### Overview

Students design, build and program a robotic “super crawler” to transport a payload from a starting position to a target launch pad, use a robotic arm with an end effector to deliver the payload in an upright position and return the robot to the starting point. Students will use the engineering design process to guide them in completing the challenge.

Students will:

• Understand ratio concepts and use rate reasoning to solve real-world problems.
• Create an engineered model, limited by criteria and constraints, designed to achieve the task of solving a complex problem.

Science and Engineering Practices

• Asking Questions and Defining Problems
• Engaging in Argument from Evidence

Disciplinary Core Ideas

• Defining and Delimiting Engineering Problems
• Developing Possible Solutions
• Optimizing the Design Solution

### Management

• This lesson can be completed individually or within a group, although groups of two to three students of varied skill levels are recommended.
• The students need to have completed enough practice programs with their assigned robots to understand how to make their robots move straight for a distance using wheel rotations. The students will be applying their knowledge of ratios and rate reasoning to determine the appropriate number of rotations for the distance required in the challenge.
• The speed of the crawler may play a role in transporting the rocket safely to the launch pad, and the speed of the arm or end effector motion may affect the delivery of the rocket to the target in an upright position. The arm end effector design and delivery method are entirely up to the designer(s) as long as they are within the design constraints and meet the criteria for the challenge.
• Students should be encouraged to draw upon their personal and cultural experiences throughout the design process.
• Students without physical access to a robot can use a virtual coding environment, such as VEXcode VR or a virtual EV3 coding environment to develop block- or text-based code that can be executed on a virtual robot.

### Background

On Dec. 29, 1980, a crawler-transporter moves the space shuttle Columbia to the launch pad before the first shuttle flight, STS-1. Image credit: NASA

How would you transport an 18-million-pound rocket and mobile launch pad three miles and deliver it upright for launch? What kind of grapple, end effector or robotic hand would be best suited for holding and moving such a massive object?

For more than 40 years, the twin crawler-transporters at NASA's Kennedy Space Center slowly traveled the gravel track between the massive Vehicle Assembly Building and the two launch pads at Launch Complex 39. These mammoth vehicles first carried the Apollo Saturn V rockets, and later the space shuttles, before they were launched into space. The technology used to build these huge, reliable crawlers capable of such herculean tasks was deeply rooted in a region where giant machines excavated and extracted veins of coal.

With the future of Space Exploration calling for super-sized exploration vehicles, NASA now needs super crawlers. Upgrades to crawler-transporter 2 in 2016 allowed for an increase in the lifted-load capacity from 12 million to 18 million pounds to support the weight of the mobile launcher and future launch vehicles, including the Space Launch System (SLS) rocket and Orion Multi-Purpose Crew Vehicle.

NASA’s Artemis program will return humans to the Moon by sending the first woman and the first person of color to the lunar surface. A foundational piece of the program is the Space Launch System, a rocket that will allow for human exploration beyond Earth’s orbit. SLS will be used in the Artemis program for a series of uncrewed and crewed missions, eventually carrying astronauts to the Moon during the Artemis III mission. NASA plans to continue sending missions to the Moon about once a year after that while also using SLS to launch robotic scientific missions to places like the Moon, Mars, Saturn, and Jupiter.

### Procedures

1. Familiarize yourself with the engineering design process (shown in the graphic below) and use the following description to frame the challenge for students.
2. #### Identify the problem

Ask students to consider how would you transport an 18-million-pound rocket and mobile launch pad three miles and deliver it upright for launch? What kind of grapple, end effector or robotic hand would be best suited for holding and moving such a massive object?

For this challenge, students will need to build a robot to simulate this rocket transportation technique.

#### Criteria for Success

For this challenge, students must:

• Equip a robot crawler to transport a payload.
• Program the robot crawler to transport the payload to a launch pad 91.5 cm (about 3 feet) away.
• Return the robot crawler to the starting point.

