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: Space Environment Pierre Rochus
Université de Liège
[email protected]
SPACE ENVIRONMENT
Contact
[email protected]
Centre Spatial de Liège
+32 43824607
+32 477372388
Space Instrumentation
and Tests Laboratory
+32 4 3669647
+32 4 367 5613
+32 4 3669505
[email protected]
Deputy General Manager R&D
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Professor
Centre Spatial de Liège
Liege Science Park
Avenue du Pré-Aily
B-4031 Angleur-Liège
Belgium
Aerospace and Mechanical
Engineering Dept..
Bât. B52/3 LTAS - IES
chemin des Chevreuils 1
4000 Liège 1
Belgique
Local : +2/414
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Introductory course to the space environment
Reference for this course:
Chapter 2 of Spacecraft Systems Engineering
(Third Edition) Peter Fortescue, John Stark and
Graham Swinerd – 2003
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http://www.scostep.ucar.edu/
http://www.scostep.ucar.edu/comics/booklets.html
CAWSES-II is an international program sponsored by SCOSTEP (Scientific Committee on Solar-Terrestrial Physics) established with an aim of
significantly enhancing our understanding of the space environment and its impacts on life and society. The main functions of CAWSES are to
help coordinate international activities in observations, modeling, and applications crucial to achieving this understanding, to involve scientists in
both developed and developing countries, and to provide educational opportunities for students of all levels. As part of Capacity Building effort, a
series of educational comic books have been produced under the supervision and guidance of Prof. Y. Kamide.
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Space Design = Aircraft Design
Durable structure, can withstand a certain margin of safety, "destruction" of nature.
1kg in GTO costs 6.000 € to 25.000 €
P ground radio station 50 kw for d< 100km
Interplanetary satellite P P<2W
d 1 billion km
Data compression on board
The European aircraft manufacturer invested more
than € 10 billion (spread until 2012) to develop a
competitor to the Super Jumbo Boeing, the 747.
Specific to Space:
• launch
• the space environment,
• lack of maintenance possible (extreme reliability) and
• the very strong limitation of budgets:
Mass, power, size, rate of data transfer.
Total cost of the project is 690 million euros
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•
The « sentinel’s » will
be several successors
but smaller
Envisat
ENVISAT is a very big satellite.
Its mass is 8200 kg including 2050 kg of instruments and 300 kg of
propellant for an impressive space of 10 m x 4 m x 4 m (bigger than a
bus!).
The solar panels dimensions 14m x 5m and can have a power of 6.6 kW,
the energy being stored in 8 nickel-cadmium batteries of 40 Ah each.
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AIRBUS A380-800, …,
Antonov An-225 Mriya
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Effects of the space environment on the design of spacecrafts and instruments
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4 Cluster satellites investigating the Earth's magnetic
environment and its interaction with the solar wind in
three dimensions.
Launch is not easy
•Ariane 501 failure on 4 June 1996
•Orbit : Elliptical polar orbit, 19 000 to 119 000 km, 57 hour period.
•Advances our knowledge of space plasma physics, space weather and the Sun-Earth connection and has been key in
improving the modeling of the magnetosphere and understanding its various physical processes.
•Cluster satellites are the first to be able to make detailed, three-dimensional study of the changes and processes taking place
in near-Earth space. In the beginning of the mission the satellites are only a few hundred kilometers apart, so they will be
able to study small-scale features in the surrounding space. Later they may be separated as much as 20 000 km and thus get a
broader view of the events happening in larger scale.
The satellites' distance will vary between 19 000 and 119 000 km from Earth. As they move in and out of Earth's magnetic
shield they will be able to investigate the magnetic boundary areas of near-Earth space, and outside of Earth's magnetic shield
they will also be fully exposed to supersonic solar wind. They will be able to study the interaction between the Earth's
magnetic field and the solar wind, especially in such areas as the polar cusps, where the solar wind particles get through.
Another interesting phenomenon is the acceleration of plasma particles during magnetic substorms in the magnetotail.
•The four Cluster satellites were able to study the physical processes involved in these and other phenomena by visiting these
key regions. The four-point measurements will allow differential plasma quantities to be derived from the results for the first
time.
•The key regions the Cluster satellites explored are solar wind and bowshock, magnetopause, polar cusps, magnetotail
and auroral zone .
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Regions visited in the in northern hemisphere spring
(left) and northern hemisphere fall (right).
The Pioneers
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Launch is not easy
Constantin Edouardovitch Tsiolkovski
Russian (1857-1935)
Hermann Oberth
Romanian-German (1894-1989)
Robert Hutchings Goddard American (1882-1945)
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Launch is not easy
Von Braun
GAGARIN KOROLEV
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Launch is not easy
André Bing
Patent: nested launchers (1911)
Karel Jan Bossart (February 9, 1904 in
Antwerp – August 3, 1975, San Diego,
California) was a pioneering rocket designer
and creator of the Atlas ICBM.
His achievements rank alongside those of
Wernher von Braun and Sergei Korolev but as
most of his work was for the United States Air
Force and therefore was classified he remains
relatively little known.
Karel Bossart
HERGE
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Launch is not easy
A Belgian general, grandfather of Astronautics
Casimir Coquilhat Erasmus
In 1873, Major General Casimir Coquilhat Erasmus (18111890) published his last article (16 pages) in
Memoires de la Societe Royale des Sciences de
Liège.
Trajectories of rockets into space, this article contains
the mathematical formula for rocket propulsion, which
determines the performance of its function in a vacuum.
Long attributed to Konstantin Tsiolkovsky (1857-1935), who
(re) discovered twenty-five years later and made known
in his writings on astronautics, this equation is actually
the work of a Belgian military!? ?
Casimir-Coquilhat Erasmus (1811-1890) was a great expert on guns in the
young army of Belgium, making this his career from 1830 to 1874. This
military personality was good at mathematics, and gifts as a writer on
technical issues. Influenced by both the courses he had received at the
University of Liege by the treaties of pyrotechnics and artillery manuals
used to train officers, he completed April 11, 1871 the drafting of the
document trajectories of rockets in a vacuum.
Without realizing it, the Belgian general Coquilhat throws, with his fine
mathematical demonstration, one of the foundations of what will be the
twentieth century, space travel. This was known as the Tsiolkovsky
equation should now be called the equation Coquilhat!?
