Title: Grundlagen der Biosphrenforschung
1Fundamentals of Biospherics
Fundamentals of Biospherics
Biosphere1 Ecological Aspects Moon-Paramter
This analysis describes the fundamentals of the
very young discipline "Biospherics" and the
characteristic environmental conditions on the
moon. Following the Apollo13-mission is
described. This mission showed the need of an
exact knowledge of the ecological environmental
parameters within space-projects.
The vision of the biospherical research is to
create a closed bioregenerative system which is
meant to be as lasting as biosphere1 the earth.
One can see by means of the term lasting that
even our planet earth is dependant on the solar
stability, which will get out of ist life
supporting balance within the next billions of
years. The name for this new discipline,
BIOSPHERICS, was first discussed at the First
International Conference on Closed Life Systems
in London in 1987. A resolution from the Second
International Conference on Closed Life Systems
in 1989 in Krasnoyarsk, Siberia, defined the
goals of this new discipline
1. Biospherics
Fundamentals of Biospherics INTRODUCTION
To crate working models of the Earths biospere
and ist ecosystems and thus to understand better
the regularities and laws that control ist life.
To create biospheres for human life support
beyond the limits of the Earths biosphere. To
create ground-based life support systems that
provide a high quality of life under the extreme
conditions of the Earths biosphere, as at polar
latitudes, deserts, mountains, and underwater.
To use closed ecological systems to develop
technologies for the solution of pollution
problems in urban areas and for developing high
yield sustainable agriculture.1
Mähring Michael 9231282
1) Peter Eckart in Spaceflight Life Support
Biospherics"
2Fundamentals of Biospherics
The life support systems so far used in manned
spaceflight are mechanically controlled storage
systems. For the most part, vital necessities
such as oxygen and food are produced on Earth and
stored onboard, not regenerated as they are here
on Earth. Likewise, waste products such as carbon
dioxide and urine are chemically stored, not
recycled. In contrast, Earth is bioregenerative,
i.e., plants, animals and especiallly
microorganisms regenerate, recycle, and control
lifes necessities. (...)
Biospherics and spaceflight research
Fundamentals of Biospherics BIOSPHERICS AND
SPACEFLIGHT RESEARCH
Since so far all attemts to build a large
bioregenerative life support system that would
support a large number of people in space,
without supply of umbilical cord to Earth, have
failed, the stay of man in space is still limited
by the amount of life supporting consumables that
can be carried onboard. Human presence on Moon or
Mars will be characterized by long mission
duration and by very limited chances of ressupply
from Earth. This leeds to the need for a high
degree of self-suffiency which cannot be achieved
by techniques presently applied in the life
support subsystems of the currnt manned projects.
Future life support in space will involve the
progressive integration of biology based
components into life support systems, gradualy
replacing physico-chemical, i.e., first
generation subsystems, leading to a scenario of
fully closed, so called Controlled Ecological
Life Support Systems (CELLS). The development of
CELLS technology is a complex and long-term
activity. Due to this complexity, theoretical
predictions for the evolution of such closed
ecological systems are very diffcult and need to
be supported and corrected by experiments and
observations both on ground and in space. To
date, at least on the ground, many experiments to
study those systems have been set up, e.g.,
BIOS-1 to 3 and Biosphere2, to mention only the
biggest and most prominent ones."1
Mähring Michael 9231282
In this point two sciences which wouldnt be
associated on the first look merge ecology and
space research. Space research enlarges the
classical concept of ecology (Ernst Haeckel,
1866), which refers to the interaction of waters,
landscape and atmosphere because of the
integration of space.
1) Peter Eckart in Spaceflight Life Support
Biospherics"
3Fundamentals of Biospherics
Two billion years ago the first tiny
microorganisms that appeared on Earth had to
survive in an environment with no oxygen, lethal
ultroviolet radiation, poisonous gases, and
extreme temperature variation, i.e., conditions
that would be lethal to much of todays life.
Over millions of years, organisms interacted with
geological chemical processes gradually changed
the environment by putting oxygen into the
atmosphere and forming a green mantle surface of
Earth, where sunlight could be converted into all
kinds of life supporting consumables. The
microaarganisms which survive without oxygen but
produce it are called anaerobs. By creating the
atmosphere they set up one fundamental of Earths
life support system. James Lovelock wrote in his
Gaia Hypothesis The biosphere is a
self-regulating entity with the capacity to keep
our planet healthy by controlling the physical
and chemical environment.6 In fact Biosphere1
provides all consumables that we need for living.
Man is able to breathe, drink, and eat in
comfort, because millions of organisms and
hundreds of processes are operating in a
coordinated manner out there in the environment.
Its remarkable that all this comfort is for
free. Life support is a vast, diffuse network
of processes operating on different time scales.
Unfortunately, there is a tendency to take
natures services for granted because no money
has to be paid for them.2 The science of
ecology deals with this system which may be
analyized and also ist life supporting processes
mabe identified. To do this one must think about
the environment as a whole and partition the
landscape into functional units in some
systematic manner. A) Natural areas operate
without energetic or economic flows directly
controlled by humans. Theses are basic
solar-powered sources dependent on sunlight and
other natural forces that are indirect forms of
solar energy, e.g., wind and rainfall. B) The
domestic environment includes agricultural lands,
managed woodlands and forests, and artificial
ponds and lakes. This part of the landscape is
made up of what ecologists call subsidized
solar-powered systems. The Sun provides the basic
energy, but the source is augmented by human
controlled work energy in form of human labour,
machines, fertilliers, etc.. c) The developed
environment includes cities, industrial parks,
and transportaion corridors. From the standpoint
of energy use the fabricated environment is
comprising fuel-powered systems. 2 The three
main-components which provide life on Earth are
atmosphere (air), hydrosphere (water), pedosphere
(soil). The pedosphere is the result of the
physical scenting and organic activities (plants,
microorganisms) .
