Development Roadmap and Business Case for a Private Mars Settlement

Abstract

Mars has long been considered the next target for human spaceflight after the Apollo missions. NASA has made this clear in the past, with their many architecture proposals for crewed Mars missions. All these proposals, from the Space Exploration Initiative to the current Journey to Mars, highlight the priorities and constraints of a government agency: extreme risk aversion, long development times, and risk mitigation and science maximization through high mission cost. The lack of a need for revenue and an expected financial security can also be seen in the architectures, which pay little attention to financial feasibility, and focus on technical aspects. Despite all this planning, government agencies have accomplished little beyond Low Earth Orbit since Apollo due to political interests and instability. A fully public mission to Mars seems always further away, and little progress seems to be done in that regard by the public agencies. In recent years, a new approach to space has appeared in the form of the New Space companies. These companies enjoy some advantages over government agencies: clear strategic goals, financial stability, and higher tolerance to risk. These are created by the private source of funding, which requires a source of revenue and a business plan, and is relatively independent of public opinion, which allows the companies to take higher risks without justifying their expenses to the public. Private companies have also shown in recent years that they have the technical abilities to produce space hardware of the same quality as government agencies, with a surge of a new generation of rockets and satellites, so it would seem that they are better posed than these agencies to undertake a mission to Mars. The only piece missing is the business plan that would allow a private company to fund itself during the process. This project studied the business case for a private Mars colony, considering technical and economic constraints. It defines a possible architecture and business plan, identifying sources of revenue and customers, and technical constraints. The project evaluates the feasibility of a short-term business case based on Mars resources. The author intends to show the other extreme of Mars architectures: fully private funding and very time constrained. This would add a new point of view to the field, and hopefully lead us to the much desired human landing on our red neighbor in the near future. This project was completed as the author's individual project on the Master of Space Studies at the International Space University in Strasbourg, France.

Introduction

Plans for a human mission to Mars have existed since before the first human spaceflight. Werner Von Braun possibly published the first ever crewed Mars mission architecture in 1952.¹ After Apollo, Mars started to be considered the next logical step for human space exploration,² and several other mission proposals followed, the most notable being the Space Exploration Initiative in 1989,³ Mars Direct in the early 1990 s,⁴ and currently NASA's Journey to Mars.⁵ However, a publicly funded mission to Mars seems always further away, and public agencies seem to make little progress toward them.

There are reasons to believe though, that a private mission to Mars is more likely to happen than a public one. Business is a stronger driver than others usually used for human spaceflight (national pride, science, inspire new generations, etc.). This is shown for example in the quick advances of the Commercial Crew Program by Boeing and SpaceX (started 2010, expected flight in 2017) compared to NASA's progress with the Orion crew capsule (started 2004, expected flight in 2023).^6,7 Private companies are also relatively free of political risk when compared to public agencies, and their business structure usually leads to lower cost and development times than public projects: for example, the total cost for development of Falcon 9 plus the Dragon capsule is just under $850 million,⁸ compared to the combined cost of $18 billion of SLS plus Orion.⁹ For all these reasons, it may be then interesting to study how a private company could lead the effort toward a Mars settlement, to inform the general discussion of the problem.

This project aims to study the feasibility of a possible business case for a private Mars settlement. The project is based in two assumptions:

(1) Private companies have a higher risk tolerance than public agencies. This can lead to shorter development times and more aggressive technology demonstration schedules, as SpaceX showed with Falcon 1.¹⁰

(2) A mission to Mars can be performed with current technology, or technology that could be ready during the next decade (before 2026). The only development needed is that of the specific mission hardware. Many Mars mission proposals are based on existing or near-future technology.^4,11,12

With these assumptions, the project aims to create a roadmap for the establishment of a base on the Martian surface before 2030, within the framework of private commercial space. The goal is to provide a new point of view into crewed Mars programs with shorter-term, fully private missions instead of the usual long-term, fully public proposals from the past.

These two assumptions lead to the two constraints of the project, which are as follows:

(1) The funding for the program shall come exclusively from private investors. Public agencies may act as customer for the company, but not as investor or stakeholder for the general program.

(2) The first crewed landing on Mars shall happen before 2030, ideally in the 2026 launch window, with 2029 as backup. This imposition will drive the program to a more accelerated pace and will show that the two assumptions stated above are realistic and feasible.

While the constraints may seem arbitrary, there are good reasons for them. On the one hand, restricting the funding to exclusively private investors frees the program from most political constraints that affect NASA and other agencies, and allows it to focus on technological and economic challenges, ideally using the most optimal solution to the many engineering challenges of a Mars mission. Public agencies can act as partners or customers, but not as investors or stakeholders. On the other hand, restricting the first crewed landing on Mars before 2030 forces the program into an accelerated development pace, which can show that the assumptions above are realistic and feasible. Moreover, a private investment can hardly afford 20-year-long development times, as NASA intends in their Journey to Mars.⁵ It is almost a necessity then to reduce the time to first mission to a minimum.

To study the feasibility of the business plan, a general strategy for the development of the settlement will be developed based on the constraints of the project, available technologies, and available sources of income. From this, one of the existing Mars architecture will be adapted to serve as a guideline to develop high-level costing, which will be used for the business case. Finally, the feasibility of the business case is studied based on the cost of the program and the possibilities of income from the different sources.

The project was completed as the author's individual project at the Master of Space Studies at the International Space University. The final report is available at the ISU library¹³

Technical Elements

The study of the business case begins with the definition of the technical elements. First, previous Mars architectures were studied and selected for evaluation. Then, available technologies are reviewed to identify which Mars architectures would be feasible to develop within the time constraint of landing before 2030, along with ways to reduce costs or additional sources of income.