The first page of the article, remained confidential, of General Coquilhat
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Launch is not easy
Launch is not easy
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Some simple and paradoxical considerations about the difficulty of realising launchers
leaving the Earth, which justify :
• the need to "develop ingenious plumbing techniques”,
• much political will and
• much money to make a vehicle which leaves Earth.
Escape velocity of Earth : 11 km/s or
Classical bombshell speed :
Best airplane
40.000 km/h
5.400 km/h
3.000 km/h
Difficult
U
G.M T
 6.10 7.J
RT
G.M T  398.600 km 3 / s 2
The potential energy of a mass of one kilogram at the Earth's surface is: 6 107 J .
This energy must be given to a mass of one kg for the release of the Earth (ignoring the tedious details such as friction in the air, which
would further aggravate the conclusions). One might imagine that this energy is given to ground by the explosion of a chemical reagent
product chosen properly, such as a mixture of hydrogen and oxygen (One of the best choices).
The heat of combustion of the combination liquid hydrogen / liquid oxygen that is transformed into a kilogram of water is < 2.107. J which
is considerably less than the energy needed to remove the water body from the Earth.
Naively, by comparing these two figures, one could understand the arguments of a professor of physics and chemistry that in 1926,
refuted the idea of Goddard want to go to the moon with chemical energy, the following words:
"This foolish idea of shooting at the Moon is an example of the absurd lengths by which vicious specialisation will carry scientists ... For a
projectile entirely to escape the gravitation of the Earth, it needs a velocity of 7 miles a second. The thermal energy of a gram at this speed is
15180 calories... The energy of our most violent explosive - nitro-glycerine - is less than 1500 calories per gram. Consequently, even had the
explosive nothing to carry, it has only one tenth of the energy to escape the Earth ... hence the proposition appears to be basically unsound.
Impossible
However, one could argue, on the other hand, with the same simplistic reasoning that space travel should be made trivial : the energy
resource is relatively cheap; for example, if one takes a kWh at 0.125 €, 1 kg launch into space should cost only 20 kWh, or 2.5 €! This is
trivial!
Trivial
The answer to these paradoxes should not depend on the skill with which we can carry out the plumbing of the launcher but must be
justified on simple physical arguments.
The first paradox is actually based on an assumption that is false and this was known long before that Professor of Physics did his remarks
to Goddard. Thus, Jules Verne, himself, knew the real solution to this paradox, with its launcher gun in his journey "from the Earth to the
Moon" .. The second paradox, it is not false, but it is not feasible in the near future.
The space flight in practice is between these two extremes: it is not impossible but it is difficult to achieve.
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6.000 €
17.000€
However, one could argue, on the
other hand, with the same
simplistic reasoning that space
travel should be made trivial
energy resource is relatively
cheap, for example, if one takes a
kWh to 0.125 €, 1 kg launch into
space should cost only 20 kWh, or
4 € which is trivial!
!
?
ve
e
o
s
y
h
W
i
s
n
e
p
x
4.400 €
11.800 €
2.000 €
6.700 €
6.700 €
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"From the Earth to the Moon
(1865 )": a huge cannon of 300
meters long which was to propel
to their distant goal, travelers
enclosed in a shell carefully
padded. (Tsiolkovsky put them in
a bath damping the acceleration).
But the human body is a fragile
structure (like the electronics), it
can support up to 10 g for a time
as short as of about 10 seconds
and 5 g maximum for a more
reasonable time . We must reach
a speed of about 8 km / s for a
low Earth orbit. If you want to
limit the acceleration to 5 g, the
barrel must have a length of 600
km!.
A shorter barrel (like in Verne’s The idea of using a gun is of course a preconceived idea, associated with
book) will kill its occupants and the explosive power; in fact, an explosive is just what should not be done:
the speed should not be too high when in the atmosphere due to higher
electronics systems.
friction and then we must accelerate once outside the atmosphere.
V=at; e=1/2at²; e=1/2v²/a
One might still think about the gun (and in fact we think again and seriously
to it): D. Clery, Supergun : U.S. sets sights on space, New Scientist, 19
September 1992) for defense systems to send or structural components of a
future space station.
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The Problem of Space Travel: The Rocket Motor
Das Problem der Befahrung des Weltraums, Der
Raketen-Motor (1928) ,
Hermann Noordung alias Potocnik (Czech
captain of the Austro-Hungarian army) , (18921929)
The solution is to "reverse the process,
instead of firing to the Moon that we want
to reach, we return the gun and fire toward
the Earth
The reaction will raise the gear "as high as
one wants."
http://www.hq.nasa.gov/office/pao/History/SP-4026/preface.html
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With the chemical
energy alone and with
current rockets at
current levels, we can
only reach the Moon,
Venus or Mars. The
other planets we are
not reachable.
In the 1960s, studies are realised of alternative propulsion systems with high speed of ejection to minimize the fuel
load on board. Findings in the years 1960-1970: the growth of the mass of the system with the power required makes
the system unusable in practice. These studies were restarted since 1995 with success.
In 1960, we conclude that we must use nuclear energy to go beyond Venus - Mars.
In 1962, one discovers the gravity-assist (Although in the thesis of Enrico Fermi) .----> Missions at JPL
Mariner 10: 1974 Earth Venus Mercury
Pioneer 10: Earth-Jupiter - Interstellar
Pioneer 11, Voyager 1 : Earth-Jupiter-Saturn-Interstellar
Voyager 2: Earth-Jupiter-Saturn-Uranus-Neptune-Interstellar
Ulysse: Earth-Jupiter-Out of the Ecliptic
Galileo (small C3): Earth-Venus-Earth-Earth-Jupiter
Today, the impossible becomes reality
- Electric catapult
- Reusable launcher
- Single-stage launcher
Mission with the aid of electrical propulsion: Beppi Colombo to Mercury.
Solar Electric Propulsion Tether + solar concentrator +MHD + Solar Sail + solar Laser?
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Unusual Operating Space Environment.
Conditions of microgravity, vacuum, electromagnetic or particulate external flows
combine their effects and produce significant and rapid thermal cycling, outgassing and contamination, electrostatic charges
and electrical breakdowns, ageing effects and erosion of materials ...
