Lunar Rover Vehicle Design : Research-Working Experience at NASA Human Exploration Rover Challenge
Lunar Rover Vehicle Design : Advisors
Ravi Margasahayam Dr. Ashiqur Rahman
NASA-Jet Propulsion Laboratory
Mechanical & Wheel Engineering Material Engineering
Dr. Lafifa Jamal Prof. Anower Khan
Robotics & Communications Science & Report Writing
Md Khairul Islam
Bangladesh Team Leader at NASA
Team Leader & Led Engineer
The next stage of lunar rovers will prove to be an integral piece of future space markets.
These rovers will also be expected to participate in an eventual colonization of Mars.
The original human-powered lunar buggy pictured above is named Bangabandhu Rover 71, designed and built by Team 71 Bangladesh.
This buggy was built for racing on a simulated extraterrestrial obstacle course at Marshall Space Flight Center.
This simulated obstacle course is NASA’s annual competition named NASA Human Exploration Rover Challenge and its mission is to develop new technology for future mission planning and crewed space missions to other worlds.
So this obstacle challenge is different from any other race that exists in the world. Because it was designed to mimic the types of the terrain potentially found on the moon, Mars, or other distant destinations and our astronauts will soon explore.
Bangabandhu Rover 71 is a lightweight, advanced technology and sensor-based, suspension-based, mechanically fastest rover that is usually made for the Nasa human exploration rover challenge.
NASA human exploration rover challenge can’t be described in just one word. Each year hundreds of students from high schools, colleges, and universities around the world just like us begin an eight to ten-month journey.
First of all, every team has to face a quiz round, and then they have to go through the engineering design process.
All over the competition, all teams have to show their abilities in computer and mechanical engineering, computer modeling, fabrication, welding, and 3D printing.
In addition to modeling and building the rovers, the team must also utilize a host of other skills to showcase their work including marketing, communications, web and social media design, even fundraising.
That’s because the Rover challenge is more than just a race, it combines several aspects of real-world careers into one exciting experiential design challenge. After all the design and testing are done, the teams pack their bags and rovers and head to the rocket city.
This Rover Challenge aligns with the Artemis mission that helps To create networking with NASA scientists and engineers, to develop long-lasting relationships with peers and colleagues around the world, to enhance their skills in the STEM- Science, Technology, Engineering, and Math- field.
Oh, yeah, and to earn a year’s worth of bragging rights. While rover challenges put students in the driver’s seat of their education it’s still a race, a race where awards and prizes are offered for many accomplishments.
Not only by completing the course with the shortest vehicle assembly time and race times all while avoiding costly penalties but for having the lightest rover, the best report, the best website, being the most-improved team, and so much more awards available for teams.
NASA’S CHALLENGE JOURNEY:
NASA is neither affiliated, sponsors nor endorses any Rover competition other than the NASA Human Exploration Rover Challenge.
NASA’s Human Exploration Rover Challenge aligns with the Artemis mission to return to and explore the Moon by 2024. The Artemis program will prepare us for the Moon and propel us on to Mars.
NASA plans to send the first woman and next man to the Moon by 2024, and develop human presence by 2028.
The NASA Human Exploration Rover Challenge (NHERC) is an annual competition and the first race of this competition, in 1994, was held on July 16, the 25th anniversary of the Apollo 11 launch.
After some period since 1996, the U.S. Space & Rocket Center hosts. The NASA Human Exploration Rover Challenge (NHERC), prior to 2014 referred to as the Great Moonbuggy Race.
The first two events were held at the original track used for testing lunar rover candidates.
An Explanation of Shuttle Columbia Disaster
This rover competition emphasizes designing, constructing, and testing technologies, including tools, mobility devices, and traversing in unique environments. So this course required some specific requirements let me elaborate.
This competition course requires two students, one female and one male, to traverse a terrain of approximately 0.50 miles (805m) that includes a simulated field of asteroid debris—boulders from 5 to 15 inches across; an ancient stream bed with pebbles approximately 6 inches deep; and erosion ruts and crevasses of varying widths and depths.