Proposed Mars Architectures

The different Mars architectures in the literature can be classified in two general groups: traditional architectures, with high-cost missions that reduce risk through more complex hardware and architecture, and that prioritize low risk versus science return or cost; and Mars Direct-style architectures, which reduce risk through new techniques and hardware, attempting to optimize cost, risk, and science gain simultaneously. NASA's Space Exploration Initiative 90-day report³ and even von Braun's Das Marsprojekt¹ are of the first kind, and of course Mars Direct⁴ is the model of the second kind. NASA's Design Reference Architecture (DRA) 5.0, has components of both types of architecture, and newer concepts such as Mars One are essentially an adaptation of Mars Direct to their particular needs. This highlights the quality of the Mars Direct concept, and how much the idea of trading cost and risk weighs on the mission designers.

The recent architectures most relevant to this project (for their level of detail, their cost, or their analogy value) are NASA DRA 5.0, Mars Direct, and Mars One. Other existing plans, such as the SpaceX architecture, are not included for lack of public details at the time of writing, and others, such as SEI or the Aldrin-Purdue, are not included for their high price tag or not being up to date.

Appendix Table A1 shows a comparison of the key elements of each of the studied architectures. All data are taken from publicly available sources. These data will later be used to adapt one of the architectures for the feasibility study.

Available Technologies

After reviewing the possible architectures, a technology assessment needs to be done to determine which technologies can be used within the study's constraints, that is, must be available before 2026. It was considered that a certain technology complied with this requirement if it had or was expected to have a technology readiness level (TRL) of at least seven by 2026. The assessed technologies cover all the most important elements of the architecture, and will be used later on to derive requirements and constraints on the development roadmap. The technologies were divided in three categories: launchers, space segment, and (Mars) surface segment.

Launchers

Four heavy launchers should be available for a Mars campaign by 2026. None of them is in service yet, so many of the numbers are purely estimates. A launcher was considered to be of the heavy class if the payload mass to geostationary transfer orbit is larger than 10 t. Only commercial launchers of the heavy class with currently available data have been considered (e.g., the planned orbital launcher from Blue Origin is excluded). Table 1 shows the relevant parameters of the launchers considered for the study.

Table 1.

Relevant Parameters of Available Launchers

	Falcon Heavy¹⁴	Vulcan¹⁵	Ariane 6¹⁶
Provider	SpaceX	ULA	Arianespace
Best payload^a	53 t LEO	33 t LEO	10.5 t GTO
	21 t GTO	15 t GTO
Fairing diameter	5.2 m	5.4 m	5.4 m
Cost	US$90 M	US$100 M	US$140 M
Date of first flight	Q4 2016	2019 basic	2020
		2023 heavy
Notes	Reusable boosters	Reusable first stage engines	Fully expendable

Payload performance of the heaviest version.

Space segment

The space segment of the mission can be divided in two parts: elements limited to Earth orbit, to assemble the Mars transfer vehicle or to taxi crew, and elements for the interplanetary transit and Mars entry, descent, and landing (EDL). A summary of the available systems follows.

Earth orbit elements

Earth orbit elements of interest are related to on-orbit assembly, and include the different assembly techniques, orbital tugs, and crew taxis. The only assembly technique with extensive heritage and TRL higher than 7 is on-orbit docking, which has been used since the Apollo era to ready spacecraft in orbit. No orbital tugs are currently in used, but United Launch Alliance (ULA) is developing the Advanced Cryogenic Evolved Stage (ACES), which could act as a reusable space tug and should enter operation around 2024.¹⁷ As for crew taxis, several companies are developing commercial crewed vehicles that could operate in Earth orbit under NASA's Commercial Crew Program: SpaceX is working on Dragon 2, Boeing on Starliner, and Sierra Nevada on Dream Chaser. All of these should be ready to fly by end of 2017.^18–20 The Russian Soyuz could also be used, if it could be procured commercially.

Interplanetary transit and Mars EDL

The vehicle used for the Mars transit and EDL is one of the main elements of the architecture. In Mars Direct-style architectures, the transit vehicle will also act as surface habitat, making it the vehicle where the crew will spend the majority of their mission time.

The different systems to be reviewed for the interplanetary transit will be the seven systems outlined in The New SMAD²¹: power, structure and mechanisms, propulsion, communications, thermal control, attitude control, and navigation and guidance. Since it is a crewed vehicle, life support will also have to be included. Finally, EDL systems will be needed for the landing vehicle.

A very short summary of the review is provided here. The complete version is available in the final report of the project.¹³

• Power: power production schemes relevant for a Mars settlement include solar photovoltaic and nuclear reactors (both TRL 7 or greater). RTGs would not produce enough power for a settlement. Power storage schemes with TRL 7 or higher include fuel cells and batteries, and supercapacitors might reach that TRL by 2026.

• Structure and mechanisms: monolithic structures have been used in space for decades and enjoy TRL 9. Alternatively, expandable structures have current TRL 9 for space applications, but would need to be developed for surface missions.

• Propulsion: only chemical and solar electric propulsion have TRL 9 as of now. It is unclear whether private industry would be allowed to use nuclear thermal propulsion, which might be available by 2026 (from Russia²²).

• Life support: physicochemical systems have been extensively used and have TRL 9. Closed-loop systems are still in very early stages.

• EDL: thermal protection systems and propulsive landing systems can be used for crewed vehicles and have TRL 9. Aerodynamic decelerators would have to be developed for this size of vehicles.

• Communications: radio communications are extensively used and have TRL 9. Laser communications have already been demonstrated in space up to lunar distances.²³

• Other systems: other systems, namely thermal control, attitude control, and navigation and guidance, would have little influence on the overall architecture and all have systems with TRL 9 available.

Surface segment

The surface segment includes the habitat, crew mobility vehicles and suits, and the Mars Ascent Vehicle. For the habitat, systems will include communications, power, structure, life support, and thermal control. These will be very similar to the spacecraft systems, but designed to work in the Martian atmosphere and on the Martian surface. This will mostly affect the structure and active thermal control systems that will have to operate under gravity, and the Martian surface will enable other sources of power generation. Finally, the habitat will also be paired with some sort of ISRU system, forming the whole base.

