INTRODUCTION TO AEROSPACE

ENGINEERING

BY

Ms. G. Sravanthi
Assistant Professor

Mr. R. Suresh kumar

Assistant Professor

INSTITUTE OF AERONAUTICAL ENGINEERING

(Autonomous)
Dundigal, Hyderabad - 500 043
AERONAUTICAL ENGINEERING
Early Flight to
World War I
 Overview

• Early Uses of Lighter-than-Air Flying

Machines
• Heavier-than-Air Flying Machines
-The US Army's Reaction to the Wright Brothers' Invention
-The Army's Requirements for the First Military Aircraft
• Early Uses of Airpower
Early Years of Flight
Introduction
• Man first flew aloft in a balloon in 1783
• Airpower did not have an immediate
impact
• Flying machines were not readily accepted by land
oriented officers
• Airpower's first major impact was not until World War
I
Balloons

• Mongolier Brothers flew first hot-air balloon in 1783

• Ben Franklin saw first balloon flight and immediately
saw the military potential
• First used for military purposes by the French in
1794 at Maubege
• Union and Confederate forces employed balloons
during the American Civil War
Balloons (Cont)

• Adolphus V. Greely, the grandfather of military

aviation in US, revived interest in military capability of
balloons in 1891
 -1892 -- Greely balloon used to direct artillery fire during the
Battle of San Juan Hill
• Interest in balloons dropped quickly with the
development of heavier-than-air vehicles

Dirigibles

・Steerable balloons - often called '^Airships"

• 1884 - first successful flight in a dirigible
• Ferdinand Von Zeppelin - person most readily
identified with dirigibles
-Zeppelins first flown in 1900
 -Germans used to bomb England in WW I
-Germans used to fly observation cover for their surface
fleet in WW I
・ Vulnerable to winds and ground fire
The Early Years of Flight

Uses of Balloons and Dirigibles

-Reconnaissance
-Artillery spotting
-Bombing (extremely limited prior to WW I) -Morale
Booster/Mail/Escape Means
 -Air transport of supplies

Early Pioneers of Flight

• Otto Lilienthal - studied gliders and first to explain the

superiority of curved surfaces
• Percy Pilcher -- built airplane chassis
• Octave Chanute - Developed a double winged-
glider/wrote history of flight tol900
• Samuel P. Langley - First to secure government
support to develop an airplane
-Failed twice to fly from houseboat in 1903 -Congress
 withdrew monetary support

Orville and Wilbur Wright

• First to fly a heavier-than-air, power-driven machine -

17 December 1903
-Flight traveled 120 feet and lasted 12 seconds
• Approached flying scientifically and systematically
• Used experience of Lilienthal, Pilcher and Chanute
• Built a glider in Dayton in 1899
-Moved to Kitty Hawk, N. Carolina in 1900
Reactions to the Wright's Invention
• US government was very skeptical at first
-Not interested because of the Langley's failures
• Britain and France were very enthusiastic
• President Roosevelt directed the Secretary of War,
W. H. Taft, to investigate the Wright
Brothers' invention in 1906
• Dec.1907 - Chief Signal Officer, BG James Allen,
issued Specification #486 calling for bids to build
the first military aircraft
 Signal Corps Specification
#486
• Established the requirements for the first military
aircraft. Aircraft must be able to:
-Carry 2 persons
-Reach speed of 40 mph
-Carry sufficient fuel for 125 mile nonstop flight
-Be controllable in flight in any direction
-Fly at least one hour
-Land at take-off point, without damage
-Be taken apart and reassembled in one hour
-No Military Operational Requirements Specified

11
 Specification # 486 (Cont)
• 41 proposals were received, only 3
complied with specifications
• US Army signed contract with Wright Brothers
on 10 Feb 1908
• Wright Brothers delivered the first military
aircraft on 20 Aug 1908
• US Army accepted the first operational aircraft
on 2 Aug 1909
The Early Years of Flight
Closing Remarks
• Until WW I balloons, dirigibles and aircraft were
primarily reconnaissance vehicles
• Early on, the flying machines were not seen as
weapons of war
• Few believed the flying service was ready to be
a separate air force
• The potential uses of the airplane would
evolve considerably during WW I