2. Fundamentals of Ecology Biosphere1
Fundamentals of Biospherics ECOLOGICAL
PARAMETERS BIOSPHERE1
James Lovelocks Gaia Hypothesis
methods
Mähring Michael 9231282
1) James Lovelock in The Ages of Gaia" 2)
Eckart Peter in Spaceflight Life Support
Biospherics"
4Fundamentals of Biospherics
To summarize the single components and their
interactions according to their characteristics,
the term Life Support Systems is beeing used.
It means production of food, recycling of water,
cleaning of air, recycling of waste, etc..
Earths life support system has the ability to
suspend disturbances such as storms, fire, phases
of pollution, loss of yields or vulcan
activities, because the organisms ond the
ecological processes are able to adjust to it
elestically.
life support systems
For a better understanding of the complex
ecological world at ground level, it is helpful
to think in terms of levels of organizational
hierarchies. A hierarchy is defined as an
arrangement into a graded series of compartments.
The levels of ecological hierarchiy are A)
Biosphere B) Biogeographic Region C)
Biome D) Landscape E) Ecosystem F)
Biotic Community G) Population (species) H)
Organism Processes at lower levels are often
constrained in some way by those at higher
levels. Accordingly, sudy or management of any
one level is never complete until relevant
aspects of adjacent levels are also studied or
managed. An important consequence of the
hierarchical organization is that as components
are combined to produce larger functional wholes,
new properties emerge that were not present or
evident at the level below. (...) Ecology is a
discipline that emphasizes a study of both, parts
and wholes. While the concept of the whole beeing
greater than the sum of the parts is widely
recognized, it tends to be overlooked by modern
science and technology, which emphasize the
detailed study of smaller and smaller units.1
2.1. Levels of Ecological Hierarchy
Fundamentals of Biospherics THE ECOLOGICAL
HIERARCHY
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
5Fundamentals of Biospherics
In order to describe something as complex as an
ecological system one has to begin by defining
simlified versions of the real world, I.e.,
models, which encompass anly the more important
or basic properties or functions. Such complex
ecosystems as Biosphere2 are too complicated to
get scientific results. In en ecosystem model
one distinguishes the following components
Tab. 2.1
Fundamentals of Biospherics ECOSYSTEM MODELS
The symbols which are used for the description of
an ecological model are taken from H.T. Odums
Energy Language
Mähring Michael 9231282
pic. 2.1 Energy Language
6Fundamentals of Biospherics
If you put the components together, a basic
result is shown in the following figure
pic. 2.2 Main Components of an Ecological System
Fundamentals of Biospherics ECOSYSTEM MODELS
Shown are two properties P1 and P2 which
interact at I to produce or affect a third
property P3 when the system is driven by the
forcing function E. Five flow pathways are shown,
with F1 representing the input and F6 the output
for the system as whole. Also shown is a feedback
loop, sgnifying that a downstream output, or some
part of it, is fed back, i.e., recycled, to
affect or control an upstream component or
process. To use and experiment with models for
any thearetical or practical purpose, the chart
models must be converted to mathematical models
by quantifying properties and drawing up
equations for flows and their interactions.7
Like all kinds and levels of biological systems,
ecosystems are open systems, that means things
are constantly entering and leaving, even though
the general appearence and basic functions may
remain constant for long periods of time.
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
7Fundamentals of Biospherics
There are two major biotic components. First is
an autotrophic, i.e., self-nourishing component.
Autotrophic organisms are capable of
sysnthesizing the organic compounds which they
contain from inorganic sompounds, e.g., water,
carbon dioxide, nitrites. Based on the source of
energy used for organic synthesis, they may be
divided into phototrohic, using electromagnetic
emission in the visible spectral region, and
chemotrophic, which receive energy as a result of
oxidation of different substances, e.g., iron,
sulfur, hydrogen, nitrates. The second major
unit is the heterotrophics, i.e.,
other-nourishing, component, which utilizes,
rearranges, and decomposes the complex materials
synthisized by the autotrophs. Fungi,
non-photosynthetic bacteria and other
microorganisms, and animals, including humans,
sontitute the heterotrophs, which concentrate
their activities in and around the brown belt
of soil and sedimetn below the green canopy.
Cities are also heterotrophic Systems. Natures
capacity to support the ever more expanding and
demanding cities is beeing stretched to the limit
in many places. Thus, recycling water and wastes,
growing food on rooftops, and using solar energy
directly to heat buildings and produce elecricity
are some of the things that need to be done on a
larger scale than they are at present. The
terrestrial and aquatic ecosytems are contrasting
types. Land ecosystems and water ecosystems are
populated by different kinds of organisms.
Despite wide differences in species composition,
the same basic ecological components are present
and function in the same manner in both
ecosystems. On land, the predominant autotrophs
are usually rooted plants, ranging sizes from
grasses to large forest trees. In shallow water
situations rooted aquatic plants occur, but in
vast open waters the autotrophs are microscopic
suspended plants called phytoplankton that
include various kinds of algae, green bacteria,
and green protozoa. Because of different sizes in
plants, the biomass of terrestrial systems may be
very different from that of aquatic systems.
Plant biomass may be 10000 or more grams of dry
matter per m² in a forest, in contrast to 5 rams
or less in open waters. Despite this biomass
discrepancy, 5g of phytoplankton are capable of
manufacturing as much food in a given amount of
time as are 10000g of large plants, given the
same input of light energy and nutritients. This
is because the rate of metabolism of smaller
organisms is much greater per unit of weight than
that of large organisms.1
Ecosystems
Fundamentals of Biospherics ECOSYSTEMS
Mähring Michael 9231282
Niche and profession are two interesting terms in
ecology Nature, just like well-ordered human
societies, has its specialists and its
generalists when it comes to niches or
professions. In general, specialists are
efficient in the use of their ressources.
