Building Commercial Space

American Institute of Aeronautics and Astronautics
1
Building Commercial Space Infrastructure
Alex A. Thatcher1
Mensa, Boise, ID, 83713
Keith Taggart Ph.D.2
SPEC Innovations, Manassas, VA, 20109
and
Steven Dam Ph.D.3
SPEC Innovations, Manassas, VA, 20109
Development of low-cost earthside habitation will pay for a transition into space with the
profits and technology derived. By bringing necessary earthside technologies up to speed, the
transition into space becomes easier. To circumvent currently prohibitive costs, building
should be modular. Two design concepts for commercial space stations with rotational
gravity can be created from this approach. Able be built in the next five to ten years at a
fraction of the cost of the International Space Station using available or soon to be available
launch capabilities. These designs can be built from a few types of modules constructed on
the ground, lifted into low earth orbit, and assembled in space using either manned or
teleoperated assemblers. These stations could support space tourism, space-based
manufacturing, space-based power assembly and testing, asteroid exploration or exploitation
(Near Earth Asteroids – NEAs, transitioning the modules for usage as mining vehicles to
establish claims and settlement), research for radiation mitigation techniques, research in
long term effects of low gravity (not micro gravity) environment, low gravity research in
general, lunar exploration and resource exploitation, satellite repair, and debris collection.
These initial space stations are the first steps in building a cislunar infrastructure but must
be built so as to provide a reasonable return on investment.
I. Introduction
Habitation. A permanent presence in space. A seemingly insurmountable feat, due to cost. Currently,
everything for space use is custom built, in very limited quantities. This is not conducive to space development due
to the extreme costs, but necessary because there is nothing comparable at a lower cost. What if there were though?
A feasible starting point then, is introducing habitation that can transition to space usage, initially mass-produced to
consumers for earthside use. As it is mass-produced, the cost of production may dramatically decrease over a very
short amount of time, creating a unique situation where many that never had homes could now own one. The return
on investment (ROI) could be staggering, if handled correctly, low cost housing is in desperate need around the
world. For example, according to the BBC there is a 27 million home shortfall in India. Instances of up to eight
people living in a one-bedroom house are common.[i
]
In this paper we examine more closely the first Stage, Developing Commercial Space Robustness, by beginning
on Earth. Once income generates from the earthside development, it will fund conversion for space applications. Via
retrofitting, implementation to the earthside products, to keep them cutting edge, guarantees continuous sales of
earthside products.
1
President/Loc Sec, Southern Idaho Mensa, 5332 N. Five Mile Rd. Boise ID 83713.
2
Chief Technology Officer, SPEC Innovations, 10440 Balls Ford Road, Suite 230, Manassas, VA 20109.
3
Chief Executive Officer, SPEC Innovations, 10440 Balls Ford Road, Suite 230, Manassas, VA 20109.
Downloadedby166.137.8.53onMarch13,2016|http://arc.aiaa.org|DOI:10.2514/6.2014-1898
SpaceOps 2014 Conference
5-9 May 2014, Pasadena, CA
AIAA 2014-1898
Copyright © 2014 by Alex Thatcher, Keith Taggart, Steven Dam and SPEC Innovations. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.
SpaceOps Conferences