Environmental constraints to be taken into account in the design of optical systems are:
• Thermal stresses (the effects of thermal cycling, reliability and ageing effects on electronical components,
mechanical and thermo-elastic stresses, outgassing of materials)
• Mechanical stresses (vibration, acceleration, shock)
• Radiation constraints (UV, high-energy particles, …)
• Vacuum conditions (outgassing, drying, micro-welding, effects of residual gases)
• Microgravityeffects
• Atomic oxygen and residual atmosphere (in LEO)
• Micrometeorites and space debris
• Contamination generated by the satellite.
• Electrifyingt environnement
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high reliability for long lifetimes
use of approved or well characterized materials.
using well established processes with good reproducibility (qualifiability)
Presentation of a reduced and arbitrary choice of the environmental parameters.
A powerful synergy of actions between these parameters.
Immediate vicinity of the earth from low orbit station to geostationary orbit.
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Specificity of Space Related Developments
Eclipse
LAUNCH
ORBIT
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Space Environment & Constraints
o VACUUM (OUTGASSING, MULTIPACTION......)
o THERMAL CYCLING: ECLIPSE TO FULL SUN
o RADIATION & PARTICLES ( ATOMIC O , e-, p+, UV, μ- METEORITES, DEBRIS)
o UP TO 15 YEARS LIFE IN ORBIT (IUE 18 years)
Eclipse
ORBIT
- SPECIAL MATERIALS & PROCESSES ( LOW CTE & OUTGASSING )
- CAREFUL THERMAL DESIGN
- PROTECTIVE PAINT / SHIELDS / ESD PREVENTION/ RADIATION HARDENING
- HIGH RELIABILITY & REDUNDANCY
•
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Large Space Simulator
The Large Space Simulator (LSS)
provides close simulation of in-orbit
environmental conditions thereby
ensuring optimisation of the design
and verification of spacecraft and
payloads. Its exceptional test volume
makes it an excellent tool for testing
large payloads.
The specific design features and
excellent performance characteristics
of the LSS mean that a number of
tests can be carried out under high
vacuum conditions, including: For
thermal tests:
• solar simulation
• infrared radiation
• vacuum temperature cycling
• photogrammetry for deformation
measurements
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PRE-OPERATIONAL SPACECRAFT
ENVIRONMENTS
Pre-launch environment
Long : 5 à 10 years
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Design
AIV
Qualification
Transport
Storage (often longer
than foreseen)
Choose the most advanced technologies (maybe not yet mature at the start of the design)
Some assembly operations can lead to higher stresses than expected
Sometimes more severe than the launch, low cycle fatigue
Shocks, lifetime (rupture mechanics), contamination
Contamination, coating, mechanisms in dry and clean atmosphere
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Dynamic Environment
Mechanical sollicitations (vibrations transmitted through
the structure) :
- continuous or small variation accelerations
- sine vibrations L.F. ( f< 100 Hz)
- transient vibrations L.F. ( f< 100 Hz)
- shocks H.F. ( 100 < f < 2.000 Hz)
- random vibrations H.F. ( 100 < f < 2.000 Hz)
Acoustic sollicitations (vibrations transmitted through
the air) ( f < 10 KHz)
- Acoustic excitation : sound pression field
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The launch phase
The most impressive stage ...
Concorde (supersonic transport aircraft):
The SATURN V rocket (which rushed
to the Moon) is the most noisy rocket
ever built: 210 dB
Level of takeoff noise 119.5 Decibels
Noise Level in Decibels approach 116.7
Noise level Decibel lateral 112.2
The Airbus A380: Approach: 98dB, lateral: 94.9 dB; Overview: 94.8 dB
The reference intensity expressed in watts per square meter (10-12W.m = W0-2) or the ratio of the pressure generated on the reference pressure, expressed in pascals (Pa P0 = 2.10-5). It was chosen because it can be easily
manipulated figures that do not become extremely large or small (see article logarithmic scale), and because this approach better reflects what the human ear in terms of loudness.
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Random vibration
Function over time
Fourier transform of the autocorrelation
Function of time variations minus
average periodic phenomena
Power Spectral Density
Static acceleration
A speed of ~ 9.5 km / s must be reached
History depends on the launcher and that is inhabited or
not.
Acceleration is stronger on small payload launchers:
SCOUT, Pegasus rocket or spacecraft (launched from an
airplane).
For a 50 kg PL to the extinction of the last stage, at 3s 13g
600 kg 4.5 g
Shuttle 3g
Warning for CubeSat's : less favorable
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Need
Need to
to make
make qualification
qualification tests
tests simulating
simulating the
the launch
launch
 Allows vibration (200-kN
shaker) on 3 axis under cryogenic
and vacuum conditions (down to
15K).
Shaker 4522 LX:
Slip table: 1500 x 1500 mm²
 Head expander: 1500-mm diameter
 Maximum sine force 200 kN
 Maximum random force: 160 kN
 Bandwidth: 5-2000 Hz
Shaker 2016U:

Slip table: 900 x 900 mm²
 Head expander: 900-mm diameter
 Maximum sine force: 88 kN
 Maximum random force: 72 kN
 Bandwidth: 5-3000 Hz

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HYDRA multi-axis vibration test facility
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HYDRA to complement the electrodynamic vibration test facilities. Compared to those
facilities, it can:
test much larger test specimens
test much heavier test specimens
test in any direction without changing the configuration
test with larger displacements
Envisat FM on HYDRA
test at lower frequencies
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•
•
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Physical properties machines
The Test Centre has a series of machines to
accurately determine the physical properties of
spacecraft systems or subsystems. These
machines include:
Weighing scales:
The Test Centre can weigh items from a few grams
up to five tonnes with a very high accuracy thanks
to a set of state-of-the-art scales and calibrated
weight standards.
Centre of gravity and moment of inertia:
The combined machine SHENCK W50/M6
equipped with L-shaped adaptors allows engineers
to determine the centre of gravity and the moment
of inertia of spacecraft up to five tonnes and three
metres in diameter.
Dynamic balancing:
Depending on the mission, engineers may require
that the spacecraft be perfectly balanced when
spinning. The Test Centre is able to measure
products of inertia, to balance or to spin spacecraft
up to five tonnes, either in air or in vacuum, using
SHENCK E5 and E6 machines.
