Exploring Mars with Rovers
Tonight, we will take an exploration of the planet surface of Mars through the eyes of rovers. We will focus on the Mars Exploration Rovers, Spirit and Opportunity, and then discuss the larger rover, Curiosity. But first, let's go back in time to understand how Spirit and Opportunity made it to the surface of Mars.
Launching the Rovers
To get the rovers to Mars, we flew over to Kennedy Space Center in Florida and got up close with the Delta II rocket, built by the Boeing company. The rocket has three stages and nine airlit solids to provide extra lift. After ignition, the rocket reached orbit around Earth in just a minute and 30 seconds. We then dropped away the airlit solids and lit the second stage. We also spun the spacecraft to increase stability and lit the third stage to put us on a direct trajectory to Mars. After a seven-month journey, we approached the surface of Mars at 16,000 miles per hour.
Landing on Mars
As we hit the upper atmosphere of Mars, the friction caused the heat shield of our rover to reach temperatures of 1600 degrees centigrade. We then deployed a supersonic parachute to slow down and changed our angle of attack. The heat shield was discarded, and we used retrorockets to slow down further. We deployed airbags to cushion the landing and went through a series of bounces until we came to a stop. This process took about 45 minutes.
Deploying the Rover
Once the rover stopped, we deflated the airbags and opened up the lander petals and solar arrays. Now powered, we could start transmitting data back to Earth. The rover also took a panoramic image to determine its location. The next day, we stood up the vehicle, deployed the front wheels, and began exploring the surface of Mars.
Scientific Exploration
Spirit and Opportunity were designed to search for signs of water on Mars. They acted as roving geologists, examining rocks and analyzing their composition to understand the history of Mars. We also looked for scientifically exciting sites and took images to transmit back to Earth.
Driving on Mars
Finally, we drove the rover off the lander using batwings and got all six wheels on the surface of Mars. Spirit was the first rover to touch a rock called Adirondack, but unfortunately, it did not communicate back. Despite this setback, we continued our exploration of Mars.
During the seven-month period of driving through interstellar space, there was a significant solar flare that caused disruptions. To fix the computer onboard the spacecraft, it was turned off and then back on again. However, the computer's memory became full after eight days, and it had to be erased to continue functioning.
Despite being designed to explore the surface of Mars for only 90 days, the rovers Spirit and Opportunity exceeded expectations. Spirit communicated for over five years and traveled almost five miles, while Opportunity has been on the surface for over a decade and traveled over 25 miles.
Mars is an interesting place to explore due to its unique features, such as the Olympus Mons, the largest known volcano in the solar system. The rovers captured images of dust devils and discovered meteorites from other planets or the asteroid belt.
Opportunity is currently exploring Endeavour Crater, where it has found evidence of deep water and changes in salinity. Similarly, Spirit detected changes in salinity as it climbed Husband Hill, indicating the presence of water in the past.
Curiosity, launched in 2011, has already completed its one Martian year mission and traveled over 9 kilometers on the surface. It was launched using an Atlas rocket and has been a successful mission so far.