A very short summary of the review is provided here. The complete version is available in the final report of the project.¹³

Base systems

• Power: though the Mars environment might support power production schemes such as wind turbines and geothermal generators, for now only solar photovoltaic has TRL 9 on Mars. Nuclear fission reactors are under development²⁴ but private companies might run into political problems with nuclear power.

• Structure: the main difference with orbital structures would be the inside layout, adapted to a gravity environment. Otherwise, both inflatables and monolithic structures are possible.

• Communications: both radio and laser could be used from the surface as well. Mars rovers have also demonstrated the use of satellite relays on Mars orbit.

• Life support: only difference with orbital systems will be the design of pumps, ventilation, and other fluid-transport systems to work under gravity, which is standard practice on Earth and could easily be adapted to Mars' reduced gravity.

• Thermal control: thermal systems would have little influence on the overall architecture and was not studied in depth.

• Crew mobility: crew mobility includes rovers and EVA suits. Current suits would have to be adapted to operate under gravity, since they only work in microgravity. Different rover mobility systems have been tried and tested both on the Moon and Mars, and options with TRL 9 exist. Rover power systems can provide more trade-offs, choosing between fuel cells, batteries, solar photovoltaic, RTGs, and internal combustion engines.

• Resource utilization: immediate uses include propellant production and life support closure. Different production schemes for propellant, atmosphere, and water from Martian atmosphere and soil simulants has been extensively tested on Earth.^4,25,26 Food production from Martian soil remains at very low TRL.

Mars ascent vehicle

Launching from Mars directly to Earth requires a similar change in velocity (delta-V) than launch from Earth to LEO. This means that the Mars Ascent Vehicle is essentially a two-stage rocket, with the only new technology being maybe the selected engine. The main extra consideration when compared to Earth-based launchers is the amount of time that the vehicle has to sit on the Martian surface before launch, several years in most architecture. This constraint will affect the design of the vehicle, and the level of quality controls that it must undertake. However, as a technology component it can be considered to have TRL 7, pending the design and production of the flight hardware.

Available Sources of Income

As explained in the Introduction, the settlement is to be financed completely with income related to the Mars activities. Four different types of sources of income were identified and explored for the study: natural resources, science, technology spin-offs and alternative uses, and entertainment. These different sources will influence the selected architecture, since the technology and techniques used will have to somehow have the potential to produce revenue and some income for the whole mission. Finally, Phobos and Deimos were also included in the analysis, considering that they could be part of orbital infrastructure similar to the one proposed in the Aldrin-Purdue architecture,²⁷ or even the main source of income.

Natural Resources

Natural resources refer to raw materials and derived products manufactured on Mars. These are the most straightforward candidates for a source of income. The potentially usable natural resources for precursor missions include raw regolith and samples, and in situ production of rocket propellant, life support resources, and manufactured products.

(1) Regolith and samples: given the value usually placed on Mars sample return missions, samples from the Martian surface have traditionally been given a high monetary value and could be a source of income for initial missions. The array of missions proposed for sample return (NASA's Decadal Survey,²⁸ Red Dragon,²⁹ and Mars-Grunt³⁰ to name a few) show that there would be customers (governments, space agencies) interested in buying Mars samples. NASA could be expected to pay around US$10 M/gram based on past mission proposals, while other agencies would pay less. However, samples from Mars have such a high price because none have been acquired so far, except for the limited number of Martian meteorites found. Market elasticity for Martian samples could be very low, with prices and demand decreasing rapidly as the resource becomes more common. This could be partially offset initially by extending the regions on which the samples are collected, but eventually the value will decay consistently.

(2) Rocket propellant: rocket propellant is the main contributor to the mass of any spacecraft using chemical rockets, and many Mars architectures consider in situ propellant production an enabling technology. It could be possible to use Mars-produced propellant to supply other missions to Mars, potentially creating a market for propellant. However, its main use in the initial stages would be that of cost reduction for any support missions.

(3) Life support resources: Mars is supposed to contain all the resources needed to sustain human life.⁴ In principle, one could extract all the resources needed for life support from the Martian surface. However, they would have little value outside the settlement and missions to and from it. They would have no commercial value for the initial settlement.

(4) Manufactured resources: Mars also has available the majority of the resources used to manufacture modern components. In principle, metals, plastics, and different gasses can be extracted from Mars with known methods.⁴ In situ manufacturing is also one of the highest priorities for the settlement, to avoid the “spare part problem” pointed for the Mars One architecture,³¹ so it would be interesting to try to make it into a source of income. If anything is supplied from Mars to Earth, it would be end products. Anything that could be sold from Mars to Earth would need to have added value in the form of prestige or scientific interest to compensate the huge transportation costs. In this case, manufactured products such as jewelry and art pieces would potentially see some market on Earth. It is reasonable to imagine that many wealthy individuals would pay the extremely high prices of a “made on Mars” decorative piece. Although this market could potentially exist, the settlement would have to be fairly advanced to have a surplus of production capability to sustain it.

Science

Science is the main motivation for most Mars missions, space agencies like NASA and ESA are willing to spend several billion dollars on missions whose only return is of scientific value. Given that humans are more efficient field workers than rovers, a crewed mission and an eventual settlement would have an immense value when it comes to science. Scientific return would then be a huge incentive for national agencies to participate in the missions as customers. The best way to profit from scientific return may be to provide payload capacity for customer-selected instruments in rovers and orbiters, or to sell astronaut time, or tickets to Mars directly, once the surface outpost is set up.

