About Sustaining Supply Technology for Manned Spacecraft E-Book

Christian Zschoch

• Herausgeber: Books on Demand
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 235

Veröffentlichungsjahr: 2020

Beschreibung

At the present time, space travel is characterized by separately developed technologies of the space-traveling nations. Depending on fixed financial budgets and expensive technology companies, the developed spaceships are strongly designed just for a specific mission profile in order to reduce costs and risks as far as possible. Because of their less sustainable supply concept, these spacecraft allow only a limited mission duration and require regular supply deliveries in addition. On the other hand side, mission periods continue to lengthen with the planned exploration of Mars, asteroids or other objects that are even more distant. These missions will require high sustainable supply concepts in order to enable autonomous and long-term life support of human mission participants. The now existing solutions do not yet meet these requirements, so the current approach of spacecraft design had to undergo a conceptual review. The research made in the context of this work led to the design of a new generation of spacecraft, which supports with its optimized hull construction such extended long-term missions in terms of durability, variability and life support. All its embedded biological and chemical processes have, on the one hand, the primary aim to enable humans a long stay in space and, on the other hand, to be independent of an external mission supply. The performed research activities also included the necessary mechanical and energetical functions for which an extreme lifetime extension of up to 60 years was aimed.

Leseprobe

Declaration of Authorship

I hereby declare that the thesis submitted

"About Sustaining Supply Technology for Manned Spacecraft"

is my own unaided work. All direct or indirect sources used are acknowledged as references.

I am aware that the thesis in digital form can be examined for the use of unauthorized aid and in order to determine whether the thesis as a whole or parts incorporated in it may be deemed as plagiarism. For the comparison of my work with existing sources I agree that it shall be entered in a database where it shall also remain after examination, to enable comparison with future theses submitted. Further rights of reproduction and usage, however, are not granted here.

Neufahrn, January 10th 2020

city, date

signature

Abstract

At the present time, space travel is characterized by separately developed technologies of the space-traveling nations. Depending on fixed financial budgets and expensive technology companies, the developed spaceships are strongly designed just for a specific mission profile in order to reduce costs and risks as far as possible. Because of their less sustainable supply concept, these spacecraft allow only a limited mission duration and require regular supply deliveries in addition.

On the other hand side, mission periods continue to lengthen with the planned exploration of Mars, asteroids or other objects that are even more distant. These missions will require high sustainable supply concepts in order to enable autonomous and long-term life support of human mission participants. The now existing solutions do not yet meet these requirements, so the current approach of spacecraft design had to undergo a conceptual review.

The research made in the context of this work led to the design of a new generation of spacecraft, which supports with its optimized hull construction such extended long-term missions in terms of durability, variability and life support. All its embedded biological and chemical processes have, on the one hand, the primary aim to enable humans a long stay in space and, on the other hand, to be independent of an external mission supply. The performed research activities also included the necessary mechanical and energetical functions for which an extreme lifetime extension of up to 60 years has been aimed.

In comparison with the already existing designs for large-scale space stations or spacecraft having a low integration of sustainable support systems, the spaceship concept presented here offers a much higher compactness, a lower mass, and a variety of constructively implemented life support functions. The properties of this advantageous spaceship design can also be used stationary on planets, moons or asteroids, if a certain degree of gravity is available after landing.

The scaling of the described spacecraft and its contained systems is in general adjusted to supply one single person. But, however, the therefore required minimum turnovers for plant biomass, drinking water, and nitrogen would also already cover the needs of a second person. Only the preparation of breathing air needs to be enlarged, for which purpose an external source of electrical energy can be added. In order to realize even higher capable spacecraft of this type, the dimensions of the components described can be further increased, which will extend the life support to a higher number of travelers.