This challenge has a weight factor and time requirements that encourage the rover’s compactness, lightweight, high performance, and efficiency. As part of the competition—before teams’ first time on the course—rover entries are tested to see that they would fit into a lander equipment bay, a maximum 5 feet long by 5 feet tall by 5 feet wide in volume.
This student design challenge encourages the next generation of scientists and engineers to aid in the design process by providing innovative designs and unique perspectives. The challenge also continues the agency’s legacy of providing valuable experience to students who, someday, may be responsible for planning future space missions, including crewed missions to other worlds.
To draw ambitious, innovative high school and college students into the next great era of space exploration — helping NASA develop ingenious new technologies and solutions to explore a variety of solar system destinations in the decades to come.
Team 71’s Bangabandhu Rover 71, basically a human carrying rover for the off-road that was made by some mechanical engineering mechanisms. Rover distributed in two parts. One of them is the rover body/chassis part and the second one is the outer part.
The chassis is perfectly foldable and the rover chassis is 8 feet long, 0.6 feet tall.
Rover has a folding point in 3.5 fits so that it easily fulfills NASA’s required maximum 5 feet long by 5 feet tall by 5 feet in volume.
For building this Bangabandhu Rover, Team 71 worked at our laboratory see pictures below of our main chassis, foldable joint & our incomplete first rover:
WORKING ON LATHE, WELDING, ELECTRIC SAW CUTTER
The chassis is a very important part of a rover and plays the key role of load-bearing or structurally supporting the object in construction and function. Bangabandhu Rover 71’s mechanical foldable chassis part is very simple, it looks like a triangular prism tube with a hinge mechanism for the fold.
The hinge mechanism uses a door but here, we take the technology and introduce it in our rover for perfect folding movement. This door hinge mechanism in our rover works for folding and holds two solid parts of the rover that typically allow only a limited angle of rotation between a fixed axis of rotation.
3D MODELING WHEEL
2D DESIGN BASIC WHEEL (below)
The second part of the rover is the outer parts and it locates the farthest from the main body (chassis part). It contains the wheel, steering, seat, suspension, shock absorber, differential, gear, brake, chain, safety kit, communication-technology, sensor, etc.
In this NASA Human Exploration Rover Challenge we all have to design, build, and test vehicles that are capable of traversing hills up to 5 feet(~1.5 meters) high and pathways inclined up to 30 degrees in their direction of travel.
And also vehicles should be capable of having a turning radius of 15-foot (4.57 meters) or less. Moreover, Vehicles should be designed for both speed and the ability to perform on the unique terrain.
So wheels will be a key factor for this kind of Rover, in that case, we all have to design and fabricate non-pneumatic wheels, inclusive of the outer surface (treads) making contact with the terrain and the supporting structure (rims, spokes, etc.).
And only hubs containing bearings or bushings may be commercially used as a component of the wheel. In Bangabandhu Rover 71, we used 4 pieces of the custom wheel which are shock absorber based mechanical soft wheels.
Given it is a human-powered rover so we break the conventional theory and introduce a double power-up system by using two mechanical differentials on the back and front sides.
As a result, we can ensure the highest efficiency and speed as well. In the steering system, we use the conventional rack-and-pinion mechanism steering system that is so effective in off-road movement.
As we all can guess, the rover requires two-seat and here we use a suspension based custom seat because it ensures the highest percentage of the safety of the off-road.
Let’s come to the most important part of this rover, the paddle system. Paddling is an important part of every non-electric rover because it is the only power source of that rover.
So here we introduced the latest technology in our rover that is the retro-direct mechanism paddling system.
This mechanism allows the drivers’ seat opposite each other but paddling together and in one direction. This mechanism helps to make the rover unique, besides there is some use of computer engineering and modeling, communication technology, and sensors.
Many of the drivers are injured so NASA requires real-time communication with the drivers for safety issues. NASA’s competitions field requires two types of communication one is direct audio communication and another one is a live video streaming.
TELEMETRY AND COMMUNICATION:
Here Team 71 introduces new technology and builds a duplex communication system that can communicate with two or more connected parties or devices that can communicate with one another in both directions.
