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International Workshop on EOSS for Remote Sensing, 20-23 Nov. 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 1
New Concepts of Small Satellites for
Remote Sensing
Rainer Sandau
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 2
OUTLINE
1.Whatisa smallsatellite?
2.Small satmissions: Facts & Trends
3.Costreductionmethods
4.Applicationareaswithexample
5.Aboutthefutureof smallsatellitesforremotesensing
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 3
Definition-Confusion
ESA:
•Small
350kg –700kg
•Mini
80kg –350kg
•Micro
50kg –80kg
EADS Astrium
•miniXL
1000kg –1300kg
•Mini
400kg –700kg
•Micro
100kg -200kg
CNES
•Mini
500kg + P/L(Proteus)
•Micro
120kg + P/L (Myriade)
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 4
1 M$
10 M$
100 M$
cost
1 yr
2 yrs
5 yrs
response
time
examples
CubeSat:
1 kg, ca. 2 yrs, 0.2 M$
ENVISAT:
8 t, 15+ yrs, 3 ×
109$
mass
1 kg
10 kg
100 kg
10 000 kg
Pico
Nano
Micro
Mini
Small Satellites
Large Satellites
1000 kg
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 5
WhySmall Satellites
Classification parameters
Mass/Volume
Costs
Preparation time
have large influence on
Launch costs
number of opportunities
adoption of new applications
temporal resolution (through constellations)
reliability/continuity (replacement)
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 6
The advantages of small satellite m
issions are:
more frequent mission opportunities and therefore faster return of
science and for application data
larger variety of missions and therefore also greater diversification of
potential users
more rapid expansion of the technical and/or scientific knowledge base
greater involvement of local and small industry.
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 7
Small satellite m
issions are supported by
several contemporary trends:
Advances in electronic miniaturization and associated performance
capability;
The recent appearance on the market of new small launchers (e.g.
through the use of modified military missiles to launch small satellites);
The possibility of ‘independence’in space (small satellites can provide
an affordable way for many countries to achieve Earth Observation
and/or defense capability, without relying on inputs from the major
space-faring nations);
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 8
SpaceMission
GroundSegment
Launch
Segment
SpaceSegment
S/C monitoring& control
P/L datareception& archives
P/L dataproducts& distribution
Small & microlaunchers
Piggyback
New privat & seedcapital
Spacetourism
S/C bus
P/L
Open systems
Automation
“Internet”Technology
Increasing on-board autonomy
Multi-session operations
Ground station networks
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 9
CostReductionMethods
Method
Mechanism
Comments
Programmatic
Schedule Compression
Reduces overhead of standing arm
y;
forcing program to m
ove rapidly does
drive down cost
Often results in a poor design due to lack
of up-front mission engineering; must
reduce work required to be consistent
with schedule
Reduce Cost of Failure
Allows both ambitious goals and
calculated risk in order to m
ake major
progress
Fear of failure feeds cost-growth spiral;
major breakthroughs require accepting
the possibility of failure—
particularly in
test
Continuous, Stable Funding
Maintains program continuity; maintains
team
together
Program delay will be funding break
+ 2–4 m
onths
Minim
ize Documentation
Reduces programmatic overhead for
creating, reviewing, and m
aintaining
Critical to document reasons for key
decisions and as-built design
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 10
CostReductionMethods(cont.)
Personnel
Improved Interpersonal
Communications
Dramatically reduces errors and
omissions; conveys understanding as
well as data
Large programs use form
al, structured
communications through specified
channels
Small Team
Clear, nearly instantaneous
communications; high morale; strong
sense of personal responsibility
Problem if a key person drops out — but
in practice it rarely happens.
Co-located Team
Improves communications
Best communications are face-to-face,
but AMSAT and others don’t seem to
need it
Empowered Project Team
Rapid decision making; strong sense of
personal responsibility; can make
“sensible” decisions
Eliminates a major function of the
managem
ent structure
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 11
CostReductionMethods(cont.)
System
s Eng.
Trading on Requirem
ents
Eliminates non-critical requirem
ents;
permits use of low-cost technology
Makes traditional competition difficult
Concurrent Engineering
Allows schedule compression; reduces
mistakes; increases design feedback
High non-recurring cost relative to
lowest cost programs
Design-to-Cost
Adjusts requirem
ents and approach until
cost goal has been achieved;
Spacecraft have rarely used it
Large Margins
Reduces testing; better flexibility;
reduces cost of eng, manufac., and ops
Margins traditionally kept sm
all for best
perform
ance —
drives up develop. cost
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 12
CostReductionMethods(cont.)