13

Summary

• Early Uses of Lighter-than-Air Flying

 Machines
• Heavier-than-Air Flying Machines
-The US Army's Reaction to the Wright Brothers'
Invention
-The Army's Requirements for the First Military
Aircraft
• Early Uses of Airpower

14
History of Flight
 Aviation Through the Ages
lOOOB.Cto 1250A.D
• Man's observations of the earth around him aroused his
curiosity and often inspired him to attempt the impossible.
How did man's lack of knowledge of the physical laws of
nature sometimes bring him tragedy?
• The Greek myth of Daedalus and his son Icarus was written
around 1000 B.C. The myth states that after Daedalus built
the labyrinth the king of Crete threw him in it to test it. He and
his son Icarus escaped by building wings of wax and flying
away. However Icarus flew too high and the wax in his wings
began to melt. His wings collapsed and he plunged to his
death in the sea.
• Kites flown around the year 400 B.C. in China were ancestors
of modern aviation and the airplane. In the year 1020 A.D.
Oliver of Malmesbury put on a pair of wings and leapt from
the top of an abbey. He landed very hard and broke his legs.
Luckily he survived the crash. Many others attempted to fly
with "wings" but all failed, sometimes fatally.
 Aviation Through the Ages
1250 to 1750

I was one of the first to experiment with the

science of flying. Unfortunately my writings and
sketches weren't discovered until three hundred
years after my death.
Leonardo da Vinci spent most of his life exploring
flight and left the world about 160 documents of
sketches and observations about flight. He made
important discoveries about the center of gravity,
the center of pressure, and streamlining. But like ■

so many people of his time he was obsessed with

learning to fly like a bird. What is the difference
between simply gliding and really flying like a bird?
 Aviation Through the Ages
1750 to 1850
What forces cause smoke to rise in a fireplace? This was what
sparked Montgolfier's curiosity.
Joseph and Etienne Montgolfier designed the first
successful flying craft. Their observations led them to believe
that burning created a gas, which they called "Montgolfier's
gas," causing a craft to rise. They constructed a balloon made
of cloth and paper. The first aviators were a duck, rooster, and
a sheep. Then in 1783 a crowd in Paris watched as a
Montgolfier balloon carried two French men. The way the
balloons worked is hot air and gases filled the balloon causing
it to lift. Once it was in the air it simply went wherever the wind
took it. To counter this problem Henri Gif fa rd designed a
round oval shaped balloon called a blimp and combined it with
a steam engine to make it steerable. When gasoline engines
were invented they became a major source of transportation
across the Atlantic Ocean. The Hindenburg zeppelin disaster in
1937 caused the end for these large airships.
 Aviation Through
the Ages 1850 to
1900
Sir George Cayley set in motion the future
study of aerodynamics in a single sentence.
"The whole problem is confined within these
limits, namely to make a surface support a
given weight by the application of power
to the resistance of air."
Sir George Cayley experimented with
gliders at his home in Yorkshire. He was
the first to discover how wings work.
aircraft that was heavier than air. He is
now recognized as the father of aviation.
He came up with many principles of
heavier-than-air flight.
Cayley discovered that wings are lifted on the
air. He also constructed the first
 Aviation Through the Ages
1850 to 1900
In 1896, the German engineer,
Otto Lilienthal, tested several
monoplane and biplane gliders.
He built and flew the first glider
capable of carrvins a oerson. but died when he crashed in

gust of wind before he could

finish his powered plane.
a sudden
The structure of an airplane as we know it today was in its
formative years. What are the parts of a plane and how
does each function?