It takes data from the ground-station and then transmitted to the receiver of the driver and on the other hand, it’s also able to catch the data from drivers and transmit to the ground station.
For transmitting audio voice, we use a two-way radio communication system that is also known as a handheld transceiver (HT). Sometimes we called it a “walkie talkie” or a “handheld.”
During NASA’s race time, we have to maintain real-time audio communication for safety issues. In that case, we use the “MOTOROLA 2 Way Radio 5720” that gives us a range of 1-3k kilometers.
MOTOROLA 2 WAY WALKIE TALKIE
Direct your attention to the video transmitting part first of all let me share some pictures.
TRANSMITTING LIVE VIDEO
For transmitting live video streaming, we use radio technology, as I previously said the motive to make this rover is to run in the low-gravity vacuum of the Moon and to be capable of traversing the lunar surface for helping astronauts.
So, in Earth-Moon-Earth communication (EME) is based on radio communications technique that relies on the propagation of radio waves from an Earth-based transmitter directed via reflection from the surface of the Moon back to an Earth-based receiver.
So in the rover, we ensure the same communication technology that is First-person view (FPV).
An FPV video transmitter(VTx) is an electronic circuit which transforms the video signal from a power source into a radio frequency alternating current to apply to the antenna, and the antenna radiates the radio waves and then the FPV video Receiver (VRx) extracts the information from the received waves.
The FPV has four essential parts which are FPV video transmitter(VTx), FPV video Receiver (VRx), camera, and monitor. Here the video transmitter(VTx) sends the video from the FPV camera to a video receiver.
The signal received can be processed then displayed on a monitor in a video form with the video transmitter(VTx) connected to an FPV camera. Here in the rover, we use the most popular FPV 5.8 GHz frequency that gives us a range of 10-20 kilometers.
COMPUTER ENGINEERING AND MODELING-
In this Rover, we use some advanced sensors and an artificial intelligence-based safety alarming system.
Computer modeling is very important at an engineering project, a 3D design can easily show dimensions in the 3D space of objects and their relationships and that will help us to visualize space, movement, access, and so on.
The great thing about the 3D models are, they can be physically created using 3D printing devices and in our rover, we use some 3d printing parts.
First of all, we designed some 2d sketches of our Rover, then we finalized one of our 2d designs and then went for the 3d modeling in SolidWorks. It helped to develop our mechanical systems from beginning to end. And also helped with planning, visual ideation, modeling, feasibility assessment, and prototyping.
In our rover, we did need some 3d printing help, especially needed for assembling and fixing the audio and video transmitting devices to our Rover. We used SolidWorks for Rover simulations, it helped us in R&D and overall build the BANGABANDHU ROVER 71.
TASK, OBSTACLE AND MATERIALS-
This NASA Human Exploration Rover Challenge offered so many awards and for achieving all those awards NASA gives participants 14 obstacles and 5 tasks all over the race.
All the obstacles and tasks, carry points, and if participants complete that task/obstacle then they will get the task/obstacle’s point.
Let me share all the obstacles and tasks names:
Undulating Terrain, Crater with Ejecta, Transverse Incline, High Butte – Martian Terrain, Large Ravine – Martian Terrain, Sand Dunes – Martian Terrain, Crevasses, Ice Geyser Slalom, Lunar Crater, Bouldering Rocks, Tilted Craters, Loose Regolith, Pea Gravel, Undulating Terrain and the task are Spectrographic Analysis, Instrument Deployment, Core Sample Retrieval, Solid Soil Sample Retrieval, Liquid Sample Retrieval.
NASA’S SIMULATED EXTRATERRESTRIAL OBSTACLES
NASA’S SIMULATED EXTRATERRESTRIAL TASKS
All the obstacles and tasks carry different things and requirements. Well, let me share some interesting tasks that most of the participants always love to do.
In this NASA Human Exploration Rover Challenge, a participant has to collect some solid soil samples and some liquid samples, and the collection of samples are contained in a storage area or vessel on the rover.
And also all the team has to collect one core sample while on or off the Rover.
Moreover, in this Rover competition, there was a required task that is instrument deployment. For this task, the instrumentation must be a solar-powered instrument that the teams have to deploy in the proper compass orientation.