Therefore, they often become abundant when their
ressources are in ample supply. But the
specialist is vulnerable to changes or
perturbations that adversely affect ist narrow
niche. Since the niche of nonspecialized species
tends to be broader, they are more
1) Eckart Peter in Spaceflight Life Support
Biospherics"
8Fundamentals of Biospherics
adaptable to changing or fluctuating
environments, even thogh they are never so
locally abundant as the specialist. We see the
same pattern in agriculture. The best sollution
is diversity of cultivars and crop species, so no
matter what the conditions, there wont be a crop
failure. This is natures plan.1
natures plan
Fundamentals of Biospherics THE LIFE SUPPORT
SYSTEM OF BIOSPHERE1
The few common species in a particular
community are called ecological dominants.
Although domiinants may account for most of the
standing crop and community metabolism, this does
not mean that the rare species are unimportant.
Should conditions become unfavorable for the
dominants, rarer species adapted to or tolerant
of the changes may increase in abundance and take
over vital functions. Whether a high species
diversity increases resistance stability, i.e,
the ability of the ecosystem to remain the same
in face of disturbaces, is a question much
debated by ecologists and most important when
designing a bioregenerative life support system
for spaceflight.7
Something that is absolutely essential and
involved in every action of life on Earth is
energy. The primary energy source of
heterotrophics is food. For autotrophs it is
light and indirect solar enegries, i.e. wind and
rain, required for photosynthesis. In addition,
human societeies require large amounts of
concentrated energy in the form of fuels. The
behaviour of energy is governed by two laws,
known as the laws of thermodynamics. The first
law states that energy may be transformed from
one form, such as light, into anoter type, such
as food, but is never created or destroyed. The
second law states that no process involving an
energy transformation will occur unless there is
a degradation of energy from a concentrated form
such as fuel, into a dispersed form, such as
heat. Organisms and Ecosystems maintain their
highly organized, low-entropy, i.e.,
low-disorder, state by transforming energy from
high to low utility states. Anyway, entropy is
not at all negative. Since the quantity of energy
declines in successive transfers the quality of
the remainder may be greatly enhanced. As
mentioned before, the primary source of all
processes on Earth is the Sun. It emits radiation
energy, i.e., electromagnetic radiation. Solar
radiation is in the middle range of this
spectrum, with wavelenghts largely between 0.1
and 10?m. It consists of visible light and two
invisible components, ultraviolet (UV) and
infrared (IR) light. The visible range is the
energy used in photosyntheses, the UV is lethal
for the protoplasma. The long wave infrared
radiation is the heating part of the sunlight.
Radient energy reaching the surface of Earth on a
clear day is about 10 UV, 45 visible, and 45
IR. Vegetation absorbs the blue and red visible
wavelenghts, which are the most useful for
photosynthesis, and the far IR strongly, the
green less strongly, and the near IR very weakly.
25 of the solar energy is used for recycling
water.
3. The Life Support System of Biosphere1
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
9Fundamentals of Biospherics
fig. 3.1 Solar Energy Flow through the Biological
Food Chain
Fundamentals of Biospherics ECOSYSTEMS
Photosynthesis is the most efficient process
for tapping the small portion of solar radiation
that can be upgraded to hig-utility organic
matter. The basic photosynthetic process is
chemically an oxidation-reduction
reaction 6CO2 6H2OC6H12O2 6H2O One
distinguishes C3- and C4-plants, which depends on
the fixation of carbondiocid. In most plants,
carbondioxid-fixation starts with the formation
of three carbon-compounds, but recently it was
discovered that certain plants reduce
carbondioxid in a different manner, starting with
four corbonxylic acids. C3-plants account for
most of the worlds primary production, like
wheat, rice, potatoes. Crops of tropical origin,
such as corn, sorghum, and sugarcane are
C4-plants.
photosynthesis
Mähring Michael 9231282
10Fundamentals of Biospherics
3.1. Materials Cycles
The more or less circular paths of the chemical
elements passing back and forth between organisms
and environment are called biogeochemical cycles.
In this context, bio refers to living organsims
and geo to rocks, soil, air and the water of the
earth. Like water, the vital nutrient elements,
e.g., carbon, nitrogen, phosphorous, etc., are
not homogenously distributed or present in the
same chemical form throughout the ecosystem.
Rather, materials exist in compartments or pools,
with varying rates of exchange between them.
pic. 3.2. A Biogeochemical Cycle
Fundamentals of Biospherics MATERIALS CYCLES
Biogeochemical Cycles
Mähring Michael 9231282
11Fundamentals of Biospherics
From the standpoint of the biosphere as a
whole, biogeochemical cycles fall into two
groups gaseous types with large reservoir in the
atmosphere, and sedimentary types with a
reservoir in the oils and sediments of Earths
crust.
pic. 3.3. The Major Cycles of Biosphere1
Fundamentals of Biospherics MATERIALS CYCLES
Mähring Michael 9231282
12Fundamentals of Biospherics
It is divided in two phases the upstream phase,
driven by solar energy, and the downstream phase,
which provides goods and services that humans and
the environment require. More water evaporates
from the sea than returns as rainfall, and vice
versa for the land. Thus, a considerable part of
the rainfall that supports land ecosystems and
most human food production comes from water
evaporated from the sea.
3.1.1. The Water Cycle
pic. 3.4. The Hydrological Cycle
Fundamentals of Biospherics MATERIALS CYCLES
The Water Cycle
Mähring Michael 9231282
13Fundamentals of Biospherics
Nitrogen is constantly feeding into and out of
the atmospheric reservoir and the rapidly
recycling pool associated with the organisms.
Both biological and nonbiological mechanisms are
involved in the dentrification, which puts
nitrogen into the air, and nitrogen fixation, the
conversion of gaseous nitrogen, which is not
usable directly by autotrophs, into ammonia,
nitrite, and nitrate, which are usable.