AIRPLANE
An airplane is a vehicle heavier than air, powered by an
engine, which travels through the air by the reaction of air
passing over its wings.
FUSELAGE
The fuselage is the central body portion of an airplane
which accommodates the crew and passengers or cargo.
COCKPIT
In general aviation airplanes, the cockpit is usually the
space in the fuselage for the pilot and the passengers: in
some aircrafts it is just the pilot's compartment. LANDING
GEAR
The landing gear, located underneath the airplane,
supports it while on the ground. WINGS
Wings are the parts of airplanes which provide lift and
support the entire weight of the aircraft and its contents
while in flight.
 EXPERIMENT 2
Equipment:
・ 2 sheets of notebook paper
・Hold two sheets of notebook paper about four
inches apart. Blow between them. Instead of
flying apart they come together. The air
moving rapidly between the two pieces of
paper has less pressure than the air pressing on
the outer sides of the paper.
 Equipment:
Ping-pong ball
Tank-type vacuum cleaner Connect the hose to the blower
rather than to the suction end of the vacuum cleaner. Turn the
switch on. Hold the hose vertically so the stream of air goes
straight up. Release the ping-pong ball into the stream of air
about a foot from the nozzle. Slowly tip the nose so that air
shoots at an angle. The ball will stay suspended in the
airstream. The force of gravity upon the ball tends to make it
drop out of the airstream. However, the fast moving airstream
lessens the air pressure on the portion of the ball remaining in
the airstream, overcoming the force of gravity, which results in
the ball remaining suspended.
 Aviation Through the Ages
1900 to 1935

• "Only those who are acquainted with practical

aeronautics can appreciate the difficulties of attempting
the first trials of a flying machine in a 25mile gale... but...
we were determined... to know whether the machine
possessed sufficient power to fly."
• That was Wilbur Wright's statement to The Associated
Press, January 5, 1904.
• At 10:35 a.m. on December 17,1903 the world's first
successful airplane known as the Flyer I accelerated
along its launching rail and flew through the air. Twelve
seconds later it landed 100 yards away on the soft sand
at Kill Devil Hills near Kitty Hawk, North Carolina. The
pilot Orville and his brother Wilbur had experimented for
four years with kites and engines to make the first
successful flight ever.
• The brothers had made their own engine that weighed
200 pounds and had four cylinders. It could make 12
horse power, a sixth of the engine power of a small car.
It had no seat and the pilot had to lay in a cradle in the
bottom wing.
 Aviation Through the Ages
1900 A.D to 1935 A.D
The Wright brothers continued to perfect their plane and it was in a
Wright biplane that the first transcontinental flight was made by
Calbraith P. Rodgers, in 1911.

The key to their success was to learn how to control the plane.
How were they able to accomplish this task?

In 1914 World War I broke out. At first planes were used mostly for
reconnaissance, but later planes developed into biplane and that
are still in modified use today. The compass was an important
instrument to these early fighters. How do they work? How has the
triplane fighters and bombers. Experiments were done with even
more sets of wings, but most failed. The main fighters of the war
were the British Sopwith "Camel," its cousin, "The Snipe," and the
famous German Fokker Df.l which was flown by the infamous Red
Baron. Aerial tactics and strategies were developed during the
middle of the war. Germany developed many fighter tactics
technology changed over the decades?
 Aviation Through the
Ages
1900 to 1935
After the war General Billy Mitchell became an advocate
for military aviation. He and his pilots achieved many
firsts in the field of aviation during these golden years.
But the Europeans were leading the race in commercial
flight. It wasn't until Ralph Pulitzer offered a trophy to
promote high-speed flight and began a national craze for
air races that the American public began to take notice.
In 1918, the Post Office Department started airmail
service in the United States. The first Mailwing was built
by Pitcairn Aviation, Inc. In 1926, Congress passed the
Air Commerce Act. This established an Aeronautics
Branch within the Department of Commerce. They were
authorized to license planes and pilots and provide
standards for commercial flight. And in 1927, Charles
Lindbergh completed the first transatlantic flight. He
instantly became a world hero.
Amelia Earhart was the first woman to fly solo across the
Atlantic in 1928.
 Aviation Through the Ages
1935 A.D to 1950 A.D

New technologies developed throughout the course of

World War II. The motto was if you commanded the
skies you could win the war.
World War II implemented almost exclusively
monoplanes. Both sides of the war manufactured
literally thousands of fighters and bombers. The main
Allied planes included the British Supermarine Spitfire
Mk.IV, the American P-51 Mustang, the American C-
4(J Corsair, the American B-17, and the American B-
29 Superfortress. The Grumann F6F Hellcat was first
used in 1943 and became the premier carrier fighter
plane. The main Axis planes were the Bfl09, the
Junkers Ju-22, and the Stuka dive-bomber. The
mainstay of the Japanese forces was the feared
Mitsubishi Zero-sen. Our hangar also includes the
North American T28 B and the AT- 6 Texan, other
planes from this period.
 Aviation Through the Ages
1935 A.D to 1950 A.D
The major air battle of WW II was the Battle of
Britain. For days the much larger
German Luftwaffe attacked the
British Isles, but the small number of
British Spitfires always seemed to
know exactly where and when the
German bombers would be
attacking and how large of a force.
The reason for this was a relatively
new technology called radar allowed
the British ground stations to detect
and identify the size, speed,
distance, and trajectory of the
German bombers and send their
Spitfires on perfect intercept
missions.
Aviation Through the Ages
1935 A.D to 1950 A.D