2
Commercial Space projects have expanded greatly in the last 20 years. INTELSAT communications satellites,
GPS commercial uses, SpaceShip One/Two, Bigelow hotels in space, SpaceX product line and ISS support, to
mention a few among many others. Bigelow Aerospace, creators of the “space hotel” just mentioned, is a prime
example of a model that could be considered for the approach laid out in this paper.
Bigelow began his ascent into the world of billionaires with his Budget Suites of America hotel chain. He has
since gone on to create Bigelow Aerospace creating space stations. The same model can be followed by others and
they must be encouraged with endorsements of these activities and assistance in their development of more
commercial space risk/reward projects combining cutting edge technology and successful commercial ventures.
Government one-off projects, flights, and structures will not provide the robust infrastructure that will be needed to
support the development of space. The following are specific steps to be addressed in this paper around commercial
efforts:
1) Establish Early Organization
2) Develop Robust Outreach
3) Develop and Sustain Living Enetrise Architecture and Action Plan
4) Raise Funds
5) Encourage Commercial Space, especially Heavy Lift
6) Encourage and Fund Technology Development
7) Plan Space Infrastructure Evolution
8) Encourage Building Space Infrastructure
II. Near-Term Commercial Infrastructure:
Why Commercial Space Stations? SpaceX has already demonstrated that it can resupply an operational space
station [2
] and within the next few years it will likely demonstrate that the Dragon Module can carry men as well as
supplies into space, launched on the Falcon 9. [3
] The development of the Falcon Heavy is proceeding apace and its
capability is projected by SpaceX to be 50 metric tons to 200 km orbit. [4,5
] The Commercial Space Station Design
Concepts that we propose in Figure 4 can be assembled in space from modules that can be put into Low Earth Orbit
using the Falcon Heavy booster.
The 7m long × 5 m diameter
modules will constitute the living and
work areas under rotational gravity as
shown in Figure 5. Construction
would require 24 modules for Type 1
and 30 modules for Type 2 plus
additional tubing for the spokes as
well as any couplings, required
construction equipment and the initial
quarters for the construction crew.
About 35 Falcon Heavy launches,
roughly one a month, carrying 40
metric tons per launch to around
400km orbit would be required. The
modules are sized to fit in the
projected dimensions for the Falcon
Heavy Shroud. In addition, about 4
Falcon 9 launches each carrying a
construction crew of 6 and half of
their supplies for their nine month stay would be necessary. Another 4 Falcon 9 launches would deliver the other
half of the supplies half-way through each nine month tour. Total construction time should be about 3 years from
first launch with the limiting factor being the rate at which Falcon Heavy launches can be mounted. Teleoperated
construction equipment will be able to move the plug-and-play modules into position and make structural as well as
Figure 1: Commercial Space Station Design Concepts.

3
initial plumbing and electrical connections. In order for teleoperation to work the operators must be close at hand to
avoid latency problems. In addition, prudence dictates that humans be available to solve any issues that arise and to
propose near real time modifications to assembly procedures and yet to be built and launched hardware.
Module Mass Calculation: We calculate the mass of a
single module by modeling it as a five layer tube with internal
structure as shown in Figure 2.
The mass of any element is calculated as M=A×T×Rho
where M is the mass in metric tons, A is the surface area of the
element in m2
, T is the thickness in m, and Rho is the density
in metric tons (MT) per m3
.
The outer layer, shown as orange in Figure 2, is for
insulation, temperature moderation, and impact protection. We
model it as 0.01m thick, with a white surface, and made of
layered Mylar and Kevlar:
M=220m2
×0.01m×1.4MT/m3
= 3.1MT
The pressure vessel is two layers of 0.005m high strength
Aluminum, shown as blue:
M=220m2
×0.01m×1.4MT/m3
= 3.1MT
The floor (4×7m2
) and brace/divider (1.5×7 m2
), shown as blue and white, are made of 0.01m high strength
aluminum:
M= 38.5m2
×0.01m×2.7MT/m3
) = 1.0MT
In addition, on the average, there is one pressure vessel end plate for each module made of 0.01m thick high
strength Aluminum:
M=20m2
×0.01m×2.7 MT/m3
= 0.5MT
A 0.01m thick layer of sealant, shown in green, seals small holes until permanent repairs are made:
M=220m2
×0.01m×2.0MT/m3
= 4.4MT
The interior, shown in red (plus both sides of the end cap), is modeled as 0.005m thick structural plastic with a
foamed core to reduce weight, provide strength, and provide additional insulation:
M= (220+7×7+2×20)m2
×.005m×1.4MT/m3
=2.2MT
So the module structure mass is just
MM = (3.1+5.9+1.0+0.5+4.4+2.2) MT = 16.2 MT
We use the density of pure Aluminum for high strength Aluminum since we do not know which alloy would be
used and all have density fairly close to that. The densities for the other materials are what we consider to be
reasonable estimates based on limited reading.
We estimate that the Falcon Heavy will be capable of launching 40MT into a roughly 400km circular orbit so
the payload mass margin for a module is about 145% if the Falcon Heavy performs as projected. This leaves
Figure 2: Module Conceptual Design