Technology Spin-offs and Alternative Uses

A successful business plan to colonize Mars would have to monetize the technology development from early on the program. This approach is also being taken by asteroid mining companies such as Planetary Resources, which is monetizing their technology developed for asteroid mining with Earth observation applications.³² Several categories can be identified for the required technologies where a possible market could be found: interplanetary satellites, high-speed deep space communications, in situ resource utilization (ISRU) technologies, asteroid mining technologies, and Mars payload delivery. Other capabilities, such as launchers and Earth observation, are likely to be spin-ins into the Mars campaign, given the current status of the commercial market.

(1) Interplanetary satellites: the capability of private interplanetary travel is the first thing that needs to be developed for the Mars campaign. Current efforts for affordable interplanetary spacecraft are mostly focused on CubeSat-based platforms for asteroid mining. Bigger satellites might be needed for a Mars settlement, especially as part of the infrastructure (communications relays, positioning satellites) and as part of resupply missions. If an interplanetary spacecraft bus and its components were developed in-house for the Mars effort, it could be sold to commercial customers along with the whole assembly and integration, and the interplanetary operations. Many countries might be interested in this service, which would allow them to send their own missions to Mars without the impressive upfront investment in technology development that these usually require.

(2) High-speed space communications: a Mars settlement would most likely require the creation of a laser communications network to provide high-speed communications with the crew. High-speed deep-space communications would also be necessary for many scientific missions, such as deep space near Earth object observatories, or extend the capacity of current missions, allowing for less on board processing and more data collection. It also has a possible outreach and publicity value, as they would allow video broadcast of scientific achievements. If a high-speed deep space network was created, transponder capacity could be sold for a fee to commercial customers (mainly asteroid and Moon mining companies) or to government and public agencies for scientific missions.

(3) ISRU technologies: even though all different kinds of technologies and techniques for ISRU need to be developed for Mars applications, the uniqueness of the Martian environment make it unlikely that specific hardware could be used in other bodies (Moon or asteroid mining for example). The most likely resource to be used in other applications from ISRU technologies is the know-how and the experience with operating automated machinery in extraterrestrial environments, or with pressure suits.

(4) Asteroid mining: if Phobos or Deimos are part of the final architecture, techniques very similar to those of asteroid mining, if not the same, would be needed for resource extraction and surface operations. This technologies and techniques could be used in asteroid mining applications.

(5) Mars payload delivery: once the capacity for interplanetary travel and Mars EDL is developed, a business similar to that of Astrobotic can be proposed. Astrobotic will offer payload delivery to lunar orbit and/or surface, including rover delivery if requested.³³ Delivering payloads to and from Mars space would have many interested customers, mainly countries that specialize in specific space technologies, such as Canada with rovers and robotics.

Entertainment

Entertainment is one of the largest industries in the world, especially sports and reality shows. A colony on Mars, or just a Mars mission, could be an immense source of entertainment products. Mars One estimated the revenues from a Mars colony as “10 Olympic Games”,³⁴ or about US$ 45B, until the first year after the first human landing. Aside from the credibility of their estimation, their reasoning still stands, and the revenues from entertainment may be high enough to make an effort on it worth the time.

Phobos and Deimos

Phobos (and Deimos to a lower extend) are possibly very valuable resources of Mars. Their low gravity allows easy access with little propellant consumption, and they can provide a good starting point for a Martian orbital infrastructure. Possible uses for them include the following:

(1) Regolith samples: same reasoning applies as for the Martian samples. Prices would be lower (in the order of $1 M/g, based on the Phobos-Grunt mission), but the samples would be more accessible than the Martian surface. This could provide an early source of revenue for precursor missions.

(2) Rocket propellant: if volatiles are present, Phobos and Deimos could provide propellant, water, and oxygen for crewed missions. Any in situ resources would have an important cost-reducing effect in the long term. Developing the moons as a resupply station may be interesting for different Mars missions, but it might not be so for surface operations.

(3) Manufacturing: there are many proposals for regolith utilization, from landing pads and structures to heat shields. Heat shield production on Phobos could also be an enabling capability for reusable taxis to and from the Martian surface. Other elements could also be extracted from Phobos and Deimos, with techniques similar to asteroid mining.

(4) Radiation protection: Phobos and Deimos could provide a radiation safe haven for an orbital outpost on Mars orbit.

(5) Vehicle assembly and reusability: the moons could provide a staging point for surface missions, for example, as meeting point for interplanetary and surface spacecraft. In the long run they could help with reusable surface vehicles.

(6) Scientific value: same as for Mars' surface, scientific return could be sold to customers, either as a service or as payload capacity.

Analysis and Results

The possible sources of income and available technologies create new constraints for the mission architecture, and will define the general strategy of the Mars effort. A new Mars architecture can be created, in this case based on previous proposals. This new architecture will be used to study the feasibility of the business case.

Additional Constraints and General Strategy

Given the constraints of the study (fully private funding and first crewed landing before 2030), current technologies will impose new constraints on the architecture. These are as follows:

• Earth-orbit elements: given the commercially available launchers and the masses required in LEO for Mars architectures, on-orbit refueling or a distributed launch scheme similar to ULA's³⁵ will be needed.

• Power: the low TRL of the different power production schemes, and the political difficulties that usually go with nuclear power, constrains power production to solar photovoltaic.

• Structure: expandable structures are needed, considering the fairing sizes available in commercial launchers.

• Propulsion: low TRL of the different propulsion methods constrains propulsion to chemical. Considering the resources available on Mars, a methane engine will have to be developed at least for the Earth return vehicle (ERV).

Other systems, such as EDL and crew mobility systems have very low TRL and need to be developed early on in the program. The rest present all high TRL across the board and do not impose limitations to a high-level design.

These extra constraints can now be combined with the potential sources of income to create a general strategy for the development roadmap leading to the first mission. This general strategy will determine which Mars proposal the selected mission architecture will be based on, and influence aspects of the development and precursor missions:

• Satellite technology: the earliest, most accessible sources of income would be based on satellite technology and communications. These capabilities will need to be developed first, to provide further funding for the plan.

