Last week, the 8th-grade Earth Science students at Arrowhead Middle School continued to study our solar system. Since the week had focused primarily on the technology we use to explore space, I thought that Friday would be the perfect time to talk about my favorite research area—robotics! So the focus of Friday’s lesson was on Mars exploration, and my goal was to provide the students with some hands-on experience studying how robots are being used to collect data and perform scientific experiments on Mars.
I began with a quick review of the space exploration technologies that the students have been studying in class, such as orbiters and landers, and described how NASA has been using these technologies to study Mars. Next, I introduced the rovers that NASA has designed to study the climate, geology, and history of Mars: Sojourner, Spirit, Opportunity—and the new NASA rover currently en route to Mars—Curiosity.
For the remainder of the class, I had the students perform their own Mars exploration mission to learn about the many difficulties that NASA scientists must overcome when communicating with and performing experiments with robots that are a tremendous distance from Earth. For example, since the scientists at NASA only have a 3-hour window each day in which they can communicate directly with the Mars rovers, they must pre-plan an entire day’s worth of actions and experiments that can be sent to the rovers during this brief time. For the remainder of the day, the rovers then attempt to perform these actions without any further instruction from Earth, and any failures in completing these actions must wait until the following day to be corrected.
To demonstrate this process, the students were separated into two teams, which competed against each other using remote-controlled “rovers” within a simulated Martian environment to complete a variety of Mars science objectives, such as analyzing unique minerals, searching for signs of water and alien life, and retrieving atmospheric data.
Each team was composed of two groups: the NASA scientists, which were responsible for determining the current mission and planning the daily sequence of rover actions that they hoped would complete their mission (such as driving forward, turning left or right, or driving backwards), and the rover drivers, which would then execute exactly the provided sequence of daily rover instructions—outside of view of the Martian environment and without further instruction from the NASA scientists. After each day’s actions had been performed by the rover drivers, the NASA scientists would reconvene to determine how accurately their actions had been carried out, and whether any further adjustments would be necessary to complete their current mission.
Since each action provided to the rover drivers had to be specified with an exact time duration (e.g., drive forward 2 seconds, turn left 1/2 second, or drive backwards 1 second), each team first had to perform calibration measurements on their rover, during which they determined the average distance traveled by their rover for a variety of time durations and directions. These measurements were then used by the NASA scientists when planning their daily rover actions, and the ultimate success of these actions depended significantly on how accurately these initial measurements had been taken.
Throughout the day, the students had varying levels of success with this activity. The first class period did not carefully measure how far their rover traveled over different periods of time, and subsequently had a very difficult time planning actions that would cause their rover to end up in the desired location. For the next two classes, we made sure to stress the importance of the calibration stage of this activity, and watched closely that both teams took accurate measurements. This caused the teams to be much more effective at predicting where their rovers would end up, and allowed them to successfully complete many more of the mission objectives.
Of course, the students would still occasionally get frustrated when the rover actions they had planned caused their rover to end up very far from the desired location, or, even worse, to become stuck in the dangerous Martian rocks. However, this caused the students to begin to appreciate the difficulty of performing scientific experiments with robots on Mars, and that these are the same frustrations that the NASA scientists struggle with and have to overcome every day. Overall, the students all had a lot of fun participating in this activity (and I certainly had a lot of fun watching them try to drive their rovers around without looking!), and I think this activity did a good job of conveying some of the complexities of using robots to explore difficult environments in the real world.