4
considerable payload mass in each launch for attitude and spin control, power, water, and HVAC equipment;
recycling and waste collection equipment; fuel, water, air, and waste storage tanks; as well as control computers,
wiring, and servos. While the engineering and construction of all of this equipment to fit within the space constraints
of the modules and the payload weight of 40 MT is most definitely not simple, we believe that the risk for doing this
in the next five to ten years is low. We also believe that all of this equipment can be built into the modules on the
ground in such a way that the modules will be plug-and-play when assembled in space.
Usability: Both stations are designed with an approximately 35m outer radius, which is where occupants’ feet
would be. With a rotational rate of 3.1 rpm this gives rise to an experienced gravity of .38g, where g is the gravity
constant at the earth’s surface of 9.8m/sec2
, the same as the surface gravity of Mars. [6
]. If the rotational rate is
reduced to 2.1 rpm the experienced gravity is 0.17g, the same as the surface gravity on the moon. So either space
station type could duplicate the surface gravity of Mars or the Moon for purposes of physiological research, training,
and/or acclimation. A simple calculation shows the total volume under gravity to be about 3300 m3
or 117,000 cubic
feet. The total floor space under gravity would be about 7200 square feet or about 300 square feet per module. If a
module were turned into a hotel room or an office with a hall as shown in Figure 5, the living/working area would be
about 200 square feet, roughly the same as an economy cabin on a cruise ship, adequate for two people. Many
different configurations are possible so the station could be multi-functional. Activities that could be supported
include:
•Closed Environment Research
•Space Tourism
•Space Based Manufacturing
•Space Based Power Assembly and Testing
•Asteroid Exploration
•Research for Radiation Mitigation Techniques
•Satellite Repair
•Research in Long Term Effects of Low Gravity (not micro gravity) Environment
•Low Gravity Research in General
•Plant Growing in low gravity
•Lunar Exploration and Resource Exploitation
•Debris Collection
•Control and Maintenance of Nearby Satellites such as Space Telescopes
1. Cost Estimates: We estimate below the cost to establish either a Type 1 or Type 2 Space Station as described
above (costs and lift masses are from “An Analysis of Low Earth Orbit Launch Capabilities” [5]):
Launch Costs (Projected)
•40 Falcon Heavy Launches
– 35 × 40 MT = 1400 MT to about 400 km
•24 Modules plus up to 440 MT of additional construction materials for Type 1
•30 Modules plus up to 200 MT of additional construction materials for Type 2
– 35 × 120 M$ per launch = 4.200 B$
– 5 × 120 M$ per launch = 0.6 B$ Contingency
•12 Falcon 9 Launches
– 4 × 6 Construction Crew and supplies
– 4 × 10 = 40 Metric tons of supplies
– 8 × 56 M$ per launch = 0.45 B$
– 4 × 56 M$ per launch = 0.23 B$ Contingency
•Total Launch Costs to Construct
– 4.7 B$ plus 0.9 B$ Contingency
Construction Costs (Much Less Precise)
•30 Modules at 200 M$ each equals 6.0 B$
•5 Modules at 200 M$ each equals 1.0 B$ Contingency
•Crew Cost

