TO GEO AND BEYOND:
Gateway Earth Space Access
University of Edinburgh
Policy Lead, Gateway Earth Development Group
University of Oxford
Market/Economics Lead, Gateway Earth
Reinventing Space Conference
Vidmar 2 Reinventing Space Conference 2016
TO GEO AND BEYOND:
Gateway Earth Space Access Architecture
University of Edinburgh; Policy Lead, Gateway Earth Development Group
Royal Observatory Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ, United Kingdom; +44 (0)131 6688 461
University of Oxford; Market/Economics Lead, Gateway Earth Development Group
Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom; +44 (0)186 5282 643
Gateway Earth Development Group seeks to design a technically and economically viable architecture for
interplanetary space exploration. We are proposing to utilise space tourism as an enabler for the development of a
space station in Earth’s geostationary orbit (GEO), at which interplanetary spacecraft could be build and serviced to
take astronauts on missions across the Solar System. Access to this space gateway will be provided by deploying re-
usable vehicles, which will in stages - through Low Earth Orbit (LEO) - deliver goods and people to the station.
Gateway Earth itself will be a combined governmental space station and commercial space hotel, located in GEO.
At this location it is close to the edge of Earth’s “gravity well”, and so it is a great place for interplanetary spacecraft
to dock both as they depart for, and as they return from, distant Solar System destinations. This would apply to both
robotic and crewed missions. For the same reason it is a great place to assemble the interplanetary craft, which
would then avoid the craft having to withstand the rigors of launch and re-entry through Earth’s atmosphere. Space
tourism revenues will provide a significant part of the funding needed to both build the complex and supply the
regular reusable tug service.
At present, various elements of the concept are being developed independently by different space engineering firms
and agencies; some large, and others small and entrepreneurial in nature. Our aim is to synthesize all these disparate
activities, and have them focus on making the overall Gateway Earth concept possible. This paper will provide a
status update on progress to date and invite feedback on key modules of the projects’ architecture.
KEYWORDS: Space Access; Space Station; Geostationary Orbit (GEO); Gateway Earth; Solar System
Exploration; Space Tourism; Space Hotel; Private-Public Partnership; Future of Space Travel
Copyright © 2015 by the authors. Published by the British Interplanetary Society, with permission.
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GATEWAY EARTH DEVELOPMENT GROUP – SHAPING THE FUTURE OF SPACE ACCESS
Gateway Earth Development Group (GEDG), which was launched in a fringe meeting at Reinventing Space
conference in Autumn 2015, is seeking to promote research and development based on inter-disciplinary, inter-
organizational and international cooperation with a view to advocate a new Space Access Architecture for maned
and robotic Earth Observation, In-orbit Servicing, Interplanetary Exploration and Space Tourism. Our goals can be
best summed up as:
“Gateway Earth Development Group seeks to develop a technically and economically viable architecture
for interplanetary space exploration. We are proposing to utilize space tourism as an enabler for the
development of a space station in (Earth’s) geostationary orbit (GEO), at which interplanetary spacecraft
could be build and serviced to take astronauts on missions across the Solar System. Access to this space
gateway will be provided by deploying re-usable vehicles, which will in stages (through Low Earth Orbit -
LEO) deliver goods and people to the station.” (Gateway Earth Development Group, 2016b, p.1.)
More specifically, at the core of this venture is
“The Gateway Earth station placed in the GEO orbit. The station itself is partly funded by space tourism
and other commercial businesses; there is a regular tug service between LEO and GEO – again largely
funded by commercial space businesses; and this Gateway may be used by governmental astronauts (NASA
and other) both as a place to assemble interplanetary craft, and as a starting and end point for subsequent
journeys across the solar system gravity plateau. Almost the entire system is reusable. The governmental
space program budgets only need to provide funding for part of the “Gateway Earth” complex, and for
paying the operators for “taxi rides” both from Earth to LEO and from LEO to GEO. The capital costs for
government are therefore limited, and this, together with the consequential lightweight/low energy design
of the interplanetary spacecraft, will thereby dramatically reduce the costs compared with missions
performed in the “traditional” ways.”(Webber, 2015a, p.3)
This paper will firstly outline the overall vision for this Space Access Architecture proposal, the supporting
economic rationale and the current level of technological development and readiness. We invite feedback and
comments on our proposal and look forward to suggestions for addressing some of the challenges.