Zusammenfassung

In der heutigen Zeit sind Weltraumreisen durch die einzeln entwickelten Technologien der raumfahrenden Nationen geprägt. Gebunden an begrenzte finanzielle Budgets und teure Technologieunternehmen werden die derzeit entwickelten Raumschiffe stark an ein vorgegebenes Missionsprofil gebunden, um die entstehenden Kosten und Risiken weitestgehend zu reduzieren. So erlauben diese Raumflugkörper auf Grund ihrer wenig nachhaltigen Versorgungskonzepte lediglich befristete Missionszeiträume und erfordern zudem regelmäßige Versorgungslieferungen.

Jedoch vergrößern sich die Missionszeiträume mit der geplanten Erforschung von Mars, Asteroiden oder ferneren Objekten stetig, weshalb nachhaltigere Versorgungskonzepte benötigt werden, die eine autarke und langfristige Versorgung von menschlichen Reisenden ermöglichen. Die derzeitigen Lösungen genügen diesem Anspruch nicht, weshalb das aktuelle Raumschiffdesign einer konzeptionellen Überarbeitung bedurfte.

Die im Rahmen dieser Arbeit erfolgten Forschungen führten zum Entwurf einer neuen Raumfahrzeuggeneration, welche mit ihrer optimierten Hüllenkonstruktion solch ausgedehnte Langzeitmissionen in Bezug auf Haltbarkeit, Variabilität und Lebenserhaltung vielfach unterstützt. Alle darin integrierten biologischen und chemischen Prozesse haben das primäre Ziel, dem Menschen einerseits eine lange Aufenthaltsdauer im Weltraum zu ermöglichen und dabei andererseits unabhängig von einer externen Missionsversorgung zu sein. Die ausgeführte Arbeit umfasst auch die hierzu erforderlichen mechanischen und energetischen Funktionen, für welche eine extreme Verlängerung der Betriebsdauer auf bis zu 60 Jahre angestrebt wurde.

Im Vergleich zu den vorhandenen Entwürfen für groß dimensionierte Raumstationen oder Raumflugkörpern mit einer wenig nachhaltigen Systemintegration, bietet das hier vorgestellte Raumschiffkonzept eine höhere Kompaktheit, eine geringere Masse sowie eine vielfach konstruktiv unterstützte Lebenserhaltung. Die vorteilhaften Eigenschaften dieses Raumschiffdesigns sind auch stationär auf Planeten, Monden oder Asteroiden nutzbar, sofern nach der Landung ein gewisser Grad an Gravitation zur Verfügung steht.

Die Skalierung des hier beschriebenen Raumflugkörpers und seiner Einzelsysteme wurde auf die Versorgung einer einzelnen Person abgestimmt. Alle dazu erforderlichen Mindeststoffumsätze zur Nahrungs- und Trinkwasserversorgung sowie des Stickstoffkreislaufes decken jedoch auch bereits den Bedarf einer zweiten Person. Dazu muss für die Atemluftaufbereitung einzig eine externe elektrische Energiequelle ergänzt werden. Zur Realisierung noch leistungsfähigerer Raumflugkörper dieser Bauart kann die Dimensionierung der beschriebenen Komponenten weiter vergrößert werden, um die Versorgung auf weitere Reisende zu erweitern.

Contents

List of Figures

List of Tables

List of Abbreviations

Introduction

1.

Microbiology as a Driver for an Organically Integrated Spaceship Concept

2.

Outer and Inner Structure of a Self-Sufficient Spacecraft

2.1 A basic Hull Design of a Gravity Supporting Spacecraft

2.2 Inner Spaceship Structures for Functional Purposes

2.3 Hull Wall Construction

2.3.1 Thermal Hull Compensation Flow

2.3.2 Inner Spaceship Walls and Floors

2.3.3 Planking Materials and Weight of the Spaceship Hull

2.3.4 Implementation of Hull Leadthroughs

2.3.5 Meteorite Protection Fabric

2.3.6 Thermal Hull Insulation

2.3.7 Radiation Protection Measures

2.3.8 Qualitative Hull Checks

3.