5
– 18 person years × 8760 hours per year × $2000 per hour equals 315 M$
– 9 person years × 8760 hours per year × $2000 per hour equals 160 M$ Contingency
– 12 person years × 3000 hours per year × $2000 per hour equals 72 M$ Training
– Equipment and Supply Cost 500 M$
– Ground Support 500 M$
– Contingency 500 M$
•Total Construction Cost about 7.4 B$ plus 1.7 B$ Contingency
Return on Investment: So the total investment required to establish the space station is about 12.1 B$ plus 2.6
B$ Contingency. It is instructive to look at this as if it were financed as a high risk mortgage for 30 years at 15%.
The monthly payments would be 153 M$ and the total financed cost would be around 55 B$. The rental charge
needed to meet just this cash flow would be 153 M$ / 7200 square feet or $ 21,250 per square foot per month. This
would mean charging roughly 1.6 M$ for a one week stay in a “hotel” room not including transportation, food, and
services. While we are sure that the project would not be financed as a 30 year fixed rate mortgage, the numbers
seem daunting. This is especially true when you consider how we currently finance risky technology ventures where
the investors expect a much larger return than 15% per year on their investment. It certainly seems that new means
of financing need to be formulated.
2. Thoughts on Operating Costs: Consider supplies and trash removal for 10 Permanent Residents and 10
Visitors.
•Food
– Assume 3000 calories per day per person
– Assume 3 calories per gram
– One kilogram of food per person per day
– Multiply by 2 for “packaging” gives about 15 metric tons per year
– Roughly the same amount of waste needs to be returned to earth
•Supplies, including food, water, and other consumables could be handled with weekly or bi-weekly
visitor transport on Reusable Falcon 9 launches
•Recycle versus Renew
– 4.3 Metric Tons of Atmosphere
•5 Metric Tons of Reserve in Pressurized Storage
•1% loss per week
•About 5 Metric Tons Replacement per year
– Water
•40 gallons per person per day
• 0.15 cubic meters
•20 people need 3 cubic meters or 3 metric tons per day
•Assume a week to recycle the water with 1% loss
•Requires 21 cubic meters of water stored
•Plus 0 .21 cubic meters replacement per week or
•About 12 metric tons per year
– If Recycle Efficiency falls below 95% per week then replacement cost could become
problematic.
To take this design to the next stage, a number of systems engineering trade studies needs to be applied to this
initial architecture. Creating system models of this architecture will support the trade studies and enable more
detailed design work. The Action Diagram in figure 3, on the next page, captures the various stages of the space
station’s life cycle as a means to derive more complete requirements for the space station.

6
III. Moving Past the Stations
Stations could be disassembled and lifted to higher orbits, into L4 and L5, used as components of ships
(specifically mining ships), when they become obsolete, or even while in operation depending on the mission
dynamic. Perhaps a module could be rotated into station use and then transitioned out. This would allow for an ever
expanding network and presence into space. But what to do with the modules once the moon is reached, or NEAs?
Another station could be built, by dropping modules that had been integrated with a mining ship, for and M or S
type asteroid, but a polyurethane two Component formulation from an exotic foam formulation company can be
used to fill and seal a Carbonaceous (C-Type) Asteroid or a Moon cave. Much like sealing foam readily available to
consumers, such as Tuff Stuf, the foam will expand and fill all the cracks and passages. Initial development costs
may be low enough using pre-existing companies such as Smooth-On who already have experience with industry
and government contracts for unique formulations.
Most testing can be completed earthside and must be done in environmental extremes to match variations
possible on multiple asteroid environments. Low budget zero-g testing and vacuum environments can be acquired
through the Zero G Corporation providing a product for proof of concept and larger scale funding into space. Final
testing will be done on an already existing Bigelow station or one of our space stations - if built. Deployment will
require development of a “bunker buster” type missile and launch system. Once a cavernous C-type is located (or
other desired location) the missile can be deployed and should fill the cavern, if not, a failsafe will burn off the foam
before expansion. The foam filled cave will then be ready to be drilled out. The pre-existing modules can then be
plugged into the foam, or a structure can be built inside a foam sealed cavern. This begins the process of establishing
a habitable environment with the overall cost factor, in human risk and dollars, being dramatically less than
previously conceived methods as well as establishing a claim and presence in a matter of hours or days instead of
weeks or years. The Foamaroid concept may seem ludicrous, but it solves radiation issues, time issues, cost issues,
and debris issues, that almost any other option does not.
Figure 3: Module Conceptual Design

