Simplified Extraterrestrial Cargo and Crew Landing Vehicles for the SLS

Notional crewed ELV-3 on the surface of the Moon

by Marcel F. Williams

During NASA's Constellation program, the American space agency chose Boeing's Altair concept as the landing vehicle design to  return American astronauts to the surface of the Moon. As a two staged (descent and ascent) crew landing vehicle and as a single stage cargo landing vehicle,  the Altair was supposed to be housed in the large payload fairing of the Ares V super heavy lift rocket. But in 2010, the Constellation program was  canceled by the Obama administration, a decision that became law in April of 2011. And this ended the development of  Ares V and Altair lunar landing vehicle. 

Notional Altair crew landing vehicle (Credit: NASA)

Notional Altair cargo landing vehicle (Credit: NASA)

A year later, Congress began funding a new heavy lift program, the Space Launch System (SLS),   while continuing to fund the development of the  Orion component of the Constellation program. While there has been no significant Congressional funding for a lunar landing vehicle, a large variety of a vehicle concepts have been proposed to return American astronauts and cargo back to the lunar surface by several space companies.  

2.4 meter super lightweight cryotank (Credit: Boeing Aerospace)

Here, I propose another  reusable extraterrestrial cargo and crew landing vehicle (the ELV-3) concept that would be much simpler than Boeing's Altair vehicle. The ELV-3 would be launched by the SLS and utilized  to  deploy very large and heavy cargo or crews to the lunar surface. And with the addition of a HIAD or an ADEPT deceleration shield, the ELV-3 could also deploy largo cargoes and crew to the surface of Mars.

Notional ELV-3 lunar lander display retractable panel

X-ray view of three tank configuration for ELV-3

View of ELV-3 radiator and side thrusters

Top x-ray view of ELV-3 and its three tank configuration

Technologically, the notional ELV-3 spacecraft proposed here would be a substantially simpler vehicle than Boeing's canceled Altair spacecraft. Instead of the Altair's descent vehicle's four liquid oxygen tanks accompanied by four liquid hydrogen tanks, the ELV-3 would have just two 2.4 meter in diameter hydrogen tanks plus one 2.4 meter in diameter liquid oxygen tank, all linear aligned within an octagonal shaped cruciform.

 The problems associated with eight feedlines, differential tank pull due to unuasable propellant, increased tank heating resulting from the numerous tank penetrations, problems with pressure control during burns and long coastal phases caused by the large number of tanks are significantly reduced by reducing the cryotank numbers from eight down to just three. Utilizing just three tanks also reduces the overall mass of the tank weight.

Problems associated with the RL-10 exhaust plume just a few meters above the lunar surface during landings could be alleviated by using side thrusters positioned well above the surface. Additionally, the IVF (Integrated Vehicle Fluids) ullage gas fueled thrusters could also be automatically extended outwards away from the side panels (more than 8.4 meters in diameter) for exceptionally large payloads that extend beyond the diameter of the octagonal panels.

While the deck of the  ELV-3 would be approximately two meters higher than the Altair, the ELV-3 would have the advantage of a substantial amount of empty space on each side of the linear aligned propellant tanks. Twin retractable wall panels on each side could  accommodate a rectangular cargo area at least 7.2 meters high by 2.2 meters by 2.8 meters.

ELV-3 - Cargo Lander

One 2.4 meter in diameter LOX tank

Two 2.4 meter in diameter LH2 tanks

IVF thrusters utilize ullage gasses 

Dry mass: 8 tonnes

Propellant mass: 31 tonnes

Maximum cargo mass to lunar surface from NRO (Near Rectilinear Orbit):  30 tonnes

Maximum cargo mass to lunar surface from LLO: 39 tonnes

Twin mobile lunar cranes stored within the ELV-3 side cargo areas with additional cargo located at the top central area

The large dimensions of the side cargo areas would also be able to accommodate twin mobile lunar cranes with telescopic booms extending well above the the top deck.  Each electric powered crane would be equipped with a cable hook for unloading large payloads and with cable clamshells for digging up and redepositing lunar regolith. With each mobile crane already weighing more than 12 tonnes, the deposition of lunar regolith (weighing approximately 1.5 tonnes per square meter) into the automatically expanded regolith bins of the other vehicle could increase each crane's counter weight by more than 18 tonnes. This would allow each mobile crane to be able to easily offload payloads on top of the ELV-3 weighing nearly 30 tonnes. If devices are deployed to the lunar surface to magnetically extract iron and other metallic dust  from the top ten centimeters of lunar regolith then the deposition of this much heavy material into the regolith bins could easily increase the counter weights of the mobile cranes by more than 100 tonnes.