Secondly, we aim to present the current effort led by the Development Group, both its constitution and objective as
well as preliminary findings and future challenges. We invite interested parties to join our endeavor and welcome
scrutiny of our structure and work areas.
Finally, we contextualize these efforts in line with recent advances in space engineering and propose new work and
development areas to take our mission forward.
GATEWAY EARTH – A GATEWAY TO SPACE
Key Elements of the Gateway Earth Architecture
Gateway Earth Space Access Architecture, reduced to its simplest form, is tackling the issue of how to regularly,
and at low cost, ascend from the surface of the Earth, exit of Earth’s gravity well, and across the relatively flat
geopotential plateau towards the gravity wells of neighboring planets (Webber, 2015a). In order to keep the cost
down and as a matter of technological prowess, reusability is essential element of any proposed solution.
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Figure 1. Gravity Well Diagram and Gateway Earth Space Access Architecture. © Gateway Earth
Development Group, 2016
The proposed solution is a (7 or) 8 stage infrastructure (Webber, 2012a,b, 2013a,b,c, 2014, 2015a,b), as outlined
below (and illustrated on the Figures 1 and 2):
Step 1 – Reusable Launch to LEO: The craft designed to provide the service between Earth’s surface and LEO
(Step 1) needs to be designed to handle the demands of transferring each way through our atmosphere, and of course
such vehicles already exist (eg Soyuz, Dragon, etc). Ongoing developments at this stage for the Earth to LEO craft
are approaching reusability.
Step 2 – LEO Node: There is a need for a continuing LEO station, such as the ISS, as the LEO node of the
architecture. Space travelers will take two effective shuttle rides to reach their interplanetary craft at Gateway Earth
complex; first they ride up to the ISS node – then they transfer to the LEO-GEO tug. And of course the process is
repeated on returning from their interplanetary trip; first they dock at Gateway Earth, then they take a tug down to
LEO, finally they take the last leg to the surface using the traditional aero-thermal braking approach for atmospheric
The following steps 3, 4, 5 are in fact interrelated and carried out in parallel.
A key focal point of our architecture is Step 3 - Installing Gateway Earth Station more or less near the rim of
Earth’s gravity well. This then becomes the effective start and end point for interplanetary missions. It serves as a
Space Hotel and a construction and fueling hub for interplanetary vehicles.
Step 4 - Regular tug service: their main purpose is to shuttle back and forth between LEO and GEO to take space
tourists, and their associated supplies, to their GEO space hotel. The tugs are in fact a business operation in their
own right. They are refueled, and restocked, in LEO each time before they make their next trip to GEO. So, Step 5 -
LEO refueling component is an important part of the logistical infrastructure. This might be provided as a separate
commercial venture, or partly supported by government funding.
Step 6 – Interplanetary Vehicles Built and Launched from Gateway Earth. The Gateway is also the place to
where the vehicles return after their journeys. Therefore, the interplanetary vehicles themselves do not need to be
built to withstand the rigors of a launch from Earth’s surface, either from the point of view of structural strength or
aerodynamics. And furthermore, they do not need to possess the weighty thermal control system associated with
atmospheric re-entry, or the powerful motors needed to provide the energy for getting from the Earth to GEO.
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Another way of thinking from the “gravity well” perspective is to view the “getting to the edge” part of the
operation as “powered flight”, and traversing the vast interplanetary spaces as much more like “gliding”. Much of
the structure for the interplanetary “glider” craft can therefore be built using additive manufacturing techniques.
Step 7 – Lunar or Planetary Lander and ISRU: In furthering the reach of Space Exploration mission, Landers
and ISRUs could be built at the Gateway Earth Complex to complement orbital missions. Given the fact that size
and shape are less relevant due to in-orbit construction, these vehicles could be far more advanced than the current
Step 8 – Trajectories to Interplanetary Space Destinations: Though a key frontier for routine space travel,
gateway Earth Space Access Architecture equally support short as well as long-distance missions. The returning
interplanetary space travelers of the future will consider Gateway Earth station as “home” on coming back in an
interplanetary Aldrin cycler from, say, the vicinity of Mars.
Figure 2. Gravity Field Diagram and Gateway Earth Space Access Architecture. © Gateway Earth
Development Group, 2016
It is estimated that the current NASA spending is at a level up to ten times lower than at the height of the Space
Race (0.5% of GDP in comparison to 5%GDP), when the most significant manned supra-orbital missions were
attempted (Apollo programme) (Webber, 2015a). Given that the opinion polls indicate that this budgetary provision
is deemed adequate by the public, it is unlikely government funding will increase significantly in the near future.