Instrumentation was crude in comparison to

today's technology. In the early days
pilots relied on landmarks and
sometimes even preset bonfires to
guide them along their way. What were
the early instruments like and what
were their functions? How has
instrumentation evolved through the
ages?
In the late 1940's, the military had
developed the jet engine and began
changing over to jet fighters. This
resulted in faster and better performing
craft. New aviation records were set. In
1947, Chuck Yeager broke the sound
barrier.
Aviation Through the Ages 1950 A.D to
1975 A.D

After Chuck Yeager's supersonic flight in 1947,

aviation entered a new era dominated by jets. The
years following the war saw the aviation industry grow
in leaps and bounds. The military airforce developed
more effective planes to address the arms race with
Russia. The B-47 and B-52 bombers were built to be
used to deliver nuclear bombs. They were the world's
heaviest bombers and could hold up to 99,206 pounds
of bombs. Early bombers flew so high that the crew
had to wear pressure suits but later they were used at
low altitude because they were harder to locate with
radar.
 Aviation Through the Ages
1950 A.D to 1975 A.D

In September, 1955, a contract was awarded to North

American Aviation for the X-15 plane which could fly at
4,500 miles per hour at an altitude of at least 70,000 feet.
54 percent of its total weight was its fuel (18,000 pounds).
The total weight of the X-15 was 33,000 pounds. Though
only three of this type of plane were built they flew a total
of over 200 times. The highest speed ever reached was
about 4,525 miles per hour or Mach 6.72.
 Aviation Through the Ages
1950 A.D to 1975 A.D
In 1958, the first American commercial jet, the 707,
was put into service by the Boeing Company. The
commercial liners were an instant hit with passengers
who appreciated the faster flying time. Again new
records were set. By 1966
both Lockheed and Douglas Aircraft Corporations^
had entered the commercial industry giving rise to
competition and the development of new
technologies.
During the Vietnam War the use of military air
power was somewhat limited by policy in
Washington. President Nixon launched the only
strategic bombing campaign of the war. Many
fliers were shot down over Southeast Asia. They
were recently honored in a ceremony dedicating
the Missing Man Monument at Randolph Air Force
Base, in Texas.
 Aviation Through the
Ages
1975A.D to 2000A.D
・ Aviation has changed much since the beginning of time.
・ The world's first supersonic commercial passenger aircraft operating regular
scheduled flights was the Concorde. It was developed jointly by Great Britain and
France during the 1960s and 1970s when the Comet 4, the DC-3, and the
Constellation were in regular service. No other supersonic aircraft can fly as fast
and as far as the Concorde without needing mid-flight refueling. Some military
aircraft can fly faster, but need in-flight refueling. The Concorde flies literally on the
edge of space, high through the atmosphere. Passengers are even capable of
seeing the earth's surface.

・ The Nighthawk (F-117A) first flew in 1981 and began combat in 1989. This jet was
designed to avoid detection and mount precision attacks. It is the first stealth
combat aircraft in the world. It has a top speed of 593 mph (955 kph) and is loaded
with 5,000 lbs. of weapons. The choice of weaponry varies from laser- guided
bombs, air-to-air missiles, or air-to-surface missiles. Two types of weapons can be
carried at one time. The outside of the Nighthawk is coated with a special material
that absorbs some of the radar signals that strike it. It is protected by 24 hour
security with armed guards all around it. Authorized personnel must pass a palm
print test to get near the aircraft.
 Aviation Through the Ages
1975A.D to 2000A.D
• The CL-415, or "Firebird," is a very
important aircraft. This aircraft is
amphibious, which means it can be
operated from land or water. It was
developed by Canadair to stop raging
forest fires. However, it is also useful for
search and rescue missions, especially on
the sea. It can search for survivors for up
to seven hours before refueling. It can
scoop water into its tanks. Through doors
in the bottom of the aircraft it drops water
on the fire.
• The age of computers continues to impact
the aviation field. Today's technology is
exciting and it seems as if "the sky's the
limit" as we look into the future.
Aviation today and
tomorrow