• Laser communications: laser communications will be used, given the potential profitability of high-speed space communications. High-speed communication also benefits (if not totally enables) entertainment as a source of income.

• Maximize science: the most valuable Mars-based resources are samples and science. It is necessary to maximize the number of scientific crew per mission, and the amount of samples that are brought back.

• Minimize risk: since most potential customers for crew seats are space agencies, risk minimization has to be a main driver. Besides, a private company can assume more risk during development, but losing a crew early in the program might mean its death.

• Minimize cost: the limited sources of income make cost reduction a main driver. Systems should be reused whenever possible, finding commonalities among the different elements. Infrastructure on the surface should then be progressively built on one site, increasing capabilities and opening new sources of income.

• Emphasize mobility: crew mobility must be emphasized, to maximize science return while building infrastructure on a single site.

• Direct to surface: risk reduction constrains crew operations to the Martian surface. Even though Phobos and Deimos can provide easy targets for sample return missions, they pose extra risks to the crew (radiation, long-term microgravity), meaning that the crew would actually be safer on the planet's surface.

With this strategy, a Mars Direct-style architecture is the most suitable. Not only it has the lowest price tag (cost reduction), its different backup options contribute to minimize risk, and it already emphasizes crew mobility with its internal combustion rovers. Some changes are necessary, which will be explained in the next section.

The architecture developed will be suitable for the initial missions, which aim to establish the settlement. The missions will evolve over time as the needs of the settlement changes, and would have longer surface stays, leading eventually to permanent habitation.

Adapting Mars Direct

Mars Direct will be the reference architecture for the architecture developed in this project. Since this project does not intend to focus on the technical aspects, the architecture used for costing and the business case will be based on an existing architecture. This serves to guarantee a certain level of technical feasibility, which can be used to provide order-of-magnitude estimates for the total cost used in the business case.

The Mars Direct architecture is fully developed in Robert Zubrin's The Case for Mars.⁴ Table 2 shows the most relevant mission parameters of the Mars Direct architecture, which can be complemented with the comparison in Appendix Tables A1 and A2 shows the mass budget of Mars Direct.

Table 2.

Mars Direct Relevant Mission Parameters

Crew	4
Isp (s) (launcher upper stage)	450
TMI dV (km/s) (cargo)	3.7
Transit time (days)	250
TMI dV (km/s) (crew)	4.3
Transit time (d)	180
Free return (crew)	Yes (2 y)
TCM and landing dV (km/s)	0.7
Isp (s) (ERV, hab)	380
Hab size (height × diameter)	5 × 8 m

TMI, trans-Mars injection; dV, delta-V; TCM, trajectory correction maneuvers; Isp, specific impulse.

A number of changes must be made to comply with the extra constraints shown before, namely only solar power, expandable structures, laser communications, and distributed launch (on-orbit refueling) instead of direct-to-Mars launch. The modifications will change the masses of the respective systems. An upper limit will always be selected, to get an upper limit for the total mass and, therefore, the cost.

• Solar power only: if solar power is used, power production levels will be limited to daylight hours. NASA DRA 5.0³⁶ assumes 8 h of enough daylight for photovoltaic power production, and triple the power production needs for the solar case compared to nuclear. Since most power consumption will be done by the ISRU plant, it can be assumed that the plant works only during the production hours at approximately triple the rate of working around the clock, and night-time power needs are covered by stored power. In all, Mars Direct needs 240 kW of solar power to cover for the 80 kW nuclear reactor, an ISRU plant three times as productive, and an efficient way to store power. New photovoltaic blankets developed under NASA contracts can yield specific powers greater than 500 W/kg,³⁷ meaning 1.1 t of solar panels could provide 240 kW on Mars. For power storage, methane-fueled generators similar to those used in Mars Direct to fuel rovers can be used. With power/mass ratios of 1,000 W/kg,⁴ methane could be used as a power storage method.

• Expandable structures: Bigelow's BA 330 is designed to fit within a Falcon Heavy's fairing³⁸ and expand to a larger size than the Mars Direct habitat (hab) (6.7 m in diameter and 9.5 m in height for BA 330 vs. 8 m in diameter and 5 m height for Mars Direct). Since BA 330 includes all the systems required to sustain itself in space, it would be reasonable to expect that a module the size of the Mars Direct hab could be designed to fit within the 5.2 m fairing of the Falcon. Bigelow is supposedly working on expandable planetary habitats,³⁸ but no details are available as of yet. The mass of the habitat can be estimated by scaling up Bigelow's BEAM, which is just the structure (BA 330's mass includes the spacecraft systems and scaling for the hab would be a worse estimate).

• Laser communications: laser communications do not need then to replace radio, but could complement it. The mass of a laser communication module can be estimated from current modules, namely NASA's Lasercomm Space Terminal on the LADEE mission.²³ This mass is used as an upper limit.

Appendix Table A3 shows the adapted mass budget with the changes above. Where no changes were needed, the masses from Mars Direct were used, with the idea of having an upper limit. Margins were also increased to 20% from 16%.

Regarding the other parameters of the mission, same trajectories (same delta-V) can be used. A crew of four minimizes risk while still accomplishing the other objectives, and the hab was selected to be the same size. Falcon Heavy is selected as a launcher, with a methane-fueled upper stage (the Raptor engine³⁹). This means masses in LEO of 100 t for the ERV and 117 t for the hab. At least two launches are needed per vehicle (ERV and hab) and a distributed launch scheme with on-orbit refueling will be used.