However, significant private investment was made into the Space Industry in the recent years with the entry of
disruptive innovators, such as SpaceX, Blue Origin, Virgin Galactic and many others. Reduction in cost of space
equipment and new funding sources, such as crowdfunding, has in turn provided much needed capital for small-
scale R&D and exploration of alternative technology paradigms (Adlen, 2011). New ways of working and new
space-related products are forming around innovation networks in a variety of non-traditional space environments
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Hence, many key agencies (including NASA) have been promoting public-private partnerships in the development
of new spacecraft and in-orbit as well as interplanetary operations. Though most of such projects have been limited
to exploring alternative R&D and procurement models, rather than full-out operations collaboration, the latter were
explored in some cases, with current commercial crew studies and the previous (very limited) space tourism (to the
Preliminary research showed that Gateway Earth public-private partnership proposition is commercially viable and
likely best value for money in terms of the investment of public funds (Webber, 2015a). In particular, initial analysis
of the market and cash flows established that the commercial operation of Gateway Earth station could be generating
in the order of $4.5B in revenues, assuming an optimum sized tug and hotel, both supporting 6 occupants at a time,
with about 150 tourists per year, and a ticket price of $30M to GEO (Webber, 2015a).
Furthermore, it is expected that the station could provide a range of other commercial services, from building,
launching or servicing communications satellites, to resource extraction.
Most of the technology required for establishing and running the Gateway Earth system is already available or
currently being developed by a variety of dispersed actors and through several funding streams. Hence, we see as
our mission to follow these developments and bring together the parties involved once the technology matures to the
point integration is possible. Below is a non-exhaustive list of developments currently being tracked. We invite
readers to contact our team (Technical Lead is Katy Voisey - Katy.Voisey@nottingham.ac.uk), if you spot any
critical omissions, which would otherwise be beneficial to the architecture.
Step 1 – Reusable Earth to LEO Vehicles
SPACEX and BLUE ORIGIN
Several fully or part reusable systems for automated and manned spacecraft are being developed by several
companies with substantial support of public funders. These are widely expected to become fully
operational in the near future with ease of LEO operations increasing and cost of access to LEO brought
Step 2 – LEO Station (ISS or equivalent)
THE FUTURE OF ISS
NASA is currently committed to support the ISS until 2024 or 2028 at the latest. At that point, the ISS
would be nearing the end of its useful life. It is unclear if NASA, with its current focus on Mars, will be
willing to invest into a successor station at the levels of the ISS, however it is unlikely that no LEO station
concept is to be put forward. Such plans will almost certainly involve a public-private partnership, which is
precisely in line with Gateway Earth architecture. Moreover, new players, such as China which announced
a LEO station by 2020, are entering this arena, who will likely be looking at private partners as well
Step 3 – Gateway Earth Complex
Bigelow Airspace expandable activity module (BEAM) was added to ISS in April 2016 and astronauts
entered on June 6, 2016. BEAM is part of a two-year project to test how expandable habitats perform in
space and will study how the habitat protects against temperature extremes, radiation and micrometeorite
strikes. Bigelow is also developing much larger expandable habitats which it hopes will become the
backbone of future space stations and outposts - the B330 module, for example, will provide 330 cubic
meters of internal volume.
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DARPA's Phoenix program seeks to change this paradigm and reduce the cost of space-based systems by
developing and demonstrating new satellite assembly architectures and delivery systems. Phoenix is
currently focusing on two primary technical areas of research:
a) Satlets: A new low-cost, modular satellite architecture that can scale almost infinitely. Satlets are small
independent modules (roughly 15 pounds/7 kg) that incorporate essential satellite functionality (power
supplies, movement controls, sensors, etc.). Satlets share data, power and thermal management
capabilities. They also physically aggregate (attach together) in different combinations that would
provide capabilities to accomplish a range of diverse space missions with any type, size or shape
payload. Because they are modular, they can be produced on an assembly line at low cost and
integrated very quickly with different payloads. DARPA is presently focused on validating the
technical concept of satlets in LEO.