Panel deployment of twin mobile lunar cranes  

The deployment of such mobile lunar cranes could, of course, be used to unload and transport payloads from a variety of other lunar landing cargo space craft.

Notional electric powered mobile lunar crane

The clamshell crane could also be used to deposit regolith within the surrounding walls of lunar habitats providing the large multilevel pressurized habitats with appropriate shielding against cosmic radiation (completely shielding the habitats from the heavy nuclei component). Such regolith shielding could provide the habitat with protection from micrometeorites and from the extreme thermal fluctuations from the lunar environment.

Mobile lunar crane using its telescopic boom to lift a 20 tonne SLS propellant tank derived lunar habitat from the top of an ELV-3 cargo lander. The 20 tonne payload, of course, would weigh only one sixth as much on the lunar surface.

The cargo version of the ELV-3 could also be utilized to transport large and heavy payloads to the martian surface if HIAD or ADEPT deceleration shields are utilized along with mobile cranes with lifting capabilities not too dissimilar to vehicles deployed to the lunar surface. 


ELV-3 - Crew lander

Dry mass with mass with passengers, cargo,  and radiation shielding: 16 tonnes

Maximum additional cargo to and from the lunar surface if able to refuel on the lunar surface: 14 tonnes

Notional ELV-3 crew landing vehicle

As a crew vehicle, the ELV-3 would use three pressurized modules derived from Boeing's 2.4 meter in diameter tank technology. The centrally positioned module (passenger module) would be the heaviest since it would be internally heavily shielded to protect astronauts from the exceptionally deleterious heavy nuclei component of cosmic rays. This would add at least four tonnes of extra shielding weight to the passenger module relative to the similar sized command module and airlock on opposite sides of the passenger module. The passenger module  would also serve as a storm shelter in case of a major solar event when the ELV-3 is moving through cis-lunar space.

Because of its weight and limited fuel (up to 31 tonnes of LOX/LH2 propellant), two  vehicles would be required for round trip sortie missions between NRO and the lunar surface. One ELV-3 would be used to transport the other ELV-3 and its crew to low lunar orbit while the crewed ELV-3 would land on the lunar surface and then return to lunar orbit after its mission where the orbiting ELV-3 would transport both vehicles  back to NRO.  So spacecraft such as the ULA's XEUS (up to 68 tonnes of LOX/LH2 propellant) and Lockheed Martin's MADV (80 tonnes of LOX/LH2 propellant) would be much more capable than the ELV-3 as a crew launch vehicle for sortie missions since  only one vehicle is required for sortie missions originating from NRO.

However,  once propellant producing depots are deployed to the lunar surface, only one ELV-3 vehicle would be required to transport crews between the Earth-Moon Lagrange points and the lunar surface and back. Additionally, the crewed versions of the ELV-3 would have a major advantage by being able to transport both astronauts plus more than 14 tonnes of additional payload to and from the lunar surface  when fully fueled.

After a side panel is deployed, astronauts ride an electric powered scissor lift down towards the lunar surface

If propellant producing water depots are deployed at LEO and NRO, the ELV-3 could also be used transport crews between LEO and NRO. This would provide NASA and private commercial space transportation companies with an alternate means from LEO to the Lagrange points.  

Utilizing its side cargo areas,  an unmanned ELV-3 could also be used  to deploy a multitude of mobile robots to the surfaces the Moon, the moons of Mars (Deimos and Phobos), to the moons of Jupiter (Io, Ganymede, Europa, and Callisto), and even to the surfaces of some of the the largest asteroids in the asteroid belt (Ceres, Vesta, Pallas, etc.). 