Technology
Use COTS Software
Immediate availability; dramatically
lower cost; tested through use
May need m
odification and thorough
testing; typically not optimal
Use COTS H/W
Sam
e as software
Sam
e as software
Use Existing Spares
Reduced cost; rapid availability; m
eant
for space
Only works so long as spares exist — not
applicable for operational programs
Use of Non-Space
Equipment
Takes advantage of existing designs and
potential for mass production
Typically not optimal; m
ust be space
qualified
Autonomy
Reduces operations costs
Can increase non-recurring cost
Standardized Components
and Interfaces
Reduces cost and risk by reusing
hardware; standardization is a major req.
for other types of manufacturing
Has been rem
arkably unsuccessful in
space; sub-optimal in terms of weight
and power
Extensive Use of
Microprocessors
Minim
izes weight; provides high
capability in a small package; allows on-
orbit reprogramming
Problem of single-event upsets; high
cost of flight software; very difficult to
manage software development
Common S/W
for Test and
Ops
Reduces both cost and schedule; avoids
reinventing the wheel
May be less efficient, user-friendly than
ops group would prefer
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 13
Earth Observation Request(1)
1 2 3 4 5 6 7 8 9
100m
10m
1m
0,1m
0,01m
geometrischeAuflösung
1
2
4
5
3
8
7
6
9
1 2 3 4 5 6 7 8 9
100m
10m
1m
0,1m
0,01m
Auflösung
1
2
4
5
3
8
7
6
9
GSD
SpectralResolution
PanchromaticMultispectralHyperspectral
-Hydrology
-Agriculture
-Ressource Monitoring
-EnvironmentalMonitoring
-Forestry
-IntelligenceServices
-Urban Development
-Topography
-Traffic
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 14
Earth Observation Request(2)
1
101
102
103
104
105
1
1 year
10 years
110
100
1.000
10.000
RevisitTime [h]
geometrische Auflösung[m
]
1 5
-Kartographie
-Geologie
2 6
-Forstwirtschaft
-Ozeanographie
3 7
-Landwirtschaft
-Hydrologie
4 8
-Naturkatastrophen
-Meteorologie
1
2
3
5 6
48
7
1
101
102
103
104
105
1 day
1 m
onth
1
10
110
100
1.000
10.000
ösung[m
]
1
101
102
103
104
105
1
1
10
110
100
1.000
10.000
[m]
1 5
-Mapping
-Geology
2 6
-Forestry
-Oceanography
3 7
-Agriculture
-Hydrology
4 8
-DisasterMonitoring
-Meteorology
1
2
3
5 6
48
7
GSD [m]
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 15
Possibilities
The installed Earth observation satellites show
high spectral resolution
poor temporal resolution
very high costs
Advantages of small satellites
very low costs for satellite and launch (e. g. Dnepr: 3 or 4 s/cfor 7–8 M$)
good medium spectral resolution
constellations become affordable (even for developing nations & commercial
enterprises)
good temporal resolution
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 16
Possibilities (cont.)
Revisit time with constellations in local time range with good sun elevation angles
(9:00 ... 15:00)
3 sats
∆T: 3 hours
7 sats
∆T: 1 hour
Ground coverage depends on
swath width
agility of s/c or platform
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 17
Possibilities (cont.)
Constellation of inexpensive satellites enable new applications
Examples:
DMC-1
DMC-2
RapidEye
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 18
ApplicationAreas
Disaster warning and support
Agriculture
Forestry
Ocean and Coastal Zone
Atmosphere
Weather and Climate
Ice and Snow
Mapping and Geographic Information System Applications
Land Use/Cover Change
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 19
The m
ain application fields of small satellites related
to disaster warning are:
Cyclones and storms,
El Nino,
floods,
fires,
volcanic activities,
earthquakes,
landslides,
oil slicks,
environmental pollution,
industrial and power plant disaster.
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 20
Rationale
Every year burn
Ca. 109ha savannah area
Ca 107ha tropical rain forest
Ca. 106ha Mediterranean vegetation
Ca. 108ha boreal forests
The impacts on
atmosphere (green house effect, ozone,
aerosol, relation CO/CO2),
climate
global carbon cycle
are poorly investigated
Up to now -there exists no system in orbit
dedicatedto fire observation
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 21
Signatures of Vegetation Fire and Background
Spectra contain information on land surface, atmospheric gases and
aerosols
The second atmospheric window (MIR) is the optimum for the „hot spot“
detection
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 22
BIRD Payload Segment
Mass of s/c: 94 kg
Mass of p/l: 30.2 kg
WAOSS-B
MWIR
TIR
Wavelength
600-670nm
840-900nm 3.4-4.2µm 8.5-9.3µm
Focal length
21.65mm 46.39mm 46.39 mm
Detector
CCD
CdHgTe
CdHgTe
Ground pixel size
185m
370m
370m
Ground sampling
distance
185m
185m
185m
Swath width
533km
190km
190km
1 at 572km Orbit altitude
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 23
BIRD Launch: 22. October 2001
Launcher:
PSLV-C3 (India)
Launcher payloads: TES (ISRO), PROBA (ESA), BIRD
(DLR)
Orbit:
568km circ., i = 97.8 (sun-
synchronous)
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 24
First Im
age: 05/11/2001, 9:42 UTC
Investigation of Pixel Co-
Registration
Mid-wave Infra-Red channel (3.4-
4.2µm)
(semi-transparency overlay)
WAOSS-nadir channel(840-900nm)
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 25
First Fire Evaluation From Space -
BIRD gives temperature and area extent of Australian bush
fires
4.Jan.2002
10:08 local time
BIRD-
image,
MIR-channel
Fire colour
coded
5.Jan.2002
10:08 local time
BIRD-image,
MIR-channel
Fire colour
coded
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 26
3. M
IR-
channel
Detail from the BIRD-image at
04.Jan.2002
1. NIR-channel
2. TIR-channel
4. Fire fronts and temperature distribution
5.