3.1.2. The Nitrogen Cycle
pic. 3.5. The Nitrogen Cycle
Fundamentals of Biospherics MATERIALS CYCLES
The Nitrogen Cycle
Mähring Michael 9231282
14Fundamentals of Biospherics
Carbondioxid is mainly distributed in four major
compartments atmosphere, oceans, terrestrial
biomass, and soils, and fossile fuels. The
atmospheric pool is small in comparison to the
amounts in the other compartments, but it is a
very active pool which is beeing increased by the
burning of fossil fuels and the clearing and
plowing of land for agriculture.
3.1.3. The Carbon Cycle
pic. 3.6. The Carbon Cycle
Fundamentals of Biospherics MATERIALS CYCLES
The Carbon Cycle
Mähring Michael 9231282
15Fundamentals of Biospherics
The phosphorous cycle is an example of a
sedimentary cycle of utmost importance.
Phosphorus is required for the energy-transformati
on that distinguishes living protoplasma from
nonliving material. Organisms have devised any
mechanisms for hoarding this element. Hence, the
concentration of phosphorus in a gram of biomass
is usually many times that in a gram of
surrounding environment.7
3.1.4. The Phosphorous Cycle
pic. 3.7. The Phosphorous Cycle
Fundamentals of Biospherics MATERIALS CYCLES
The Phosphorous Cycle
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
16Fundamentals of Biospherics
The idea that organisms may be controlled by
the weakest link in an ecological chain of
requirements goes back to Justus Liebig. An
extended concept of limiting factors may be
restated as follows The success of an organism,
population or community depends on a complex of
conditions. Any condition that approaches or
exceeds the limit of tolerance for the organism
or group in question may be said to be a limiting
factor.1 Liebigs law is most applicable to
steady-state conditions where inflows balance
outflows, and least applicable under transient
state conditions, where flows are unbalanced and
where rates of function will likely depend on
rapidly changing concentrations and the
interactions of many factors.
3.2. Limiting Factors
Fundamentals of Biospherics MATERIALS CYCLES
Limiting Factors
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
17Fundamentals of Biospherics
Moon is orbiting Earth once in about four
weeks. Since Moons orbital and ratational period
coincide, always the same side of the Moon is
facing the Earth. The mass of the Moon is 7359 x
1022kg, the radius is 1738km, Gravitation
1,62m/s2. Moons surface reflects 0,07 of the
incoming sunlight (albedo). More parameters are
listed in the following table
4. The Moon
Fundamentals of Biospherics THE MOON - Parameters
Tab. 4.1. Moon-Parameter
Mähring Michael 9231282
Theres hardly any atmosphere on the Moon, the
pressure is less than 10-13 bar. This is because
the Moon has not got enough gravity to hold light
atoms such as hydrogen or oxygen. On the
equator, and for all latitudes except very close
to the poles there is a 14-day-night,
14-day-light cycle. On the poles the night takes
about half an Earths year, same with th
pole-day. At the equator the temperature
changes between 80K and 390K during one lunar
day. Below one meter depth, temperature can be
assumed constant over time at about 230K. At high
latitudes, NASA recommends the following
approximation for a given latitude ? T
Täquator cos1/9?
18Fundamentals of Biospherics
The temperature at the poles is basically
unknown, bur guessed to be as low as 40K in some
permanently shaded areas. Lunar soil is
basically composed of oxygen (42), silicone
(21), iron (13), calcium (8), aluminium (7),
and magnesium (6).
Fundamentals of Biospherics THE MOON Physical
Properrties of the Lunar Surface
4.1. Physical Properties of the Lunar Surface
Tab. 4.2. Chemical Composition of Lunar Soil
Mähring Michael 9231282
19Fundamentals of Biospherics
The thermal inertia parameter ? determines the
rate of cooling of the soil, e.g. rocks cool down
faster and heat up faster than regolith. The
thermal conductivity is very low (comparable to
styrofoam). Geologically, one can distinguish
the marae and the terrae (highlands). The marae
are dark, level plains (floor of the basins).
They can be generally found only on the near side
of the Moon. The terrae are lighter and older
than the marae and densely cratered. They cover
all of the far side and parts of the near side.
The soil of both the marae and terrae consists of
well graded sandy silts with average particle
sizes of 0.04 0.13mm.
Fundamentals of Biospherics THE MOON Lunar
Ressources
4.2. Lunar Ressources
Many materials are, at least theoretically,
attainable on the Moon, e.g., water, cements,
glass, and metals. Regolith may be used for
radiation shielding and thermal insulation. A
very promising potential processing method is the
reduction of ilmenite. The two proposed reactions
with hydrogen and methane, respectively, yield
iron, water, carbon dioxide
Hydrogen Reduction FeTiO3 H2 ? Fe TiO2
H2O Carbomethyl Reduction 4FeTiO3 CH4 ? 4Fe
4TiO2 H2O CO2 The water can be split by
electrolysis to yield hydrogen and oxygen.
Extraction concepts are based upon the treatment
of lunar soils, rocks, or their components by
physical, chemical, or electrochemical means. All
those concepts need high amounts of energy for
oxygen release and/or reagent recycling.
Corresponding average power requirements are in
the order of 100 to 1000kW. 1
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
20Fundamentals of Biospherics
Tab. 4.3. Techniques for the Extraction of
Hydrogen, Oxygen and Water from Lunar Soil
Fundamentals of Biospherics THE MOON Lunar
Ressources
Mähring Michael 9231282
21Fundamentals of Biospherics
4.3. Radiation
Fundamentals of Biospherics THE MOON - Radiation
Basically all of the electromagnetic radiation
in the solar system is emitted by the Sun. On the
lunar surface the electromagnetic radiation is
the same as above Earths atmosphere, which means
1390W/m². In general, the solar radiation
density may be written as a function of the
distance from the Sun I I0/r2 r Distance
from the Sun in AU I0 Radiation energy flux at
1AU ... 1390W/m2 The absence of an ozon-layer
is the reason for the high UV-radiation on Moons
surface. Some materials, such as plastic, may be
destroyed.
