and
1969
and 7 atmospheric data
First probe to orbit Mars rather than just fly past.
1971 Mariner 9 Photo mosaics had many spectacular features,
including giant volcanoes and canyons
First spacecraft to land successfully on another
1975 Viking 1 and 2 planet (July 1976). Conducted soil analyses and
searched for possible signs of life

First landing of a rover (Sojourner) on Mars (in
1997). Used a new landing method with parachutes
1996 Pathfinder
and airbags. In addition to taking pictures, the rover
visited rocks and performed spectroscopic analyses
Rovers Spirit and Opportunity have ranged
Mars
2003 Exploration for unprecedented distances and are continuing
Rovers to operate more than two years past their
design life
Mars Arriving in March, the orbiter will spend six
2006 Reconn aissance months adjusting its orbit before beginning
Orbiter science operations

The history of Mars exploration has also been marked by painful
failures. Several Soviet probes failed in the 1960s and early 1970s, as
did two of NASA’s Mariner missions. Communication was lost with
the Mars Polar Lander (launched in 1999), while the Mars Climate
Orbiter, launched in 1998, burned up in the planet’s atmosphere.
The ambitious Russian Mars ’96 spacecraft mission was also lost.