MetOp PLM on the Moment of inertia (MOI) Lshaped adapter
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Large European Acoustic Facility (LEAF)
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Acoustic noise tests form an integral part of the verification process
of space hardware. The qualification and acceptance of spacecraft
and their payloads by acoustic noise tests assure that no damage
will occur to these structures during the launch phase. When
considering the layout of an acoustic test facility, the main objective
is to simulate realistic spectral noise pressure levels, comparable to
those generated by the launcher engines and by the airflow passing
along the fairing during the atmospheric flight.
The Large European Acoustic Facility (LEAF) provides the required
environmental performance and offers a great variety of noise levels
and spectral shapes as well as test sequences and durations in
order to meet different user requirements.
The noise generation system consists of four different horns with low
cut-off frequencies of respectively 25, 35, 80, and 160 Hz
complemented by three high-frequency noise generators. A
maximum overall noise level of 156 decibels can be achieved;
provisions have been implemented to extend the level up to 158.5
decibels.
Furthermore, the acoustic chamber rests on springs to prevent
propagation of vibration to the structure of the building. With a mass
of 2000 tonnes, the chamber is very well suited for modal survey of
large structures.
The instrumentation of the acoustic facility includes a microphone
mounting system which allows an easy distribution of up to 32
microphones in appropriate locations around the test article. The
large number of suspension points distributed throughout the
chamber and standard moving trolleys offer considerable flexibility
for spacecraft suspension. The noise inside the acoustic chamber is
automatically controlled and adjusted in real time by an acoustic
control console using the average 1/3 octave spectrum of up to 32
microphones. This automatic control permits rapid adjustments to
the spectrum, achieving the desired result in less than 30 seconds
with a very tight tolerance (< ±0.5dB in the high-power bands).
The LEAF is totally remote-controlled.
Since the acoustic noise in the LEAF is generated by pressurised
gaseous nitrogen, the risk of test article contamination is excluded.
.
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Accelerations tolerable for men
Acceleration limits tolerated by man
in the 5 directions (left-right
symmetry)
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Static pressure environment
The atmospheric pressure decreases during
the launch.
The rate of depressurization under the
shroud depends on the size of ventilation
holes in relation to volume.
For Ariane, the static pressure decreases at
a rate of 10 mbar / sec.
For the shuttle that contains pressurized and
unpressurized elements, there is a pressure
and leak control.
Special attention to the
components of optical
instruments (filtered and
calibrated ventilation holes)
and (micro-perforated)
thermal blankets
•
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EMC / EMI Compatibility
The very strongly volume limited budget can lead to problems
EMC / EMI
Tests on harnesses and connectors  flight later in the planning of FM
Great care is required during payload
integration to ensure that
electromagnetic interference does not
present a hazard.
Rarely compliant  negotiation spec. necessary
E (V/m)
Hazards may be in a variety of forms
but the most severe are cases in which
EMI may result in the activation of
part of the payload which could lead
to death of attendant personnel,
perhaps via the ignition of an onboard propulsion system.
Figure 2.6 shows the EMI
environment anticipated for the
Pegasus launch vehicle whilst
undergoing integration at the Western
Test Range.
f (Hz)
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Relative effects of environment on the
material according to the orbit
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Microgravity
Why training of astronauts
in a pool?
An immersed astronaut is not in
weightlessness! He is supported by the liquid
medium which gives him a mobility more or
less comparable to that observed in space.
Problem of on ground testing of flexible optical structures (example Suspension
device for the XMM telescope)
The apparent absence of gravity (centrifugal effect canceling gravity) prevents any
natural convection. Only forced convection in a pressurized enclosure (space
cabin for example) can appear in space.
Lack of sedimentation, presence of dust in the field of view, difficult localization of
fluids in reservoirs, non controlable liquid / gaz interface, design of deployable
structures where the mechanical inertia becomes dimensioning and difficulty of on
ground testing .
Future solution: SMART STRUCTURES which can adapt to gravity for on ground testing
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58
XMM
mirrors
Optical testing of flexible mirrors of
XMM / NEWTON
EUV
Detector
Filter wheel
removable
diffuser
7500
Camera
Vertical vacuum chamber
X telescope
Optical bench
Facility
Pumping
System
Valve
Photomultipliers
Seismic
bench
Cassegrain
collimator
Water inlet
Laser
source
Source
Pumping
System
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He bottle
EUV
source
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FOCAL X
Diameter : 4.5 m
Height : 12.2 m
Volume : 191 m³
vertical collimator Ø80cm
with EUV source
vertical x-ray and EUV
detectors
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Jeux lunaires
G lune =G terre/6
Record du saut à la
perche : 37m
Record du saut
en longueur :
55 m
Vacuum
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Vacuum
Convective Exchanges negligeable when the pressure is less than 10-4
torr.
In space, the pressure is less than 10-6 torr when the altitude is above 200
km and virtually all satellites have a higher perigee.
In orbit, the vacuum is such that all the convective exchange with the
environment are eliminated.
For an electronic device located inside a unpressurized satellite, the only
means of heat dissipation are radiation and conduction. (The fundamental
difference with the behavior on the ground)
Outgassing / Sublimation / Contamination: materials can outgas and later recondense on the cooler parts, modifying their thermo-optical properties of
absorption and emission.
Se, Cd, Zn are excluded for sublimation, the presence of polymers is to
minimize .... (Test μVCM to select materials)
Drying: Most organic matrices for glass or carbon
fibre composites realization are hygroscopiques. In h (km)
empty space, under vacuum, water is outgassing This
leads to dimensions reductions (A few tens of µm 50
per meter length). This dimensional change must be 100
taken into account in the design of sensitive
200
structures
THE RISK OF COLD WELDING
Specificity of vacuum lubrication
P (mBar)
1
<10-3
<10-6
500
<10-8
700
<10-10
36.000
10-17
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The thermal environment
Effects of thermal cycling
Reliability and lifetime of electronic components
Thermoelastic stresses and strains
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Launch Environment & Constraints
Thermal Cycling
TYPICAL OPERATING TEMPERATURE RANGES:
o ANTENNAS & EXTERNAL EQUIPMENTS: -160oC TO +120oC
o INTERNAL BOXES (CONTROLLED ENVIRONMENT): -10oC TO +60oC
THERMAL FATIGUE, DISJOINTING,
DELAMINATION, CRACKS & DISTORTIONS ARE
EFFECTS OF THERMAL CYCLING
THERMAL COATINGS (PAINT…) AND
SHIELDS ARE USED TO LIMIT
TEMPERATURES & GRADIENTS
THERMAL CYCLING AND SOLAR SIMULATION IN
VACUUM ALLOW TO VERIFY SURVIVAL AND TO
EVALUATE DISTORTIONS
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Simulation on ground of thermal environment
Examination of optical properties.
