The Robot with an Achilles' Heel

The Robot with an Achilles' Heel

1The Maple Street Robot Club had three weeks to get ready for the city Robot Rally. Their robot, Bolt, had to roll through a cardboard maze, pick up a foam block, and drop it into a bucket. On the first day, Mr. Okafor tipped a giant bin of tiny screws, gears, and wires onto the table.

2"We have to sort all of these first," he said. Priya stared at the mountain of parts. Sorting them seemed like a Herculean task. It took Priya, Jun, and Mateo two whole afternoons of hard work.

3Jun wrote the first program for Bolt, and it worked on the first try. So did his next program, and the one after that. "You have the Midas touch," Priya told him.

4Mateo built Bolt's gripper arm. He tinkered with it every day, tightening a screw here and bending a wire there, until the arm could grab the block without dropping it.

5Next, the club tested Bolt on the smooth gym floor. The robot zipped through the first turn. Then its left wheel began to slip, and Bolt slid sideways into the maze wall. The same thing happened on every test. Bolt could steer, grab, and drop the block, but that slippery wheel was its only weak spot. "That wheel is Bolt's Achilles' heel," Mr. Okafor said.

6The night before the rally, Mateo asked, "What if we add a second arm and rewrite the whole program?" Priya shook her head. "That would open Pandora's box," she said. "If we change one thing, five new problems could pop out." Instead, the club wrapped a thin rubber band around the left wheel so it would grip the floor.

7At the rally, Priya felt jittery. Her hands shook as she set Bolt at the start line. Bolt rolled through the maze, scooped up the block, and dropped it into the bucket. The run was flawless, without a single bump or slip. The crowd cheered. Bolt's weak spot had become a strong one.

Myth Notes

Hercules: In Greek and Roman myths, Hercules was a hero known for his great strength. He finished twelve very hard jobs that seemed impossible.

Achilles: In Greek myths, Achilles was a great warrior. When he was a baby, his mother dipped him in a magic river to protect him, but she held him by one heel. That heel was the only place he could be hurt.

Pandora: In a Greek myth, Pandora opened a jar, often called a box, that she was told to keep closed. All kinds of troubles flew out into the world.

King Midas: In a Greek myth, King Midas wished that everything he touched would turn to gold.