Systems for Life Support

3.1 Plant Species for Space Planting

3.2 Hydroponic Planting

3.3 Nutrient Solution Management

3.4 Nutrient Solution Circulation

3.5 Illumination of the Plantings

3.6 Photosynthetic Respiration Air Regeneration

3.7 Respiration Gas Pressure Changes

3.8 Human Nutrition and Planting Management

3.9 Salt Extraction

3.10 Drinking Water Condensation

3.11 Air Circulation Management

4.

Systems for Energy Supply and Organic Material Processing

4.1 Internal Energy Supply

4.1.1 Bioreactor Units to the Degenerative Fermentation

4.1.2 Biogas Storage Tanks

4.1.3 Methane Gas Reformer Units

4.1.4 Overflow Lifter Pump

4.1.5 Simplified Hydrogen Fuel Cells

4.2 External High Energy Sources

4.2.1 Solar-based Energy Generation

4.2.2 Radioisotope Generator

4.2.3 Cold Fusion Reactor

4.3 External Material Collection

4.3.1 Hydrodynamic Material Lock

4.3.2 Static Charge Generator

4.4 Energy Dispatching Nets

5.

Simplified Apparatuses for Electro Mechanics, Navigation and Spacecraft Propulsion

5.1 Internal Drives, Environment Sensors and Navigation Solutions

5.1.1 Hydromagnetic Bearings, Floating Direct Current Motors and Magnetic Gearwheels

5.1.2 Navigation Projection System

5.1.3 Environment Sensors and Control Instruments

5.1.4 Optical Display Scanning and Rotation Balancing

5.1.5 Antennas and Radio Communication System

5.2 Spaceship Propulsion

5.2.1 Space Engine Suspension

5.2.2 Review of alternative existing Propulsion Solutions

5.2.3 Centrifugal Mass Space Engine

5.3 Personal Living Space

6.

On Board Software

6.1 Electronics Hardware

6.2 Computer Operating System

7.

Conclusions

Acknowledgements

Bibliography

List of Figures

Fig. la: Top view of the outer hull structure

Fig. lb: Side view of the outer hull structure

Fig. lc: Rear view of the outer hull structure

Fig. Id: Single frame profile with size ratio

Fig. 2: Mounting of the landing gear

Fig. 3a: Top view of the inner structure

Fig. 3b: Side view of the inner structure

Fig. 3c: Rear view of the inner structure and the MCB

Fig. 4: Circulation of the thermal compensation flow through a spaceship segment

Fig. 5: Insulation and radiation shielding layers of the spaceship hull

Fig. 6: Pivoting mechanism of the planting racks

Fig. 7: Cross section of a hydroponic planting channel

Fig. 8: Rate of ammonium to nitrate conversion and following denitrification

Fig. 9: Cut view of a nutrient solution transport channel for variable gravity

Fig. 10: Archimedean screw pump for pumping the nutrient solution

Fig. 11: Diagram to the growth rate, light stick distance and illumination intensity

Fig. 12: Influence of the ambient air by the oxygen, carbon dioxide and nitrogen cycle

Fig. 13: Cut view of two water condensers with an underlying bioreactor-fuel-cell-unit.

