POTENTIAL FOR ADVANCEMENTS IN REMOTE SENSING 
USING SMALL SATELLITES 
R. Sandau’,K. Brieß 2 
’German Aerospace Center, Rutherfordstr. 2, 12489 Berlin, Germany, rainer.sandau@dlr.de 
“Technische Universität Berlin, Institute of Aeronautics and Astronautics, Marchstr. 12, 10587 Berlin, Germany, 
Klaus.Briess@ILR.TU-Berlin.de 
KEY WORDS: Earth observation, small satellites, systems, sensors, platforms 
ABSTRACT: 
Small satellites for remote sensing - how is a small satellite characterized, what is the basis for it and what are the trends, how can 
small satellite missions be achieved, what are the cost drivers and what the application areas. The paper gives some insights in related 
facts and trends. The requirements concerning GSD and revisit time for the manifold application areas indicate the wide range of 
application for small satellites. By means of the fire monitoring micro-satellite BIRD one design approach is exemplified. For disas 
ter monitoring applications trends are given concerning the ground, programme and space segments are given. 
1. INTRODUCTION 
Small satellite missions can be achieved by using different 
approaches and methods. One approach is to focus on a single 
task and use available off-the-shelf technology to build a small 
satellite system (bus and payload) for the intended remote sens 
ing purpose. Another possible approach is to take full advan 
tage of the ongoing technology developments leading to further 
miniaturization of engineering components, development of 
micro-technologies for sensors and instruments which allow to 
design dedicated, well-focused high-performance Earth obser 
vation missions. 
Since the advent of modem technologies, small satellites using 
off-the-shelf technologies or missions focused on specific 
physical phenomena have also been perceived to offer an oppor 
tunity for countries with a modest research budget and little or 
no experience in space technology, to enter the field of space- 
borne Earth observation and its applications. Small satellite 
technology is a major mean to bring within the reach of every 
country the opportunity to operate small satellite Earth observa 
tion missions and utilize the data effectively at low costs, as 
well as to develop and build application-driven missions. It 
provides the opportunity to conduct or participate in Earth 
observation missions using small, economical satellites, and 
associated launches, ground stations, data distributions struc 
tures, and space system management approaches. 
The situation in the field of small satellite missions for Earth 
observation has matured in the last ten years. This may be, for 
instance, observed from the topics and the quality of contribu 
tions to the series of conferences taking place in Berlin, Logan, 
at the annual IAC or conducted by space agencies like ESA or 
CNES. 
ESA: 
Small 
Mini 
Micro 
350 kg - 700 kg 
80 kg - 350 kg 
50 kg - 80 kg 
EADS 
miniXL 
1000 kg- 1300 kg 
Astrium: 
Mini 
400 kg - 700 kg 
Micro 
100 kg-200 kg 
CNES: 
Mini 
500 kg + P/L (Proteus) 
Micro 
120 kg + P/L (Myriade) 
Table 1. Confusion of small satellite definitions 
But what exactly is a small satellite? Table 1 gives some exam 
ples how different entities define or name small satellites in 
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dependency on their products or programmes. To end this con 
fusion, IAA proposed a simplified definition (see table 2). 
Figure 1 refers to additional features which are essential when 
discussing small satellite characteristics like cost and response 
time. 
• mini satellites 
< 1000 kg 
• micro satellites 
< 100 kg 
• nano satellites 
< 10 kg 
• pico satellites 
A 
OQ 
Table 2. Small Satellite definition of IAA (Sandau, 2006) 
Small Satellites 
CubeSat: 
1 kg, ca. 2 yrs, 0.2 M$ 
Large Satellites 
ENVISAT: examples 
8 t, 15+ yrs, 3 x 10 9 $ 
Pico Nano Micro Mini 
1kg 
10 kg 
100 kg 
1000 kg 
10 000 kg 
1 M$ 
10 MS 
100 MS 
1 yr 
2 yrs 
5 yr» 
mass 
cost 
response 
time 
Figure 1. Some features of small satellites 
At UNISPACE III (Background Paper, 1998), the costs of 
developing and manufacturing a typical mini-satellite was indi 
cated to be US$ 5-20 million, while the cost of a micro-satellite 
was correspondingly US$ 2-5 million. The cost of a nano 
satellite could be below US$ 1 million (prices as of 1999). 
Whereas the development and production time for large satel 
lites is observed to be 15+ years, the corresponding time for 
minis should be 3-5 years, for micros 1.5 years, for nanos about 
1 year, and for picos less than 1 year. Of course, cost and dura 
tion figures are to be considered ball park figures. They are 
bases on the usage of state-of-the-art technology by professional 
teaips. They may deviate considerably if key technology is to be 
developed and/or the implementation teams are at the beginning 
of the learning curve. Figure 1 is complemented by two exam 
ples showing the edges of the feature ranges.