Links and References

Robust Lunar Exploration Using an Efficient Lunar Lander Derived from Existing Upper Stages

 

Altair spacecraft

Tanks for a Great Idea

Game Changing Propellant Tank

2.4 meter composite cryogenic tank at Boeing Developmental Center

Pioneering and Commercial Advantages of Permanent Outpost on the Moon and Mars

Lockheed Martin's Reusable Extraterrestrial Landing Vehicle Concept for the Moon and Mars

(Part IV) A Practical Timeline for Establishing a Permanent Human Presence on the Moon and Mars using SLS and Commercial Launch Capability

Three Mars Regolith Habitats (MRH) connected to a transparent martian biosphere covered with a water shielded biodome.

by Marcel F. Williams

Part IV: Mars

Once NASA has established a permanent human presence in high Mars orbit in the form of a microgravity storm shelter (BA-330), microgravity Deep Space Habitat (DSH), and a rotating simulated gravity producing space station (AGH-SS), the American space agency can then proceed to establish a permanent human presence on the surface of Mars.

An Ares CLV-7B with payload joined with an  ADEPT deceleration shield needed to safely enter  the martian atmosphere before landing. An additional attitude control module is added to enable thrusters to  control the angle of the vehicle's entry into the  martian atmosphere.

2032

SLS Launches:


SLS Launch 34: Two CLV-7A (Cargo Landing Vehicle) to LEO to be deployed to high Mars orbit by OTV-125 vehicles and deployed to the martian surface by ADEPT decelerators

The First CLV-7A  will have an  ATHLETE robot that will deploy electric powered excavation vehicles, sintering vehicles,  backhoe, lifting crane

The Second CLV-7A   will deploy at least 160 KWe of  nuclear power to the  martian surface with at least a 10 year lifetime for the fueled reactors.

SLS Launch  35: Two CLV-7A (Cargo Landing Vehicle) to LEO to be deployed to high Mars orbit by OTV-125 vehicles and deployed to the martian surface by ADEPT decelerators

The first CLV-7A will deploy  a mobile hydrogen tanker (MHT)   plus  four   Water Bug regolith water extraction robots to the martian surface

The  second  CLV-7B will carry two mobile water tankers (MWT), two mobile LOX tankers (MLT) 


SLS Launch 36: Two CLV-7A (Cargo Landing Vehicle) to LEO to be deployed to high Mars orbit by OTV-125 vehicles and deployed to the martian surface by ADEPT decelerators

The first CLV-7A will deploy  a second mobile hydrogen tanker (MHT)   plus  four   Water Bug regolith water extraction robots to the martian surface

The  second  CLV-7B will carry two mobile ground transport vehicles

SLS Launch 37: Two Ares-ETLV-4 crew landers to LEO. They will self deploy themselves to high Mars orbit and deploy themselves to the martian surface attached to ADEPT decelerators

Commercial Launches:

1. Private commercial launch companies will continue to deploy ADEPT  deceleration shields to LEO. The deceleration shields will be transported to high Mars orbit  by NASA's growing fleet of  Orbital Transfer Vehicles (OTV-125). The ADEPT shields will allow NASA to use cargo landing vehicles (CLV-7B) and crew landing vehicles (ETLV-4), originally designed for lunar missions, to deploy cargo and crews to the martian surface. 

2. ACES  68 WPD-LV will be deployed to the lunar surface and to the surface of Mars and Deimos, replacing NASA's WPD-LV-7A propellant producing water depots

Note: 

1. All SLS and commercial launched vehicles for Mars will be deployed to Mars during the 2033 launch windows. 

2. Reusable OTV-125 will continue to be deployed to LEO with every SLS launch that uses an upper payload fairing

Two Lunar Regolith Habitats (LRH) next to a lunar biosphere domed with lunar regolith bags to protect it against excessive cosmic ration, micrometeorites, and extreme thermal fluctuations.

2033

SLS Launches:

SLS Launch 38:  A single CLV-7B carrying a Mars Regolith Habitat (MRH) will be launched to LEO to be deployed to high Mars orbit by an OTV-125  and deployed to the martian surface by ADEPT decelerators

SLS Launch 39: A second CLV-7B carrying a Mars Regolith Habitat (MRH) with a equipped with a medical level will be launched to LEO to be deployed to high Mars orbit by an OTV-125  and deployed to the martian surface by ADEPT decelerators

SLS Launch 40: A single CLV-7B carrying a Lunar Regolith Habitat (LRH) will be deployed to LEO. The lunar habitat will be used as an aquaculture facility for raising shrimp and fish.