Fig. 14: Cut view of ventilation unit with floating direct current motor

Fig. 15: Air flows in the concept spaceship

Fig. 16: Arrangement of the bioreactor-fuel-cell-units

Fig. 17: Cut view of a bioreactor

Fig. 18: Cut view of a biogas tank

Fig. 19: Counterflow reformer with inlet funnel for hydrogen production

Fig. 20: Cut view of the overflow lifter pump

Fig. 21: Single cell of a fuel cell block

Fig. 22: Integration of the radioisotope generators

Fig. 23: Principle of the electrostatic nuclear fusion

Fig. 24: Principle of an electrostatic acid fusion

Fig. 25: View of the MCB

Fig. 26: Hydrodynamic material lock

Fig. 27: Cut view of the floating direct current motor

Fig. 28: Circuit of the floating direct current motor

Fig. 29: Cut view of the nutrient solution pump bearing

Fig. 30: Functional scheme of a magnetic gear

Fig. 31: Navigation projections on the CINA

Fig. 32: Arrangement of the navigation room

Fig. 33: Arrangement of the CINA instruments

Fig. 34: Sensor arrangement for movement detection

Fig. 35: Denitrification and balancing tank system

Fig. 36: TABAS/LCP computer simulation

Fig. 37: Transmitting- and receiving antennas at the spaceship front

Fig. 38: Side view of a gravitation pendulum

Fig. 39: Gravitation pendulum endpoints

Fig. 40: Principle of a mass-centrifugal engine

Fig. 41: Screenshot of a CLEO application

Fig. 42: CLEO thinking process

List of Tables

Table la: Material list outer frame

Table lb: Material list inner structure

Table lc: Material list outer planking

Table Id: Material list inner planking

Table 2: Light intensities of the planting lights, depending on the growth height

Table 3: Plant density and biomass portions

Table 4: Oxygen and carbon dioxide balance

Table 6: Daily nutrient supply of a space traveler

Table 7: Thermal energy balance

Table 8: Internal electrical energy balance

Table 9a: Sensors and controls for flight operations

Table 9b: Sensors and controls for the environment

Table 9c: Sensors and controls of the power supply

Table 10: Sensor detection of celestial objects

Table 11: Composition of the spaceship mass

Table 12: Energy demands of the CLEO system

Table 13a: Threshold variables of the CLEO kernel

Table 13b: Example parameter of a logic word

Table 13c: Logic connections of single logic table entries

List of Abbreviations

General abbreviations:

LiDis n

Living Disk

Spaceship class, specifying the maximum number of supported persons

LED

Light Emitting Diode

LCD

Liquid Crystal Display

ARM

Advanced RISC Machines

Spaceship components:

OHS

Outer Hull Structure

CT

Central Tunnel

LT

Lengthwise Tunnel

MCB

Material Collection Bay

NAV

Navigation Room

BFT 1-2

Biological Fermentation Tanks

GAT 1-2

Biogas Tanks

CWT 1-4

Clean Water Tanks

DBT 1-4

Denitrification and Balancing Tanks

PU 1-4

Propulsion Units

OS 1-8

Outer Segments

Outer spaceship segments in clockwise order, starting with the first segment it front direction

IS 1-8

Inner Segments

Inner spaceship segments in clockwise order, starting with the first segment in front direction

Spaceship circuits:

HTC

Hull Temperature Circulation

ISA

Inner System of Air Circulation

PS 1-4

Propulsion Steam 1-4

IBE

Internal Biological Energy

RBE

Radioactive Decay Based Energy

FBE

Fusion Based Energy

Functional units:

CINA

Central Installation for Navigation and Automated Processes

CLEO

Computers Local Environment Operator

TABAS

Tank Balancing Adjustment System

LCP

Light Controlled Propulsion

GSC

Generator for Static Charge

MRU 1-2

Methane Reformer Units

SFC 1-2

Submerged Fuel Cells

WCU 1-4

Water Condensing Units

NSPU

Nutrient Solution Pump Unit

DCM 1-2

Floating Direct Current Motor

HCF

Hull Circulation Fan

ICF

Inner Air Circulation Fan

Introduction

Space flight raises a great fascination on us humans since its origin. And even in the days before, futurologists and scientists of many countries were planning and describing journeys to far distant planets, asteroids, or solar systems. At all these times, such thoughts were influenced by the available technical possibilities, whereby all developed exploration plans had to be rejected soon or later.

