2312

Finally the small waved a hand. “Fitz Wahram and I often work together on various system issues. We were just now deciding to visit a mutual acquaintance.”

“Wang?” Swan said. “Wang of Io?”

“Why… yes,” the inspector said, looking up at her curiously. “Wang is an associate of ours, as he was of Alex. We were working together.”

“As I mentioned to you,” Wahram said in his low croak. “When we were coming back from Tintoretto.”

“Yes, yes,” Swan said sharply. “You asked me to join you on that trip, without really explaining why.”

“Well…” The toad man’s broad face was looking a little discomfited. “It’s true, but you see, there are reasons to be discreet…” He looked down at Genette as if hoping for help.

“I’m going,” Swan said, interrupting their glance. “I want to go.”

“Ah,” Wahram said with another quick glance at Genette. “Good.”

Extracts (1)

Take an asteroid at least thirty kilometers on its long axis. Any type will do-solid rock, rock and ice, metallic, even ice balls, although each presents different problems.

Attach a self-replicating excavator assembly to one end of the asteroid, and with it, hollow out your asteroid along its long axis. Leave the wall at least two kilometers thick at all points except for your entry hole. Assure the interior integrity of the wall by coating it with a dura of suitable strength.

As your assembly hollows the interior, be aware that ejection of the excavated material (best aimed toward a Lagrange salvage point, to collect the salvage fee) will represent your best chance to reposition your terrarium, if you want it in a different orbit. Store excess ejecta on the surface for later use.

When the interior is hollowed out, leaving an empty cylinder at least five kilometers in diameter and ten kilometers long (but bigger is better!), your excavator assembly will return to the access hole and there reconfigure itself into your terrarium’s propulsion unit. Depending on the mass of your new world, you may want to install a mass driver, an antimatter “lightning push” engine, or an Orion pusher plate.

Beyond the forward end of the cylinder, on the bow of your new terrarium, attach a forward unit at the point of the long axis. Eventually your terrarium will be spinning at a rotational rate calculated to create the effect of gravity on the inner surface of the interior cylinder so that when you are inside, you will be pulled to the floor as if in a gravity field. This is the g equivalent, or gequivalent. The forward unit will then be connected to the bow of the terrarium by a geared axle, to allow the forward unit not to spin but instead to stay fixed. It will be nearly weightless in this bowsprit chamber, but many functions of the terrarium will go better without the spinning, including docking, viewing, navigating, etc.

It is possible to build an interior cylinder that spins freely inside an asteroid that does not spin-the so-called prayer wheel configuration-and this does give you both an interior with g effect and a non-spinning exterior, but it is expensive and finicky. Not recommended, though we have seen some good ones.

When stern and bow are properly installed and configured, and the asteroid is set spinning, the interior is ready to be terraformed.

Begin with a light dusting of heavy metals and rare earths, as specified for the biome you are trying to create. Be aware that no Terran biome ever began with the simple ingredients you will be starting with on an asteroid. Biospheres need their vitamins right from the start, so be sure to arrange for the importation of the mix you want, usually including molybdenum, selenium, and phosphorus. These are often applied in “puff bombs” set off along the axis of the cylindrical space. Don’t poison yourself when you do this!

After that, string the axis of the cylinder with your terrarium’s sunline. This is a lighting element, on which the lit portion moves at whatever speed you choose. The lit portion of the sunline usually starts the day in the stern of the cylinder, after a suitable period of darkness (during which any streetlights overhead will serve as stars). The lit portion of the line, appropriately bright, then traverses the sunline from stern to bow (or east to west, as some describe it), taking usually the same time as a Terran day, as measured by the latitude of your biome on Earth. Seasons inside your terrarium will be rendered accordingly.

Now you can aerate the interior to the gas mix and pressure you desire, typically somewhere between 500 and 1100 millibars of pressure, in something like the Terran mix of gases, with perhaps a dash more oxygen, though the fire risk quickly rises there.