the red planet. With far greater mobility than the 1997 Mars Pathfinder, these robotic

explorers have trekked for miles across the Martian surface, conducting field geology

and making atmospheric observations. During the rovers’ landings parachutes deployed

to slow the descending spacecraft, rockets fired to slow them still more just before

impact, and airbags inflated to cushion their landing.

After bouncing and rolling to a halt, a protective structure of petals opened and brought the

landers to an upright position, providing a platform from which the rovers drove onto

the Martian surface. Since leaving their landing sites, the twin

rovers have sent more than 100,000 spectacular, high-resolution, full-color images of the

Martian terrain as well as detailed microscopic images of rocks and soil surfaces to Earth.

Each rover weighs nearly 400 pounds. Their initial warranties of 90 days on Mars has,

to everyone’s surprise and delight, has turned into years.

It can take nearly 20 minutes for radio signals sent from earth to reach Mars…so the Rovers

couldn’t be driven in real time. Typical speed was just yards per hour…but Rover

driving was always a white knuckle experience. After an 8-week, mile and a half trek through

a desert of broken lava, Spirit finally reached the Columbia Hills. After reaching the Columbia

Hills Spirit found a variety of rocks indicating that early Mars was characterized by impacts,

explosive volcanism, and subsurface water….but it had become a monumental challenge for Spirit

because its solar panels….its only source of energy had gotten dusty and produced just

half as much power as they used to. Over 1,300 commands were sent to Spirit in

an attempt to elicit a response but no communication has been received from Spirit since March

22, 2010. Its total mileage remains unchanged at 4.80 miles. A series of attempts to revive

Spirit finally ended. What is really important is not only how long Spirit worked or how

far Spirit drove, but how much exploration and scientific discovery Spirit accomplished.

Opportunity however continues to function.

The next generation Rover however is ready to carry on with even more advanced instrumentation……and

its name is CURIOSITY. Curiosity is almost twice as long and five

times heavier (2,000 pounds) as Spirit and Opportunity. But before Curiosity can explore

Mars, it has to get there. The nose cone, or fairing, carrying the Mars

Science Laboratory (Curiosity) falls open like a clamshell and falls away. After this,

the rocket’s first stage cuts off and drops into the Atlantic Ocean.

The rocket’s second stage, a Centaur engine, is started and boosts the spacecraft out of

Earth orbit and sends it toward Mars. Once the spacecraft is in cruise stage toward

Mars, it begins communicating with Earth. The last stage gives the spacecraft a final

push for its 8 ½ month cruise to the red planet.

Hitting the atmosphere at about 13,000 miles per hour, the spacecraft begins to slow down.

While slowing down, the spacecraft uses thrusters to help steer toward the landing site.

It throws off weights to rebalance the spacecraft, so that it is lined up for the parachute deployment.

Once it is below the speed of sound, the heat shield separates and the spacecraft looks

for the ground with the landing radar. Once it reaches an altitude of about 1 mile,

the spacecraft drops out of the back-shell at about 200 miles an hour. It then fires

up the landing engine to slow it down even further.

Once it has descended to about 60 feet above the ground, and going only about 2 miles per

hour, the rover separates from the descent stage. As the rover is lowered, the wheels

deploy in preparation for landing. Once the rover is safely on the ground, and

touchdown has been detected, the descent stage cuts the rover loose. It flies away leaving

Curiosity safe on the surface of Mars. One of the first things Curiosity does after

landing is to deploy the mast, which supports many cameras and instruments.

The Curiosity rover has 10 science instruments including:

A gas chromatograph, a gas spectrometer, and a tunable laser spectrometer to identify a

wide range of organic compounds. An x-ray diffraction and fluorescence instrument

named CheMin designed to identify and quantify minerals in rocks and soils.

A Hand Lens Imager to take extreme close-up pictures of rocks and soil revealing details

smaller than the width of a human hair. An Alpha Particle X-Ray Spectrometer to detect

different elements in rocks and soils. A Camera mounted on the Mast capable of capturing images

of the rover’s surroundings in high resolution and color.

An instrument named ChemCam capable of vaporizing thin layers of material from rocks or soil

designed to identify atoms and capture detailed images of the area.

The drill on the arm allows it to grab some of that rock and deliver it to the laboratory

instruments inside the body of the rover. And the Radiation Assessment Detector to analyze

the radiation environment at the surface. This information will be necessary for planning

human exploration of Mars and its ability to sustain life.

Those instruments can get us even closer to understanding whether life could have existed

on Mars.

Curiosity will be exploring the red planet for at least 2 years ……and ….there’s

no telling what we will discover.