Rajeshuni Ramesham

Electronic nose for space program applications.

The ability to monitor air contaminants in the shuttle and the International Space Station is important to ensure the health and safety of astronauts, and equipment integrity. Three specific space applications have been identified that would benefit from a chemical monitor: (a) organic contaminants in space cabin air; (b) hypergolic propellant contaminants in the shuttle airlock; (c) pre-combustion signature vapors from electrical fires. NASA at Kennedy Space Center (KSC) is assessing several commercial and developing electronic noses (E-noses) for these applications. A short series of tests identified those E-noses that exhibited sufficient sensitivity to the vapors of interest. Only two E-noses exhibited sufficient sensitivity for hypergolic fuels at the required levels, while several commercial E-noses showed sufficient sensitivity of common organic vapors. These E-noses were subjected to further tests to assess their ability to identify vapors. Development and testing of E-nose models using vendor supplied software packages correctly identified vapors with an accuracy of 70-90%. In-house software improvements increased the identification rates between 90 and 100%. Further software enhancements are under development. Details on the experimental setup, test protocols, and results on E-nose performance are presented in this paper along with special emphasis on specific software enhancements.

Reliability Issues of COTS MEMS for Aerospace Applications

During the last decade, research and development of microelectromechanical systems (MEMS) has shown a significant promise for a variety of commercial applications including automobile and medical purposes. For example, accelerometers are widely used for air bag in automobile and pressure sensors for various industrial applications. Some of the MEMS devices have potential to become the commercial- off-the-shelf (COTS) components. While high reliability applications including aerospace require much more sophisticated technology development, they would achieve significant cost savings if they could utilize COTS components in their systems. This paper reviews the current status of MEMS packaging technology from COTS to specific application provides lessons learned, and finally, identifies a need for a systematic approach for this purpose.

Evolvable hardware system at extreme low temperatures

This paper describes circuit evolutionary experiments at extreme low temperatures, including the test of all system components at this extreme environment (EE). In addition to hardening-by-process and hardening-bydesign, “hardening-by-reconfiguration”, when applicable, could be used to mitigate drifts, degradation, or damage on electronic devices (chips) in EE, by using re-configurable devices and an adaptive self-reconfiguration of their circuit topology. Conventional circuit design exploits device characteristics within a certain temperature/radiation range; when that is exceeded, the circuit function degrades. On a reconfigurable device, although component parameters change in EE, a new circuit design, suitable for new parameter values, may be mapped into the reconfigurable structure to recover the initial circuit function. This paper demonstrates this technique for circuit evolution and recovery at liquid nitrogen temperatures (-196.6°C). In addition, preliminary tests are performed to assess the survivability of the evolutionary processor at extreme low temperatures.

Selective diamond seed deposition using electroplated copper

A process for selective seeding of conducting substrates (inolybdenun and copper) with submicron diamond particles has been studied. In this process, copper is electroplated through a photoresist mask, and the electroplating is performed in a stirred solution of CuSO4 and H2S04 into which O.l in size diamond particles have been added. This resulted in a continuous layer of diamond particles embedded in the electroplated copper. After the removal of photoresist, this layer has been used to seed further CVD (chemical vapor deposition) diamond growth selectively. Morphology and Raman analysis of both the as-plated copper/diamond matrix and the filir that resulted after further CVD diamond deposition have been reported.

Reliability of Ceramic Column Grid Array (CCGA717) Interconnect Packages Under Extreme Temperatures for Space Applications

Ceramic column grid array packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performance, compatibility with standard surface-mount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, flight avionics, and payload electronics. As these packages tend to have less solder joint strain relief than leaded packages, the reliability of CCGA packages is very important for short-term and long-term space missions. CCGA interconnect electronic package printed wiring boards (PWBs) of polyimide have been assembled, inspected nondestructively, and subsequently subjected to extreme temperature thermal cycling to assess the reliability for future deep space, short- and long-term, extreme temperature missions. In this investigation, the employed temperature range covers from −185°C to +125°C extreme thermal environments. The test hardware consis...

Characterization and Synthesis of Circuits at Extreme Low Temperatures

This chapter describes circuit evolutionary experiments at extreme low temperatures, including the test of all system components at this extreme environment (EE). Standard circuit designs have their target behavior limited to particular ranges of temperature, which usually does not achieve the extreme temperatures encountered in some planets of our solar system. One approach to this problem is the use of reconfigurable devices programmed by adaptive/evolutionary algorithms. Through reconfiguration, the new characteristics of the devices at EE may be fully explored and correct functionality can be recovered. This chapter demonstrates this technique for circuit characterization, evolution and recovery at liquid nitrogen temperatures (−196.6°C). In addition, preliminary tests are performed to assess the survivability limitations of the evolutionary processor at low temperatures.

Qualification Testing of Engineering Camera and Platinum Resistance Thermometer (PRT) Sensors for MSL Project Under Extreme Temperatures to Assess Reliability and to Enhance Mission Assurance

Package qualification and verification (PQV) of advanced electronic packaging and interconnect technologies and various other types of qualification hardware for the Mars Exploration Rover/Mars Science Laboratory flight projects has been performed to enhance the mission assurance. The qualification of hardware (engineering camera and platinum resistance thermometer, PRT) under extreme cold temperatures has been performed with reference to various project requirements. The flight-like packages, sensors, and subassemblies have been selected for the study to survive three times (3×) the total number of expected temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware including all relevant manufacturing, ground operations, and mission phases. Qualification has been performed by subjecting above flight-like qual hardware to the environmental temperature extremes and assessing any structural failures or degradation in electrical performance du...

Reliability of high I/O high density CCGA interconnect electronic packages under extreme thermal environments

Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surfacemount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions.

Environmental testing of COTS components for space applications

Research and development of microelectromechanical systems (MEMS) has shown a significant promise for a variety of commercial applications. For example, accelerometers are widely used for air bags in automobiles, MEMS inkjet print heads are used for printers, gyroscopes for guidance and navigation and pressure sensors for various industrial applications. Some of the MEMS devices have potential to become the commercial-off-the-shelf (COTS) components. Aerospace requires more sophisticated technology development to achieve significant cost savings if they could utilize COTS components in their systems. A miniature gas chromatograph instrument designed as a space station project will provide onorbit detection, identification, and quantification of potentially toxic trace volatile organic compounds in the human-supporting environment. The instrument consists of several commercial off-the-shelf (COTS) valves, pumps and sensors. This paper describes the thermal environmental requirements and protoflight/qualification thermal test results for the COTS parts at cold and hot temperature extremes. The objective of this study is to qualify several COTS components for specific thermal/dynamic environments to assess their reliability. All COTS components life tested were believed to meet the 3x mission operational life requirements. Test results will be presented.

Temperature-Adaptive Circuits on Reconfigurable Analog Arrays

This paper describes a new reconfigurable analog array (RAA) architecture and an integrated circuit (IC), and its use to map analog circuits that adapt to extreme temperatures. Evolution-driven adaptation takes place on the RAA IC, guided by algorithms implemented in a field programmable gate array (FPGA) collocated with the RAA in the extreme temperature environment. The experiments demonstrate circuit adaptation over a wide temperature range, from extremely low of -180degC to high of 120degC.