SLS Launch 41: Two CLV-7A (Cargo Landing Vehicle) to LEO to be deployed to the lunar surface.

The First CLV-7B will deploy an inflatable 32 meter in diameter Kevlar biosphere to the lunar surface

The Second CLV-7B will deploy the biosphere's connecting airlocks (2.4 meters in diameter),

Environmental Control and Life Support Systems (ECLSS) and panel components for the internal construction of housing and work spaces  and geodesic dome components.

Notes: 

1. Odyssey 5 crew will depart EML1 during an April 2033 launch window, arriving in high Mars orbit in October 2033  to join 12 astronauts who are already in Mars orbit from the previous Odyssey flight.

2. Mars surface outpost components  will be transported by OTV-125 spacecraft from EML1 during May 2033 launch windows, arriving in high Mars orbit in September of 2033. 

3. A crew of six (four Americans and two foreign guest astronauts) will be the first humans to set foot on the surface of Mars in November of 2033, landing an ADEPT shielded Ares-ETLV-4 on the martian surface. A second landing of six will occur, three months later in February of 2034. Afterwards, crewed flights to the martian surface from high Mars orbit will occur every six months. 

4. The Ares ETLV-4 crew lander can land on the surface of Mars with enough propellant to return to low Mars orbit. A second  option lands the Ares ETLV-4 on the surface of Mars   with only enough hydrogen to return to Mars orbit; liquid oxygen would be supplied by mobile LOX tankers (MLT) deriving their oxygen supplies from propellant depots located near the martian outpost.  A third option lands the Ares ETLV-4 on the martian surface almost empty with both LOX and LH2 supplied from the Mars outpost for its return trip to orbit.

5. Eight  Odyssey 4 and Odyssey 5 crew members will depart Mars orbit in January 2035, returning to cis-lunar space in September of 2035 aboard the Odyssey 4. They will leave 16 crew members behind in Mars orbit aboard the AGH-SS and on the surface of Mars at the Mars outpost. 

6. The inflatable lunar Kevlar biosphere will 32 meters in diameter with a safety factor of four. Lunar regolith bags two meters thick will shield the upper hemisphere from micrometeorites, excessive radiation, and from extreme thermal fluctuations. The upper hemisphere of the lunar biosphere will provide a spacious recreational area under the geodesic dome. The lower hemisphere of the lunar biosphere will provide ample accommodations for housing, laboratories, and food production: agronomy, aquaculture, poultry.

 

Crewed Ares ETLV-4 coupled with a protective ADEPT deceleration shield. The Ares ETLV-4 can land on the martian surface with enough propellant to return to low mars orbit. 

2034


1. SLS Launch 42: An MRH (Mars Regolith Habitat) agronomy habitat will be deployed to LEO with an Ares-CLV-7B and an OTV-125 destined for the martian surface. 

2. SLS Launch 43: An MRH aquaculture habitat will be deployed to LEO with an Ares-CLV-7B and an OTV-125 destined for the martian surface. 

3. SLS Launch 44: Two Ares ETLV-4 spacecraft plus an OTV-125 will be deployed to LEO destined for high Mars orbit.

 
4. SLS Launch 45: Two Ares CLV-7A (Cargo Landing Vehicle) to LEO to be deployed to LEO destined for the martian surface:

The First Ares CLV-7B will deploy an inflatable 32 meter in diameter Kevlar biosphere to the martian surface

The Second Ares CLV-7B will deploy the biosphere's connecting airlocks (2.4 meters in diameter),

Environmental Control and Life Support Systems (ECLSS) and panel components for the internal construction of housing and work spaces  and transparent Kevlar biodome. 

Notes:

1. Mars biosphere: The the top hemisphere of the inner dome of the  Mars biosphere will be covered with a transparent UV filtering layer. The outer area will be  shielded from excessive cosmic radiation with a transparent water filled biodome. This will allow natural sunlight to enter the dome.

The martian moon Deimos will be utilized for the production of hydrogen, oxygen, and water eliminating the need to import water from the Earth's moon in order to provide water and propellant for interplanetary vessels returning to cis-lunar space. 

2035


1. SLS Launch 46: Two CLV-7B spacecraft will be deployed to LEO destined for the surface of the martian moon, Deimos:

The first CLV-7B  will deploy mobile ground excavation vehicles, lifting cranes, and regolith sintering vehicles. 