Only today, for the first time in history, the available technologies are so advanced that enlarged space travels seem to be possible. Having now this technical opportunities, mission objectives like a manned permanent lunar base, asteroid visits, or a flight to Mars are coming more and more into the reach of mankind. These upcoming long space flights will require various innovative and sustainable spacecraft system solutions for a large number of supply issues, which then have to be integrated into a universal spaceship design. All these individual solutions must be properly dimensioned and be balanced to each other, so that – depending on the mission duration, the mission target, and the number of space travelers – closed material and energy cycles are created. Moreover, require such manned long-term missions a higher consideration of human kind of living and the physiological needs of all embedded organisms to survive such journeys as healthy as possible.

Due to the lack of super-fast space engines, whose technology is unlikely to become real in the foreseeable future, the idea of generation ships, as they were conceived by the physicist John Desmond Bernal in the 1920s, are probably the most technically plausible method to make a journey to destinations outside our solar system (Bernal et al. 1929). Bernal's vision of a multi-hundred-meter-long, rotating spaceship cylinder, which could be used as a permanent home for tens of thousands of people, embodies already the basic idea of the integration of sustainable life support components into a permanently used spacecraft.

The design concept presented here, also takes up this approach and combines many miniaturized and simplified spaceship components, making the spacecraft based on it smaller and – with a reduced crew – also cheaper to build and maintenance.

During the development of this design concept, varied research activities have been executed since 2007, out of which the results are summarized in this document. The experiments for building up a data basis to the different topics of spaceship design, support the made assumptions with verifiable results and thus could be used for a detailed simulation of the individual systems. As a result out of this experimental design phase, also already existing solutions of current spaceflight have been discarded, or more suitable alternative solutions have been found for them.

Even only the number of topics considered for this work is both overwhelming and intriguing. From bio-chemical and physical processes, to the cultivation and degeneration of plants, from optical lens systems to the programming of processor cores, the palette reaches. In order to keep an overview of all activities and to structure the development work, the different design topics have been divided into diverse sub-projects. Their related detail documentation was recorded in a structured form and was generally made available via an internet homepage.

These results can be viewed on the website WWW.PROJEKT-SPACESHIP.DE.

The design of the concept spaceship described in this document is protected by copyright laws with all its individual developed components. In order to grant a permission for a commercial use, please ask the author directly or use the related form of the project homepage.

1 Microbiology as a Driver for an Organically Integrated Spaceship Concept

If a permanent supply for space travelers has to be implemented into a completely closed spaceship environment, the holistic consideration of all organic interactions within the surrounding ecological system has to be discovered first. This concerns the microbiological processes of food growing and processing as well as the respiratory influence on the oxygen and carbon dioxide content in the air.

The life support systems on board a long-term used spaceship must support all possible human material cycles in order to prevent a shortage of life essential raw materials. The main material cycle begins with the decomposition of excreta and waste in bioreactors, which disintegrates the introduced substrate via anaerobic digestion and produces a usable amount of methane gas at the same time. Analogous to the natural recycling processes, the remaining and liquefied residues can subsequently serve for the nitrification of a circulating nutrient fluid, which can be used for a hydroponic plant cultivation. While the so inserted plants are growing, they continuously regulate the levels of carbon dioxide CO2 and oxygen O2 in the respiration air, but they also have their own demands on their environment, which is why additional components for energy, lighting, ventilation, and heating are required. And last but not least, it is moreover important to involve a person, who continuously drives all these processes and supports them with their microbiological material processing.

If the biological process chains are not completely integrated into a sustained life support system, and if one of the material cycles ends at a certain point, the system will automatically reach a shortage situation after a limited system runtime, since required basic substances cannot be provided to the following processes at this place. And because most of these processes are based on microorganisms, the failure or absence of even one single integrated life form can cause an artificially material balance to tip over.

