by Mark Ollig
“The Curiosity landing is the
hardest NASA mission ever attempted in the history of robotic planetary
exploration,” said John Grunsfeld, associate administrator for NASA’s Science
Mission Directorate, at NASA Headquarters in Washington.
Equipped with 17 on-board cameras,
this six-wheeled, 1,982-pound, car-sized, robotic-rover called the Mars Science
Laboratory (MSL) Curiosity, traveled more than 350 million miles on its voyage
to Mars.
Currently, the MSL Curiosity rover
is located approximately 158 million miles away from us, stationed on the
surface of the planet Mars since its landing Aug. 5.
Curiosity is being powered not by
solar cell panels (as were the previous, smaller rovers, Spirit and
Opportunity), but with something called a Multi-Mission Radioisotope
Thermoelectric Generator (MMRTG).
The MMRTG draws its power by
generating electricity from the heat caused by the natural decaying of the 10.6
pounds of Plutonion-238 which is encased inside the rover.
The Plutonion-238 is a non-weapons
grade material, and is constantly dissipating heat, which powers the Mars rover
during the day and night.
There are advantages to using this
“nuclear battery” (as NASA calls it) instead of solar cells – which are
dependent upon sunlight.
Some advantages of using the MMRTG:
• Curiosity will be able to operate
24 hours a day.
• Longer mission: Using the MMRTG
with Plutonion-238 means Curiosity should have a minimum operational lifetime
of 14 years.
• The MMRTG is smaller and lighter,
compared to a typical rover’s solar power plant.
• There is no need for a separate
heating system, as “waste heat” from the MMRTG is circulated throughout the
rover and is used as a thermal control system to keep its instruments,
computers, mechanical devices, and communications systems within their
operating temperature ranges.
• MMRTG has little or no sensitivity
to cold, radiation, or other effects from being in space or in the Martian
environment.
• Much more of the surface of Mars
will be able to be explored.
“Curiosity is a geo-chemical
experiment we are sending to Mars,” said Ashwin Vasavada, Mars Science
Laboratory deputy science manager of NASA’s Jet Propulsion Laboratory.
Curiosity is seeking to find
evidence of the conditions needed which could have sustained life on Mars in
the past.
“We’re not actually looking for
life; we don’t have the ability to detect life if it was there. What we are
looking for is the ingredients of life,” said John Grotzinger, project
scientist, Mars Science Laboratory Mission.
Scientists are looking to see if
Mars could have ever supported microbial life.
This robotic, exploring vehicle
takes with it to Mars, 10 science instruments.
The total size of these instruments
is 15 times larger than the scientific payloads the Spirit and Opportunity Mars
rovers have.
One of these tools includes
Chemistry and Camera (ChemCam).
ChemCam is a laser-firing device
that will shoot a highly focused pulsed laser beam at rocks from a distance.
The beam, according to NASA, produces a flash of light from the ionized
material, or plasma, which can be analyzed to identify chemical elements in the
target. This laser device is the first of its kind to be used on Mars.
Another instrument Curiosity will
use is a drill and scoop, which is located at the end of its 7-foot robotic
arm.
This will allow the rover to gather
soil and powdered samples of various rock interiors; these samples will be
filtered and sent into one of Curiosity’s instrument laboratories for further
analysis.
Curiosity is located inside the Mars
Gale Crater, which has layers of rock extending from its mountainous edges. The
specific scientific experiments designed for exploring these layers are within
the rovers driving distance.
NASA reported observations from
orbit over Mars “have identified clay and sulfate minerals in these lower
layers, indicating a wet history.”
Some have said Gale Crater was once
a large lake or ocean.
Curiosity has an onboard central
computer that continuously monitors its operational status, and verifies
commands are being executed. This computer also manages communications to and
from Earth, and to spacecraft orbiting Mars which can relay any information
from the rover to Earth.
The planning for this latest Mars
rover exploratory operation began in 2004.
The cost for the Curiosity mission
to Mars: $2.5 billion.
The Curiosity rover will be able to
traverse the surface of Mars at a top speed of 1.5-inches per second.
I had finished my junior year of
high school when on July 20, 1976; NASA’s Viking 1 Lander became the first
spacecraft to successfully land on Mars after detaching from the Viking 1
Orbiter, which continued to circumnavigate the red planet.
The Viking 1 Lander took soil sample
measurements and sent pictures of the Martian landscape back to Earth.
The second picture sent to Earth was
a 300-degree panoramic view of the Martian surface. You can see this picture
at: http://tinyurl.com/ct76qts.
The picture of the famous “Face on
Mars” located in the Martian Cydonia region, taken in 1976 by the Viking 1
Orbiter, can be seen here: http://tinyurl.com/8emryo9.
The Viking 1 Lander used two
Radioisotope Thermal Generator (RTG) units which contained a plutonium 238
element.
The Viking 1 Lander was operational
on the Martian surface region called Chryse Planitia, for six years. It ended
communications with the Earth on November 13, 1982.
The Viking 1 Orbiter ended
communications Aug. 17, 1980; however, it will continue to orbit Mars until
2019.
To stay current on the
up-to-the-minute news regarding NASA’s latest robotic rover mission to Mars,
check out the MSL Curiosity Rover homepage at: http://mars.jpl.nasa.gov/msl/.
