SPACE RESOURCES AND PRODUCTS OF INTEREST
Three major resources
(1)Regolith: oxides and metals−Ilmenite 15% −Pyroxene 50% −Olivine 15−Anorthite 20% (2)Solar wind volatiles in regolith: −Hydrogen 50 –150 ppm −Helium 3 –50 ppm −Carbon100 –150 ppm ( 3)Water/iceand other volatiles in polar shadowed craters −1-10% (LCROSS) −Thick ice (SAR)
Three major resources
(1)Atmosphere: −95.5% Carbon dioxide, −2.7% Nitrogen, −1.6% Argon (2) Water in soil: concentration dependant on location −2% to dirty ice at poles (3) Oxides and metals in the soil
NEAR EARTH ASTEROIDS: ~85% OF METEORITES ARE CHONDRITES
Ordinary Chondrites 87%
FeO:Si = 0.1 to 0.5 Pyroxene Fe:Si = 0.5 to 0.8 Olivine Plagioclase Diopside Metallic Fe-Ni alloy Trioilite -FeS
-» Source of metals(Carbonyl)
Carbonaceous Chondrites 8%
Highly oxidized w/ little or no free metal Abundant volatiles: up to 20% bound water and 6% organic material -» Source of Water/volatiles
Enstatite Chondrites 5%
Highly reduced; silicates contain almost no FeO 60 to 80% silicates; Enstatite & Na-rich plagioclase 20 to 25% Fe-Ni Cr, Mn, and Ti are found as minor constituents
-» Easy source of oxygen
CREDIT: Johnson Space Center Engineering Directorate / L-8: In-Situ Resource Utilization Capabilities by Jerry Sanders, November 2016.
ISRU PROPELLANT'S APPLICATION - TIPS TO KNOW
A Propellant need to meet many criteria to be considered as basis for transportation architecture. First, it must have thermal stability to operate in a liquid rocket engine, means the ability to cool engine throat critical heat flux, avoiding thermal decomposition and coking in engine coolant channels, as well as offers sufficiently high engine specific impulse (Isp).
From a vehicle system, it is the combined characteristic of propellant Isp and bulk density in meeting the vehicle impulsive velocity (DeltaV) mission requirement that offers either the lowest mass or lowest propellant tank volume that warrants the selection. So...
The cryogenic Liquid Hydrogen(LH2), with its Normal Boiling Point at 36.6 degree Rankin, has an excellent gravimetric heat of combustion (energy per mass) and can generates an High Engine Specific Impulse when combusted with Liquid Oxygen (LO2). Used in launch vehicles for first stage and upper stage applications, it is the fuel of choice for In-Space Propulsion Stage because that high Isp value.
Its disadvantage is that, because it has a low volumetric heat of combustion due to its low density and boiling point, it required techniques for tank insulation and Cryo-Fluid Management to reduce its boil-off. These additional complexity and low dry mass for the stage, reduce its overall usable propellant mass fraction.
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The Composite Cryogenic Propellant Tank project will develop and ground demonstrate large-scale composite cryogenic propellant tanks applicable to heavy-lift launch vehicles, propellant depots, and future lander systems. The primary objective of the Composite Cryotank Technologies and Demonstration (CCTD) project is to mature the technology readiness of composite cryogenic propellant tanks at diameters that are suitable for future heavy lift vehicles and other in-space applications.
Establishment of a Spaceport network Architecture
ESTABLISHMENT OF A SPACEPORT NETWORK ARCHITECTURE
To make easy and economical the access into orbital and deep space destinations, we need to create a network of Spaceports at specific locations with the use of natural resources or In Situ Resource Utilization (ISRU), said a report of Wiley J. Larson from Stevens Institute of Technology (USA), seconded by Mr. Tracy R. Gill, Mr. Robert P. Muellert and Mr. Jeffrey S. Brinkt, all from Kennedy Space Center, NASA.
As part of the International Space University Program 2012, the world wild team of Operations And Service Infrastructure for Space (OASIS) propose an interdisciplinary answer to the problem of economical space access and transportation. Because the approach includes engineering, scientific, financial, legal, policy and societal aspects, by a public-private partnership, OASIS proposes the creation of an International Spaceport Authority (ISPA).
Like oases in the desert, the Spaceports network presented outlines a pioneering, multi-purpose logistics network of safe havens, enabling human and robotic expansion into the hostile space environment. A spaceport is an infrastructure that provides services for space vehicles and facilitates their departure and arrival.
Current launch systems are unable to provide sufficient mass to orbit at an acceptable cost - often place a spacecraft as well as five to ten tons of propellant into orbit. This propellant boosts the spacecraft to its desired destination but consumes much of the launch system's volume and energy. The OASIS team proposes placing the propellant and other support items in a convenient location in space, allowing to lift more spacecraft mass into Low Earth Orbit (LEO). Once spaceports prove to be effective, the World Wild team proposes the creation of a network of spaceports that include locations on the Moon, and Mars' moon Phobos to further enable space exploration.