4.3.1. Electromagnetic Radiation
4.3.2. Ionizing Radiation
pic. 4.4. Radiation in Space
Mähring Michael 9231282
22Fundamentals of Biospherics
There are three different kinds of relevant
ionizing radiation in space Solar Cosmic Rays
(SCR), Galactic Cosmic Rays (GCR) and the Van
Allen-Belts. The Suns radiation may be
subdivided in a regular and an irregular portion.
The regular portion, the solar wind, is a
proton-electron gas that blows away from the Sun
in radial direction. The solar wind exists
because the Suns corona is very hot (2 x 106K),
thus, literally boiling off ist outer
atmosphere. The irregular portion, solar flares,
are produced by storms in the solar
magnetosphere. These eruptions yield very high
radiation doses within very short periods of
time. Solar flares show a correlation with the
11-year solar cycle. The largest events normally
occur in the onths following sonspot maximum. The
total energy released during a flare may range
from 1021 to 1025 Joules integrated over the
three phases of a flare precursor, flash, and
main phase. The occurence of solar flares is
basically not predictable and, thus, the warning
period is only a few minutes to hours.
Fundamentals of Biospherics THE MOON SCR and GCR
solar cosmic rays (SCR)
galactic cosmic rays (GCR)
The galactic cosmic radiation (GCR) is a
permanent radiation that consists of particles
originating from ouside the solar system. Emitted
by distant stars and even more distant galaxies,
GCR diffuses through space and arrives at Earth
and Moon from all directions. The most important
temporal variation in flux is associated with the
11-year solar cycle. During solar maximum, when
the interplanetary magnetic field strength is
greatest, cosmic ray particles are scattered away
from the Earth. This produces a GCR flux minimum.
pic. 4.5. GCR Proton Flux Reduction Factors at
Solar Maximum Conditions
Mähring Michael 9231282
23Fundamentals of Biospherics
Allthough not very numerous, these particles
constitute a deeply penetrating radiation due to
their extremely high energy. Thus, spacecraft
shielding is not very effective in reducing the
variation dose. Fortunately, GCR flux is
comparatively low, wo it does not pose a serious
threat to humans. For example, several particles
have probably passed through your body since you
sarted reading this paper.
Fundamentals of Biospherics THE MOON The Van
Allen-Belts
The Van Allen-Belts
The Van Allen-Belts are doughnut-shaped regions
which surround the Earth. They consist of
energetic particles, i.e., electrons and protons
that were caught by Earths magnetic field. They
are relevant for orbiting space stations.
pic. 4.6. The Van Allen-Belts
Mähring Michael 9231282
24Fundamentals of Biospherics
A direct interaction occurs when a particle is
suddenly stopped by collisions resulting in a
release of energy which may remove electrons from
nearby atoms or molecules, and ions result.
Indirect encounters occur when the high energy
particle, usually an alectron, is deflected by
another charged particle. The deflection causes a
release of energy, i.e., radiation, which also
may produce radiation. The close encounter
process is commonly referred to as
Bremsstrahlung.1 In either interaction, the
effects of the ionizing radiation are
proportional to the amount of energy absorbed by
the surrounding material. To quantify this
absorbed radiation, a unit of measurment called
Gray Gy was defined. To express the effects
of radiation on humans, the dose equivalent H is
used. The SI-unit of H is the Sievert Sv 1Sv
1J/kg 100rem 10000ergs/g
4.4. Radiation Effects
Fundamentals of Biospherics THE MOON Radiation
Effects
Tab. 4.7. Probable Radiation Dose Prompt Effects
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
25Fundamentals of Biospherics
For example A 1Gy dose of 200 keV X-rays
gives a biological equivalent dose of 1 Sv, but a
1 Gy dose from protons givs a biological
equivalent dose of 2 Sv. The large Sv value for
protons accounts for the increased biological
damage. (...) For the characterization of
radiation damage in plants, e.g., gene mutation,
chromosome aberration, or cell lethality, induced
in space, a parameter D, for summarized damage,
has been introduced. It classifies and summarizes
the sensitive biological effects and ist
biophysical approach to the preliminary
estimation of the auality factors of densely
ionizing radiation.1
Example
Fundamentals of Biospherics THE MOON Radiation
Effects
Symptoms
Acute early effects of radiation exposure occur
within a few days or less. They are usually
assaciated with the exposure to a high dose of
radiation over a short period of time. Acute
radiation exposure is indicated by symptoms of
radiation sickness, e.g., nausea, vomiting,
accompanied by discomfort, loss of appetite, and
fatigue. At higher dosages (gt 2Sv) also diarhea,
hemorrhaging, and hair loss may occur after a
latent period of up to two weeks. Delayed, late
effects of radiation exposure occur many years
after prolonged exposure to radiation at a low
dose rate. Delayed effects include cancers of the
lung, breast, digestive system, and leukemia. As
a rough rule of thumb, an astronauts chance of
fatal cancer is increased approximately 2 to 5
for each 0.5Sv exposure during his/her career.
The approximate dose rates on the lunar surface
during a solar minimum are as follows Sonnenwind
0,5 Sv/Jahr GCR 0,2 Sv/Jahr Sonnenflackern
1-50 Sv/Ereignis Radiation can also have
many effects on materials, e.g., gas evolution,
change in mechanical, electrical, and optical
properties, and even complete mechanical
breakdown. Materials dmage depends not only on
radiation dosage and material, but also on the
kind of radiation, rate of application, and load
and temperature of the material.
Mähring Michael 9231282
Materials Damage
1) James Lovelock in The Ages of Gaia"
26Fundamentals of Biospherics
As mentioned earlier, Moon has got no
atmosphere or megnetic field or Van Allen-Belts
ro shield solar cosmic rays (SCR) and galactic
cosmic rays (GCR). Shielding stops or alters
the trajectory of high energy particles before
they encounter the more sensitive human tissue.
