ABSTRACT
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The ‘‘maturing’’ of advanced micronanotechnology (MNT) concepts for space
applications faces a very similar dilemma similar to that faced in the commercial
world.1,2,3 NASA has pioneered a means of evaluating the maturity of new tech-
nologies, known as the technology readiness level (TRL) scale that has now found
widespread use in government and industry. As shown in Table 6.1, the TRL scale
ranges from levels 1 through 9, with levels 1 to 3 being at the so-called ‘‘low-TRL,’’
that is basic research into demonstrating the proof-of-concept. Levels 4 to 6
correspond to ‘‘mid-TRL’’ development, which is the reliable demonstration of
subsystems based on the new technologies, and finally, levels 7 to 9 (high-TRL)
correspond to successful utilization of these technologies at the system or subsys-
tem level in NASA’s space missions. A large majority of the exciting MNT
concepts are at the low TRL stage, sometimes referred to as the ‘‘technology push’’
stage, with the daunting challenge of having to bridge the ‘‘TRL gap’’4 to success-
fully transition to the high-TRL space applications or ‘‘technology pull’’ stage. The
TRL gap, sometimes referred to as the ‘‘valley of death’’ in the commercial sector,
therefore represents an order-of-magnitude increase in effort (and consequently
funding) that is required to make the transition to high TRL. The primary reason
that most new technologies fail to bridge the TRL gap is that because of their
relatively low maturity, they do not have a compelling mission ‘‘pull’’ to drive
further system-level development.