b) Payload Orbital Delivery (POD) system: The POD is a standardized mechanism designed to safely
carry a wide variety of separable mass elements to orbit—including payloads, satlets and electronics—
aboard commercial communications satellites. This approach would take advantage of the tempo and
“hosted payloads” services that commercial satellites now provide while enabling lower-cost delivery
DRAGONFLY (from Henry, 2015)
DARPA’s Space Systems/Loral (SSL) contract is funding a study of on-orbit robotic assembly for GEO
communications satellites. The program will evaluate ways to build satellites in space, in particularly in
size or shape which would otherwise not fit a standard launch vehicle. The first phase of the program is to
demonstrate how assembling satellites on orbit could lower satellite cost and mass, while at the same time
enable higher satellite performance. The company has also submitted a proposal to NASA for collaboration
on taking the concept to a ground demonstration, followed by a flight application. The Dragonfly concept,
which is designed to have both military and commercial applications, is for satellites to self-assemble from
an efficiently stowed state while in orbit, with a focus on the installation and reconfiguration of large Radio
Frequency (RF) antenna reflectors.
Step 4 – LEO to Gateway Earth (GEO) Tugs
Jupiter is a proposed space tug spacecraft concept by Lockheed Martin, which was initially conceptualized
as a 2015 bid proposal to NASA for an International Space Station cargo resupply services contract. The
proposal was not accepted by NASA, and future Lockheed plans for the concept are unknown.
Cannae’s advanced propulsion system could be applied to a space freighter concept, serving as a Tug.
Parom might be a ton heavier than Progress and will feature a new design. Its larger size means it will be
able to ferry more people and cargo, reducing the number of annual cargo shipments to the ISS from four to
three. A pressurized cargo bay with an internal volume of some 18 cubic meters can take 2.4 tons of
supplies, including 400 kilograms of water and more than 50 kg of air. A new feature will be a six-tank
cluster with 1.8 tons of propellant. The original concept for Parom drawn up in 2005, however, saw this
vehicle as a reusable inter-orbit space tug. It also envisioned Parom not as a cargo spacecraft. Instead, cargo
in payload containers destined for a space station will be taken into an orbit 200 km high by launch
vehicles. Parom will then dock with the payload containers and deliver them to the space station. Because
of this, Parom was to have been built around a pressurized transfer passage with docking ports at each end.
Vidmar 8 Reinventing Space Conference 2016
Each of these two docking ports can be used to dock with the payload containers, a space station or any
Step 5 – Refueling in LEO (extracted and adapted from Messier, 2016b)
DARPA orbital express was a tech demonstration between DARPA and NASA in 2007, aimed at
developing a “safe and cost effective approach to autonomously service satellites in orbit. It consisted of
two spacecraft: the ASTRO servicing satellite and NEXTSat serviceable satellite. The project hoped to
demonstrate several satellite servicing operations and technologies including rendezvous, proximity
operations and station keeping, capture, docking, fluid transfer (specifically, hydrazine on this mission),
and ORU (Orbit Replaceable Unit) transfer. In March 2016 DARPA announced a new project - RSGS
(Robotic Servicing of Geosynchronous Satellites),
NASA’s Raven system will be attached to the International Space Station (ISS) to track crew and cargo
vehicles as they arrive at and depart from the station. The data Raven collects will be used to demonstrate
real-time navigation sensors and algorithms that will be incorporated into future servicing spacecraft and
NASA's Restore-L is one of the first attempts at a servicing mission. The spacecraft, set to launch in 2020,
will refuel the aging Landsat 7 remote sensing satellite that was launched back in 1999.
ROBOTIC REFUELING MISSIONS (RRM)
NASA’s RRM 3 mission, which is scheduled to launch in 2018, will demonstrate refueling using xenon
and cryogenic fluids. The previous refueling effort transferred hydrazine, which is widely used in
The commercial spaceflight provider Orbital ATK is taking a slightly different approach to its robotic
servicing system. The company's mission extension vehicle (MEV) will dock with a satellite and provide
attitude control, station keeping and end-of-life disposal. MEV-1 is due to launch in the fourth quarter of
2018, with service commencing in May of the following year. Intelsat has signed up as the first customer.
