Prototype Mars Rover Completes Simulated Mars Trek

From: (by way of Jan Wee <>)
Subject: Prototype Mars Rover Completes Simulated Mars Trek
Date: Wed, 11 Jun 1997 08:33:52 -0500

Dear discuss-lfm members,


I believe that Sheri Klug, PTK Advocate from Idaho,
participated in the TEST DRIVE.  Sheri, if you are accessing
your email, perhaps you can give us an update on the 

Jan Wee, moderator

Douglas Isbell
Headquarters, Washington, DC             June 10, 1997
(Phone:  202/358-1753)

Diane Ainsworth
Jet Propulsion Laboratory, Pasadena, CA
(Phone:  818/354-5011)

RELEASE:  97-130


     NASA's newest, six-wheeled prototype Martian rover -- 
nicknamed Rocky 7 -- has successfully passed its most rigorous 
field test yet, traveling six-tenths of a mile over rugged, Mars-
like terrain, while conducting science experiments and snapping 
580 photographs along the way.

     The week-long series of field tests, carried out May 23-30 at 
Lavic Lake, an ancient lake bed about 175 miles east of Los 
Angeles, CA, was designed to simulate several weeks of a real Mars 
rover mission and to test the rover's ability to drive much 
greater distances than current rovers.  In addition, Rocky 7 
conducted five simulated science experiments in real-time and 
collected samples of soil and rocks that would be retrieved and 
returned to Earth by a later Mars mission.

     "One of the chief objectives of these tests was to test Rocky 
7's ability to traverse farther over a wide variety of terrain 
with more Mars-like characteristics than we did in the last set of 
tests in December 1996," said Dr. Samad Hayati, Rocky 7 task 
manager at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA.  
"The rover actually traveled about 80 percent farther than it 
traveled in the last set of tests, over three distinct terrains, 
using a minimum of instructions from us to guide its way."

     The Rocky 7 rover represents the newest model of rovers that 
may be sent to Mars in the years 2001 and 2003.  It looks, 
however, very similar to its predecessor, Sojourner, which will 
land on Mars on July 4.  Rocky 7 weighs slightly more than 
Sojourner at 33 pounds and has about the same dimensions -- 
measuring 19 inches wide by 25 inches long by 12.5 inches tall.  
Rocky 7 also sports the same six-wheeled chassis and spring-less 
"rocker-bogie" mobility system, which allows the vehicle to 
conform to the contours of the surface and scale objects almost as 
tall as itself without tipping over. 

     Continued robotic exploration of Mars in the next century 
will focus on the search for water and evidence to confirm hints 
that life may have existed once in Mars' early history.  
Successive Mars missions will be designed not only to examine the 
planet's composition, atmosphere and weather, but also to identify 
natural resources that could be mined and used for eventual human 
expeditions to the red planet.

     The southern side of Lavic Lake, located in the Twenty-Nine 
Palms Marine Corps Base near Palm Springs, CA, was chosen for the 
field tests because it is a playa, analogous to some regions of 
Mars, with areas of lava flow, cracked mud, terrain strewn with 
basalt rocks and an alluvial fan. 

     Rocky's travels began on a basalt flow covered with 
cobblestones resting in a layer of wind-blown silt, which offered 
a variety of obstacles for the robot to hurdle.  Engineers tested 
some of the rover's new features, such as a 12.5-inch manipulator 
arm with four degrees of freedom.  Mounted on the front of the 
vehicle, the arm carried a "point reflectance" spectrometer that 
could be extended four inches in any direction to study the color 
of various surfaces.  In future rover missions on Mars, science 
instruments on the rover arm will help researchers determine the 
composition of surface soils and rocks.     

     Engineers also tested a 4.5-foot, antenna-like mast, which 
would be deployed once the future rover was out and about on Mars.  
The mast has three degrees of freedom and can be used in much the 
same way as an arm to deploy science instruments against rocks or 
align them in the nadir, or down-pointing, position.  Two science 
instruments -- a Moessbauer spectrometer and a nuclear magnetic 
resonance spectrometer -- were mounted on the mast to study surface 
rocks with different types of coatings, such as red iron oxide and 
desert varnish, which might be found on Mars.  To carry out the 
variety of science experiments performed during the week, Rocky 7 
had to raise its mast 85 times.   

     Rocky 7 carried a pair of stereo imagers on the front and 
back of the vehicle, which acted as its "eyes."  The rover was 
furnished with simulated descent imaging to recreate landing, then 
asked to deploy its mast and begin each traverse and sequence of 
imaging and science experiments.

"Images and science measurements were obtained in several 
regions of the basalt flow," said Dr. Richard Volpe, chief 
engineer on the rover development team at JPL.  "This pavement of 
basalt boulders and outcrops offered many terrain obstacles for 
rover navigation and numerous targets for the rover to measure 
cobbles and the underlying dust."

In the second journey, the rover set out over the playa, 
strewn with craters and ejecta fields, and traveled into a crater.  
Using its mast and arm, the vehicle was able to measure properties 
of the mud-cracked floor.  Rocky 7 also took images of its own 
tire tracks to help scientists update its location.  

"The rover conducted several long traverses across the playa 
floor, taking images of the tracks left by its wheels so that we 
could trace its path," said Dr. Raymond Arvidson, science team 
lead and chairman of the Earth and Planetary Sciences Department 
at Washington University, St. Louis, MO.  "The tracks are used to 
update positional information, after the observations are 
completed and help us map out the vehicle's next route."

The last excursion was the most challenging -- an obstacle 
course taking the rover over an alluvial fan extending from the 
nearby mountains.  There, Rocky 7 was asked to use its science 
instruments to look for evidence that water had been transported 
to the sediment and to explore the region for cobbles and boulders 
that had come from volcanic rocks, just as it will do on Mars some 

"Imaging and spectroscopy data were acquired for the fan 
rocks and fine-grained sediment, and samples of the sediment were 
collected," Arvidson said.  "The data are currently being analyzed 
and will be used to fine-tune rover designs and operations and to 
evaluate what can be learned about ancient lake environments and 
desert pavement formation." 

By the end of the week, the rover had returned 580 images to 
remote operators in the field and those stationed at JPL.  The 
field test simulated 32 days of a real Mars rover mission.

Classrooms across the country and as far away as Finland 
participated in a remote driving test on the last day of the field 
work. The demonstration was designed to determine how well the 
vehicle could be controlled remotely using a World Wide Web 
operator interface called the Web Interface for Telescience.  Six 
schools in California, Oregon, Georgia, Idaho, Texas and Finland 
participated in the exercise to command the rover from their 
classrooms, as scientists will do one day from their home 

     Additional information about the field tests is available on 
the World Wide Web at: 


     More information about rover development for future Mars 
missions is also available at: 


The Rocky 7 rover development and field testing was 
supported by JPL's Robotics and Mars Exploration Technology 
Program Office for NASA's Office of Space Science, Washington, DC.