Mars Rover
Written by John Carl Villanueva

A mars rover is a wheeled robot designed for exploration on the planet Mars. There are currently two operational rovers on Mars as of this day, September 25, 2009: Spirit and Opportunity. The two rovers were deployed on opposite sides of the planet; Spirit on January 4, 2004 and Opportunity on January 25, 2004.
Both robots belong to the Mars Exploration Rover Mission. The mission's main objective is to find and then characterize rocks and soils that may provide clues to the possible existence of water on the Red Planet.
As of this writing, Opportunity is departing from a large meteorite dubbed Block Island while Spirit, which has been stuck since May 1, continues to perform scientific investigations using its remote sensors and robot arm.
Each mars rover communicates with Earth-based scientists using omnidirectional antennas that transmit information to either Deep Space Network (DSN) antennas on Earth or to any spacecraft orbiting Mars, which in turn relay the information to land-based stations on Earth. Most of the data is sent through the Mars orbiter Odyssey.
Spirit and Opportunity are not the first rovers to have successfully landed and carried out their missions on Mars. In July 4, 1997, the mars rover Sojourner, along with its lander (which was later named the Carl Sagan Memorial Station), made a successful touchdown on the planet. Since that day until September 27 of the same year, over 17,000 images were beamed to Earth by the lander and the rover.
Both Spirit and Opportunity have the following basic instruments: a Panoramic Camera, Miniature Thermal Emission Spectrometer, Mossbauer Spectrometer, Alpha Particle X-Ray Spectrometer, Magnets, Microscopic Imager, and Rock Abrasion Tool.
One of the goals of each mars rover was very modest (i.e. compared to what they have actually achieved) – to drive up to a total of 1 Km. According to the readings on their odometers, Spirit has already covered 7.7 km of Martian terrain while Opportunity has recorded an outstanding 17.5 km. Both distances are way beyond what was originally expected.
There were a couple of attempted rover landings on Mars in the 1970's. Unfortunately, they all failed to accomplish their missions after getting damaged during crash landings. One crucial innovation that led to the success of the Mars Exploration Rover Mission was the use of a multi-cell balloon that simply bounced and rolled on Mars' surface after impact.
Each mars rover was encapsulated by these balloons so that when they hit the ground, the force the robots absorbed were not enough to damage them.
We've got our own home-made Mars Rover articles here in Universe Today. Earlier, we mentioned that Opportunity was just departing from a large meteorite dubbed Block Island. Read more about that encounter by clicking on that link.
The Mars Exploration Rover Mission has its own site. You can even read each rover's latest activity there. If you'd like to read more about the Sojourner, here's a link to its own site too.
Tired eyes? Let your ears help you learn for a change. Here are some episodes from Astronomy Cast that just might suit your taste:
Nucleosynthesis: Elements from Stars
Advanced Propulsion Systems
Filed under: Astronomy
Tags: Mars, Mars Exploration Rover, mars rover, Mars Rovers, Opportunity, Sojourner, Spirit Rover
