Technology advances at different paces specific to each industry. Could the satellite and aerospace industry be the next to witness a revolution in engineering?
ENGINEERING.com recently spoke with Dr. Slade Gardner, Lockheed Martin (LM) Fellow, about the latest in additive and subtractive manufacturing techniques and what they could mean for the industry. The video above and Q&A below document interview highlights.
Jim Anderton (JA): Slade Gardner, a Lockheed Martin Fellow, has been working with Wolf Robotics on some interesting innovations that just might define the future of manufacturing. Is that safe to say Slade?
Slade Gardner (SG): That’s safe to say, Jim. We’re defining what the future boundaries of manufacturing might be. We’ve configured a multi-additive robotic cluster, which performs a lot of different manufacturing operations, with robotic automation.
It also incorporates what we call the digital transformation. This is bringing sensors into the production environment in order to measure, quantify, analyze and quality assure the structures that we’re building.
[The structure] was built about half way up and we placed a propellant tank in a cradle. We then built the rest of the structure around the propellant tank. We’ve capped it off at the top, but we’re going to continue to build upon it.
JA: Historically for engine, aircraft and satellite design, propellant tank design has always been an factor in design from day one. Could additive manufacturing turn that paradigm upside down?
SG: One of the things we’ve been doing at Lockheed Martin Space Systems is using additive manufacturing to build titanium propellant tanks.
Our partnership with Wolf Robotics has been very important in bringing this mission of the factory of the future into this particular test bed.
Wolf Robotics configured this system for us; they’ve integrated polymer extrusion, subtractive machining, process monitoring, 3D scanning and we also have a very special added feature for this demonstration.
We’re borrowing technology from the University of Texas at El Paso, where they’ve developed the capability to embed copper wire directly into a polymer structure. We’ve actually mounted the UTEP copper wire additive head on one of our robots. Along the face of the model, there are two copper traces. This wire that’s embedded in the structure is important because it brings a new level of functionality to the additive structure.
JA: Could thermistor wire be used for an embedded sensor net?
SG: [It could be used for] sensors and data transfer, but because this is solid core copper wire, it’s also useable for power transmission.
A lot of the additive focus for conductors in the industry has been with inks or pastes and they’re good for data transmission, but this is real copper core wire, which could also transmit power.
JA: For example, data and power transmission being integrated into the structure of the airframe of the satellite bus?
SG: Yes, that’s right. It’s exciting.
JA: In terms of pressure, vessels and structures tend to be standard geometric shapes like spheres, and there are good classical physics reasons for doing this, because those are structures that you can machine or form.
If we go additive, you gain the ability to do things like put internal structure into some things. How is that going to change how air frames or satellite buses will look in the future?
SG: It’s going to dramatically change the way they look, the way they are designed and the way they function.
A propellant tank that goes on a satellite typically has baffles inside. Those baffles are a complex design, laid out according to the mission requirements. Those designs and design capabilities will be revolutionized with the additive process.
There are internal trap volumes that are now possible with additive manufacturing and there are shapes and size limitations as well. We’re qualifying additive manufactured titanium propellant tanks for our commercial space programs. The historic limitation of a propellant tank is about 46 inches in diameter and that limitation is currently based on the forging capability for that class of structure.
By using additive manufacturing, we’re no longer limited to 46 inches in diameter. That is a size limitation that is removed because of additive manufacturing.
JA: In terms of structures like the SR71, the U2, the F-117 stealth fighter, all of these were designed in shapes that were never seen before. With technology like this, are we going to see shapes that we cannot recognize as conventional aircraft and spacecraft?
SG: I believe we are.
I think we’re going to see a revolution in the internal geometry that we don’t see. For instance, have you ever seen a satellite that looks like this model? I think satellite architecture is going to evolve very quickly, as well as aircraft architecture.
JA: How long do you think it will be until this will become commonplace in satellite and spacecraft design?
SG: It’s a difficult question to answer because there are so many things that need to come together to achieve the final result.
I think it’s going to happen quicker than we think. I think we’re going to look back and reflect on how quickly additive manufacturing and multi-robotic clusters and the digital transformation occurred, because there’s so much tremendous business value in complex engineered structures that can be harvested from that combination.
For more information, visit Lockheed Martin’s website here.