There’s a lot of extra-terrestrial waste (trash) floating around Earth and beyond in outer space. Estimates vary but tend to coalesce at between 25,000-30,000 pieces of trackable human-made objects orbiting Earth because of accidents or uncommissioned payloads.

This includes used satellites, spacecraft parts and more — very dangerous to active spacecraft, space stations, satellites and astronauts, challenging the resilience of space launches, and operations and supply chain. But just as in a junkyard on Earth, there are things worth salvaging and reusing, repurposing and reclaiming, with the goal of achieving a sustainable space environment.

“Many of these fragments still have value,” said Luz Sotelo, assistant professor of mechanical engineering at Purdue University. “We’re looking into ways we can safely reuse some of these reclaimed and recycled materials, along with resources found on the moon, to create in-space production sites that help sustain human activities in space.”

Sotelo is co-principal investigator and the Purdue lead on an almost $3 million grant from the National Science Foundation (NSF) for a project called “Understanding the Sustainability Framework for Convergent In-Space Manufacturing.” Weiwei Mo, associate professor of civil and environmental engineering at the University of New Hampshire, is the principal investigator and UNH lead.

“We are at the infancy of figuring out how to create the logistics for in-space manufacturing, but ultimately the goal is to produce a space mission using materials and resources from space and to be able to leave the Earth’s resources for other much-needed purposes,” Mo told UNH Today.

Sotelo will bring her research acumen in multi-process/multi-material additive manufacturing, nondestructive evaluation and convergent manufacturing to bear on the project. Her research is part of a larger nationally leading effort at Purdue around in-space servicing, assembly and manufacturing (also known as ISAM). The work takes place under the umbrella of Purdue’s eXcellence in Manufacturing and Operations (XMO) initiative and its physical manufacturing laboratories spin-off, the Manufacturing Materials Research Laboratories (MMRL). XMO and MMRL are Purdue’s latest nation-centric initiatives and multi-faculty laboratories aimed at strengthening America’s manufacturing and economic resilience.

Sotelo is working on the NSF project with Mo and colleagues from Purdue, UNH and Baylor University, along with valued collaborators at NASA that include John Vickers, principal technologist at the Space Technology Mission Directorate.

“For the coming industrial revolution of space to advance, we must ensure the sustainability of our space environments,” Vickers said. “A new holistic vision for in-space manufacturing in concert with recycled materials technologies is essential to our successes for the future space economy and exploration."

Their research not only has scientific and commercial potential but is vital for space commerce, security and exploration. The award abstract puts it this way: “With the democratization and commercialization of space poised to springboard the next generation of space technologies, scientific discoveries and explorations, distinct advantages will be realized by whichever nation first establishes these factories-in-space for manufacturing, assembly, repair and reclamation in non-terrestrial environments.”

“Purdue Engineering has a long tradition excelling in space exploration, manufacturing and sustainability. We are excited that we have the expertise to contribute to this sustainable in-space manufacturing program,” said Weinong Chen, associate dean for research and innovation in the College of Engineering.

Ajay Malshe, inaugural director of MMRL and the R. Eugene and Susie E. Goodson Distinguished Professor of Mechanical Engineering in the Purdue College of Engineering, said, "The goal is to create sustainable environs for space and Earth."

A number of technologies will be investigated as enablers for in-space manufacturing, targeted at creating the capability to fabricate one-off parts at the point of need from resources in space. These technologies include computational modeling and additive and forming manufacturing, as well as tools for nondestructive performance evaluation, lifecycle assessment and verification of these unique manufacturing capabilities under simulated space conditions.

“The award aims to study the circular economy — with its model of recycle and reuse to reduce waste and conserve resources — to outer space,” Sotelo said. “The world is already striving to overcome centuries of industrial progress that came at a price, with attendant challenges of changing climate, dwindling resources and environmental pollution. Anything that can be done to enable sustainable space industries will impact positively the Earth and space environments.”