Delta-v: Designing the Asteroid Mining Ship 'Konstantin' (minor spoilers)

When I set out to write a novel about the world's first commercial asteroid mining expedition, the research led me interesting places...

The resources in near Earth asteroids could be the catalyst that finally launches human expansion in our solar system-- securing a future for both our species and our entire biosphere. But asteroid mining won't be easy. To succeed humans will need to forget how we've mined on Earth for thousands of years and invent completely new methods.

Imagine trying to mine a mountain that's in free-fall. Now imagine that instead of a mountain, it's actually a colossal gravel pile falling alongside you, with nothing stable to bolt onto--the minerals consisting of razor sharp crystalline particles that have never been smoothed by erosion and which can chew up machinery and even bullet-proof fabrics. Now add the complications that you're also in a near-perfect vacuum, and being bombarded by solar and cosmic radiation. Toss in physiological deterioration from micro-gravity, the psychological effects of isolation, and little or no outside help if anything goes wrong with the unproven equipment -- and you're just starting to understand the magnitude of the challenge.

In Delta-v a significant portion of the story is set aboard the mining ship, Konstantin. This spacecraft drives the action, constrains and enables the characters--both on Earth and in space--and provides the means to voyage to the asteroid Ryugu. The final design of my ship is the result of detailed research as well as consultations with physicists, aerospace engineers, and asteroid mining entrepreneurs. Form follows function in every aspect of its systems, giving the vessel a distinctive, even surprising appearance.

Over the next few weeks I'll be adding web pages with more images and design notes that detail the development of the different asteroid mining machines depicted in Delta-v. Be sure to watch my Twitter feed to discover when I've added new content here.



 
 

Image 1 - The Luxembourg flagged asteroid mining ship, Konstantin, on station 3 kilometers from Ryugu. Note the solar mast with photovoltaic array designed to remain in sunlight while the bulk of the ship stays in the asteroid's shadow. This serves to shield the crew from solar flares. Additional shielding from galactic cosmic rays is obtained after arrival by extracting water from the asteroid. Because Ryugu has only 1/62,000th the gravity of Earth, the Konstantin does not orbit the asteroid but instead uses what's known as a 'bang-bang' control for station-keeping. Gasses processed from the asteroid provide fuel for the modest station-keeping requirements.


This image was rendered from a detailed model of the Konstantin commissioned for Delta-v. (Ship model by Anthony Longman; Ryugu model by Mattias Malmer, based on Hayabusa2 lidar data from JAXA).

  
 

Image 2 - A closer view of the Konstantin, illuminated by running lights. Were the crew to remain in micro-gravity for the entire multi-year expedition, they would suffer severe physical deterioration. Thus, the Konstantin is a spin-gravity vessel. Three radial arms extend 106-meters from its central, inflatable habitat (or 'hab'). The central hab rotates like a wheel, while the z-axis of the ship (the axle) does not rotate. Each radial arm is traversed via a tunnel that ends in an inflatable hab module.


When the central hab is 'spun up' at nearly three revolutions per minute, the inflatable habs at the end of each radial arm experience the equivalent of one Earth gravity in acceleration. Two of the three habs are crew quarters, while the third is a fabrication habitat (or 'fab hab'), containing CNC milling and 3D printing equipment, as well as small chemistry, geology, and robotics labs.

Note: a 200-meter rotational radius is generally considered the minimum that an untrained human can tolerate without risk of motion sickness related to the Coriolis effect ; however, a 100-meter radius (or less) can be tolerated with some additional training.


Note also the four robotic 'Honey Bee' optical mining craft docked on the z-axis, just beneath the central hab, and forward of the reflective solar shield. These largely autonomous robots are typically deployed in a terminator orbit around Ryugu. They 'bag' boulders pulled from the asteroid's surface by other robots, and concentrate sunlight via twin parabolic reflectors to 'spall' the surface of a boulder in bursts, releasing volatiles, and powdering the regolith for later processing in the refinery.


 
 

Image 3 - The Konstantin has three radial arms for reasons of spin-stability. Simpler 'bolo' designs, where just two masses bound by a cable rotate around an axis to simulate gravity, are not spin-stable. Likewise the radial arms of the Konstantin are arrayed at asymmetric angles to account for the significant difference in mass between the crew habs and the heavier fab hab.

Note also the rail-mounted weights atop each radial arm; these weights automatically move up or down the arm's length to account for subtle mass differences between the three habs as crew and materiel move between them.

At the top of the image four 'mule' utility craft are docked at the ship's upper airlock. This airlock is set high enough above the rotating radial arms to accommodate a forty-degree thrust cone for docking vessels, the impact of which might otherwise damage the rotating habs or transfer tunnels.

