This is the first of a two part article. The second article is NASA's Kennedy Space Center: Visualizing the Possibilities.
For decades, NASA has built upon its design and manufacturing knowledge to power some of the world's greatest achievements in space exploration. As the space shuttle program nears retirement, the Constellation era begins with another technology that is changing the way NASA operates, the use of 3D technology.
When the space shuttle was being designed in the 1970s, NASA was primarily focused on flight operations. In addition to being the first orbital spacecraft designed for reuse, the decision to move forward with the shuttle program came with many other requirements that engineers needed to address. The spacecraft had to carry different payloads to low Earth orbit, provide crew rotation for the International Space Station (ISS), and perform servicing missions. It also had to recover satellites and other payloads from orbit and return them to Earth.
With even the most advanced technology, the limitations of 2D drawings forced NASA to limit its scope and focus primarily on flight. As a result, very little consideration was given to manufacturing processes or human factors engineering. At Marshall Spaceflight Center, in Huntsville, Ala., where engineers are still tasked with designing spacecraft and propulsion systems, the directive was to design the best vehicle possible. Once the vehicle was transported to Kennedy Space Center, NASA's primary launch site and installation for launch systems design, engineers had to adapt ground operations to the as-built vehicle.
Because the shuttle was designed primarily for flight and astronaut tasks in orbit, engineers at Kennedy had to develop "work-arounds" for nearly every task required to prepare the vehicle for launch, making the space shuttle very expensive to operate.
"If you're spending money on ground operations, you're not spending it on in-space operations," says Charlie Dischinger, who leads the human factors engineering team at Marshall.
|Steven Phillips in the foreground and Charlie Dischinger is in the background.|
Using DELMIA, a digital manufacturing software suite from Dassault Systmes, the team at Marshall can go beyond the requirements for a good flight design to assess manufacturing processes and human tasks. As 3D design and simulation tools have been introduced to portions of the space shuttle program, the international space station and other projects, they have made a considerable impact. Introducing these tools at the outset of the Constellation program is even more significant as it reduces manufacturing and ground operations costs, and fundamentally changes the way NASA engineers operate.
Before even considering launch operations at Kennedy, the Materials and Process Laboratory at Marshall ensures that a design can be cost-effectively and feasibly manufactured. The team that performs manufacturing simulation has been using DELMIA since the late 1980s and for the last few years has been focused on driving efficiencies in the Constellation program.
For example, while simulating a welding process for the Ares I rocket, the Constellation program's crew launch vehicle, the team found that the weld head could not properly move into position without colliding into another piece of hardware. In order to operate properly, the weld head needed to remain perpendicular to the joint, which simulation showed was impossible to do with the current design. The information was presented back to the design team and the parts were changed.
"Identifying an issue like this early in the process keeps the project on time," said Steven Phillips, who leads the advanced processes and digital solutions team within the Materials and Process Laboratory at Marshall. "If we had not found the problem, it would have been a big hit to our schedule and it could have damaged some very expensive equipment."
In another simulation, the team was asked to investigate the possibility of reusing Apollo-era hardware to weld joints on the Ares I rocket. Re-using the old tooling could save time and money, but committing to the tooling was risky without having complete certainty that it would work as intended. Simulation identified a key kinematic problem that would have prevented the welding arm from reaching a number of weld locations. As a result, the machine was modified before any work began and the project was completed on schedule and without interruption.
Much of the work done by Marshall's human factors engineering team influences tasks that occur after manufacturing is complete. Worksite analysis is performed to evaluate a human's reach, posture, line of sight and other elements that contribute to a project's feasibility.
For example, once a vehicle is manufactured it must be transported to Kennedy and prepared for launch. Until recently, NASA would build a vehicle and then determine how to transport it, a practice that has changed with the use of 3D simulation during the design phase. Now, Marshall's human factors team simulates how a person would interact with the vehicle to secure it to a barge for transport. Doing so ensures that the vehicle incorporates features that will allow it to be secured easily. It also ensures that humans have access to, and can reach the hardware they need to perform tie-down operations.
In the case of the Ares I Upper Stage rocket, Marshall and Kennedy worked together to simulate how it would be unloaded from the barge and transported to the vehicle assembly building at Kennedy. The project required two cranes to lift the rocket from its horizontal position for transport, into its vertical position for launch. The teams simulated the entire operation, including the hardware that would be used and the people involved. The result is a full set of instructions that validate the process for a safe and successful transportation of the vehicle. Once the vehicle is stacked, Kennedy takes over and gets ready for launch.
By working in a 3D virtual environment, engineers throughout NASA can simulate almost any process before it occurs. Doing so not only improved relationships between engineers at different facilities, but it saves money on manufacturing and ground operations that can be better spent on exploration and in-flight activities.
Peter Schmitt is VP Sales Americas, DELMIA for Dassault Systmes and Les Goldberg,is Executive Account Manager, Aerospace and Defense, DELMIA for Dassault Systmes