1983-1986 : Hipparcos
 Thermal balance and
thermal vacuum tests
 Optical Calibration
1988-1995 : ISO
(Infrared Space Observatory)
 Performance measurements at
vacuum & 5K.
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Cryogenics
• Produce, maintain, use low temp
• Thermodynamic temperature scale : T (Kelvin) = T (° C) + 273.15
(Definition of absolute zero)
• Domain cryogenic : T <120 K
• Cryogenic Fluids (cryogens)
temperatures of:
• - Nitrogen (field around 80 K [-193 ° C])
• - Hydrogen (about 20 K [-253 ° C])
• - Helium (about 4 K [- 269 ° C])
• • LHe, LH2, LNe, LN2, LAr…
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Gamme des Cryofluides
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Table de propriétés des cryo-fluides
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Table de propriétés des cryo-fluides
Universitéde
deLiège
Liège
Université
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Le marché des cryo-fluides
L’hélium : (5,3.10-6 dans l’air)
•Très utilisé dans les domaines des mesures physiques à basse température, des supraconducteurs.
•Coût de plus en plus élevé (de 3.4€ à 10 €/litre selon quantité)
•Provient des puits de gaz de naturel (USA, Algérie, Qatar,Pologne, Australie…)
L'hydrogène : (5.10-7 dans l’air)
• très largement employé dans les années 60, moins utilisé actuellement. Le danger potentiel dans son utilisation. Les risques
d'inflammabilité de l'hydrogène dans l'air existent entre 4 et 75%. Ce mélange est détonant entre 19 et 57 %. Et l'énergie nécessaire
pour provoquer l'ignition est seulement de 0,02 mJ (10 fois inférieure à celle des autres hydrocarbures).
• l'hydrogène existe sous 3 variétés isotopiques ; hydrogène (H2), deutérium (HD et D2 :1 neutron en plus par noyau), tritium (2 neutrons
par noyau).
Le néon : (1,8 .10-5 dans l’air)
L'azote : (0,78 dans l’air)
• bon marché ( environ 0,1 €/litre)
• distribué industriellement par camion citerne calorifugé en tout point de stockage.
• bonne chaleur latente de vaporisation (210 kJ.kg-1) , utilisation facile et peu contraignante (son transfert peut s'effectuer avec un
minimum de calorifugeage, boite en polystyrène…) .
• éviter de porter des vêtements en laine qui, une fois imbibés d'azote liquide, entretiennent un flux de gaz très froid pouvant provoquer
des
brûlures. Leur préférer des vêtements en Nylon. Le risque de brûlure directe par projection de liquide sur la peau est peu probable
(phénomène de caléfaction).
• risque le plus dangereux = anoxie (diminution progressive de la teneur en 02 de l'air lors d'évaporation d'azote liquide. (teneur O2 < 17
% =début de risque majeur).
L’oxygène : (0,21 dans l’air)
• peu utilisé en cryogénie
• risques liés à sa forte réactivité
L’argon : (9,6.10-3 dans l’air) Utilisé dans les calorimètres de détecteur
Coût assez élevé (≈ 8 €/litre)
Le krypton : (1,1.10-8 dans l’air) Utilisé dans les calorimètres de détecteur
[email protected]
Autres sources pour basses
températures : les “réfrigérateurs”
Pour petites puissances jusqu’à 3 K, les cryogénérateurs
(machines à flux alterné)
• Gifford-Mac Mahon (200 W @ 80K /1KW élec - 2W@20 K/1KW “à la
prise”)
• Stirling (10 W @ 80 K/1KW élec- 1W @ 20 K /1KW élec)
• à tube à gaz pulsé (pulsed tube) (actuellement 1,5 W @ 4 K )
– souvent bi-étagées (écran thermique au 1er étage)
– 1 à 2 Hz
– qq W à 15 K, 100 W à 80 K
Pour de grosses puissances, les machines à flux continu
• réfrigérateur ou liquéfacteur (LHe, LN2…)
(turbodétendeurs+échangeurs+compresseur)
De quelques dizaines de watts jusqu’à 18 kW W à 4 K
[email protected]
CRYOGENERATEUR :
Exemple d’utilisation de Machine GIFFORD-Mac MAHON
[email protected]
Exemples de « petits » réfrigérateurs
ou liquéfacteurs hélium
(L’Air Liquide)
Compresseur
(15 bars 290 KW -69 g/s)
Boîte froide
Hélial 2000
(500 W ou 150 l.h-1LHe)
Boîte froide Hélial 2000
[email protected]
Exemples de « gros » réfrigérateurs
ou liquéfacteurs hélium
Carnot limit
18 kW @ 4.5 K
33 kW @ 50 K to 75 K - 23 kW @ 4.6 K to 20 K - 41 g/s liquefaction
P input : 4.2 MW
[email protected]
CRYOGENIE, VIDE, SUPRACONDUCTIVITE
Quelques références bibliographiques
Thèmes Titres
Auteurs
Cryogénie
Notes de Cryogénie
J.VERDIER
Éléments de Cryogénie
R. CONTE
Cryogénie, ses applications en supraconductivité
Helium Cryogenics
S. VAN SCIVER
Cryogenic Process Engineering
K. TIMMERHAUS
Cryogenic Systems
R. BARRON
Experimental Techniques in Low Temperature G. WHITE
Physics
Cryogenics (revue mensuelle)
Heinemann
Handbook of cryogenic engineering
J.G. WEISEND II
Cryogenic Engineering
T. FLYNN
Thermique
Initiation aux Transferts Thermiques
J. SACADURA
Éléments d'Échanges Thermiques
WEILL
Heat Transfer
M. BECKER
Heat Transfer at Low Temperatures
W. FROST
Supraconductivité
Introduction to Superconductivity
A. ROSE-INNES
Superconducting Magnets
M. WILSON
Superconductivity in Particle Accelerators
CERN
La Supraconductivité
A. TIXADOR
Matériaux et Gaz
Materials at Low Temperature
R. REED
Data Series on Material Properties
J. TOULOUKIAN
Encyclopédie des Gaz L'AIR LIQUIDE
Vide
Bases de la Technique du Vide, Calculs,
Tables LEYBOLD-HERAEUS
Le Vide
P. DUVAL
Notions de base en Technique du Vide
G. ROMMEL
Les Calculs de la technique du vide
G. MONGODIN
Editeurs
Langue
CEA/SBT-LCT/1-86
Masson
Institut International du Froid Techniques de l'Ingénieur
Plenum Publishing Corporation
Plenum Publishing Corporation
Oxford University Press
Oxford University Press
F
F
F
A
A
A
A
Elsevier
Taylor and Francis
Marcel Dekker MDI
A
A
A
Technique & Documentation
Masson
Plenum Press
Plenum Press
F
F
A
A
Pergamon Press
Clarendon Press Oxford
ACCELERATOR SCHOOL CAS- 89/04
Hermès
A
A
A
F
American Society for Metals
Mac Graw Hill
Elsevier
A
A
F
Leybold-Heraeus
Masson
Société Française du Vide
Société Française du Vide
F
F
F
F
[email protected]
Thermoelastic and mechanical stresses
• Mechanical vibrations induced
by thermoelastic deformations at
each entry and exit eclipse.