7
Figure 4: How to Build a Foamaroid
IV. Difficulties / Opportunities
There are sufficient difficulties concerning the design, construction, and operation of these Space Stations not
addressed in this paper to provide many, many optimists with the opportunity to solve them for several years. These
should not be perceived as barriers, but instead hurdles, that in accomplishing, the benefits and payoff far outweighs
any cost. Everything listed below has been resolved in some manner before, the trick will be how to make it work
for space. We have listed some of the more difficult and interesting challenges below:
• Power
• Radiation Protection
• Orbital Debris
– Collision Protection
– Collision Avoidance
• Station Dynamics and Control
– Orbital Change of a Spinning Station
– Attitude Control
– Spin Control
– Coriolis Effect Mitigation
• Recycling
– Atmosphere
– Water
– Waste
• Economic Viability
• Liability / Insurance

8
Despite the difficulties, we believe that the space station design concepts shown in this paper could be built within
the next ten years if the initial design financing could be found and a small dedicated design team put to work within
the next two years. With more information in hand another team could examine the economic viability of such a
space station and put together a business plan within three years.
V. Conclusion
We have shown that it is reasonable to take the first step in the development of Commercial Space Infrastructure. As
space becomes more and more accessible, using already proven technology and manufacturing methods will lower
costs significantly. With the inherent modularity in our technology it can be a key component in the expansion into
space. We have estimated total development cost for two Types of LEO Space Stations with rotational gravity to be
a small fraction of some estimates of the cost to build the ISS. [5] We have shown that the approach of using
modules constructed around one basic structure type, built on earth, and then launched into a 400 km orbit and
assembled into a space station is viable. We have discussed the difficulties / opportunities inherent in the detailed
design and construction of such a space station and suggested that a small design team could do a detailed design
and work out solutions to many of the difficulties in about two years. Finally, we suggest that with the more detailed
information available, a full business plan could be put together in about three years to solicit construction financing
with guaranteed ROI and potential for unlimited growth. The success of this endeavor would provide a concrete
example of how commercial space ventures can move us down the road towards space development, reminding us
of the grandeur, importance, challenge, and urgency of our vision as we look towards the sky and people see what
we have done.
References
1
Vaidyanathan, R., “India Seeks House Building Boom”, BBC News TV, UK (April 8 2012).
2
Nelson, Katherine; SpaceX Media Release, October 28, 2012.
http://www.spacex.com/press.php?page=20121028
3
“Transporting Crew: To ensure a rapid transition from cargo to crew capability, the cargo and crew
configurations of Dragon are almost identical, with the exception of the crew escape system, the life support system
and onboard controls that allow the crew to take over control from the flight computer when needed. This focus on
commonality minimizes the design effort and simplifies the human rating process, allowing systems critical to
Dragon crew safety and space station safety to be fully tested on unmanned demonstration flights and cargo resupply
missions”; SpaceX, November 2, 2012. http://www.spacex.com/dragon.php
“The SpaceX CRS-1 mission also represents restoration of American capability to deliver and return cargo to the
ISS -- a feat not achievable since the retirement of the space shuttle. SpaceX is also contracted to develop Dragon to
send crew to the space station. SpaceX's first manned flight is expected to take place in 2015.”; SpaceX, September
21, 2012. http://www.spacex.com/updates.php
4
Falcon Heavy Overview, SpaceX, November 2, 2012. http://www.spacex.com/falcon_heavy.php
5
Mullery, Collin et. al.: “An Analysis of Low Earth Orbit Launch Capabilities”, George Mason University
(2012).
6
To understand this consider that the experienced gravity is provided by the floor of the space station being
accelerated in a circle continuously and is equal to the centripetal force exerted by the structure to provide this
acceleration. This can be written as f×g = r×2
, where f is the fraction of earth normal gravity, g is the gravitational
acceleration at the earth’s surface, 9.8 m/sec2
, r is the radius of the floor of the space station, and = 2/T where T
is the period of the station rotation in seconds. Some simple algebraic substitutions and manipulations give f =(r/g) ×
(2/T) 2
. Further substitution gives f = r/ (894×2
), where T = ×60 where  is in minutes. This is all for ease of
calculation. For r = 35m and  = 0.33 min or 3 rpm f = .35. For r = 35m and = .5 min or 2 rpm f = .15.

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