The device was built by the teams and that required the following components:
A solar cell, a functioning on/off switch, and a power-indication light that illuminates when the switch is on and operates on solar power.
A sensor that is always used with other electronics and that can detect events or changes in its environment and send the information to other electronics.
In the rover, for using all sensors teams have to use development boards like Arduino, raspberry pi, jetson nano, etc.
In our Rover, we used a lot of sensors like Analog pH sensor, soil sensor, gyroscope sensor, water sensor, moisture sensor, optical sensors, liquid level sensor, wheel speed sensor or vehicle speed sensor (VSS), and Friction-type magnet strain sensor, etc.
The NASA Human Exploration Rover challenge is more than just a race because it represents NASA’s commitment to providing opportunities for youth to participate in activities that will prepare them to be the next member of a workforce that will lead NASA’s robust space exploration program.
This Rover Challenge combined several aspects of real-world careers into one exciting experiential design challenge.
To network with NASA scientists and engineers, to develop long-lasting relationships with peers and colleagues around the world, to enhance their skills in the STEM- Science, Technology, Engineering, and Math- field.
NASA’s mission is to involve ambitious innovative high school-college students from all over the world into space exploration for helping NASA develop ingenious new technologies and solutions to explore a variety of solar system destinations in the decades to come.
Bangladesh is quite new in space exploration so that Bangladeshi students can’t get an opportunity to explore themselves in space exploration. We all are grateful to NASA for this challenge because NASA’s mission makes an opportunity from all over the world including Bangladesh.
Bangladeshi students are strongly passionate about space-engineering, space science, rocketry, aeronautics, and all space science field, but unfortunately, they didn’t get the proper opportunity for exploring themself.
But this the biggest platform and opportunity for exploring themself that’s why Team 71 trying to promote this platform and opportunity all over in Bangladesh. And interestingly NASA loves that thing because Team 71 believes in ” SPACE FOR EVERYONE”.
This NASA’s challenge has a special award for this kind of work named- STEM Engagement Award. It is normally awarded to the team that is determined to have best inspired the study of science, technology, engineering, and math (STEM) related topics in their own community.
And they have to make sure that not only presented a high number of activities to a large number of people but also delivered quality activities to a wide range of audiences. I personally believed that’s the best thing that NASA and participants did for the upcoming generation.
Concerning NASA’s award, in Bangladesh, we are trying to introduce STEM activities and opportunity, NASA’s opportunity, and also, trying to familiarize the NASA Human Exploration Rover Challenge and the process of taking part in this competition including the team’s own experience. Team 71 believes this NASA’s Rover challenge is more than just a race because this Rover Challenge represents NASA’s commitment to providing the opportunity for youth.
STEM EXPLORING, ROADSHOW, WORKSHOP, SEMINAR
STEM EXPLORING AND OPPORTUNITY SHARING WITH UNIVERSITIES STUDENTS
Earlier this 2020, we visited many school-college and universities all over Bangladesh and did a lot of workshops and seminars but due to this pandemic we shifted it online and we did some virtual STEM engagement sessions.
Let me add some words about Team 71 workshop, seminar, and virtual session. Here we focus on the STEM engagement and activity and NASA’s opportunity for international students.
Team 71’s team members share their personal experiences, Introducing the students with Bangabandhu Rover 71, sharing the engineering mechanism and how they can do it. And also shared our failure story, and importantly why we failed?
Because I believe every failure story makes everyone stronger. At the ending time of every seminar, we tried to share our experience of how they can start their journey with low resources setting and make their dream big.
TEAM 71 APPLICATION
We got a lot of response from all over Bangladesh. People wanted to be connected with us and they wanted to know more about NASA’s opportunity.
Interestingly the number of students is huge as a result, so we launched an android application for all which will update them about NASA’s opportunity and our Team 71.
Moreover, we are still working on it, every day we get a lot of mails, messages and interestingly some people want to join with us as a volunteer.
Lunar Rover Vehicle Design
Edited by Jack Argiro, Jason Kauppila, Helen Wu, Qilin Guo, Calvin Ma, Gihyen Eom & Alexander Fleiss