Humanity's Biggest Machines Will Be Built in Space (popularmechanics.com)

When rockets can no longer hold oversize payloads, building in space might be the best way to go. Popular Mechanics: Headquartered in Mountain View, California, Made In Space is working to make that dream a reality. For the past few years, they've operated the Additive Manufacturing Facility, one of the only 3D printers in space. While the AMF sits comfortably aboard the International Space Station, Made In Space has plans to launch a new printer that would operate exclusively in the vacuum of space. Their prototype, called Archinaut, is scheduled to launch later this year. Future machines like Archinaut will be able to print nearly everything in orbit -- where there's no limit on size. "We can manufacture a structure that couldn't support its own mass if it were on Earth," says Made In Space CEO Andrew Rush. "The only practical limitation you have is how much material you're providing to the system." The first Archinaut prototype is mostly just a proof-of-concept and won't be constructing mile-wide satellites anytime soon. "First you crawl, then you walk, then you run," says Rush. "We'll start out with manufacturing space-optimized trusses and booms and reflectors to provide a supply capability that we can't currently achieve." But once this tech gets off the ground, it can be used to build structures as big as their owners want them.

Comments

No gain until we get primary materia from space

[Eloking]

I fail to see what's the gain between launching a rocket with 1 ton of preassembled componned or 1 ton of materia used by a space 3D printer to build those component. And unless there's 0% loss during the 3D printer process, I would even say it's less efficient that way.

The only way I can see a real gain is if most of the materia weight come directly from space. For instance, asteriod mining.

Re:No gain until we get primary materia from space

[AndroSyn]

I fail to see what's the gain between launching a rocket with 1 ton of preassembled componned or 1 ton of materia used by a space 3D printer to build those component.

Think along the lines of large objects that could not be launched from Earth pre-assembled, especially items that have large empty spaces inside of them.
Also. you can assemble some items in space that would collapse under normal Earth gravity. Building in space, means that the object only needs to be able to stay together in micro-gravity, which gives you a bit more freedom in structural designs.

The only way I can see a real gain is if most of the materia weight come directly from space. For instance, asteriod mining.

The current problem with mining materials in space is, we simply do not have the infrastructure in place to mine, purify and process minerals into finished metals in space. Sure it would be nice to see this some day, but in the mean time it's cheaper to launch your raw materials off Earth, especially if they're in the form of powdered metals, those pack very nicely into rockets. Besides I've heard there is some weird South African guy selling used discount rockets, not sure I'd trust him with my life, but with a pile of titanium powder, sure.

In short, you need to build the salt box pioneer shack in space before you build the steel furnace in space. We're barely past the salt box shack stage.

Flexibility and cost

[sjbe]

I fail to see what's the gain between launching a rocket with 1 ton of preassembled componned or 1 ton of materia used by a space 3D printer to build those component.

The 3D printer doesn't require you to decide what to make with it prior to launch and it allows you to skip the delivery lead time for a product which could be substantial. Otherwise you are correct. You probably would need some sort of 3D printer like technology to manufacture a lot of stuff in space simply because a lot of the manufacturing techniques we use on earth simply wouldn't be viable due to supply chain issues and the need for compact and flexible production equipment.

The only way I can see a real gain is if most of the materia weight come directly from space. For instance, asteriod mining.

Asteroid mining is an idea that won't happen for a very long time. There are several huge obstacles to it including: 1) The fact that we don't have any mining or refining equipment that is space worthy nor any reasonable prospects of getting such equipment anytime soon. 2) The extravagant cost of getting the equipment (which again we don't have) to the asteroid and doing useful work with it. 3) Most useful products require multiple materials/components which cannot be sourced from a single asteroid even if it were financially viable to do so. For a long time to come it's going to be a lot cheaper to launch stuff from earth than to mine it from an asteroid.

Also the biggest obstacles actually are not material weight. We just haven't addressed the hard issues because it's SO expensive to get to orbit that they haven't been worth worrying about. But even if you drop cost to orbit to zero, the cost of building the technology and infrastructure to manufacture in space will likely dwarf even the current launch costs. Think of it this way. Ford builds cars and one of its assembly plants costs north of a billion dollars to create. That is just for final assembly. The cost of the production facilities and parts to build the product in its supply chain easily costs 100 times more than that (there are about 30,000 parts in a typical car). And we have proven and well developed sources of raw materials. All that to build a product we know how to make with proven technology we can manufacture with economies of scale. Making something the cost and complexity of cars in space at any sort of scale would cost a large fraction of the world GDP for the foreseeable future.

Space based manufacturing is arguably a worthwhile goal but we need to be realistic about how long it will take to make it economically viable.