#### Engineering Constraints

• Once students run the program, they must not touch or apply any outside force to the robot or the payload.
• Only programmable motors can be used for arm controls, no sensors.
• The challenge relies solely on wheel rotations for distance and power management for speed. No other sensors may be employed in the challenge.
3. Show students the playing field designed.
4. Explain constraints, including rules and time limits, as detailed in the student guide
5. Take questions from students regarding the challenge.
6. Monitor student teams for teamwork and to make sure all team members are actively engaged in the challenge. Note: Students will tend to gravitate toward their interest and comfort areas. Though a balance of strengths in a team is important, make sure all team members get some experience with all aspects of the challenge: brainstorming, designing, building, programming, troubleshooting and presenting.
7. When time is up or as each team is ready, have them run the course. Have other teams serve as judges and scorekeepers for each run.
8. Due to the variety of solutions and student skill levels, groups may finish at different times. Students who finish early can explore the extensions section below or add features to their robot such as messages on screen, flashing lights, sounds, etc.
9. After all students have completed the challenge, provide teams with time to create a reflection about their challenge and design process experience. Reflections should include a component for academic language, and detail the obstacles faced and how they arrived at solutions. These reflections can take the form of a written sample or class presentation.

### Discussion

• What did you try that didn’t work out? How many times did you try it?
• What did you do when things didn’t work out like you expected?
• If given more time, what would your next step look like?

• What obstacles did you or your group face in this challenge?
• How did you and/or your group confront these obstacles?
• What was your favorite part of the engineering design process?
• What do you think you have learned from this process you didn’t know before?
• Consider asking students about their knowledge of heavy machinery: Big jobs sometimes require heavy machinery. What heavy machines with wheels or “tracked wheels” have you seen?
Answers will vary. Examples could be tractors, combines, backhoes, dump trucks, bulldozers, etc. Ask probing questions to learn more about students’ background knowledge about these machines. Perhaps relatives work with heavy machines or they have a tractor or combine at home for farming.

### Assessment

Points for this challenge will be as follows:

 Carry the payload from the start position to the target without loss 10 points Deliver the payload in an upright position 20 points Return the super crawler to the starting position 10 points Payload not delivered upright for launch -2 points Loss of payload -2 points (each instance) Touch the payload or super crawler outside of the start position -2 points (each instance)

Example scoring rubric:

 Expert Proficient Intermediate Novice Prototype Description Drawing clearly marks key features of the prototype critical to the function and meets the needs of the problem. Description fully discusses all components of the prototypes and how they address the needs of the problem. Drawing clearly marks key features of the prototype critical to the function and meets most of the needs of the problem. Description discusses components of the prototypes and how they address the needs of the problem. Drawing marks a couple key features of the prototype critical to the function and meets a couple of the needs of the problem. Description discusses components of the prototypes. Drawing marks a key feature or two. Description and design reflect only the personal interests of the group. Challenge Completion Scored 50 points Scored 36-49 points Scored 21-35 points Scored Below 0 - 20 Designing Reflection Reflection fully acknowledges the need to fail and make multiple iterations, yet is still forward thinking to the next steps of the design. Reflection fully acknowledges the need to fail and make iterations, yet is still forward thinking to the next steps of the design. Reflection fully acknowledges the need to fail and make iterations and there are next steps but these are undefined. Reflection discusses the success of the first or second prototype and points to this as the final product. Thinking Reflection Reflection fully acknowledges the obstacles during the process and provides concrete examples of learning as a result of these obstacles. Reflection acknowledges the obstacles in the process and provides a concrete example of learning as a result of these obstacles. Reflection acknowledges the obstacles in the process and makes an unspecified claim about learning as a result of these obstacles. Reflection discusses the success without mention of obstacles or learning opportunities.

### Extensions

Students can do further research on sensors included with their robot to improve the design and make their Super Crawler more effective. After researching and practicing programs using sensor capabilities along with rotations and arm movement, the challenge could be repeated with turns or obstacles in the pathway to the target.

### Explore More

This material is based upon work supported by the NASA STEM Educator Professional Development Collaborative at Texas State University under the NASA cooperative agreement award number NNX14AQ30A.