Aluminium is used extensively as shielding
material, since it combines both high density and
lightness. Spacecraft ecteriors typically have
several grams per cm² of aluminum shielding. On
the Moon one would use Regolith for passive bulk
shielding. It is not the optimal material, but
since it is achievable on the Moon, it would be
cheaper to use it, than to transport shielding
material from the Earth to the Moon. To get a
similar shielding as an Earth, one would have to
pile up a 5m thick layer of Regolith. Moon
itself serves as a shield because on ist surface
the radiation does not arrive from all directions
like in free space. Obviously, extensive
research on the electrostatic shielding from
cosmic radiation has been conducted.
Unfortunately, no detailled information on these
studies could be obtained. For man, chemical
radioprotection (CRP), like APAETF have been
developed both in the US and the former Soviet
Union. The highly effective APAETF demonstrates a
dose reduction factor of 3. Small doses of this
compound protect against relatively high levels
of radiation. The major criteria for the design
of CRP are that they have to be active taken
internally, they have to be rapidly absorbed and
distributed to the tissues from the
gastrointestinal tract, that they are free of
negative side effects, and effective during
fractioned and prolonged radiation.
4.5. Radiation Protection
Fundamentals of Biospherics THE MOON Radiation
Protection
passive bulk shielding
Electromagnetic Shielding
Chemical Shielding
Mähring Michael 9231282
27Fundamentals of Biospherics
Gravity fields play a very important role in
manned spaceflight. From the beginning of their
existence humans, animals and plants are used to
the effects of gravity on Earth. Thus, the most
dramatic environmental characteristic of
spaceflight is the state of microgravity when
flying in free space or when beeing exposed to
reduced gravity on other planets of the solar
system. This results in extensive physical,
physiological and psychological defects.
5. Gravity and Microgravity
Fundamentals of Biospherics GRAVITATY AND
MICROGRAVITY
5.1. Effects of Lower Gravity
In the state of microgravity, there is a large
number of damages of the human body A
significant shift of intravascular and
extravascular fluids in the human body takes
place in microgravity. This shift is evidenced by
a calf girth decrease (Abnahme des Wadenumfangs)
of nearly 30, head congestion (Blutstau im Kopf)
and associated facial puffiness
(Medikamentengesicht). (...) Past manned
missions have also shown that bone and muscle
atrophy occurs in space crews, which is
proportional to the length of time spent in
microgravity. In general, muscle atrophy precedes
skeletal atrophy with the greatest reduction in
muscle mass occurring during the first month.
Calcium loss (Osteoporosis) begins slowly in the
first week and increases gradually over the next
several months (average rate 0,5 per month
peak rate in some bones 3-5 per month). A loss
of this magnitude is conceivable only for a one-
to two-year period. The overwhelming majority of
calcium loss is from the eight bearing bones.
Unlike other physiologic adaptations, this
calsium loss does not seem to reach a plateau.
Thus, measures have to be taken for long-term
manned missions, like the provision of artificial
gravity.1 It is currently not known, though,
what amount of stress, I.e., gravitational force,
must be maintained to prevent osteoclastic
demineralization of the weight bearing bones.
Finally, microgravity is known to cause an
atrophy of the bone marrow and the immune systeme
leading to the so called space-anemia and a
defect of the T-lymphocytes. The significance of
the possible space-immunosuppression goes beyond
the danger of a simple infection. In particular,
T-lymphocytes also help fight off growing
neoplasms, and a suppression of this system may
hamper the astronauts ability to fight off a
cancer while in orbit. It was discovered,
though that T-cells maintain their normal
functioning level in space by beeing provided to
artificial gravity.
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
28Fundamentals of Biospherics
It might be necessary to introduce artificial
gravity to space stations or even bases on Moon
or Mars. What is called artificial gravity is in
fact a centripetal acceleration produced by
rotation ? ?² x r ? centripetal acceleration
m/s² ? Angular velocity 1/s r Radius m
As indicated in this equation, a specific
increase in artificial gravity level can be
achieved either by increasing the radius or the
angular velocity. This translates a trade-off
between cost and complexity, which depend on r,
vs. Physiological/psychological concerns, which
depend on ?.
5.2. Artificial Gravity
Fundamentals of Biospherics ARTIFICIAL GRAVITY
At a radius of 60m one need 4rounds per minute
(rpm), to achieve 1g. Since centripetal
acceleration is a linear function of the radius,
a linear gravity gradient runs from the center of
the habitat to the outer rim. By far the most
remarkeable effects in a rotating habitat are
caused by the Coriolis force. The Coriolis force
is applied to any object moving linearly with the
velocity v within a rotating sytem and ist
magnitude is
pic. 5.1. Induced Gravity
Mähring Michael 9231282
29Fundamentals of Biospherics
Any object moving in a direction not parallel
to the axis of rotation will, thus, experience
Coriolis force in a way indicated in table 5.2.
The Coriolis acceleration may be defined as Ac
Fc/m
Fundamentals of Biospherics ARTIFICIAL GRAVITY
Coriolis Forces
Tab. 5.2. Directions of Coriolis Force for an
Object Moving in a Rotating Habitat
Movement of a subject within a rotating
environment gives rise to peculiar stimulations
of the bodies sensory systems. Coriolis
cross-coupled angular accelerations occur within
a rotating environment when an angular motion is
made about an axis not parallel to the system
axis of rotation. These cause gyroscopic forces
which produce symptoms of vertigo,
disorientation, or nausea. These symptoms are
referred to as motion sickness. The most complete
simulation of rotating a habitat, yet, was
conducted by North America Rockwell Space
Division which rotated four men for seven days at
a radius of 22m. Concerning maximum angular
velocity sustainable by humans three points of
reference could be established. 1) A speed of
1rpm is not disturbing even to those subjects who
are highly susceptible to vestibular
effects. 2) At a speed of 4rpm some
individuals will be naturally immune to motion
sickness, while others will have motion sickness,
but will adapt after a few days. 3) A speed
of 10rpm will cause Coriolis sickness in most
individuals if the transitionfrom stationary
environment to the 10rpm environment is abrupt.