There also are other organizations working on satellite fuelling, for instance DLR in Germany with DEOS
Step 6 – Interplanetary Craft Manufacturing at Gateway Earth
3D PRINTED HABITAT CHALLENGE (http://www.nasa.gov/3DPHab)
NASA and partners are holding a $2.5M competition to build a 3D printed habitat for deep space
exploration. Phase 1, which ran through Sep 27, 2015 was a $50k design competition to develop
architectural concepts that take advantage of 3D printing capabilities - the top 30 submissions were judged
and prize money awarded. Phase 2 offers $1.1M now open (as of Oct 6, 2016) for new ways to build
habitats for future explorers using readily available indigenous and recyclable materials for structural
MADE IN SPACE (http://www.madeinspace.us/)
Made in Space is a company specializing in engineering and manufacturing of 3d printers for use in micro
gravity. There’s was the first manufacturing device used in space (in November 2014). On April 29, 2016,
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the first ever space-based commercial manufacturing facility was installed on the ISS - using Made in
Step 7 – Lunar or Planetary Lander and ISRU
NASA is preparing for human exploration of Mars, and the MOXIE investigation on the Mars 2020
mission aims to address key knowledge gaps, including: a) demonstration of In-Situ Resource Utilization
(ISRU) technologies to enable propellant and consumable oxygen production from the Martian atmosphere,
and b) characterization of atmospheric dust size and morphology to understand its effects on the operation
of surface systems. MOXIE collects CO2 from the Martian atmosphere, compresses and stores it, then
electrochemically splits the CO2 molecules into O2 and CO. The O2 is then analysed for purity before
being vented back out to the Mars atmosphere along with the CO and other exhaust products.
RESOLVE (Regolith and Environment Science and Oxygen and Lunar Volatiles Extraction) is the next
step in lunar exploration. It is designed to be placed on a rover and driven over the surface of the moon for
nine days to map the distribution of the water ice and other useful compounds seen those previous
missions. RESOLVE will also drill into the lunar surface and heat the material collected so that we can
measure the amount of water vapor and other compounds that are present, thus showing how future
missions could gather and then use these valuable resources.
RESOURCE PROSPECTOR (https://www.nasa.gov/resource-prospector)
NASA’s Resource Prospector mission, which is in formulation, aims to be the first mining expedition on
another world. Using a suite of instruments to locate elements from a lunar polar region, the planned rover
is designed to excavate volatiles such as hydrogen, oxygen and water from the moon. Building on the
findings of the Lunar Crater Observation and Sensing Satellite (LCROSS) and Lunar Reconnaissance
Orbiter (LRO) missions that proved the existence of water on the moon, Resource Prospector plans to take
the next step and harvest those resources.
Step 8 – Interplanetary Vehicles and Associate Technologies
LightSail is a crowd-funded initiative led by The Planetary Society. They are sending a small spacecraft
into Earth orbit carrying large reflective sails (32 square meters or 344 square feet). This is being developed
as a novel propulsion system for interplanetary veichles. LightSail successfully completed a test flight in
June 2015 that led the way to a second, full-fledged solar sailing demonstration in 2016.
There are many other designs for Space Access architecture out there, for example recently Elon Mask of SpaceX
announced their plans for Interplanetary Transport System for taking humans to Mars, which includes 200 “seats”
per vehicle at potentially $200k ticket a-piece (Misra, 2016). However, as these plans are unpicked, there are many
questions which remain to be answered and some doubts about parts of the project were already expressed (Lopatto
2016; Grush 2016), in addition to concerns about the validity of the business model, in particular availability of
funding. In any case, such a solution would not provide a scalable solution for smaller interplanetary payload
Some commentators, for example Torchinsky (2016), actually suggested fixes to the SpaceX plans proposing
elements compatible with Gateway Earth architecture, such as keeping a key part of the habitational module for
transport to and from Mars in a “garage” Earth’s orbit between flights (presumably having ways to do maintenance
and other improvements, which would call for a Gateway Earth type station), fueling tanks in LEO, etc. Hence,
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some parts of the Gateway Earth architecture could actively support SpaceX’s plans (in orbit refueling and
meintenance) and if at least some of the design becomes a reality (large reusable boosters, large fuel/cargo tugs,
etc.), those solutions would easily fit in the Gateway Earth systems as stand-alone as well.
A further alternative architecture is a modular approach to developing planetary travel, such as NASA plans to test
habitats in cislunar space before moving on to Mars (Messier, 2016a). These are also compatible with Gateway
Earth plans, as they involve in orbit development of habitat modules (which is easiest near an existing station) and
As noted in pervious analyses of Gateway Earth architecture (Webber, 2015a,b), there are a number of identifiable
key challenges and consequent next steps.