The second  CLV-7B  will deploy four small nuclear reactors for providing up to 160 KWe of electric power.


2. SLS Launch 47: An OTV-125 plus two CLV-7B spacecraft will be deployed to LEO destined for the surface of the martian moon, Deimos:

The first CLV-7B will have two cargo levels and will deploy mobile water, hydrogen, and water tankers to the surface of Deimos

The second CLV-7B will have two cargo levels and will deploy a plasma arc pyrolysis and syngas refinery to Deimos for the production of water, hydrogen, and water. The upper level will deploy another mobile hydrogen tanker.


3. SLS Launch 48: An OTV-125 plus a single CLV-7B carrying a Lunar Regolith Habitat (LRH) will be deployed to LEO. The lunar habitat will be used as poultry  facility for producing chickens and eggs.

4. SLS Launch 49: An OTV-125 plus two CLV-7B will be deployed to LEO destined for the lunar surface

The First CLV-7B will deploy an inflatable 32 meter in diameter Kevlar biosphere to the lunar surface

The Second CLV-7B will deploy the biosphere's connecting airlocks (2.4 meters in diameter),

Environmental Control and Life Support Systems (ECLSS) and panel components for the internal construction of housing and work spaces  and geodesic dome components.

Notes

1. With five habitat modules and two biospheres, NASA's lunar outpost would be complete and capable of housing up to 200 personal-- if desired. 

2. Deimos water and propellant producing facility will allow NASA to fuel spacecraft operating in Mars orbit and interplanetary spacecraft heading back to cis-lunar space. 

3. Launch windows to Mars from cis-lunar space will occur in June and July of 2035 with payloads and personal arriving to high Mars orbit in December of 2035 or January of 2036. 


So, under this architecture, NASA will have permanent outpost on both the Moon and Mars, and artificial gravity outpost in high Mars orbit by the middle 2030s. The DOD will have permanent outpost on the Moon and an artificial gravity outpost at EML4 by early 2030s. This will be possible thanks to a combination of regular launches by the SLS (up to four launches a year by the late 2020s) and private commercial launch vehicles in the 2020s and the 2030s.

Propellant producing water depots are the key to substantially enhancing the payload capabilities of both the SLS and private commercial launch vehicles under this scenario. However, NASA's current plan of relying on propellants  that have to be terrestrially produced  and launched from the Earth's enormous gravity well would severely curtail the payload capabilities and sustainability of   the SLS and private commercial launch vehicles. 

Links and References


A Practical Timeline for  Establishing a Permanent Human Presence on the Moon and Mars using SLS and Commercial Launch Capability

 Part I

Part II

Part III

NASA Ames Research Center Trajectory Browser

What about Mr. Oberth?

Inflatable Biospheres for the New Frontier

Protecting Spacefarers from Heavy Nuclei

ADEPT Technology for Crewed and Uncrewed Missions to the Planets

Links and References

Transformable Hypersonic Aerodynamic Decelerator: Transformable and Reconfigurable Entry, Descent and Landing Systems and Methods

Landing on Mars with ADEPT Technology

Landing on Mars with ADEPT Technology

Links and References


Trajectory Optimization for Adaptive Deployable Entry and Placement Technology (ADEPT)

Hypersonic Deployable Decelerators

Establishing a Permanent Human Presence on Mars with a Lunar Architecture

ETLV-2 coupled with an ADEPT deceleration shield on its way the martian  surface

 

by Marcel F. Williams

"As we reported in August 2013, even after the SLS and Orion are fully developed and ready to transport crew NASA will continue to face significant challenges concerning the long-term sustainability of its human exploration program. For example, unless NASA begins a program to develop landers and surface systems its astronauts will be limited to orbital missions of Mars. Given the time and money necessary to develop these systems, it is unlikely that NASA would be able to conduct any manned surface exploration missions until the late 2030s at the earliest."

NASA Office of Inspector General
February 25, 2015

-------------------------

It is generally agreed by both the Congress and the Executive Branch  that sending humans to the surface of Mars, sometime in the 2030s, should be the long term goal of the National Aeronautics and Space Administration (NASA).  However, the intermediate destination during the 2020s needed to develop and to mature such space faring capability has been subject to controversy. While some have advocated a return to the lunar surface as a bridge towards Mars, others have argued that the  development of a lunar architecture could actually siphon off  necessary funds for sending humans to the martian surface.