An example of such a balance disturbance is known from the Biosphere 2 project, which was used to study a capsuled closed ecosystem and was in 1994 successful in a hermetically sealed operation for a period of six months. Some months before, a first long-term trial failed during the years 1991 to 1993, as the concrete walls in the system performed an unexpected assimilation of oxygen, which made the experiment dependent on an external oxygen supply. Irrespective of this, the project impressively showed how a large number of organisms could take over the full supply of eight persons, which was very close to the ideal picture of a closed material loop (Nelson et al. 1994).

In contrast to this, there are also examples that argue against excessive incorporation of life forms into a life support system. Because if an organism does not find ideal living conditions in a closed environment, evolutionary and unpredictable changes in the metabolism of these life forms will modify their behavior. A well-known example is thereto the uncontrolled colonization of the Mir space station with mutated microorganisms that had the ability to corrode aluminum and plastics of the station construction (Novikova 2004). In such a situation, not only the physical health of the astronauts is in danger by the excessive exposure to microbe-enriched air, it is also very difficult to keep the spacecraft structurally intact, as it was realized in the case of the Mir space station after only 15 years of use.

Because the material research provides only partially corrosion-resistant materials for such a case, material thicknesses with sufficient reserves have to be planned for a spaceship construction in order to allow a maximum mission duration that corresponds to four times the service life of the Mir space station. In addition to this, can electrical and electromechanical systems be encapsulated in plastics or integrated in a simplified version, so that massive electrical insulations and circuit-short proof distances between electrical conductors are ensured. With the usage of such resistant solutions, as they are mostly described below, the operation of the foreseen spacecraft systems can be permanently ensured even in a microbiological high active environment.

As a conclusion of the microorganismic analysis, it can be also stated that in the design of a sustainable life support system in general a variety of specific microorganisms is required to manage all metabolic processes, but only the absolutely necessary organisms should be considered for this, which have a controllable growth rate and will remain in their defined biological habitat. This reduction of biodiversity – together with the corresponding reduction of necessary habitat types – enables the radical simplification of the Biosphere 2 approach: a noticeable reduction of volume and weight for a sustainable life support system, since a large-scale solution would be far away from the claim of this work to design a compact, self-sufficient spacecraft.

2 Outer and Inner Structure of a Self-Sufficient Spacecraft

The requirement for an ideally compact and lightweight spaceship construction was at all times challenged during its design process by the demands of its passengers, who were the largest living organisms to be considered. Therefore, with the design of the here introduced spaceship hull the basic requirements were created for

the use of an existing gravity as well as the generation of an artificial gravity,

sufficient space to implement a planting and life support system,

the optional installation of an airlock,

an optimal positioning of the navigation- and communication systems, as well as for

a multi-layered spaceship hull structure supporting a temperature management in case of one-sided solar heat exposures, general thermal insulation, radiation protection and prevention from meteorite impacts.

2.1 A basic Hull Design of a Gravity Supporting Spacecraft

In its main function, the outer hull structure (OHS) provides a solid construction for the integration of all components and attachments. The basis for this will be a support structure made of aluminum profiles, which run along all spaceship edges. The degree of hardness and the material thickness of the implemented beams should be chosen so that the construction is as lightweight and flexible as possible. For the design concept, a square frame profile with a cross section measurement of 10 x 10 centimeter and a material thickness of three millimeters has been assumed. The connection of the profiles will be carried out by welding whereby an optimal frame strength is reached.

In order to create an optimized spaceship body for human usage, specific minimum sizes and a special design are advantageous. The basic shape is formed by a circle that can be easily constructed out of curved frame components. Along its circumference, this shape has the properties of a gyro, which are very advantageous for the later operation. On Earth or in a generally landed state, the round circle disk serves as a walking floor. Out of this flat surface, a disk-shaped body has been constructed by putting two of those surfaces in parallel to each other and connecting them with 16 vertical struts along their outer circumference. Thereby, the distance between the two circle surfaces is ideally 2.3 meters, which allows for humans an upright walking. The vertical, outer struts are placed in a constant distance to each other and are made by an alternate use of solid 10 x 10 centimeter profiles and 5 x 10 centimeter double-T profiles with central openings. The combination of these profiles saves on the one hand weight, but it also allows a controlled thermal circulation through the inserted openings within the outer hull.