Subjects can adapt to 10rpm if a schedule of
stepwise increases in angular velocity is
followed.1
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
30Fundamentals of Biospherics
pic. 5.3. The Coriolis Acceleration
Fundamentals of Biospherics ARTIFICIAL GRAVITY
Coriolis Forces
Mähring Michael 9231282
Tab 5.2. ? recommended r/?-relation
31Fundamentals of Biospherics
It is obvious that there are several questions
to be examined if artificial gravity is seriously
considered for future space habitats Which
gravity levels and gravity gradients will be
required or acceptable for any biological
system? What are the physiological limits to
radius and angular velocity, i.e., Coriolis
effects? What are the engineering/cost limits to
radius and angular velocity? Will all engineering
systems still function properly under these
conditions? What countermeasures will be
necessary?
Questions
Fundamentals of Biospherics PRESSURIZED SHELLS
Because of the vacuum conditions in free space
it is necessary to provide pressurized shells in
order to house equipment, materials and, of
course, man. The design of such a pressurized
shell should be fail-safe. In particular, a hole
should not lead to complete disintegration of the
cabin (station), since man can survive for only
about 15 seconds after an explosive decompression
in space. Another important aspect is the leakage
of any pressurized spacecraft or space station in
the free space vacuum. Like any pressure vessel
it loses gas by several processes, e.g., through
diffusion through the walls, leaks through seals,
operation of air locks, and holes. It is
important to note that, in general, the loss rate
is proportional to internal pressure, which
should be, hence, as low as possible from that
point of view. The fact of any gas leakage leads
to the necessity of gas resupply, even in futere
regenerative life support systems. Of course,
this resupply has to be taken into account in
mass calculations.1
6. Pressurized Shells
Mähring Michael 9231282
1) H. O. Ruppe in Introductions to astronautics
Vol III"
32Fundamentals of Biospherics
Theres different concepts for building a lunar
base, which depend on the task of the mission. It
seems to be predictable that there will be an
increasing process of building up a lunar base.
The single steps will come closer and closer to a
kind of self supporting bioregenerative life
support system. As an example, some candidate
configurations for lunar life support, as
identified by a Lockheed study, are outlined in
figure VII.2 (vrgl. Tab. 7.1.). Each of the
conceptual design candidates was based on a
generic system structure consisting of five
subsystems (atmosphere regeneration, water
purification, waste management, food production,
and biomass production), along with three other
interfacing systems (in-sito resource
utilization, extrahabitat activity, and system
monitoring and maintenance). The designs reflect
the requirement to provide life support for a
nominal crew of 30 persons, with the capabilty to
accommodate a range from 4 to 100. A breakeven
analysis between concepts 1 and 5 was yielding a
breakeven time concept 5 of about 2 years.1
7. Lunar Base ?-1
Fundamentals of Biospherics LUNAR BASE ?-!
Tab. 7.1. Concepts
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
33Fundamentals of Biospherics
Abb. 7.2. CELLS-diagram of a lunar base
Fundamentals of Biospherics LUNAR BASE ?-1 -
Concept
Mähring Michael 9231282
34Fundamentals of Biospherics
The design of a lunar base will be limited by
environmental parameters, according to the
extreme conditions on Moon. To achieve the
smallest possible amount of diffusion, the
surface of the lunar base will be as small as
possible, also the internal pressure will be
minimalized. To be protected against cosmic
radiiation ond micrometeorits, the habitat will
be put under a layer of Regolith which may be 1
to 5m thick. During the Moon-day, light can be
passed to the interior of the habitat by optical
cables.
7.1. Design
Fundamentals of Biospherics LUNAR BASE ?-1 -
Design
pic. 7.3. The lunar habitat as designed by the
University of Houston
Mähring Michael 9231282
35Fundamentals of Biospherics
The first lunar bases will be light
inflatable structures similiar to the modules of
the ISS. As ist not possible to dig them into the
ground, one will have to pile up the Regolith
over them. As mentioned before there has to be
5m of Regolith to get the same radiation
intensity as on Earths surface.
light Moon-Modules
Fundamentals of Biospherics LUNAR BASE ?-1 -
Design
pic. 7.4. Lunar Base Plant-Module
Mähring Michael 9231282
36Fundamentals of Biospherics
pic. 7.5. Lunar Base Habitat Modules
Fundamentals of Biospherics LUNAR BASE ?-1 -
Design
Mähring Michael 9231282
37Fundamentals of Biospherics
"At 1013 p.m., April 13, 1970, as the
spacecraft of the APOLLO 13 mission neared moon,
an explosion occurred in the service module, and
alarm lights flashed on the command module
control panel. It was quickly evident that the
explosion had ruptured one or both oxygen tanks.
Computers and staff at mission control sprang
into feverish activity to plot rescue options
that would be inhabitable, because information on
"consumables" was in pieces, with no total
picture on which to base an estimate of how much
time was available to get the astronauts safely
back to earth. Precious time was wasted putting
all the pieces of information together. One is
reminded that a similar situation exists here on
Earth. We do not have the total picture of our
life support "consumables" or understand how they
interact."1
8. The Apollo13-Mission
Fundamentals of Biospherics THE APOLLO13-MISSION
pic 8.1. Pattern of the Apollo13-Mission
Mähring Michael 9231282
1) Eckart Peter in Spaceflight Life Support
Biospherics"
38Fundamentals of Biospherics
The first two days of the Apollo-Mission ran so
uncomplicated, that Joe Kerwin (Ground control,
CapCom on duty) sent the following message to the
Apollo13-crew "The spacecraft is in real good
shape as far as we are concerned. We're bored to
tears down here.1 James A. Lovell jr. replied
at 55h 46min from the Apollo13 "This is the crew
of Apollo13 wishing everybody there a nice
evening, and we're just about ready to close out
our inspection of Aquarius (the lunar-module) and
get back for a pleasant evening in Odyssey (the
command-module). Good night.1 Nine minutes
later, nobody was bored anymore. The oxygen tank
nr.2 exploded and damaged tank nr.1. Following
electricity and watersupply failed, 320000km away
from Earth. "Houston, we've had a problem
here.1
Houston, weve had a problem here...
