The privately funded and developed SpaceX Dragon just returned from a flight that was successful from start to finish. The SpaceX Dragon capsule parachuted into the Pacific on May 31, 2012 to conclude the first private delivery to the International Space Station and ring in a new era for NASA’s approach to space exploration.
SpaceX’s CEO/CTO, Elon Musk, said “Welcome home, baby,” and was said to be a bit surprised with the SpaceX Dragon’s triumphant mission.
After its initial success, the primary goal for SpaceX will be to repeat the success on future flights.
Because the unmanned supply ship’s arrival was so accurate, when it splashed down, a fleet of recovery ships was able to quickly move in to pull the capsule aboard a barge for towing to Los Angeles.
It was the first time since the shuttles stopped flying last summer that NASA got a sizable load returned from the space station – more than half a ton of experiments and equipment.
The arrival of the world’s first commercial cargo carrier concluded a nine-day test flight that was virtually flawless, beginning with the May 22, 2012 launch aboard the SpaceX company’s Falcon 9 rocket from Cape Canaveral, continuing with the space station docking three days later, and departure six hours before landing in the ocean.
SpaceX attributes a large part of its design and engineering success to CAD, CAM, and CAE software, including Fibersim from Siemens PLM Software for composite material design and engineering.
According to Chris Thompson, Vice President of Structures Engineering at SpaceX, “Time is always of the essence for us, so Fibersim’s proven ability to take us from art to part so rapidly was a critical consideration in our decision to purchase the software. Fibersim improves product quality by providing accurate engineering information to the manufacturing floor, which also helps the repeatability of the manufacturing process.” The repeatability of the manufacturing process is vital for repeated success of the space platform.
Adopting Advanced Composite Materials
For more than 50 years, commercial access to space has been limited by the high cost of flight operations. However, Space Exploration Technologies Corp. (SpaceX) has rewritten the rules of the game by adopting a new business model and cutting edge technologies to enhance reliability and reduce the cost of space access.
One significant way SpaceX enhanced the performance of its Falcon rocket and Dragon capsule was by adopting composite materials. Composites have received growing acceptance in a variety of industries, including aerospace, and the space industry has taken note. SpaceX was no exception. The design team recognized that composites could significantly enhance performance by improving the strength-to-weight ratio of the materials used to construct its spacecraft.
Once that decision was made, SpaceX conducted an evaluation of available composites engineering solutions and concluded that Siemens PLM Software’s Fibersim software was the best fit for its design and manufacturing environment.
“Based on our comparison, there was no question that Fibersim was definitely the best choice on the market for designing and manufacturing composite components to suit our needs,” said Kirk Matthes, SpaceX’s design manager.
SpaceX’s business model is derived from the philosophy that simplicity, so low-cost and reliability can go hand in hand. By eliminating the traditional layers of management and subcontractors, the company reduced costs while speeding decision making and delivery. Likewise, by keeping the vast majority of manufacturing in-house, SpaceX reduced costs, kept tighter control of quality, and ensured a tight feedback loop between the design and manufacturing teams. By concentrating on simple, proven designs with a primary focus on reliability, the company has reduced the costs associated with complex systems operating at the margin. Fibersim has proven very valuable within that design/engineering paradigm.
SpaceX used Fibersim to design and manufacture a variety of composite parts on both the Falcon rocket and the Dragon capsule. Fibersim was used to develop production fiber placement diagrams and laser projection files. It was also used to assist with actual fiber placement for the spacecraft’s thermal protection system, including the heat shield, exterior panels, insulating layers on the rocket and spacecraft, and several panels around the nose cone and engines.
Fibersim is now being employed from the outset on all new composites projects and has enabled SpaceX to reduce the design-to-manufacturing time on composite parts, such as the 5-meter fairing boattail panel by 71 percent, from seven days to two days. For other designs, the generation of manufacturing data was reduced by as much as 86 percent, from seven days to one day, using Fibersim. These time savings mean that changes are processed more quickly, designs are updated more reliably, and the overall process flows more smoothly.
SpaceX has used Fibersim to perform a variety of tasks, including creating designs, making flat patterns, working in conjunction with its finite element analysis (FEA) software, and creating laser data.
Strong Support From Siemens
As a newcomer to composites, SpaceX was also concerned about finding a software vendor that had significant composites experience so it could receive the necessary guidance and support as it embarked on working with new materials.
“Siemens PLM Software’s support is excellent,” said Matthes. “Anytime we have a problem, we can send a model to the Siemens PLM Software’s technical consultant and he helps us get through the issue. Again, as a fast-paced organization, we must continually be moving forward, and Siemens PLM Software’s responsiveness and expertise enables us to do just that.”
Siemens PLM Software also embeds the know-how derived from its years of experience in the composites industry to provide intuitive, easy-to-use features for the design of a variety of composite structures. This is integrated into the software, speeds learning time, and makes the learning experience for new users more effective. This also aids in training new users who may not have experience in designing with composite materials.
Since most of the composite parts are not especially complicated, the Fibersim Composites Engineering Environment (CEE) has proven to be sufficient. However, certain sections of the launch vehicle are characterized by complex curvature, so SpaceX opted for Siemens PLM Software’s Advanced Composites Engineering Environment (ACEE) to design those parts. ACEE exploits the inherent advantages of many different composite design methodologies –including structure-based, zone-based, and ply-based design — to enable efficient engineering of large, complex structural components and highly contoured composite skins.
Most importantly, it helps to address the changes that inevitably occur while developing a composite structure. Based upon inputs from analysis, manufacturing or further iterations of the design, the definition evolves to its final state. This can require frequent updates and changes, which are time-consuming without software created specifically for this process. ACEE is designed to meet this challenge and create a more straightforward process for managing design changes.
“ACEE provided a significant boost to our efforts to define or import laminate specifications and requirements quickly using a zone-based design methodology,” explained Matthes. “It helped speed ply definition by dynamically generating zone transitions and ply boundaries using an offset profile.”
The ability to accelerate the process and make it more accurate enables SpaceX to proceed with high speed and quality, as well set new standards for designing and manufacturing composite spacecraft both now and in the future.
As a kid who grew up during NASA’s heyday in the 60s and 70s and the more recent hiatus, I’m now very encouraged about the future of space exploration – due in large part to private enterprise — and I applaud the efforts of SpaceX. I hope SpaceX’s accomplishment ushers in a new wave of engineers, scientists, and entrepreneurial companies who will take advantage of this great opportunity.