• Difficult to simulate on ground
[email protected]
LEO effects
•Friction in the residual atmosphere (SKYLAB)
•Atomic Oxygen (100-650 km) (UV dissociation, V)
•Erosion: Kapton, Mylar
•Luminescence (Glow): Chemglaze and Z 302
log B ( Rayleighs )  7  0.0129 * H ( km)
A material less sensitive to
glow, seems more susceptible to
erosion
JOURNAL OF GEOPHYSICAL
RESEARCH, VOL. 100, NO. A5, PP.
7821-7828, 1995
[email protected]
The man-made debris and micrometeorites
Orbital velocity greater than
26,000 km / h
The orbit drift continually
slowly and wears one day
falling to Earth
- A few days at 300 km
- 25-30 years 600 km
- 100 to 200 years to 800 km
- More than 2000 years at 1000 km
[email protected]
Re-entry and Risk Assessment for the NASA Upper
Atmosphere
Research Satellite (UARS)
• Launched: 12 September 1991 inside STS-48
• Deployed: 15 September 1991
• International Designator: 1991-063B
• U.S. Satellite Number:
21701
• Dry mass: 5668 kg
• Initial Operational Orbit: 575 km by
580 km, 57 deg inclination
• Decommissioned: 15 December 2005 after
maneuvering into a shorter-lived disposal orbit
– Residual orbital lifetime reduced by ~ 20 years
[email protected]
[email protected]
[email protected]
UV (solar origin mostly)
Destructive effects even if small part of the solar energy.
Surface degradation (particularly polymers) by breaking bonds in
large molecules
The materials are weakened (loss of plasticity) and thus
become more susceptiblle to other aggressive agents such
as atomic oxygen.
Some lose their volatility -> irreversible CONTAMINATION.
•Solarisation: color turns brown; increase in the solar absorptivity. (Example = UV sensitive solar
panel: the protective glass and its adhesive darkening which reduces the useful illumination of the
cell and by absorption increases the equilibrium temperature of the cell and eventually destroys the
cell). The effect is particularly noticeable on deposits of contaminants that become brown and
opaque. They also become hard and impossible to evaporate by heating.
•The troublesome area for optical components is also 115 nm to 300 nm (energy range 10.8 to ente 4.1
eV), right in the absorption bands of optical materials. This type of radiation created a free e- / hole
pair that is trapped: latent defects in the network thereby creating a color center which absorbs the
blue end of the visible and makes the glass brownish effect of "solarization". Remedy: cerium-doped
glasses
•Besides the coating and glass, there are glues (optical cements) which can also be degraded by UV
irradiation;
•The fluorescence observed around shuttle structure is due to the excitation of molecules of residual
gases by UV radiation. This is really embarrassing when this happens with black coatings designed to
reduce stray light.
[email protected]
X, , energetic particles (e-, p+, heavy ions, induced
radioactivity and secondary particles)
•
X ET GAMMA
•of solar (flares) and galactic origin -> Localized and transient defects on electronic components.
•Light metal shroud is sufficient to protect them.
•These rays are more dangerous to humans and precautions are taken in the programming of extra vehicular exits.
•
Energetic particules (LEO: 1 - 2 krad (Si)/year with 4 mm equivalent Al shroud; GEO: 15 - 20 krad
(Si)/year with 4 mm equivalent Al shroud ; highest values correspond important solar eruption).
Ionization, displacement damage and rearrangement of electrons in optical materials (optics and
cements).
All these mechanisms lead to local structural defects and depending on the dose received:

transmission degradation (solarisation)

refractive index change

dielectric deterioration

internal residual stresses

Radio-luminescence and scintillation
•
HEAVY IONS
•These ions Iron, Carbon, Oxygen ... from solar flares and for a small part from cosmic radiation, because of their mass and
velocity, kinetic energy is large (> 1 GeV). Although the flow is very low, accidents due to these particles can be
catastrophic. These particles, very penetrating, ionize all materials; damages in semiconductors can range from a temporary
lapse to their total destruction. The highly integrated circuits are particularly sensitive to heavy ions. The thickness of metal
needed for effective shielding are several centimeters. These particles represent a serious hazard to astronauts, even inside
vehicles.
[email protected]
•INDUCED RADIOACTIVITY
This induced radioactivity is the result of the fission of atoms of the materials of the satellite by the impact
of high energy particles (protons and heavy ions). The radioactivity of the materials is low and poses no real
danger to men. (54Mn and 57Co from stainless steel; 22Na from aluminium; on the very low orbits of the
space station and shuttles, 7Be radioactive atoms are collected on the outside. This is one of minor
constituents of the atmosphere).