To make this Spaceports network, OASIS will take advantage of existing terrestrial spaceport facilities to contract launch services to transport necessary resources and payloads from Earth's surface to space. And, to reduce the initial development cost, the Team will select terrestrial spaceport facilities offering the best inclinations with low-cost, reliable and high mass to orbit.
To update, we need to make money!
The operational viability of the spaceport network is highly dependent on whether or not the network is making money and can build on its profits to upgrade its infrastructure and expand in Space. Like Private business, revenue from services must cover the operational cost and be able recover the initial investment after few years.
So, for the Short term 20 15- 25, Spaceport Node 1
The geostationary spacecraft represent a mature market that has remained stable over the past 10 years consisting of an average of about 20 spacecraft launched per year with an average mass per satellite of 4.0 tons, per spacecraft. It is expected that the number of spacecraft launched into the GEO orbit will remain between 20-23 satellites per year. However, the average mass per spacecraft is expected to increase to about 4.5 tons per satellite., as "the trend is to build heavier, more capable satellites".
In general, the Spaceport Node 1 - placed in LEO at 300 km altitude and 28 .5° inclination - provides power generation, station keeping, communication, navigation and international docking adapter allows different spacecraft to dock. Water tanks connected to the propellant generators, via electrolysis, are directly connected to the Tug Servicer. Because the it's a modular system. more elements can be added to increase the needed capability.
For the Tug, Photovoltaic arrays are avoided due to the unknown configuration of the satellite as they may cause maneuvering, approach and access problems. The tug may have to provide service to a satellite that is not in a stable attitude; thus a grappling mechanism is necessary. Additionally, tete-operated robotic arms are available, carrying interchangeable tools and cameras for video feedback to the control station.
The business case determines that initially the main service for the tug is to transfer satellites from LEO to GEO for orbital inclinations of 0° to 51.6° (ISS orbit) and circularize their orbit if necessary. Higher inclination requires a large amount of propellant, so the constraint of not going further than ISS inclination was applied. The tug carries enough propellant to deliver a 9 ton satellite from LEO to GEO and then return itself back to the depot for refueling. Returning from GEO to LEO, the tug uses aerobraking to save fuel, in order to create drag during the operation, a conical section deployable is fixed to the side of the engine nozzle structure.
Others potential services will be on-orbit fueling in LEO for Space agencies and commercial planetary missions. Normally, we use the water depot and electrolyzer to provide cryogenic L02/LH2 fueling services to spacecraft or satellites going beyond LEO. In the same idea, for governments and Space agencies, we could use the Tug to provide de-orbiting Space Debris from LEO to Earth`s atmosphere and decommissioning a large on-orbit structure at the end of life for customers like ISS, Bigelow Aerospace, Orbital Technology and Tiangong and others privates stations.
Satellite operators, the Tug can inspect, relocate, repair, up-date and assemble existing GEO and LEO satellites. Always for those commercial satellites, space agencies and insurance companies it is possible to back-up satellites for GEO satellites operator in case of emergency/failure of one of the satellites and depending on the criticality of the service provided (e.g. GPS, TDRS, Galileo).
The OASIS Team estimate the initial investment for Spaceport Node 1 at $296 M and can be recovered within 7 years with just 4 GEO satellite launches of 4.5 Tons per year.
For Medium term (2025-45), Spaceport Node 2 on the Moon
Because the Spaceport Node 2 is on the Moon, it will be able to use In Situ Resources Utilization and made water. So, this Moon`s mining operations could provide propellant to the Spaceport Node 1 and will significantly decrease his operating cost and that, increase the profit generated. The Moon spaceport could either be human or robotic and like the one in LEO, have many potential services to provide.
Node 2 is an important step towards the development of Spaceport Node 3 on moon`s Mars Phobos by providing resources and also offering a testbed for critical technologies. In fact, on Moon, an excavator will gather resources (regolith) and an ISRU plant will transform it into water. There will be a facility for propellant generation to generate propellant for the lander, which is used to lift the water tanks into orbit for storage. Another will be a spaceport that enables spacecraft to launch and land safely avoiding dust contamination and later on, consumables for life support systems as Oxygen, fresh water, and food will be provided for a human presence.
For Space agencies and Space tourism (Space Adventures Ltd., Excalibur Almaz) and Mining companies (Planetary Resources, Moon Express, Shackleton Energy), we provide the same service of Tug for Satellites from LEO to GEO and Moon orbit and back.
Ising Moon regolith we can create Solar Power Photovoltaic Arrays and beam it to Earth. This is interesting for public utilities, agriculture, fresh water production, power to cities, power to disaster sites and reduction of carbon emissions, on-orbit fuelling in LEO and Space Solar technology.
Like every road rest aera, we provide services to others moon settlers and visitors and it will be possible to establish a segment for optical communications transmission to Earth orbit and other space destinations.
The total initial investment cost for the construction of a robotic spaceport on the Moon with mining operations to provide 150t of water to Spaceport Node 1 per year is estimated at $5.3b. The payback period for the initial investment is set to 15 years. As a result, the cost of a kilogram of propellant extracted from the Moon and made available at the Spaceport Node 1 is $3,261. This corresponds to a reduction of 38% compared to the short-term Earth propellant solution.