Fire fronts and temperature
distributionfromtheimage at
05.Jan.2002
6. Fire fronts and temperature distribution
fromtheimage at 09.Jan.2002
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 27
Typical characteristics of fire fronts (BIRD, Australia, January
5,
2002)
No
Eq. fire
temp., K
Eq. fire
area, H
aFront
length,
km
Energy
release,
MW
Front
strength,
kW/m
1 2 3 4 5 6 7 8
815
715
893
>670
852
957
>690
796
0.48 2.3
0.59
<0.78
0.92 1.0
<0.51
0.39
4 7.5 3 5 10 9 4 3
130
310
210
79 300
530
62 96
30 40 70 15 30 60 15 30
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 28
Fire detection by M
ODIS and BIRD (Australia, January 5,
2002)
MODIS: Fire m
ap
BIRD: Fire m
ap
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 29
1
2
34
5
BIRD Detects Hot Spots in and around M
unich
(29.Jan.2002)
InfraredImage of region
Munich at 29.Jan.2002, local
time: 10:10
Hot spot Nr. 1:
at this time at this place wooden
waste has burned for several hours
(4m diameter, hot temperature) by
Farmer J. Kranz
(written in his working diary)
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 30
Future of Small Sats
forRemote
Sensing
New capabilities
the convergence of data acquisition and data visualization
technologies
the ready availability of new small launchers and the rise of “space
tourism”
the development of smaller, lighter, lower power satellites thatcan
act as a constellation or independently
Challenges
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 31
Convergence of data acquisition and data
visualization technologies
Example:
NASA’s “A Train”(Aqua, CloudSat, CALIPSO, PARASOL, Aura, and
OCO)
+
NDVI small sat for crop yield forecasting in a particular region,
Aerosol and cloud correction using data from the A Train.
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 32
Small launchers
& „SpaceTourism“
Gettingintospaceisstill a challengeand costly
Duringthelast 10 yearsmoresmalllaunchersat pricesreasonable
comparedto thecostof a smallsat(e.g.NASA/DLRGRACE constellationwith
EUROCKOT, SS-19 ICBM)
New impetusof „spacetourism“(Oct.4th, 2004, Burt Rutan& Paul Allan winthe
AnsarXPRIZE)
Lookingback: At theturn of thelast century, airtravelwas relativelyriskyand quiteexpensive.
Nowweflye.g. appleshalf way aroundtheworldat pricesthatarecompetitivewithlocaltransport
& production.
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 33
Biggestchallenge: developinga robust commercial
market
Small Satshaveappealedto somenationsas an instrumentof national
prideand as a meansto focusand enhancetheindustrialbaseas well
as providinga meansof attractingstudentsto a high techindustry. This
isan importantstepintothefuture. But, thisisof coursea finite market.
To developa robust market, smallsatmanufacturersmustremain
relevant and cost-effective!
SSTL, Rapid Eye and SatrecIare3 examplesof commercialventures
thathaveachievedsomestability.
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 34
Conclusions
the development of smaller, lighter, lower power satellites thatcan act as
a constellation or independently
the ready availability of new small launchers and the rise of “space
tourism”
Ground station networks integrating the different necessary components
and processes help to get the costs down
Increasing the on-board autonomy allows to reduce ground station
complexity
the convergence of data acquisition and data visualization technologies
International W
orkshop on EOSS forRemoteSensing, 20-23 Nov 2007, Kuala Lumpur, Malaysia > Dr. R. Sandau > 35
DevelopingSmall SatellitesforRem
oteSensingiswithin
the
meansof manynations
They
provideenorm
ousopportunities:
•To do m
ore
withless
•Address
localand global needs
•Focus thedevelopmentof thetechnicalinfrastructure
of a country
•Reduce
risk
in theuse
of space
Spacetechnology has a greatfuture.
Itisnottoolateto join
thespacecommunity.