Overall, the Gateway Earth proposal is not based on realizing short term sensationalist goals, but rather to develop
fluid and modular infrastructure, resilient to low governmental space budgets and mindful of the need to allow time
for the commercial businesses to emerge and develop their revenue streams. Furthermore, it should be stressed that
the primary need for this capability is premised on a very long term view of planetary and solar development that
does not require an immediate action.
However, there are many short-term reasons for building the capability for regular low-cost interplanetary travel,
including the beginnings of using the resources of space (such as the mineral content of asteroids), the continued
extension of public access to space through the development of a geostationary space tourism market segment, and
the need to begin to develop methods to protect Earth from future catastrophic asteroidal or cometary impacts, with
imperfectly known urgencies.
Therefore, GEDG endeavors to maintain the momentum by conducting a range of low cost, low risk, preparatory
activities focused on the establishing the Gateway Earth infrastructure.
Listed below, in no particularly relevant order, are a number of tasks put forward by Webber (2015a) and adopted by
the GEDG as key objectives. We believe all of these need to be funded, performed, documented, and authenticated
in order to build a case for Gateway Earth:
Commercial operators conduct statistically relevant and valid market research into demand amongst
wealthy individuals for space tourism in GEO to confirm or challenge the estimated $4B market
opportunity, with results placed in the public domain.
Commercial and/or governmental space planners conduct full economic model analysis of the Gateway
Earth infrastructure proposal, using software to compare the costs of doing space exploration via
“traditional” methods, compared with doing so using the proposed infrastructure to confirm or challenge
that the approach produces major cost savings, with results placed in the public domain.
Joint governmental/commercial operations continuing to develop and space-rate 3-D manufacturing
facilities, leading to the extension of capabilities, the development, orbital trials and demonstrations of
Earth-based demos of ISRU capabilities for creating water, oxygen, rocket fuels, building bricks, solar
cells, etc, from soil samples (governmental and commercial interests – eg markets for water on Earth).
Joint governmental/commercial work to establish the terms of a Heads of Agreement (including interface
specs) that could be used to regulate the joint international, governmental and commercial interests
involved in setting up and operating the Gateway Earth infrastructure.
Further preliminary design work for the tugs and station modules, including the layout and modus
operandi for the space hotel modules to be installed in GEO (governmental and commercial operators).
Governmental and/or commercial providers conduct essential design work for the LEO-based propellant
depots, and the demonstration in orbit of effective and safe fuel transfers.
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Further work, including market research and business case analysis, is needed to explore the feasibility
of a commercial geostationary communications satellite repair and refueling service, with some
capabilities co-located at the Gateway Earth complex (commercial operators).
Track and analyse alternative architectures and systems to assess compatibility, mutual assistance,
design parallels and cost-benefit performance with comparisons.
Below is the current state of play in the formation if the GEDG and the work tasks we put forward based on the
challenges identified above. Crowd-sourcing and crowd-funding approaches may be of significant help in modeling
the technological and economic assessment of using a Gateway Earth. GEDG is planning to launch a series of
pathfinder projects to undertake this work and is calling on individuals and organizations to assist this endeavor.
More information will be released in due course via our website: http://www.gatewayearth.space/
DEVELOPING THE DEVELOPMENT GROUP (GEDG)
The Gateway Earth Development Group (GEDG) was formed in Autumn 2015 as a cross-industry combined think-
tank and working group, bringing together various stakeholders to develop a specific long-term vision for affordable
access to interplanetary space, which uses space tourism as a key source of funds.
Figure 3. Gateway Earth Development Group logo / mission patch. © Gateway Earth Development Group,
The group sees as its mission to influence the development and integration of various aspects of the Gateway Earth
Space Access Architecture though a set of work areas (Policy, Technology, Economics/Market, Membership/PR)
and specific tasks within each of the areas, which are summed up bellow.
The Lead for this section is Matjaz Vidmar, and he is pursuing the following series of tasks:
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Refining the goal of GEDG and obtaining consensus
Determining priorities and focus
2. Measurement of Goal Accomplishment
Developing measurable objectives
3. Nominal Mission Plan Elements
Defining the characteristics of a nominal mission to use for a quantification exercise. The exercise
will have technical, business, marketing and financial elements.
4. Joint Working of Government and Commercial Entities
Determining the best entities who need to work together to ensure that “Gateway Earth” concepts
receive due consideration.
5. Links to Other Long Term Space Policy Groups
Tracking the activities of the National Space Society’s Milestones to Space Settlement activities,
and those of the AIAA’s Space Colonization Technical Committee.