The final modifications are related to risk and cost reduction. To this end, artificial gravity is eliminated (reduces development risks) and all the missions will go to the same landing site, whereas in Mars Direct you would explore a different site each time. The final mission architecture is then as follows:

In the previous opportunity, the ERV is launched to Mars from LEO, where it was placed with a distributed launch scheme (2 Falcon Heavy launches). After landing, a light truck deploys the solar arrays over the surface, along with science rovers, and starts producing LOx/CH₄ as return propellant, and rover and generator fuel. The science rovers characterize the landing site for the crewed landing. In the next opportunity, the crew is launched from LEO in the surface habitat, where it was placed with a distributed launch scheme (2 Falcon Heavy launches). The ERV for the next mission is also launched in this opportunity, in the same manner as the previous one (2 Falcon Heavy launches). Upon arrival, the crew lands near the ERV and begins the 500- daylong surface stay. The next ERV lands in the proximity of the landing site, beings creating propellant for the next crew, and deliver extra payload for the first mission. The crew returns in the ERV in a direct launch to Earth. Table 3 shows the main elements of the final architecture for the initial missions.

Table 3.

Final Architecture for Initial Missions

Objectives	Permanent settlement
Crew size	4
Number of missions	Unlimited, architecture evolves with settlement
Launchers	Falcon Heavy (Raptor)
Surface stay	500 days initially
Launches per mission	4
Space segment
Transportation	Surface hab for transit
Propulsion	All chemical, LOx/CH₄
Communications	Direct to Earth (laser)
Power	5 kW photovoltaic
Life support	Partially closed (80% for O₂, 90% for water)
Trajectories	Low energy (cargo) and fast transit (crew). Aerobraking.
Entry, Descent, and Landing	Aeroshell (reentry), parachute and propulsive.
Surface segment
Habitat	Expandable hab lands with crew
Power	240 kW photovoltaic
Communications	Mars relays. Ham radio for crew sorties
In-situ resource utilization	LOx/CH4 and water from atmosphere (propellant, rover fuel, life support)
Crew mobility	1 pressurized rover, 2 open rovers, 2 light trucks. Methane fueled (1,000 km range, 2 crew)
Life support	Partially closed. ISRU provides closure.
Mars ascent and return	2-stage (LOx/CH4) direct launch to Earth

Development Roadmap

A development roadmap can be created based on the proposed architecture to study the feasibility of the business case. To this end, the development roadmap will include only minimum capabilities necessary for the first mission. This means, the estimated cost is the minimum necessary to complete the first mission, and the highest risk. If a business case within the project's constraints is not feasible with this development roadmap, it can be inferred that a lower-risk, higher-cost roadmap will also not be feasible. Different requirements and constraints, and development times, have to be considered for this minimal roadmap.

• Development requirements: the minimum infrastructure for the architecture leading to the first crewed landing includes two relay satellites to ensure almost constant communication (one on Mars orbit, one on Earth orbit), and the ERV and Hab for the first mission. However, given the low TRL of EDL, and ISRU systems, and the need to demonstrate the ability to take off from Mars after a long stay on the surface, at least one demonstration mission of these systems should be included. That means a total of five missions (two satellite launches, one EDL/ISRU demonstration, one ERV, and one Hab) with seven launches (ERV and Hab require two launches each). Other demonstration missions, such as a demonstration of the Hab, are not considered, which is consistent with a pure protoflight approach. Finally, the distributed launch scheme, the methane engine, and the launcher, are assumed to be developed independently of the Mars effort.

• Business constraints: the general strategy calls for the use of deep space communications, hosted payloads, Mars science, and Mars samples as main sources of income. Space communications, payloads, and science require only an orbiter spacecraft to be exploited, and so will be enabled as income before Mars samples. The need for Mars samples will also push the EDL/ISRU demonstration mission to be a sample return mission. The roadmap will then include the deployment of the orbiters first, followed by the sample return, followed by the actual crewed mission.

• Development times: given the difficulty of estimating development times when so little technical detail is available, the roadmap works with the maximum time allowed by the project's constraints. That is, the crew landing with the Hab will happen at the last possible opportunity before 2030 (in January 2029). From then, the ERV launches one opportunity before (November 2026), preceded by a sample return mission in September 2024, the deployment of the Mars communication relay in August 2022, and the Earth communication relay in 2021. This leaves at least 6 years for the development of the spacecraft bus and laser communications system (and ground segment), 8 years for the EDL, ISRU, and science rover systems, almost 11 years for the ERV, and 13 for the hab. In any case, these development times should be more than enough. The design and development phase of Mars orbiter missions usually take about 6 years for development, but missions have been developed in the past in less time (Mars Express in 4 years, and Mangalyaan in 15 months). The EDL systems being developed by SpaceX can be readily adapted to Mars reentry, ISRU techniques are old technologies from the early 20th century, and a sample return mission could be done well by 2022 with the Red Dragon architecture,²⁹ meaning that a sample return by 2024 has at least 2 years of margin for completion. Finally, the ERV is similar to a Falcon 9-class rocket, which took 4 years to develop, and 13 years is about 3 years longer than what Bigelow Aerospace needed to develop the BA-330. In all, considering the assumption of this project that private industry can show lower development times than government organizations, the assigned development times should be adequate as a rough estimate.

Table 4 shows the final development roadmap, along with the objectives for each of the missions and the sources of income that each mission enables. The number of missions is the minimum needed for the architecture, as explained at the beginning of this section. Each mission is used both as a demonstration mission and as part of the infrastructure deployment effort. This is indeed a risk-prone approach, but also requires the minimum number of missions and is the minimum feasible roadmap.

Table 4.

Development Roadmap with Dates and Mission Objectives

Year	Mission	Objectives	Enabled Income
2021	Deploy earth relay	Demonstrate spacecraft bus systems	Space communications
		Demonstrate laser communications	Cislunar space payload delivery
		Demonstrate orbit operations
2022	Deploy Mars relay	Demonstrate interplanetary travel	Deep space communications
		Demonstrate deep space laser communications	Mars orbit payload delivery
		Demonstrate Mars orbit operations
2024	Mars sample return	Demonstrate EDL and ISRU	Mars surface payload delivery
		Demonstrate surface operations
		Demonstrate satellite relay	Mars samples and regolith
2026	ERV launch	Demonstrate ERV landing and surface operations	N/A
		Characterize landing site for crew
2029	Hab launch	First crew landing	Entertainment (crew)
			Crew tickets

EDL, entry, descent, and landing; ERV, earth return vehicle; ISRU, in situ resource utilization; N/A, not applicable.