• Boeing 787
designed completely on
the computer
• will carry 250 - 290
passengers on routes of
8,000 to 8,500 nautical
miles
The airplane will use 20
percent less fuel for
comparable missions than
today's similarly sized
airplane. It will also travel
at speeds similar to today's
fastest wide bodies, Mach
0.85. Airlines will enjoy
more cargo revenue
capacity.
 Martin Aircraft - Maryland

• 1937 Mini-Mariner,
the flying prototype
of the WWII flying
boat bomber

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Basic Properties of the
Atmosphere
 Essential Points
1. Heat, Temperature and Temperature Scales
2. The Electromagnetic Spectrum
3. Composition of the Atmosphere
4. Layers in the atmosphere are defined by
temperature profiles
5. How pressure varies in the atmosphere
6. Principal weather instruments
7. Earth's radiation budget
 Heat and Temperature
• Temperature: Average energy of molecules or
atoms in a material
• Heat: Total energy of molecules or atoms in a
material
・ Can have large amount of heat but low
temperatures
・ Can have high temperatures but little heat
Heat and Temperature
• The earth's outermost atmosphere is
extremely "hot" but its heat content is negligible
• The surface of the moon can reach 250 F in
sunlight and -200 F in shadow, but the vacuum
around the Apollo astronauts contained no heat.
• It takes time for things to warm up and cool off.
 Temperature Scales

・ Fahrenheit
-Water Freezes at 32 F
-Water Boils at 212 F
・ Centigrade or Celsius
-Water Freezes at 0 C
-Water Boils at 100 C
・ Two scales exactly equal at -40

1. Heat, Temperature and

Temperature Scales
 Absolute Temperature
・Once atoms stop moving, that's as cold as it can
get
• Absolute Zero = -273 C = -459 F
• Kelvin scale uses Celsius degrees and starts at
absolute zero
・Most formulas involving temperature use the
Kelvin Scale

Electromagnetic Radiation

• Radio: cm to km wavelength
• Micro waves: 0.1 mm to cm
• Infrared: 0.001 to 0.1 mm
• Visible light 0.0004-0.0007 mm
• Ultraviolet 10’9 - 4 x 10'7 m
• X-rays IO13 - IO 9 m
• Gamma Rays 1015 -1011 m

2. The Electromagnetic
 Composition of the Atmosphere
• Nitrogen 78.08%
• Oxygen 20.95%
• Argon 0.93% (9300 ppm)
• Carbon Dioxide 0.035% (350 ppm)
• Neon 18 ppm
• Helium 5.2 ppm
• Methane 1.4 ppm
• Ozone 0.07ppm
Other Components of the Atmosphere

3. Composition of the
・ Water Droplets
・ Ice Crystals
・ Sulfuric Acid Aerosols
・ Volcanic Ash
・ Windblown Dust
・ Sea Salt
・ Human Pollutants

Structure of the Atmosphere

• Defined by Temperature Profiles
• Troposphere
-Where Weather Happens
• Stratosphere
-Ozone Layer
• Mesosphere
• Thermosphere
-Ionosphere

4. Layers in the atmosphere are

defined by temperature
 Troposphere
• Heating of the Surface creates warm air at surface
• Warm air rises, but air expands as it rises and
cools as it expands (Adiabatic cooling)
• Heating + Adiabatic Cooling = Warm air at surface,
cooler air above
• Buoyancy = Cool air at surface, warmer air above
• Two opposing tendencies = constant turnover

4. Layers in the atmosphere are

defined by temperature
profiles

Stratosphere
• Altitude 11-50 km
• Temperature increases with altitude
・-60 C at base to 0 C at top
• Reason: absorption of solar energy to make ozone
at upper levels (ozone layer)
• Ozone (O3) is effective at absorbing solar
ultraviolet radiation

4. Layers in the atmosphere are

defined by temperature
 Mesosphere
・ 50-80 km altitude
・ Temperature decreases with altitude
・ 0 C at base, -95 C at top
・ Top is coldest region of atmosphere

defined by
temperature
 Thermosphere

• 80 km and above
• Temperature increases with altitude as atoms
accelerated by solar radiation
• -95 C at base to 100 C at 120 km
• Heat content negligible
• Traces of atmosphere to 1000 km
• Formerly called Ionosphere

4. Layers in the atmosphere are

defined
defined by
by temperature
temperature
 Why is the Mesosphere so Cold?