6. Eventual Conference Organization
Organize a conference or seminar as a way to bring the interested parties from industry and
government together to iron out difficulties, seek common threads, and establish the GEDG’s role
as a coordinating body for this ongoing activity.
7. Policy Papers
Ensure that they are written and published in an appropriate forum.
If you feel you can help Matjaz in this work, please contact him at firstname.lastname@example.org
The lead for this section is Katy Voisey, and she is pursuing the following series of tasks:
1. Additive Manufacturing
Track NASA “3D Printed Habitat Challenge”
Track the “Made in Space” company developments
Monitor industrial scale 3D manufacturing, and ranges of materials
Determine which parts of an interplanetary craft could probably not be built by 3D manufacturing.
2. Design Elements of Interplanetary Craft
Study low mass/low cost capabilities of orbital assembly
Follow Planetary Society “Lightsail” work
Track “SpaceCoach” developments (Spacecoach.org)
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Determine the main parameters (size, mass) of a nominal craft (and how it would, minimally, need
to be varied for different destinations).
3. Reusable Tugs
Track Lockheed “Jupiter” development
Track Cannae company product
Consider the tradeoffs of recycling of materials at “Gateway Earth”
Determine how many different types of tug needed for nominal mission, and how many of each
4. Refueling Depot Stations
Study DARPA “Orbital Express” results
Follow MDA plans
Check up on Boeing work
Determine the main parameters of the depots needed for the nominal “Gateway Earth” mission,
including how many different fuel and oxidizer types, and optimal capacities.
5. GEO Satellite Servicing
Study DARPA “Phoenix” and “DragonFly” plans.
Follow Vivisat company plans
Checkout related NASA Goddard work
Determine the basic assumption set of numbers of GEO satellites, their ages, their fuel needs, etc.
to guide estimates of GEO satellite servicing/refueling demand.
6. Building the "Gateway Earth" Complex
Study the Bigelow Aerospace work, including upcoming ISS station extension
Determine the main parameters for the space tourism hotel element of the complex, including
assumed volumes, mass, minimal functional elements, power, assumed storage, etc
Determine the scale and other basic requirements for the governmental part of the complex,
including the dimensions and power requirements for an industrial scale 3D manufacturing
7. ISRU and Planetary Landers
Follow the upcoming “Moxie” and “Resolve” missions
Develop a basic set of lander parameters (mass, size, power) for a nominal mission (with
necessary changes for a range of potential targets).
8. Optimizing the Overall System
Fully understand and develop models and charts for gravity wells
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Ultimately compute the sizing of the various elements for a nominal “Gateway Earth” full system
eg fuel requirements for tugs, capacity of LEO gas stations, mode of delivery of fuel (s) from
Earth to the refueling depots in LEO, masses of tugs, gas station, “Gateway Earth” complex,
physical size and mass of cargo supplies going between LEO and GEO, frequencies of journeys,
If you feel you can help Katy in this work, please contact her at Katy.Voisey@nottingham.ac.uk
The lead for this section is Andrew Luers, and he is pursuing the following series of tasks:
1. Market Research - GEO space hotel tourism
Design some market research to explore the potential demand, and particularly price elasticity of
demand, for visitors to a tourist hotel in GEO linked to a governmental working space station.
Explore how much extra they would pay for GEO vs LEO space hotel stays. Ultimately, this
would need to be statistically valid, amongst millionaires.
2. Market Research – GEO satellite servicing
Design some market research to explore the potential demand for such future services.
3. Market Research – public interest in the concept
Design a survey of degree of public support for Gateway Earth type activities.
4. Economics – Study previous work
Re-assess previous attempts at quantifying the economic benefits of the Gateway Earth approach.
Identify the weaknesses, and conduct research to improve any weak data sources.