Fundamentals of Biospherics THE APOLLO13-MISSION
pic 8.2. The Commando-Module Odyssey after the
Explosion of the Oxygen-Tanks
Mähring Michael 9231282
It was not exactly known how long the command
module would be inhabitable, because information
on consumables was in peaces, with no total
picture on which to base an estimate of how much
time was available to get the astronauts safely
back to Earth. Precious time was wasted putting
all the pieces of information together. One
and a half hour after the explosion, Jack Lousma
from ground control said "It is slowly going to
zero, and we are starting to think about the
lunar-module-lifeboat.1 John L. Swigert jr.
replied from Apollo13 "That's what we have been
thinking about too.1
1) Jim Domoulin, Apollo 13
39Fundamentals of Biospherics
The astronauts moved from the command module to
the moon module, which life support system had
been set up only for 45 hours, which had to be
stretched now to 90 hours to get safely back to
Earth. The analysises said, that there would be
enough oxygen, but a lack of wtare and
electricity while the carbon dioxide got more and
more. From Apollo11 they knew, that the
mechanisms of the shuttle would last about 7h
without cooling it. So the crew reduced the water
ration to a minimum, which lead to a massive
dehydration of the astraunauts, who lost during
the mission 16kg of weight (biomass), which is
50 more than any other Apollo-mission. To get
the carbondioxid-level in the lunar module down,
the angular filters from the command module had
to be adapted to the round openings of the lunar
module by using plastic bags, cardboard and tapes.
Moving from Sphere1 to Sphere2
Fundamentals of Biospherics THE APOLLO13-MISSION
pic 8.3. The Commando-Module Odyssey and the
Lunar Module Aquarius
Mähring Michael 9231282
40Fundamentals of Biospherics
The control was transferred from the command
module to the lunar module a procedure, which
had never been tested. It turned out, that the
computer-controlled sextant did not work, so the
crew of Apollo13 had to navigate by using the sun
and ist position in the window of the lunar
module. The service module on the topü of the
command module was put away only 4h before
reaching Earths atmosphere, because nobody could
say, if the heat shield of the landing module
would be able to survive the coldness of the
space without the protection of the service
module. It was also not clear if the command
module would be able to be switched on after ist
lang cold sleep. Water had condensed on all
surfaces, an arcing of electricity seemed to be
likely. But also this manouevre worked and the
condensed water rained during the deceleration in
the atmosphere from the walls "The chances of
short circuits caused apprehension, but thanks to
the safeguards built into the command module
after the disastrous fire in January 1967, no
arcing took place. The droplets furnished one
sensation as we decelerated in the atmosphere it
rained inside the command-module.1 The
Apollo13-Crew returned to Earth safely on the
17th April 1970 after 5 days, 22 hours and 54
minutes.
The Art of Improvisation
Fundamentals of Biospherics THE APOLLO13-MISSION
pic. 8.4. Return to Biosphere1
Mähring Michael 9231282
1) Jim Domoulin, Apollo 13
41Fundamentals of Biospherics
Fundamentals of Biospherics THE APOLLO13-MISSION
- Movies
To play one of the movies, click the title below
the picture
Movie 8.5. Launch of the Saturn-V
Movie 8.6. After the Explosion of the Oxygen-Tanks
Mähring Michael 9231282
Movie 8.7. The Interior of the Command Module
Movie 8.8. Back Home!
42Fundamentals of Biospherics
Picture Index 2.1., 2.2. 3.1., 3.2., 3.3.,
3.4., 3.5., 3.6., 3.7. 4.1., 4.2., 4.3., 4.4.,
4.5., 4.6., 4.7. 5.1., 5.2., 5.3. 7.1., 7.2.,
7.3., 7.4., 7.5. Peter Eckart,
Spaceflight, Life Support and Biospherics, Space
Technology Library, Munich 1996
S.1, S.18, S.19,
S.25, S.26, S.29, S.30, S.31, S.32, S.33 S.42,
S.44, S.45, S.53, S.60, S.62, S.69, S.70, S.71
S.403, S.405, S.406, S.407
8.1., 8.3. Apollo Press Release Figures, Figures
from NASA press release No 69-68 and Apollo 15
press package, http//www.nasm.si.edu/apollo/FIGUR
ES/figures.htm
Fundamentals of Biospherics PICTURE INDEX
8.2., 8.4. JSC Digital Image Collection, Press
Release Images, NASA Photo ID AS13-58-8458,
http//images.jsc.nasa.gov/images/pao/AS13/1007551
8.htm
8.4., 8.5., 8.6., 8.7. NASA Historical Archive,
Index of /history/apollo/apollo-13/movies,
http//science.ksc.nasa.gov/history/apollo/apollo-
13/movies/
43Literature Index
Fundamentals of Biospherics
Peter Eckart, Spaceflight, Life Support and
Biospherics, Space Technology Library, Munich
1996, ISBN 1-881883-04-3 Jim Domoulin, NASA,
Apollo 13, ?2000, http//www.ksc.nasa.gov/history
/apollo/apollo-13/apollo-13.html James
Lovelock, The Ages of Gaia, Bantam Books, New
York 1990 E.P. Odum, Ecology and Our Endangered
Life Support Systems, Sinauer Associates Inc.,
Sunderland, 1990 D. Nachtwey T. Yang,
Radiological Health Riscs for Exploratory Class
Missions in Space, Acta Astronautica, Vol 23, S.
227-231, 1991 C. Helmke, Synopsis of Soviet
Manned Spaceflight Radiation Protection Program,
USAF Foreign Technology Bulletin,
FTD-2660P-127/105-90, 1990 H. O. Ruppe,
Introductions to astronautics Vol III, Academic
Press, New York 1966
Fundamentals of Biospherics LITERATURE INDEX