[email protected]
Radiation shielding verification by the
method of sector analysis
[email protected]
CHARGING ENVIRONNEMENT
Ve  
mp
me
.V p   43.V p 
[email protected]
[email protected]
Choix des orbites
[email protected]
Paramètres principaux dans le choix de l’orbite pour des missions d’astronomie
Paramètres
Objectifs / performances Scientifiaues
Champ de vue (surface occultée par
la Terre sur la sphère céleste)
Temps d’observation ininterrompu
sur une source choisie
M ode observatoire d’opération
Radiation (bruit de fond)
Préférences générales
Commentaires
.
HEO/GEO
HEO/GEO
GEO, HEO ou
LEO plus DRS
LEO
Contamination
HEO/GEO
Evaporation de cryogène pour
missions IR refroidies
HEO/GEO
Très faible en LEO à cause du grand angle
de vue occulté par la Terre
Généralement très faible en LEO à cause de
la période plus courte
Voir plus bas Data retrieval
HEO acceptable au-dessus de 40.000 km
(GEO marginal)
Généralement pas de problème pour
LEO au-dessus de quelques centaines de
km
Seulement applicable à des missions
comme IRA S et ISO avec stockage de
cryogène
Lancement et opérations
Disponibilité et capacité des lanceurs
Utilisation du lanceur en partage
LEO
HEO/GEO
M asse d’injection générallement plus
grande que pour des injections plus
hautes HEO/GEO
HEO à faible inclinaison via GTO (e.g.
avec des satellites de communication
Collecte des données
Couverture des stations sol
Complexité du traitement des données
à bord et des communications
Conception du satellite
GEO or HEO
HEO
Durée et fréquences des éclipses
GEO or HEO
Contrôle thermique
GEO or HEO
M aintenance d’orbite
1
LEO
Dégradation des panneaux solaires
LEO or GEO
Perturbation de l’SCAO
LEO or GEO
Si pas de satellite de relais des données
ou si pas besoin de données en temps
réel
LEO acceptable si DRS disponible ou si
lien en temps réel n’est pas impératif
Dépend des paramètres de l’orbite
spécifique et de la demande de puissance
généralement moins bien en LEO
Contrôle thermique généralement plus
simple en HEO qu’en LEO
Dépend des paramètres spécifiques
d’orbite et de la demande en puissance
Généralement moins bon en HEO
Eviter les passages au-travers des
ceintures de radiations
Dépend du minimum d’altitude de l’orbite
,
[email protected]
Space Environment & Constraints: Orbits
Orbit
LEO (low earth orbit)
Altitude
Temperature
Vacuum
Plasma
200 tot 800 km
GEO (geostationary
orbit)
36000 km
Planetary missions
and Deep Space
n.a.
-100°C to +100 °C
16 cycles/day
10-4 to 10-9 mbar
-150 °C to +120 °C
1 cycle /day
10-9 to 10-10 mbar
-180 °C to +260 °C
to 10-14 mbar
Dense cold plasma
Hot Plasma
Thin plasma
Aurora
Radiation
Van Allen belts (partial)
Cosmic Rays
hX-ray (V)UV, Vis,
Cosmic Rays, Sun activity
IR]
Solar particle events Solar particle events
Particles (98 % e-, 2%
p+, Van Allen Belts)
Solar particle events
Impacts
Micrometeorites /
Micrometeorites/ Debris
Comets
Debris
Meteoroids
Atmosphere
Atomic Oxygen
n.a.
Planets (reactive
gasses)
[email protected]
Space Environment & Constraints*
Vacuum
NUMEROUS PROBLEMS
MAINLY DIMENSIONAL STABILITY
AND LUBRICATION
CHANGE IN OPERATIONAL
PROPERTIES OF
MATERIALS
VACUUM
MODIFICATION THERMOOPTICAL
PROPERTIES
( SEE
“TEMPERATURE”)
OUTGASSING
CONDENSATION
GAS CLOUD
MODIFICATION RADIATION
EFFECTS
THERMAL
PROBLEMS
( SEE “RADIATION”)
PERTURBATION OF
MEASUREMENTS
NUMEROUS PROBLEMS
ESPECIALLY ON
SCIENTIFIC SATELLITES
CORONA
MODIFICATION ELECTRICAL
PROPERTIES
ELECTRICAL
PROBLEMS
ARC
ELECTRICAL
PROBLEMS
* Barrie Dunn, Metallurgical Assessment of Spacecraft Parts Materials & Processes, Praxis Publishing, 1997
[email protected]
Effects of Space Environment on Materials*
NUMEROUS PROBLEMS
PARTICULARLY ON
SCIENTIFIC SATELLITES
(SEE “VACUUM”)
INCREASED
OUTGASSING
RADIATION
(VV, PROTONS,
ELECTRONS)
MODIFICATION AT
MOLECULAR LEVEL
MODIFICATION
THERMO-OPTICAL
PROPERTIES
THERMAL PROBLEMS
PERTURBATION OF
MEASUREMENTS
MODIFICATION OF THE ELECTRICAL
CHARGE STATE/ SURFACE CHARGING
INCREASED SENSITIVITY
MODIFICATION MECHANICAL
PROPERTIES
BREAKDOWN
ELECTRICAL
PROBLEMS
( SEE “ATOX” )
FRACTURES (THIN
STRUCTURES UNDER
STRESS)
OTHER EFECTS ON:
COMPONENTS, MAN,
INSTRUMENTS....
