Ben's Website

Serious musings

Electron Beam FreeForm Fabrication -- IN SPACE

ideain-space-manufacturingresearchspace3D printing

In the last post I described the basics Electron Beam FreeForm Fabrication (EBF3), here's why I'm excited about it:

Let's walk through this process:

  1. Metallic Refuse

Life and research aboard the ISS requires a lot of supplies and results in good amounts of waste.  This is the most expensive garbage in the world, and, due to the restricted lab and living space, includes completed experiments and spent supply ships along with the more obvious packaging, clothing, food, and other waste. Given the nature of space exploration, this waste components of this waste are known absolutely and excellent candidates for in-orbit recycling.  Used Progress and other supply ships, having arrived at station, could likely be stripped of components and structures that are not required for their reentry garbage truck function and again recycled into new components and structures.  Though accompanied by greater risk, ISS (or some other manned or unmanned station) could also serve as a destination for end-of-life satellites as the only place where there residual in-orbit material value may be captured.

  1. Garbage, Meet Recycler

If you introduce a metal into an electric field sufficient to overcome the intermetallic bonds, those bonds will break, freeing electrically-charged ions from the donor.  This plasmification is the basis for vacuum deposition, but what if the donor is not a pure metal but rather some alloy?  What if the donor is something like the aluminized mylar found in space (-age) blankets?

The second part of this step is an external electromagnetic field, as commonly found in mass spectrometers.  If the plasma is accelerated by an electric field and then encounters a magnetic field, the ions will arc according to the strength of the field and their mass.  With the electric and magnetic fields coarsely tuned according to the known properties of the garbage, its component atoms can be sorted into atomically-pure stacks.

  1. Sorted Feedstock

These atomically-pure stacks are highly valuable, due to their purity and location in earth orbit, as long as there is a process by which they can be made into something new.

  1. Feedstock, Meet Printer

The same combination of electric and magnetic fields used to recycle garbage can be 3D printed into new components and structures.  By selectively introducing atomically-pure feedstock into the same electron beam used for plasmification and guiding the plasma via the same magnetic field, a part could be build layer-upon-layer.  This is essentially EBF3, though instead of a translating build platform the platform could be stationary and the beam scanned across the part by varying the magnetic fields.  (Though for alloying a translating stage or translating emitter might be required...)

3D Printed, Variable Alloy Components...In Space

3D printing metallic components in space would be a game changer; it would allow recycling of substantial fractions of today's orbital garbage into new components that equal or rival their terrestrially-produced counterparts.  Further, the cycle described could also be applied to asteroidal and other in-space resources.  I don't know what technology Deep Space Industries envisions...

...but I can't see why EBF3 would not meet their needs.

Finally,

I've spent 500 words describing this concept, but it seems to be worth much more study.  While the individual elements of the described cycle exist terrestrially (and mass spectrometry has been used on many robotic space missions) they have not been integrated into a single apparatus.

Many questions accompany this concept; I hope to explore some of these going forward (as posts, and perhaps more formally), and, more than that, answer why MadeInSpace is on the ISS rather this...