5. Economics – Computer Modeling of Gateway Earth Architecture vs Alternatives
Demonstrate, via modelling, that there is a solution set within which the Gateway Earth
architecture is cheaper than the alternatives
If you feel you can help Andrew in this work, please contact him at email@example.com
Membership/Web Portal Tasks
The lead for this section is Lawrence MacDonald, and he is pursuing the following series of tasks:
1. Seeking New Members
A mix of commercial and government, US and international
2. Establishing Formal Membership Process
Develop the organizing principles
3. Membership Records
4. Managing Team Member Teleconferences
Vidmar 15 Reinventing Space Conference 2016
Regular communications between GEDG Team members
5. Providing Web Site Content
Developing the overall design, and regularly updating content to record GEDG achievements
6. Monitor the List of FAQ’s
Adding/Removing/Modifying the content
If you feel you can help Lawrence in his work, or wish to join the GEDG, please contact him at
As noted in our organizing principles:
The GEDG initiative is fueled by the resources and entrusted with the reputational prestige of its members
and support of outside organizations and governments. We will faithfully execute our mission and strive to
always build our organizational reputation through consistent high quality work products and good will
among each other and those who support our cause and those who do not.
We recognize our work products and research benefit private industry. However, our primary purpose is to
nurture, promote, and support a public good and a brighter future for humanity in general. We will always
be conscious of the impacts our work has on people, communities, and natural resources. (Gateway Earth
Development Group, 2016a, p.2)
SMALL STEPS AND GIANT LEAPS FOR GATEWAY EARTH
In summary, Gateway Earth Development Group is proposing to join the various Space Access projects into a single
coherent architecture which will be technologically and financially modular, enabling a variety of in-orbit and
interplanetary uses with a high degree of resilience. In particular, it is proposing a combined governmental and
commercial operation to augment the funding streams and provide new products and services to the businesses and
We aim to show that such architecture is not only the best value for money (for the taxpayer), but that it also deals
with several persistent problems with Space Access, such as the conflict between atmospheric dynamics’ limitations
for larger (interplanetary) spacecraft and the parallel need for substantial habitation modules for long-duration
journeys. With a manufacturing and servicing capability at the Gateway Earth hub, a space station in geostationary
orbit (GEO), such problems can be avoided. With a booming Space Tourism industry, the Gateway Earth space
hotel capability will also offer a unique view of our home planet, in addition to performing scientific and
Finally, it has often been commented that if Gateway Earth architecture is such a good solution for Space Access,
why has it not been done already? We believe the best answer is that all the elements are not ready yet. In particular,
it will take time for the space tourism industry to get established both in sub-orbital and LEO destinations before the
next destination, in GEO, can be realistically entertained. And importantly, it will likely require a significant change
in the mindset in order to have governmental and commercial operators planning and working together on quite the
scale which this requires. However, the GEDG has taken on that challenge. Come and join us!
GEDG is grateful to its originator, Derek Webber, for his visionary work in establishing our cause and bringing
about the creation of the development group. This paper represents a summative extract of the work of many GEDG
members, not solely the named authors.
Vidmar 16 Reinventing Space Conference 2016
Adlen, S. (2011). Innovation in the Global Space Industry. London: Imperial College London
Gateway Earth Development Group, 2016a. Organizing Principles [internal]
Gateway Earth Development Group, 2016b. Policy Brief [internal]
Grush, L., 2016. “The biggest lingering questions about SpaceX's Mars colonization plans”. The Verge
[Available at: http://www.theverge.com/2016/9/28/13087110/spacex-elon-musk-mars-plan-habitat-radiation-
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[Available at: http://www.satellitetoday.com/technology/2015/08/26/ssl-wins-darpa-contract-to-study-in-orbit-
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[Available at: http://www.theverge.com/2016/9/28/13086980/spacex-elon-musk-mars-plan-problems-breathing-
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of the 13th Reinventing Space Conference. Oxford, UK
Webber, D., 2012a. “Space Tourism – Essential Step in Human Settlement of Space”. Proceedings of the IAC
Webber, D., 2013a. “An Architecture for Survival”. Proceedings of the ISDC 2013, San Diego, California
Webber, D., 2014. “Bridgehead – Interplanetary Travel Becomes Routine”. Proceedings of the IAA Space
Exploration Conference, Washington, DC.
Webber, D., 2015a. ““Gateway Earth” – Low Cost Access to Interplanetary Space”, Proceedings of the 13th
Reinventing Space Conference. Oxford, UK
Webber, D., 2013b. “Getting to the Edge”. Spaceflight
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Webber, D., 2013c. “Leaving the Cradle”. Space News
Webber, D., 2015b. “Seven Steps to Space Settlement”. Spaceflight
Whitwam, R., 2015. “NASA plans to leave ISS to focus on future Mars mission”. ExtremeTech.com
[Available at: http://www.extremetech.com/extreme/219416-nasa-plans-to-leave-iss-to-focus-on-future-mars-