The extraterrestrial deployment of  huge amounts of water will be essential for any interplanetary journey.  Even if some future Mars vessels are  xenon fueled solar electric interplanetary vehicles, crewed missions between cis-lunar space and Mars orbit will still require a substantial tonnage water for drinking, washing, food preparation, the production of air and for mass shielding habitat modules  from the dangers of  cosmic radiation and major solar events. The most expensive source of water for an interplanetary vehicle within cis-lunar space is from the Earth's deep gravity well.  However, water derived from ice in the Moon's polar regions would be a substantially cheaper source since the  Moon has a significantly lower gravity well.  Water, of course,  could also be used for the production of LOX/LH2 propellant necessary for  voyages between cis-lunar space and Mars orbit. 

ADEPT payload deployment scenarios for Mars (Credit: NASA)

Because of its thin atmosphere and higher gravity, Mars is a very different world than the Moon. Still,  habitat modules, propellant producing water depots,  and mobile ground vehicles that could be  utilized on the surface of the Moon could also be used on the surface of Mars.  This could save NASA enormous amounts of money since basically the same surface architecture for the Moon could also be deployed on the surface of Mars. So no new surface infrastructure unique to Mars would not have to be developed.

Vehicles designed to deploy cargoes and crews to the lunar surface could also be used to deploy cargoes and crews to the surface of Mars. But in order to safely deploy cargoes and crews to the martian surface, such  vehicles will need to be  shielded and decelerated through the thin martian atmosphere through the ADEPT or HIAD technologies currently being developed by NASA.

HIAD  decelerator entering martian atmosphere with crew vehicle (credit: Boeing)

HIAD and ADEPT technologies simply use a large expandable heat shield  to protect a spacecraft from the frictional heating of the thin martian atmosphere (100 thinner than the Earth's atmosphere) while also decelerating the vehicle enough to eventually allow the vehicle to utilize retrorockets to hover and land on the martian surface. The weight of these decelerating heat shields approach 50% of the payload being deployed to the surface. But NASA believes that these technologies should   enable them to deploy as much as 40 tonnes of payload to the martian surface. 

C-ETLV-5 cargo lander and ETLV-2 crew lander for deploying cargoes and crew to the surface of the Moon, Mars, and on the surfaces of the moons of Mars

In July of 1962, NASA invited private companies to submit proposals for the development of a Lunar  Module (LM). Seven years later, this lunar landing craft  took Neil Armstrong and Buzz Aldrin  to the surface of the Moon. Assuming a similar length of time for the development of a new  Extraterrestrial Landing Vehicle (ETLV), proposals submitted for an ETLV  in 2016 could result in the return of humans to the lunar surface by 2023. Thus, by the 2030's, the ETLV will be a mature landing vehicle ready to deploy humans and cargo to the surface of Mars.

If we assume that NASA's annual human spaceflight related budget remains at approximately $8 billion a year  over the next 25 years, then NASA will spend approximately $200 billion over the next quarter of a century on human spaceflight related technology, operations, and activities. $8 billion a year should be enough for NASA to establish a permanent human presence on the surface of the Moon in the 2020s and on the surface of Mars in the 2030s-- if such efforts are prioritized-- especially if NASA is no longer burdened with the $3 billion a year ISS program during the next two decades. 

Ares vehicle (ETLV-2 and ADEPT deceleration shield) for landing on Mars: A. ETLV-2 begins to dock with DS (deceleration shield); B. ETLV-2 trajectory burn propels the Ares towards Mars; C. ETLV-2 undocks with the DS, turning around 180 degrees; D. ETLV-2 docks with DS in a Mars entry configuration; E.  Ares vehicle enters the Martian atmosphere; F.  ETLV-2 separates from the DS after subsonic deceleration velocity is achieved; G. ETLV-2 decelerates further towards the martian surface before hovering and landing its crew.