( SEE “TEMPERATURE” )
[email protected]
Effects of Space Environment
Atomic Oxygen*
CONTAMINATION
CLOUD
OXIDE LAYER
PROTECTION
GENERATION OF
PARTICLES
BREAKAGE
MASS LOSS
ATOMIC
OXYGEN
(ATOX)
OXIDATION
DEGRADATION
MECHANICAL
PROPERTIES
EROSION
TEXTURE CHANGE
CHANGE IN
THERMO-OPTICAL
PROPERTIES
( SEE “TEMPERATURE” )
ELIMINATION OF
CONTAMINANTS
PROPERTY
RECOVERY
RUPTURE/
DEFORMATION
[email protected]
Effects of Space Environment on Materials
Micrometeoroids & Debris*
EXPOSURE OF
UNDERLAYER
( SEE “ATOX”)
THROUGH
HOLE
LOSS OF
MATERIAL
INTEGRITY/
CRACK
INITIATION
CONDUCTIVE
PATH
HIGH
VELOCITY
PARTICLE
IMPACT
CRATERING
DEBRIS
CHANGE IN
THERMO
OPTICAL
PROPERTIES
CONTAMINATION
CLOUD
NUMEROUS PROBLEMS
PARTICULARLY
EMBRITTLEMENT/LEAK
ELECTRICAL
PROBLEMS
( SEE
“TEMPERATURE”)
OTHER EFECTS:
PUNCTURE/DAMAGE TO
VEHICLES, FUEL TANKS
SHIELDS, SOLAR ARRAYS
(SEE “VACUUM” )
[email protected]
Launch Environment & Constraints
Temperature*
INCREASED OUTGASSING
MOLECULAR
DEGRADATION
DEGRADATION OF OPERATIONAL
PROPERTIES OF MATERIALS
HIGH
TEMPERATURE
CYCLING
DEBONDING
THERMAL
MECHANICAL
FATIGUE
FRACTURES/CRACKS
LOSS OF PROTECTIVE
COATING
LOW
INCREASED
CONDENSATION
MODIFICATION
ELECTRICAL PROPERTIES
MODIFICATION
MECHANICAL PROPERTIES
MODIFICATION CHARGE
STATE
(SEE “ATOX”)
(SEE
“RADIATIONS”)
EMBRITTLEMENT
( SEE “VACUUM”)
[email protected]
Effects of Space Environment
[email protected]
Requirements / Qualification Tests
TYPICAL EQUIPMENT REQUIREMENTS INCLUDE:
o
GENERAL REQUIREMENTS (ECSS* : SPACE STANDARDS, MANAGEMENT, PRODUCT, ENGINEERING, …)
o
FUNCTIONAL REQUIREMENTS (MODES, TELECOMMAND, TELEMETRY, RELIABILITY, REDUNDANCY…)
o
PERFORMANCE REQUIREMENTS
o
SPACECRAFT INTERFACE REQUIREMENTS (ELECTRICAL, MECHANICAL..)
o
POWER SUPPLY REQUIREMENTS (VOLTAGE, CONSUMPTION, RIPPLE…)
o
MECHANICAL REQUIREMENTS (DIMENSIONS, MASS, SINUS & RANDOM VIBRATIONS, SHOCK...)
o
THERMAL REQUIREMENTS (THERMAL INTERFACE, TEMPERATURE RANGE)
*European Cooperation for Space Standardization
[email protected]
Requirements / Qualification Tests
TYPICAL EQUIPMENT REQUIREMENTS INCLUDE:
o ELECTROMAGNETIC COMPATIBILITY (GROUNDING, ISOLATION, SHIELDING,
BONDING, CONDUCTED EMISSION, CONDUCTED SUSCEPTIBILITY, EMC, RADIATED
INTERFERENCES, RADIATED SUSCEPTIBILITY, ELECTROSTATIC DISCHARGE)
o PRESSURE ENVIRONMENTAL REQUIREMENTS (DEPRESSURIZATION)
o SPACE ENVIRONMENT REQUIREMENTS ( RADIATION TOLERANCE ...)
o PRODUCT & QUALITY ASSURANCE (RELIABILITY, MATERIALS, ACTIVITIES &
CONTROLS..)
o SAFETY REQUIREMENTS (EQUIPMENTS FOR MANNED SPACE VEHICLES)
[email protected]
Requirements / Test Sequence
TYPICAL TEST SEQUENCE INCLUDES:
o PHYSICAL MEASUREMENTS ( DIMENSIONS, MECHANICAL I/F,
MASS, C of G..)
o FUNCTIONAL PERFORMANCE MEASUREMENTS (ALL MODES,
PARAMETERS….)
o ELECTROMAGNETIC COMPATIBILITY (IF APPLICABLE)
o FUNCTIONAL PERFORMANCE MEASUREMENTS (REPEAT)
o STRUCTURAL MEASUREMENTS (SINUS & RANDOM VIBRATIONS)
o FUNCTIONAL PERFORMANCE CHECK (REPEAT)
o THERMAL VACUUM TEST (TEMPERATURE CYCLING INCL.
FUNCTIONAL PERFORMANCE )
o FUNCTIONAL PERFORMANCE MEASUREMENTS (REPEAT)
o VISUAL INSPECTION
[email protected]
Specificity of Space Related Developments
Some conclusions
LAUNCH & SPACE ENVIRONMENT + UP TO 15 YEARS LIFE TIME
WITH NO MAINTENANCE IMPOSES:
o SEVERE MASS, THERMO-MECHANICAL & RELIABILITY
REQUIREMENTS
o STRICT CONFIGURATION CONTROL, MATERIAL & PROCESS
SELECTION
o STRICT ADHERENCE TO ECSS STANDARDS FOR MANAGEMENT,
SPACE PRODUCT AND SPACE ENGINEERING
o QUALIFIED MANPOWER FOR SPACE EQUIPMENT PRODUCTION
o LARGE INVESTMENTS IN FACILITIES FOR DEVELOPMENT,
PRODUCTION & VERIFICATION
SOME SME’S HAVE SUCCEEDED IN THE SPACE EQUIPMENT
MARKET FOR PART OF THEIR BUSINESS. MORE WILL SUCCEED
IN THE FUTURE, ALONE OR IN COOPERATION WITH LARGER GROUPS
•
[email protected]
Le Soleil
All the heat input to the solar system (excluding planetary radioactive
decay processes), and its mass is 99.9% of the total  the sun
dominates the space environment of the whole solar system.
• Ordinary star: Mass -2 x 1030 kg, modest by stellar standards, and is
one of ~1011 stars that form our galaxy.
• G2V star, with a yellowish appearance because its radiated light peaks
at ~ 460nm, and it is termed as a yellow-dwarfstar.
• Radius is 7 x 1O8 m.
• After the Sun, the nearest star is 3.5 light years away (1 light year =
9.46 x 1012km) and between the stars the gas density is low, with
hydrogen as the dominant species.
• The density amounts to onIy 3 atom/cm³, in comparison to the nominal
number density of our own atmosphere at sea level of 3 x 1019
molecules/cm³
• Fundamentally, a giant thermonuclear fusion reactor whose surface
temperature is ~ 5.800K. The photosphere is optically thick, and its
spectrum approximates to that of a black body.

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