Heather Miller
Elevate your design and manufacturing processes with Autodesk Fusion
Newton | Engineering and Product Development are supporting the Mars Sample Return with a lid designed using generative design in Fusion 360.
It’s one of the great, unanswered questions for humankind: Was there life on Mars? We may finally receive a definitive answer. NASA and the European Space Agency (ESA) are planning an ambitious feat with the Mars Sample Return Mission to bring rocks and soil from Mars safely back to Earth for the first time — all with the goal of discovering if life ever existed on the planet.
Currently, the Mars Perseverance rover is on the hunt to collect and store suitable samples from various locations in the Jezero Crater delta. In this area billions of years ago, scientists believe a river once flowed into a lake and deposited rocks and sediments, making it a prime spot to look for ancient signs of life.
The Mars Sample Return process
The Mars Sample Return will involve an incredible relay team of equipment, devices, and technology. The Perseverance rover will transport the samples in metal tubes to the Sample Retrieval Lander where an ESA-provided robotic arm will place them in the lander’s rocket. A pair of helicopters will also pick up other samples to deliver to the lander.
All the precious cargo is then put into orbit in the Mars Ascent Vehicle, the first rocket to launch from the surface of Mars. It will take the samples to the Earth Return Orbiter in space, where the Capture, Containment, and Return System on board can capture the samples and sterilize the containers. Once the orbiter’s months-long journey back to Earth is nearly complete, an entry vehicle with the rocks will separate from the orbiter for a safe touchdown on land.
Like any scientific endeavor in space, there are many mitigating factors to consider and challenges to solve and make this mission a reality. It’s all underway now. The expected launch of the lander is 2027 and orbiter in 2028. And the estimated shipping arrival to answer our life on Mars question is 2033. In the meantime, there’s a flurry of new designs and innovations to make the trip to Mars and back happen without a hitch.
Keeping the Mars rocks from floating away
Newton | Engineering and Product Development is one of the companies helping to develop key parts for the Mars Sample Return. But it’s not designing just any part — it’s a critical component in the transfer of the samples from the rocket to the orbiter for the trip back home.
Out in space, each metal, sample tube will be “tossed” toward the orbiter’s Capture, Containment, and Return System to land precisely in an approximately 3’ long container where a 23” diameter lid quickly snaps shut to keep it from floating away. Newton is responsible for this door mechanism called the Capture Lid Mechanism. If it doesn’t open or close, it would lead to a mission failure.
While designing a lid may sound simple, it’s anything but easy. The team must consider many variables, such as the contamination requirements, the speed the lid needs to close, and the requirement for a simple motor control system.
“There are all sorts of challenges associated with transferring objects in orbit,” says Alex Miller, lead mechanical engineer, Newton. “Once the samples float in, the lid needs to close very quickly to keep the samples from bouncing out as well as limit the contamination of the samples. It requires a very lightweight and strong door to be able to do this. That’s where generative design in Fusion 360 came in to help us with the structure of the lid.”
“We looked at other tools that do generative design or topology optimization, and no other tools were able to produce ready-to-manufacture parts as easily and as quickly as Fusion 360. Cost is a factor, too. Fusion 360 is a fraction of the cost of other tools.”
— Alex Miller, Lead Mechanical Engineer, Newton
Newton isn’t a stranger to working with NASA. They’ve worked on many other projects together, including the James Webb Space Telescope and Nancy Grace Roman Space Telescope, to name a few. But the Mars Sample Return Mission is the first time they used Fusion 360 and generative design. About a year ago, a research engineer at NASA Goddard Space Flight Center introduced Fusion 360 to Miller. According to Miller, the Mars Sample Return is a very mass-sensitive mission, and “mass equals cost in the space flight world.”
Trying Fusion 360 and generative design for the first time
The team identified one part that attaches the lid to the rotating hinge that could be mass optimized to achieve a larger torque margin for the movement. Stiffness was also crucial to close the door quickly. With generative design in Fusion 360, Newton reduced the weight of the lid by 30% while maintaining the required stiffness.
Materials were also a consideration for the optimization. The team compared steel, titanium, aluminum 6061, and aluminum 7075. Aluminum provided the most lightweight solution that met requirements. Aluminum 6061 was chosen over 7075 due to better manufacturability and lower cost while still meeting requirements with more than sufficient safety margins.
“We could easily compare the performance of different materials,” Miller says. “Using generative design in Fusion 360, we could see the variety of outcomes and how the different material options compared to each other. We were able to pick the best material very effectively and quickly.”
Prototyping a flight-ready engineering test unit
The team continued to improve the design with generative design, keeping what was working or flagging other aspects to improve. Testing provided additional proof points.
“There were a lot of people that were concerned when they saw the generative design for the lid and said, ‘Oh, those members look thin. Are you sure this isn’t going to break?’,” Miller says. “Both our analysis and physical testing showed that it was not going to break and had a higher stress margin when compared to human-made designs.”
After a few cycles of testing and improving the design, Newton is building the “engineering test unit,” which will match the flight design exactly. The prototype will undergo environmental testing, subjecting the lid to vibrations similar to what it would experience during launch and many actuations in a Thermal Vacuum chamber that simulates the space environment. It’s a crucial step in qualifying the design for flight readiness. After a second round of testing of the engineering test unit, the lid will be ready for manufacturing and delivery to NASA.
“The biggest advantage with Fusion 360 is that we have confidence knowing what we’re producing is optimal,” Miller says. “It lets us make efficient and optimal engineering decisions. We saved about a month of time using it for the Mars Sample Return.”
“Given the low cost of Fusion 360 and the ability to produce ready-to-manufacture parts with very little post-processing after the outcomes are generated makes generative design a very effective tool for us.”
— Alex Miller, Lead Mechanical Engineer, Newton
Moving forward with Fusion 360 and generative design
With the success of using generative design for the Mars Sample Return, Newton is embracing it for more projects. The team finds it a great source of inspiration to guide them when developing new concepts.
“Fusion 360 is a great tool to quickly generate optimal designs for different concepts early on in the development process,” Miller says. “We can compare and pick the best concept to move forward with. It gives us a good idea of what’s possible and what the parameters for each of those different concepts would look like.”
Once a concept is further along in the design phase, the team can pick certain components they think would lend themselves well to generative design.
“We can iterate faster than most because of our small teams and the diversity of our engineers’ skills,” Miller says, “Even then, generative design in Fusion 360 has saved us a whole lot of time with weeks and potentially months of development time.”
As artificial intelligence (AI) becomes more mainstream every day, the advantage of using generative design is readily apparent to Miller.
“I truly believe that humanity is at the dawn of the AI age and using generative design is absolutely essential for any engineering team to remain competitive in the future,” Miller says. “It’s a critical tool in our mission to provide customers with optimal solutions and ensure success. Any team or company not using AI or machine learning tools is going to quickly fall behind. Our competitive advantage lies in our early use and discovery of ways of utilizing the technology efficiently because soon I think it will become a standard tool for everyone.”