The capture of future medium-term planetary or exploratory missions, tourism and mining companies' missions will guarantee the viability of the Spaceport Node 2. In addition, if GEO Space Solar Power transmitted to Earth becomes viable due to the reduced cost of access to GEO and other technology developments, then the market will become very large.
For the long term (2045-0nwards), Spaceport Node 3
For Mining and tourism companies, space agencies science missions on the Moon and Mars, settlement on Mars, Spaceport Node 2 will provide Tug service between LEO to GEO, Moon and Mars orbit (Node 3 on Phobos`s moon) for satellites and spacecraft. That will be made by loading propellant in LEO depot and on the Moon orbit to facilitate further missions beyond the Moon and Mars.
A base on Phobos will be similar to a base on the Moon with operational support, possible propellant generation, propellant storage infrastructure and a port for transportation of resources from wet asteroids (e.g. Ceres) or transportation of people to Earth and other spaceports.
Regarding asteroid mining, going to the asteroids and getting in situ resources is one option. The other one is to capture the asteroid and transport it to the Mars orbit to extract the resources there. Between the infrastructures, a surface transportation system does not have to be used due to the low gravity of Phobos. Instead, a "clamp-on" railway or "tethered" system might be implemented.
New World, new public-private partnership
To enable easier operations between different nodes and to reduce the number of parts and procedures that need to be developed, the OASIS team proposes to standardize several elements of the spaceport network. To facilitate international cooperation and avoid miscommunication, the metric system of units should be used throughout the design, construction and operation of the network.
By the way, OASIS suggests an innovative model of public-private partnership by the creation of a new governmental authority: the International Spaceports Authority (ISPA) to assemble and operate the spaceports. Also, the Team put interest to the creation of a private transnational company - Spaceport Company (SPC), with ISPA member states as shareholders.
The proposed model allows a public entity to plan, facilitate, and regulate the initial construction and spaceport extension when the operators cannot satisfy a large amount of capital demand. The operator, a private entity, operates, develops, and provides services to customers. The model combines creation of vital connections between public and private parties and generates considerable profits, high booster for employment and tax income for member parties.
The International Space Exploration Coordination Group (ISECG), comprised of fourteen space agencies interested in peaceful exploration, created a Global Exploration Strategy that provides OASIS with an excellent opportunity to promote its vision under the framework of international cooperation and public-private partnership. According to the ISECG Global Exploration Roadmap (GER), the goal in human exploration of the Solar System is Mars.
This article is a summary of the Original Report of: ESTABLISHMENT OF A SPACEPORT NETWORK ARCHITECTURE by Prof. Wiley J. Larson of Stevens Institute of Technology, United States of America (USA), firstname.lastname@example.org And by Mr. Tracy R. Gill", Mr. Robert P. Muellert, Mr. JeffreyS. Brinkt (Kennedy Space Center, NASA)
This report was presented at the 63'd International Astronautical Congress, Naples, Italy. Copyright © 2012 by Prof. Wiley Larson. Published by the IAF, with permission and released to the IAF to publish in all forms. Learn More.
WHAT IS IN SITU RESOURCE UTILIZATION (ISRU)?
ISRU involves any hardware or operation that harnesses and utilizes ‘in-situ’ resources to create products and services for robotic and human exploration.
(1) Resource Assessment (Prospecting)/Assessment and mapping of physical, mineral, chemical, and volatile/water resources, terrain, geology, and environment.
(2) Resource Acquisition /Extraction, excavation, transfer, and preparation/ beneficiation before Processing.
(3) Resource Processing- Consumable Production /Processing resources into products with immediate use or as feedstock for construction and/or manufacturing Propellants, life support gases, fuel cell reactants, etc.
(4) In Situ Manufacturing / Production of replacement parts, complex products, machines, and integrated systems from feedstock derived from one or more processed resources.
(5) In Situ Construction /Civil engineering, infrastructure emplacement and structure construction using materials produced from in situ resources Radiation shields, landing pads, roads, berms, habitats, etc.
(6) In Situ Energy /Generation and storage of electrical, thermal, and chemical energy with in situ derived materials Solar arrays, thermal storage and energy, chemical batteries, etc.
CAN WE TRANSFORM ASTEROID INTO SPACECRAFT?
The space environment will be leveraged in the production of equipment that can only be produced in space. Micro-gravity, and partial artificial gravity, will be used to precisely control the manufacturing of products made from exotic materials. Then, that will become a useful place to produce physical goods, to enable future jobs, and to expand our global economy.
RAMA will solve the problem of transporting large supplies of asteroid resources from their natural orbits to orbits of greater use in cis-lunar space.
Made In Space propose the RAMA architecture, which turns asteroids into self-sufficient spacecraft capable of moving themselves back to cis-lunar space. The architecture is capable of transporting conventional sized asteroids on the 10m length scale as a 100 m or larger.
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