・ Stratosphere warmed because of ozone layer

・ Thermosphere warmed by atoms being
accelerated by sunlight
・Mesosphere is sandwiched between two warmer
layers
How Heat Moves

• Radiation
• Conduction
• Convection
 Magnetosphere
The Earth s Magnetosphere
Magnetosheath Plasmasphere

Lobe Region

Polar Cusp Plasma Sheet

solar wind

Geosynchronous
Orbit
Van Allen Earth's Geomagnetic
Field Lines—v .

Plasmasphere

Magnetopause -

Magnetotail
BowShock

Space Engineering 2 © Dr. X Wu,

2010
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 Effects of Spacecraft / Plasma Interactions

• plasma wave generation

• arcing and sputtering at significantly high
negative potential relative to the plasma
• spacecraft charging at high inclination
orbits
• current balance between the space vehicle
and the ambient plasma
• geomagnetic field effects

Space Engineering 2 © Dr. X Wu,

2010
 Solar Environment

Calendar Year
Sunspot NumberSunspot Number

Calendar Year
Space Engineering 2 © Dr. X Wu,
2010
 Solar Wind
• The solar wind is a stream of energized, charged particles,
primarily electrons and protons, flowing outward from the Sun
• Composition similar to the Sun's corona
- Protons (~ 70%), electrons, ionized helium, less than 0.5% minor
ions -Genesis mission
• Approximately 109 kg/s of material is lost by the sun as ejected
solar wind
• Speed: 200 - 900 km/s
• Solar sail
• Solar wind is also a plasma environment
- Not just gas
—Electrically conductive

Space Engineering 2 © Dr. X Wu,

2010
 Ionizing Radiation
• Radiation has a major impact on on-board
digital circuitry
-Long-term degradation and failure (ranges from
months to years)
-Short-term, single event effects (SEE)
• Minor (bit flips)
• Major (catastrophic burnout)

Space Engineering 2 © Dr. X Wu,

2010
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 Radiation Effects
ENVIRONMENTS EFFECTS
(increasing charged-
particle energy)

Pay load
interference

Damage to components

Electi’ostatic discharge

p ar as itic currents...
Ionospheric Plasma

Residual Atmosphere
(Atom io O xygen:)

Meteoroids &
Space Debris

Space Engineering 2 © Dr. X Wu,

2010
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Radiation Belts

Two belts (donut shaped)

• Magnetic field traps the particles
• Discovered by Explorer III in 1958
• Composed of 5
9
 -Electrons
-Protons
- Some heavy ions
• Effects
- Electrons: total dose
- Protons: total dose and SEE
-Ions: SEE

Space Engineering 2 © Dr. X Wu,

2010

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Movement of Particles

Space Engineering 2 © Dr. X Wu,

2010 61
South Atlantic Anomaly
Magnetic field weaker in South
Atlantic
Result is particle penetration
Note polar effect as well SEU
effect on UoSat-2
SEUs as World-Mau - OBC

-180-120 -60 0 60 120 180

Space Engineering 2 © Dr. X Wu,

2010 6
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 Galactic Cosmic Rays
• High energy particles from interstellar
space
• Flux inversely related to solar max
periods
• Primary effect
-Single event upsets

Space Engineering 2 © Dr. X Wu,

2010
 Radiation Effects on
Spacecraft:
Solar Cells
• High energy protons & electrons
collide with the crystal lattice
Curremt, mA

structure
• Collisions displace atoms from
their lattice sites
• Eventually, the
displaced atoms form stable
defects
• Defects change the propagation
of photoelectrons in the lattice
GaAs/Ge Solar Cell Performance after Irradiation with 500 keV Protons structure
Fluence of 1 x 1013 p/cm2

