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10 MEMS and Microstructures in Aerospace Applications

cannot be satisfied with conventional spacecraft component technology. A general
discussion on the potential of MEMS-based microsystems for GN&C space appli-
cations is presented, including the use of embedded MEMS gyroscopes and accel-
erometers in modular multifunction GN&C systems that are highly integrated,
compact, and at low power and mass. Further, MEMS technology applied to attitude
sensing and control actuation functions is discussed with brief descriptions of
several selected examples of specific recent MEMS technology developments for
GN&C applications. The chapter concludes with an overview of future insertion
points of MEMS GN&C applications in space systems.
The different micropropulsion systems, which are divided into the two major
groups of electric and chemical propulsion, are discussed in Chapter 11. Each
propulsion system is discussed with respect to its principle of operation, its current
state-of-the-art, and its MEMS or micromachined realization or potential thereof. It
is shown that the number of pure MEMS propulsion devices is limited, and that
there are still significant challenges ahead for other technologies to make the leap.
The major challenge to produce a MEMS-based propulsion system including
control, propellant, and thruster is in the miniaturization of all components com-
bined.

1.4.4 TECHNICAL INSERTION OF MEMS IN AEROSPACE APPLICATIONS
The last section of the book is in one aspect different from the previous sections; it
cannot be based on historical data. Even with the number of MEMS devices flown
on the shuttle in some experiments, there has not been a sincere attempt to develop
requirements for the space qualification of MEMS devices. Most of the authors in
this section have been involved in the development of the MEMS thermal control
shutters for the ST5 space mission, and have tried to convey this experience in these
chapters, hoping to create a basic understanding of the complexities while dealing
with MEMS devices and the difference to well understood integration of micro-
electronics.
At some point, every element is a packaging issue. In order to achieve high
performance or reliability of MEMS for space applications, the importance of
MEMS packaging must be recognized. Packaging is introduced in Chapter 12 as
a vital part of the design of the device and the system that must be considered early
in the product design, and not as an afterthought. Since the evolution of MEMS
packaging stems from the integrated circuit industry, it is not surprising that some
of these factors are shared between the two. However, many are specific to the
application, as will be shown later. A notable difference between a MEMS package
and an electronics package in the microelectronics industry is that a MEMS
package provides a window to the outside world to allow for interaction with its
environment. Furthermore, MEMS packaging must account for a more complex set
of parameters than what is typically considered in the microelectronics industry,
especially given the harsh nature of the space and launch environments.
Chapter 13 is entirely devoted to handling and contamination controls
for MEMS in space applications due to the importance of the topic area

© 2006 by Taylor & Francis Group, LLC