  
 

Image 4 - Another view of the four large Honey Bee optical mining robots, docked aft of the central hab. The Honey Bee is an asteroid mining robot designed by real-life asteroid mining company, TransAstra Corporation (and reproduced here with permission).

The reflective solar shield keeps the eighteen bladder tanks in shadow during transit to Ryugu, slowing evaporation of the methalox fuel. The ship refinery is surrounded by the bladder tanks, and the engine room is located aft. Both the refinery and the engine room are unpressurized to reduce the risk of fire. The lower airlock is located just forward of the solar shield, and is only usable once the Honey Bees are deployed.


Note the orange 'clam shell' space suits docked at the upper airlock. These illustrate the scale of the Konstantin.

  
 
Image 5 - Due to their susceptibility to shearing forces, the three radial arms of the Konstantin must fold and lock against the z-axis of the ship whenever the ship's main engines are fired. The folding operation is computer-controlled and facilitated by thrusters mounted along the box trusses on each radial arm. Likewise, the ship must be 'spun-down' prior to arm folding. This folding requirement is manageable because the Konstantin fires its main engines only twice -- first as an injection burn to depart cislunar space and then a post-injection burn forty-eight days later to match orbit with Ryugu. During the outbound transit, the ship is spun-up and the crew can enjoy spin-gravity. The arms are folded just prior to Ryugu rendezvous, and then unfolded again and the ship spun-up once more when it is on station.
 
 
Image 6 - A top-down view of the Konstantin just prior to a burn. The arms are locked in place, with the solar shield shading the fuel tanks. The upper airlock is visible, with four 'clam shell' space suits and four mule utility craft.
 
 

Image 7 - A detail from the original Sketchup model I created of the Konstantin. This view shows a closeup of the upper airlock, with four mule utility craft docked. The EMU airlock stands directly above, with four orange space suits as well as humanoid telepresence robots (Valkyries in the book, but here depicted with stand-in Sony robots). In the distance we see one of the crew habs at the end of a radial arm, reached by a transfer tunnel from the central hab. The perceived 'spin-gravity' decreases as crew members travel along the transfer tunnel 'up' toward the central hab, eventually entering microgravity once they reach the ship's z-axis.

 
 

Image 8 - A partial cut-away view of an inflatable crew quarters hab. The top hatch would be contained within a larger airlock and linked to the outermost box truss of a radial arm. Home to four crew members, each hab is divided into two main floors, plus an upper equipment/storage area and lower (bilge) equipment/storage area. The walls of the hab are half-meter-thick laminate material designed to withstand micrometeor impacts.


This view of the interior shows the 4,000-liter water tank and bathroom in the lower floor, and the living area in the upper floor. Note the pressure door in the aluminum-walled inner core of the hab, which extends through both floors.

  
 

Image 9 - A closer view of the hab's upper floor, with living area in the foreground, kitchen area and storage to the left, and adjustable partition concealing the medical bay to the right. The gym is visible just beyond the medical bay. The curving aluminum wall of the central core occupies the center of the hab and is accessed through the pressure door equipped with a borosilicate window.


Note: the galley table model is a stand-in. The book depicts a rectangular, wall-mounted galley table that can be virtually extended via augmented reality software to 'include' the occupants of the other crew hab for meetings and meals.

 
 
Image 10 - A larger cut-away view of the crew hab, encompassing the upper storage area, both floors, and bilge storage. Notice the pressure doors of the aluminum-walled inner core, one on each floor. The medical bay is visible on the upper floor, to the right, with workstations and equipment visible on the lower floor. A gangway providing ladder access between floors is hidden on the far side of the inner core in this view.
  
 
Image 11 - A deeper cut-away reveals the crew quarters within the water-lined inner core -- two beds on each floor, along with storage. Emergency access is available between crew floors and also to the upper airlock. An emergency escape hatch is also available at the bottom of the crew hab but is not safe for use unless the ship is 'spun-down'. The crew workstations on the lower floor are also visible, as are the hydroponics units in the right rear of the hab.
 
 
Image 12 - A view from the gym into the medical bay on the second floor. The inner core wall is visible on the right. The Konstantin is equipped with two medical bays -- one in each crew hab -- plus a first-aid station in the fab hab. This is necessary because it can take up to fifteen minutes to transfer between habs while the ship is 'spun-up'.
 
 
Image 13 - The lower floor of the hab, looking toward the redundant oxygen generators, water treatment system, and other equipment. Crew workstations with accordion doors closed appear on the left and the right, with hab's server rack in the foreground (a stand-in model, as the one in the book contains a full complement of servers.)
  
 
Image 14 - The lower floor of the hab, this time looking from the other side, back at the hydroponics systems and the gangway leading to the hab's upper floor. The ladder rungs are a stand-in, with those in the book larger and easier to navigate.