Analysis of the Business Case

The analysis of the business case requires an estimation of the total cost of the architecture, and the cost over time of the development. This can be then combined with the possible revenues and the time when they come in, to evaluate whether or not the sources of income are enough to fund the architecture and create profit.

Cost estimation

A high-level cost estimation was done using the Advanced Mission Cost Model (AMCM), which requirements very little technical detail to provide a cost estimation. The main parameters are the mass, the quantity to be produced, and the year of initial operational capability. The parameters for the model were taken from Larson and Pranke.²⁶

AMCM can provide a good estimate of the mission cost, but it is based on a database of government missions. One of the assumptions of this study is that private companies can achieve lower development costs, so using a government estimate for the cost would defeat the purpose of the study. To this end, an extra multiplicative parameter was added to account for lower commercial development costs. This parameter was estimated by comparing the AMCM estimates for commercial vehicles in the Commercial Orbital Transportation Services program and Commercial Crew Program with real development costs. Appendix Table A4 shows this comparison. The commercial correction factor was taken as a conservative 0.3 (meaning that private companies would do the same work for 30% of the cost estimated by AMCM).

Using the development roadmap shown in Table 4 and suitable parameters for the different vehicles, the total cost for the architecture can be calculated. It was assumed that up to three missions would be done with this architecture before it changed to adapt to the needs of the newly established settlement. Table 5 shows the estimated costs, assuming a cost of US$90 M for each Falcon Heavy.

Table 5.

Total Cost of the Architecture (in Millions of 2016 US Dollars) for One and Three Total Missions

	One Mission	Three Missions
Spacecraft cost	12,400	20,500
40% reserve	4,960	8,200
Launch costs	572	932
Total cost	17,932	29,632

Cost over time

The study of the feasibility of the business plan requires knowledge of the cost over time of the architecture. The cost-schedule relationship can be determined using the beta curve: a fifth-order polynomial in the time fraction, F.²⁶ Assuming standard parameters for crewed missions, the cumulative cost over time for the first three missions results as shown in Figure 1 below.

Fig. 1.

Cumulative cost (in millions of 2016 US dollars) for three missions. x-axis label: Year. y-axis label: Cumulative cost.

Business case

There are several sources of income available, as per the roadmap in Table 4:

• Deep space communications

• Cislunar space payload delivery

• Mars (surface and orbit) payload delivery

• Mars sample return

• Crew tickets

• Entertainment

It is hard to estimate the incomes from any of those sources. If Mars One's assumption were correct (entertainment revenues to be around US$45 B), that alone would pay for the whole three missions, and leave about 50% extra of benefit. However, they have not published any basis for their assumption, so it will be assumed to be wrong. For all the other sources, except for crew tickets, the market is still inexistent. For crew tickets, the market would be clear, since the company would be the only supplier: three missions with a total of 12 crew seats. However, constraints on the necessary performance of the different revenue sources can be derived with proper performance and demand assumptions.

The markets that can be more readily assessed are those related to vehicles that are needed for the architecture, since their cost can be calculated. These are payload delivery (both Mars orbit and cislunar space), Mars sample return, and crew tickets. A number of assumptions can be done to get an optimistic estimate of the market potential:

• Any Mars surface delivery is done with the same vehicle as the sample return.

• Production capability of one spacecraft bus per year (since the second relay is deployed 1 year after the first), and one sample return vehicle for every 2 years (each Mars launch opportunity).

• At least two crewmembers in each mission are engineers working on maintenance, and the other two tickets could be sold to agencies

• The demand covers the complete production capability since the year of initial operational capability of each vehicle to the end of the first three missions in 2033. This would mean a Mars launch rate greater than the current one (3 ships per opportunity, plus crewed missions).

Table 6 shows the number of units sold under these demand assumptions, plus the cost per unit (calculated with AMCM).

Table 6.

Units Sold and Cost Per Unit (in Millions of 2016 US Dollars) for Most Affordable Price

	Units Sold	Cost Per Unit
Spacecraft bus	9	178
Sample return vehicle	4	1,360
Crew tickets	6	4,000

Assuming a 50% profit margin over the cost, these missions would be among the cheapest Mars missions for space agencies. With a cost per unit for spacecraft of US$178 M, only the Indian Mangalyaan mission would have been cheaper (US$75 M.⁴⁰). As for sample returns, the lowest cost estimate is Russia's Mars-Grunt (about US$2.25 B⁴¹) and in this case they could be done for a price of about US$2 B. Same applies for the cost per crew ticket, which would have the added benefit of about 250 kg of samples returned for each mission, at a much lower cost per kg than sample return missions.

These demand estimates can now create constraints on the performance for the other two markets: deep space communications and entertainment. Assuming 50% margin and that the demand assumptions are correct, and with a goal of break even by the third mission in 2033, space communications and entertainment would have to produce US$2.1 B in revenues in total. The market for in-space data is expected to grow to US$1.6 B annually by 2022,⁴² not considering possible new applications such as space internet. On the other hand, assuming that Mars One was just about 3% correct, entertainment would yield enough revenues to cover the rest of the expenses on its own. However, public interest in space endeavors is much lower than in sports. It might be possible to achieve so much income from entertainment, but it would arguably be unlikely.

Business case evaluation

With the previous assessment of the markets, a final evaluation of the business case can be done. A number of important aspects about it can be already established:

(1) A huge upfront investment is required. The first income would come almost 6 years into the project, at which point the expenses are already almost US$13 B.

(2) The possible incomes from Martian resources and operations are hard to evaluate. Knowledge of the future markets is limited.

(3) Even with very optimistic assumptions, it would be highly unlikely to achieve breakeven by the third mission, some 17 years into the project.