Space Engineering 2 © Dr. X Wu,

2010 6
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 Radiation Effects on Spacecraft: Solid State
Devices
• Nominal MOS or CMOS technology
• Charged Particles:
-Voltage output of a "GATE"
switches abruptly from a "0" to a "1" at a
specified voltage
• Radiation:
-Switching threshold changes
- Drain current and output voltage also change
• Effects caused by cumulative effect of high
Change in CMOS Inverter Transfer energy protons and electrons (Cumulative
Characteristic for Condition I (Vp the Gate
Bias During Irradiation, is 0 Volts for the p- Dosage measured in rads)
Channel and +10 Volts for the n-Channel;
VJJD is 10 Volts.

Space Engineering 2 © Dr. X Wu,

2010 64
 Summary of Radiation Types
Radiation Source Particle Type Primary Effects

Trapped radiation belts Electrons Ionization damage;

Protons Ionization, SEE.

Galactic Cosmic Rays High-energy, heavy, SEE

charged particles

Solar Flares Electrons Ionization

Protons Ionization, SEE
Lower-energy, charged SEE
particles

Space Engineering 2 © Dr. X Wu,

2010
 Meteoroid/Orbital Debris
• Meteoroid population consists the remnants of comets, spent
rocket stages, fragments of rockets and satellites, other
hardware, as well as operational satellites.

Space Debris as a Function of Altitude

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2010 66
Micrometeoroids/Orbital Debris
• Example collisions
- Russia/US satellites collision
- Cerres/Ariane 3rd Stage Debris
• VERY HIGH kinetic energies
• NASA predicted results
- Fatal spacesuit damage from 0.3 to 0.5 mm particle
- Catastrophic shuttle damage from 4 mm particle

Space Engineering 2 © Dr. X Wu,

2010 67
 Micrometeoroids/Orbital Debris: Defense

• Double Wall Bumper

- 1st wall fragments impacting
particle into smaller, slower pieces
- 2nd wall stops those pieces

ESA Scientific Spacecraft

(flew through Halley's Comet dust cloud)

boost motor after firing

Fig. 3.29 Giotto spacecraft with Whipple meteor bumper.

Space Engineering 2 © Dr. X Wu,

2010 6
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Environments and Effects
Debris: Magnitude of Problem

NORAD tracks ~7000 objects larger than 10

cm
Only 5% are operational S/C Statistical analysis
suggests ~40,000 larger than 1 cm
Collisions generate more debris -ie 1985
hypervelocity ASAT test estimated to have created 106
fragments between 1 mm and 1 cm diameter

Gravitational Field
• Free Fall Environment (not Zero-G or
Microgravity) -At Sea Level: ag = 9.8 m/s2= 1.0
g
-At 200 km: ag = 9.2 m/s2 = 0.94 g
-At 1000 km: ag = 7.3 m/s2 = 0.75 g

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 -At GEO: ag = 0.2 m/s2 = 0.023 g
• Effects:
- Structures/Mechanisms: Minimum size structural components
- Propulsion: Fuel flow (ullage burns, etc)
- TCS: Fluid flow considerations (heat pipes wicking)
-etc

Spacecraft Environment Related

Anomalies
• Flare/Geomagnetic Storm
- GOES-7: lost imagery and communications, solar arrays degraded
2-3 years worth
- DSP: star sensor contamination, memory upsets, lost data, power
panel degradation
-Memory Upsets: DMSP, GPS, INTELSAT TDRSS
• Spacecraft Charging
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 - Milstar: power supply failure
-Anik: momentum wheel failure
-GOES: phantom commands
• Galactic Cosmic Ray
-Pioneer: memory anomalies

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 Conclusions
Definition of the flight environment is the first critical step.
Not all space environments will have a critical impact on a
particular mission.
After definition of the space environment is established
including results from trade studies, the next important step is
to establish a coordinated set of natural space environment
requirements for use in design and development.
The space environment definition and requirements are
documented in a separate program document or are
incorporated into design and performance specifications. The
environments specialist then helps insure that the environment
specifications are understood and correctly interpreted
throughout the design, development, and operational phases of
the program.

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