One big problem when sending things into space is, well, space. Rockets have limited payload capacity and given the costs involved, every inch counts. That's why Brigham Young University researchers have turned to origami as their inspiration. Their folding solar array is designed to be compact at launch and expand to around 10 times its size once it's deployed in outer space.
Sporting 1-cm thick solar panels on a thin flexible membrane, the array will fold down to a diameter of 2.7 m (9 ft), and unfold to about 25 m (80 ft) across.
"The main advantages are its deployed size compared to its stowed size, which makes a larger surface array possible for the same launch volume," the team's leader Larry Howell tells Gizmag. "It can also be scaled to various sizes, such as for Cubesats."
The absence of sliding parts in the solar array also decreases the likelihood of anything failing during deployment. With an array designed this way, scientists would only need to launch, deploy and monitor a single system.
While this array is expected to generate 150 kW of power, the researchers aim to create one that can generate 250 kW for use in satellites or space stations. It's an ambitious plan, especially when you consider that the eight solar arrays currently in use on the International Space Station generate a total of 84 kW of power.
The idea of a deployable solar array came about when grad student Shannon Zirbel spent a summer at the NASA Jet Propulsion Laboratory. Working along with NASA, the team got together with origami expert Robert Lang, whose previous high-tech origami work includes a folding telescope lens prototype. To create the array, they began to investigate compliant mechanisms – elastic structures that work by flexing their parts instead of using joints to achieve movement.
"If something bends to accomplish something useful, then it is a compliant mechanism," Howell tells us. "There was a realization that origami is a compliant mechanism because it gets its motion from bending flexible parts rather than from hinges or bearings."
Getting a solar array to fold up isn't as easy as creating an origami boat or frog. Aside from coming up with a proper fold design, the team also had to find a flexible material of sufficient thickness that could support solar panels, wiring and more. While they still haven't settled on a final material, their current 1/20th-scale prototype makes use of a fiberglass composite called Garolite. The final design will not only have to withstand the harsh conditions of space but also squeeze into a rocket.
"The 25 m (80 ft) array is designed to fit inside an Atlas V rocket for launch," Zirbel tells us. "It hasn't been designed for any specific satellites, but we expect to deploy it with a perimeter truss, such as the AstroMesh from Northrop Grumman."
The team believes that origami-inspired designs could also be used to create expandable nets that can catch asteroids, antennas and solar sails. They're currently working on a compliant pointing mechanism that can be used to orient devices like thrusters and antennas without using bearings.
"We see opportunities ranging from medical products, such as devices for minimally invasive surgery that are small at the incision and expand at the surgery site, space applications (such as the deployable solar array), and consumer products (devices that are compact for shipping or storage but expand for use)," adds Howell. They've also started applying the origami-based solar array design to more down-to-earth applications, and have begun looking into backpackable arrays.
In addition to its NASA funded projects, the team is about a third of the way through a four-year origami-based engineering research contract funded by the National Science Foundation and Air Force Office of Scientific Research. The researchers aim to develop new engineering systems with unprecedented performance capabilities, with insights gained from origami.
"It is stunning to consider the possibilities offered by origami-based engineering," Howell tells us. "It has the potential to change how we engineer products on earth, and beyond."
Check out a video of BYU's origami-inspired solar array below.
Source: Brigham Young University