During a flight in space – without the influence of an external gravity – the disk-shaped design now has a decisive advantage: a spaceship of this type can be rotated around its vertical center axis without changing any hull configuration, creating a centrifugal force along its circular side surfaces. By providing this force, this simple spaceship design provides a very easy way to generate an artificial gravity that allows an upright movement for humans on the inner side surfaces.

The diameter of the OHS disk should be dimensioned so that a human upright walking is also possible during a rotation phase of the spaceship. Further, the circular side surfaces should be as far away from the center of rotation as possible so that the required rotation speed can be lower. If we assume an internal rotated corridor height of 2.60 meters, the spaceship would only have a diameter of just over five meters. In order to increase the distance between the outer surfaces and the rotation center in addition, a second circular inner corridor was added to the construction, having a radius respectively a rotating corridor height of 2.07 meters. Out of this results that the rotating spaceship consequently provides an outer and inner circular walking floor. If the thickness of the required insulation, which requires in average 25 centimeters at all sides, is considered as well, the spaceship diameter of the outer hull structure will reach a total of 9.81 meters.

In order to generate an artificial gravity of 80 percent of the Earth's gravity along the outer circumference surface, a centrifugal force corresponding with 80 percent of the gravitational acceleration is needed. Measured by a kilogram of mass, this will mean a weight force of 7.848 Newton. The formula of centrifugal force is first resolved according to the required circumference velocity v and then calculated with the given Earth acceleration and spaceship radius:

With this value, the needed number of revolutions then can be determined by dividing the spaceship circumference with it and by converting the result into revolutions per minute.

Thus, to provide the intended artificial gravity along the outer hull surface, twelve revolutions per minute are required.

Due to stability reasons, the upper and lower deck surface of the spaceship disk cannot be realized as flat structure, because the inner air pressure pushes very strongly against these surfaces, and the hull material can therefore easily be overloaded. The hereto chosen solution is the usage of domed deck surfaces, which – similar to the ends of a cylindrical gas tank – absorb the forces of the internal pressure evenly. To construct the deck surfaces the spaceship rotation axis was elongated at both ends by 50 centimeters and was connected with 16 curved horizontal struts to the ends of the 16 vertical struts of the circumference surface. Analogous to the changing strut profile of the outer side wall, also this deck structure has been implemented at every second strut with the use of an opened double-T profile, while all other struts consist of the 10 x 10 centimeter profile.

In order to reduce the air resistance during atmospheric flights, but also to provide additional space for the required communication antennas, a front-pyramid made of further frame profiles was added to one side of the spaceship body, which extends over a range of four vertical side wall struts. The top of this pyramid is located two meters above the regular outer wall surface in a centered position. Its four pyramid edges are also made of 10 x 10 centimeter frame-profiles, while all inner struts are made of flat material, which creates less interference with the radio signals of the communication antennas underneath.

Starting from the spaceship front-pyramid the spaceship disk is divided into eight segments, which are – viewed from above – clockwise numbered in ascending order. Each segment is thereby defined by the space between two 10 x 10 centimeter outer frames and extends consequently over two vertical outer struts.

After this numbering, the segments can be assigned to the following functions: the segment 1, pointing to the spaceship front, is a residential and control segment. The two right and left adjoining segments 2 and 8 are planting segments, for which each the attachment an external engine gondola has been foreseen. These segments are followed by the two middle segments 3 and 7 – both pure planting segments – and the segments 4 and 6, which were again designed as combined planting and engine gondola segments. The rear segment 5 will be used as a connection segment for different tasks.

Fig. la: Top view of the outer hull structure

Fig. lb: Side view of the outer hull structure

Fig. lc: Rear view of the outer hull structure

Fig. Id: Single frame profile with size ratio