space

Adam Mann of Wired describes the interesting plans of Deep Space Industries, working on the idea of how to make money from asteroid mining: "New Asteroid Mining Company Aims to Manufacture Products in Space".

A year later, DSI wants to launch larger spacecraft called DragonFlies that can make a round-trip journey to an asteroid and bring back samples. They estimate the trip will take two to four years and can return as much as 70 kg (150 lbs) of asteroid material to Earth orbit. DSI has patented technology they claim can extract precious metals from raw asteroid material and build it into parts with a 3-D printer.

The article makes it sound like they're trying to finance space operations by selling tchochkes.

Real manufacturing of most light-yet-expensive items today involves layers upon layers of different substances fitted together into complicated objects. That kind of assembly and separate refining of hundreds of substances on an asteroid would be a true engineering challenge. It's easy to see that the ability to manufacture parts in space at large scale would be much more valuable for use in space than back on Earth.

Moon rock is expensive here on Earth, but on the moon it's as cheap as dirt. So maybe future moon colonists could make stuff out of it using 3-d printing technology?

Typically, lasers use 300 to 400 watts to melt conductive metals. But the moon material was more similar to ceramics — Bandyopadhyay’s area of expertise. He had used that material for 3-D printing through selective laser sintering, where a powder is fused with intensely focused pulses of light, layer by layer, to form a specific object. He knew that throwing metal-specific levels of power at an insulator like this would only cause most of the energy to be absorbed, and the molten material to lose viscosity.

“If you go higher, then what will happen is you will go from honey to water, and then what happens?” says Bandyopadhyay. “It flows so much that you cannot make a part. So you need to have, you know, high enough to melt, but low enough not to overflow, basically. That’s the challenge.”

Now imagining casts made from lunar regolith.

I hate the idea of having to depend on tools made from an inferior material, when slightly greater expense and more time could transport metals from the asteroid belt. Oh, wait a minute - that's the basic tradeoff of Oldowan technology in Africa, isn't it?

Steve Silberman provides an in-depth interview of Lee Billings, in the middle of writing a book about the discovery of extrasolar planets: "Five Billion Years of Solitude: Lee Billings on the Science of Reaching the Stars".

I do think humans are motivated to daydream about extraterrestrial intelligence, and, to put a finer point on it, extraterrestrial “people.” They are motivated to dream about beings very much like them, things tantalizingly exotic but not so alien as to be totally incomprehensible and discomforting. Maybe those imagined beings have more appendages or sense organs, different body plans and surface coverings, but they typically possess qualities we recognize within ourselves: They are sentient, they have language, they use tools, they are curious explorers, they are biological, they are mortal — just like humans. Perhaps that’s a collective failure of imagination, because it’s certainly not very easy to envision intelligent aliens that are entirely divergent from our own anthropocentric preconceptions. Or perhaps it’s more diagnostic of the human need for context, affirmation, and familiarity. Why are people fascinated by their distorted reflections in funhouse mirrors? Maybe it’s because when they recognize their warped image, at a subconscious level that recognition reinforces their actual true appearance and identity.

Popular Mechanics has an article that goes through some of the basics of space flight design principles: "What would a starship actually look like?"

One look at the Icarus design—or its predecessor, the Daedalus—and it’s clear what starships don’t need: wings. The only real-world spacecraft that bother with wings are ones designed to make regular landings on runways, such as the retired Space Shuttle, the upcoming Lynx (a suborbital two-seater from XCOR) or the Dream Chaser, an in-development orbital craft from Sierra Nevada. And wings aren’t even required for landings. Like the Russian Soyuz capsule, SpaceX’s Dragon currently splashes down in the ocean (though SpaceX plans to move toward rocket-powered launchpad landings).

In both the near and far-term future, experts such as Millis imagine interstellar vessels won’t spend much of their time in an atmosphere. Perhaps the small ships that carry people from surface to starship will remain winged, but truly interstellar vehicles can scrap aerodynamics and all of the design principles that are beholden to reducing wind resistance.

I got to spend a little time sitting in the Lynx prototype last fall, and I have to say it was pretty awesome.

Of course the large ships that would be capable of interplanetary or interstellar voyages have very different design requirements than something meant to land on Earth. My interest in these is broader than aeronautical design: What are the human requirements of sustaining a population for dozens or hundreds of years?