A reusable single staged LOX/LH2  ETLV capable of a round trips between the Earth-Moon Lagrange points and the lunar surface should also be capable of easily transporting crews from the surface of Mars to Low Mars Orbit-- or even all the way to the surface of Mars's inner moon, Phobos. HIAD or ADEPT deceleration shield would, again, be used to deploy the crewed ETLV safely to the martian surface. The cost of developing a crewed  lunar landing vehicle  has been estimated to be as much as $8 to $12 billion. So over the course of seven years, the cost for developing an ETLV could range from $1.1 billion to $1.7 billion per year. And that's a cost that is certainly affordable with an $8 billion a year human spaceflight related budget.

ETLV-2 at a sintered landing area being refueled with LOX and LH2 for its departure to Mars orbit. 

Regolith shielded lunar habitats cheaply derived from SLS propellant tank technology could also be deployed to the martian surface using a lunar cargo lander and a, of course, a HIAD or ADEPT deceleration shield. Regolith shielding a martian habitat to a similar degree as a lunar habitat will be necessary since the level of cosmic ray exposure on the martian surface is not substantially lower than on the lunar surface.

Three habitat modules previously deployed by a C-ETLV-5. The pressurized habitats are shielded with 2 meters of martian regolith contained within the automatically deployed regolith wall. Solar charged batteries are used to provide power for the habitat at night. But nearby nuclear power units buried beneath the regolith will also provide supplementary power for the outpost.

Ionizing Radiation on the Surface of the Moon:

38 Rem - annual amount  of cosmic radiation on the Lunar surface during the solar minimum

11 Rem - annual amount of cosmic radiation on the Lunar surface during the solar maximum

Ionizing Radiation on the Surface of Mars:

33 Rem - annual rate of cosmic radiation on the surface of Mars beneath 16 gm/cm3 of Martian atmosphere during the solar minimum

8 Rem - annual rate of cosmic radiation on the surface of Mars beneath 16 gm/cm3 of Martian atmosphere during the solar maximum

Percentage of water contained in different regions on the martian surface.

Lunar water collecting mobile vehicles using microwaves used to extract water from the regolith at the lunar poles could also  be used on much of the martian surface. The water content of the lunar regolith at the lunar poles has been estimated to be approximately 5%. The water content of the martian regolith at the lower latitudes ranges from approximately 1 to 7% depending on the region. But there are large regions near the martian equator that may have regolith with a water content as high as 7%. At higher latitudes, the water content may be as high as 30%. And at the martian poles, the water content could be as much as 70%. 

Mobile water tanker and  microwave water extraction robot on Mars.

Solar powered WPD-LV-5 water storage and propellant producing unit on the surface of Mars. Additional power can be provided by nearby nuclear power units buried beneath the martian regolith. 

Small nuclear power units will probably be necessary to supplement the solar electric power supply at a martian outpost. While batteries and electric flywheels charged during the daytime could provide power for an outpost a night, dust storms could substantially reduce solar electricity for up to a month with dust particles blanketing the solar panels.  But small nuclear power units could run 24 hours a day for several years before having to be replaced. So during dust storms, it might be wise for the outpost  to contract the solar panels while mostly relying on nuclear power until the storm is over. Such nuclear power units for Mars should also probably be  initially tested on the lunar surface in the 2020s for a few years before they are eventually deployed at a martian outpost in the 2030s.

Nuclear power unit on the Moon with its reactor buried beneath the regolith and its cooling panels above the surface. Such units could also be utilized on the martian surface (Credit: NASA).

Links and References


Adative  Deployable  Entry  and  Placement Technology  (ADEPT):

ADAPTABLE, DEPLOYABLE ENTRY AND PLACEMENT TECHNOLOGY (ADEPT) FOR FUTURE MARS MISSIONS

ADEPT Hypersonic Deployable Decelerators Adaptable, Deployable Entry Technology and Placement (ADEPT) Project

 MECHANICALLY DEPLOYED HYPERSONIC DECELERATOR AND CONFORMAL ABLATOR TECHNOLOGIES FOR MARS MISSION

Hypersonic Inflatable Aerodynamic Decelerator (HIAD)

Utilizing Lunar Water Resources for Human Voyages to Mars

Landing Large Cargoes and Crews on the Surface of Mars

 Cosmic Radiation and the New Frontier

 Utilizing the SLS to Build a Cis-Lunar Highway

The Lunar Module

Future Mars Explorers Face Dusty Challenges