After successfully cutting stainless steel in space, this company has a vision for repurposing our space junk.
Image Courtesy of Nanoracks
If entrepreneurs want to bring our society into space, they’ll bring our engineering processes there, too.
Earlier this year, Nanoracks, a Houston, Texas-based company that engages in commercial space missions, successfully sliced corrosion-resistant 316 stainless steel in space using a friction milling tool, complete with a robotic arm. Now, it’s hoping to build on that space manufacturing technology to turn spent rocket stages into space outposts.
This mission was part of an effort to “develop capabilities to be able to do commercial activity in space,” Robbie Harris, director of advanced concepts at Nanoracks, tells Popular Mechanics. His company has been working on expanding this horizon for 13 years and has put over 1,300 payloads into flight, often in collaboration with teams connected to the International Space Station.
Nanoracks began talking with NASA five or six years ago about how to reuse the upper stages of rockets as outposts in space, Harris says. These sections help transport the spacecraft. Then, once their work is done, they join a graveyard of space junk in low-Earth orbit, circling our planet at an altitude of 1,200 miles or less.
If companies like Nanoracks can develop a way for rockets to dock together while they are in orbit, Harris says, then another spacecraft could travel up to reconstruct a new one from the leftover pieces or create an entirely new habitat or fuel depot from them. That could not only create a recycling program for otherwise useless space debris, but could also mitigate the rate at which we’re creating that space junk in the first place.
“The upper stage is really a large fuel tank,” Harris explains. “Something like 90 percent of the mass of a rocket when it launches is fuel. Our concept is to take all of that volume there and then use it for something.”
Cutting Steel in Space
The steel-cutting experiment was an early step toward Nanoracks’ ambitious manufacturing goals for industrial processes in the growing space market; The corrosion-resistant steel it cut is commonly found in space debris like upper rocket stages.
“This successful demonstration of cutting metal in orbit marks a significant milestone in the journey to building infrastructure in space,” Marshall Smith, senior vice president of commercial space stations at Nanoracks, says in a statement on the company’s website.
Using a technique called friction milling, the robotic arm used a commercial cutting tool at a high speed to soften the metal while cutting it and reducing debris. The enclosure that held the robotic arm and metal samples was on a Nanoracks circuit.
NASA’s Near Space Network transmitted data from the experiment to Earth. On the ground, engineers observed the results and made plans to improve the process in future missions.
Manufacturing Space Outposts
Image Courtesy of Nanoracks
Reworking a spacecraft into an outpost that could be used for fuel storage or communications transmission could involve a variety of manufacturing processes, Harris says. Nanoracks has just begun to scratch the surface. The steps could include cutting, welding, drilling, buffing, deburring, riveting, and/or tapping—and much more.
The realities of manufacturing in space are vastly different from what we experience on the ground. Creating industrial processes in a zero-gravity environment involves unique considerations and design constraints. For example, it may be complicated handling machining debris and cutting fluid that could float around the spacecraft. When Nanoracks cut steel in space, it did not involve any lubricants; The cutting operation took place inside an enclosure.
“Carrying things through space is pretty expensive,” Ed Mehr, co-founder and CEO of Machina Labs, tells Popular Mechanics. “Carrying things like heavy dies … or heavy press equipment that cannot be changed is hard to do in space. So one big challenge is how you can just make things generally lighter.”
The fact that the spacecraft may be unmanned also poses challenges. A mechanical arm might do all of the cutting and welding, Harris says. “As you can imagine, a robotic arm really needs to be able to move around. It can latch onto different places and operate on various parts of the stage. There’s actually research going on to develop that. It sounds a little bit Star Trek-y, but it’s a real thing.”
Recycling Spacecraft
Metals and other materials from spacecraft can be reused for a variety of purposes, even though they may have odd shapes, Harris explains. “There’s a few things you could do with metallics. Construction of a platform or a structure like a large antenna comes to mind immediately. There’s also processes whereby you can use metallics or metals for fuel, like for propulsion.”
“Beyond raw materials, there are subsystems like antennas and radios that you might want to reclaim and use again another way,” Harris says. “We’ve got one concept whereby we can go to a satellite that may be obsolete or expired and add some functionality to that satellite.”
Could these outposts someday travel on their own to the moon? Harris says that is not likely. “We don’t really envision the outpost being a transport mechanism. We think of it as more like a platform. So it will tend to kind of hold its place. We eventually do want to be able to move it around a bit. It will provide … a way station you can go to if need be.”
With so many spacecraft likely to be abandoned in orbit—and an existing backlog of space junk cluttering the skies—the question arises as to whether there is an economic incentive for companies to recapture their parts rather than leaving them in space.
Harris says he’s optimistic that the materials will be in demand, especially parts from satellites that are in higher geostationary orbits and tend to be more valuable and durable. “The space economy’s still evolving. What the market is going to value is hard to predict. Activity in space is growing and that means that you need resources. Unfortunately, resources are hard to come by in space. We want to capture value from the resources that are there.”
Source: www.popularmechanics.com