This puts the feasibility of a business case, within the constraints of this project, in a very dark place: a business case for a fully private Mars colony by 2030 is likely not feasible. This conclusion is strengthened even more when other considerations are added to the demand assumptions of the sources of income. Namely, political considerations. Most space agencies are government funded projects to create industry and jobs in their countries. It would take a lot of effort to convince them of contracting with a private company, specially a foreign one, to completely carry out planetary missions, from development to end-of-life operations. This lowers even more the expectations of income, reducing the interest on the business case.

The situation is, however, not hopeless, and the business case can be improved in several ways. The estimated cost for the architecture is likely a high-end estimate, and a better evaluation will likely reduce the price tag. The cost of the architecture can be reduced further at an increased risk. Also, the sources of funding exist, they are just hard to evaluate. The most expensive part, the crewed missions, are also likely to provide the best source of income, both in paid seats and returned samples. Possible improvements are as follows:

• Increase project duration: the project constrains the first crewed landing to happen before 2030 to study possible short-term (or shorter term) architectures for a Martian settlement. However, there is no technical need for this. A longer project timeline would allow for more time to monetize previous investments (namely satellite technology and sample returns), reducing upfront investment needs, and reducing risk through a more progressive learning curve for Mars operations.

• Include public funding: given that the feasibility of the business case depends highly on the ability to sell passenger tickets on the crewed missions, a way to incentivize the agencies to buy the tickets would be to include them in the development process. A private-public partnership for the crewed missions would likely increase their cost (to reduce risk), but would incentivize public agencies to spend more money on the missions, and allow them to do so in a more progressive fashion, since they would be part of the project from the beginning of the development.

• One-way crewed trips: the way to reduce cost the most is to eliminate the return trip altogether. One-way trips to Mars have been proposed in the literature by Mars One, and other individuals such as Andrew Rader and Elon Musk,^11,43,44 Indeed, the ERVs alone amount for about 42% of the total cost. Eliminating the need for ERVs would reduce development and operations costs, as well the price of the passenger tickets. However, it would be a trade-off with total mission risk, and the need for more infrastructure at the beginning would mean a greater number of launches per mission. However, the total cost would be lower. The question remains on whether agencies would be willing to send their astronauts on a one-way trip. Since agencies are the most relevant customer of the project, catering to their needs may require existence of an ERV of some kind.

• Include non-Mars-based sources of income: this project restricted itself to Mars-based sources of income to provide a case of study for the Martian settlement. However, there is no technical need to do so, and by the conclusions about the business case, there is no business need either. Given that the technology for satellites and landers would have to be developed one way or another, there is no reason to just use them for Mars. Accessing just about 1% of the US$200 B annual global satellite industry revenue⁴⁵ would finance the whole endeavor. This could be complemented with launcher services, space-based internet, or even lunar-based services. This is precisely what SpaceX is doing with their launcher development, and their office in Seattle⁴⁶: they are tapping into other sources of income to fund their Mars development efforts.

Combinations of these options are also possible. For example, an increased project duration along with public funding would allow for development of more complicated infrastructure, such as a reusable Mars Transfer Vehicle. The increased timeline would allow more demonstration missions to reduce the added risks, while reducing long-term costs by including reusable elements. Increased development time would also allow for better infrastructure to be present for one-way trips, in that is the selected approach. However, the most interesting part is including non-Mars-based sources of income, and an increased timeline. With these, a company alone would be able to develop the complete architecture on their own by diverting income from Earth-based space applications into their Mars program. The business case for the company would then have to include all the Earth applications as part of the Mars efforts.

Conclusions

This study focused on the feasibility of a business case for a private Mars settlement within a short-term development (crewed landing before 2030) and with 100% private funding. Proposed crewed Mars mission architectures and possible Mars-based sources of income were studied. These were combined to create a Mars architecture that can be accomplished within the project's timeline, while providing sources of income for the project. A development roadmap based on a minimum infrastructure needs was created, and the potential cost of the complete project was evaluated using a parametric model. This was then used to place constraints on the sources of revenue based on demand assumptions. In short, the aim was to create a minimum-time, minimum-cost project and compare it to optimistic income assumptions. The conclusion was clear:

A fully private Mars settlement before 2030 just based on Martian resources is likely unfeasible from a business standpoint.

The business case is hardly interesting: the upfront investment is huge, the total cost estimates are not precise, the possible revenues are dubious, and the required level of risk and investment would probably not be interesting for any private company.

There are ways to improve this business case. Namely including Earth-based sources of income in the business case, and including public funding for the development. A private-public partnership would likely be able to afford a minimalistic architecture like the one presented, within the project's timeline. Further verification of the assumptions in this study is also required, to provide a more precise evaluation of the business case. Finally, possible developments in the space economy might create enough demand or interest for a private Mars effort, and create a completely new business case.

Footnotes

Acknowledgments

The author would like to thank the following people for their support and contributions to the project:

My project supervisor, Prof. Chris Welch, for his countless meetings and ideas for the development of the project.

My friends, for putting up with my constant rambling about Mars and space colonies.

My parents, for supporting me during the MSS program.

Author Disclosure Statement

No competing financial interests exist.

Appendix Table A4.

AMCM Estimates Versus Real Cost (in Millions of US Dollars, Inflation Adjusted to Year of Initial Operational Capability) for Commercial Space Vehicles

Vehicle	AMCM Cost	Real Cost	Real/AMCM
SpaceX Falcon 1 (development)	760	90	0.12
SpaceX Falcon 9 + Dragon (development)	3,092	850	0.27
Orbital ATK Cygnus (development)	360	300	0.83
Orbital ATK Antares (development)	2,710	560	0.21
SpaceX Dragon v2 (development + 6 missions)	10,000	3,144	0.31
Boeing CST-100 (development + 6 missions)	10,000	4,820	0.48

AMCM, advanced mission cost model.

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