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Technical Paper
2009-07-12
A. V. Shevade, M. A. Ryan, M. L. Homer, A. K. Kisor, K. S. Manatt, L. M. Lara
Simultaneous measurements were made for particle releases and off-gassing products produced by heating electrical wires. The wire samples in these experiments were heated to selected temperatures in a heating chamber and responses to vapor releases were recorded by the JPL Electronic Nose (ENose) and an Industrial Scientific ITX gas-monitor; particles released were detected by a TSI P-Trak particle counter. The temperature range considered for the experiment is room temperature (24−26°C) to 500 °C. The results were analyzed by overlapping responses from the ENose, ITX gas sensors and P-Trak, to understand the events (particle release/off-gassing) and sequence of events as a function of temperature and to determine qualitatively whether ENose may be used to detect pre-combustion event markers.
Technical Paper
2009-07-12
M. A. Ryan, K. S. Manatt, S. Gluck, A. V. Shevade, A. K. Kisor, H. Zhou, L. M. Lara, M. L. Homer
The Third Generation ENose is an air quality monitor designed to operate in the environment of the US Lab on the International Space Station (ISS). It detects a selected group of analytes at target concentrations in the ppm regime at an environmental temperature range of 18 – 30 °C, relative humidity from 25 – 75% and pressure from 530 to 760 torr. This device was installed and activated on ISS on Dec. 9, 2008 and has been operating continuously since activation. Data are downlinked and analyzed weekly. Results of analysis of ENose monitoring data show the short term presence of low concentration of alcohols, octafluoropropane and formaldehyde as well as frequent short term unknown events.
Technical Paper
2009-07-12
Glenn T. Tsuyuki, Chern-Jiin Lee
The Mars Scout Phoenix Lander successfully landed in the Martian northern latitude on May 25, 2008. The Robotic Arm, which was designed to dig and to transfer soil samples to other Lander instruments, contained a number of actuators that had specific operational windows on the Martian surface due to the bearing lubricant. The deployment of the Robotic Arm was planned for Sol 2 (Mars days are referred to “Sols”). A few weeks before Mars landing, the Robotic Arm operations team learned that a strict flight rule had been imposed. It specified that the deployment shall be accomplished when the actuators were at or above −25°C since the deployment activity was qualified with the actuators at −40°C. Furthermore, the deployment plan identified a window of opportunity between 13:00 Local Solar Time (LST, equivalent to dividing the Sol into 24 equal Martian hours) and 15:30 LST. Previous analytical work was focused on sizing electrical heaters to warm-up the actuators for early morning operation (8:00 LST) in the worst-cold thermal environment.
Technical Paper
2009-07-12
Jose I. Rodriguez, Howard Tseng, Padma Varanasi, Burt Zhang
Launched on India's Chandrayaan-1 spacecraft on October 22, 2008, JPL's Moon Mineralogy Mapper (M3) instrument has successfully completed over six months of operation in space. M3 is one in a suite of eleven instruments, six of which are foreign payloads, flying onboard the Indian spacecraft. Chandrayaan-1, managed by the Indian Space Research Organization (ISRO) in Bangalore, is India's first deep space mission. Chandrayaan-1 was launched on the upgraded version of India's Polar Satellite Launch Vehicle (PSLV-XL) from the Satish Dhawan Space Centre, SHAR, Sriharikota, India. The primary science objective of the M3 instrument is the characterization and mapping of the lunar surface composition in the context of its geologic evolution. Its primary exploration goal is to assess and map the Moon mineral resources at high spatial resolution to support future targeted missions. M3 is a cryogenic state of the art “push-broom” near infrared imaging spectrometer with high signal to noise ratio and spatial and spectral uniformity.
Technical Paper
2009-07-12
Gani B. Ganapathi, Eric T. Sunada, Gajanana C. Birur, Jennifer R. Miller, Ryan Stephan
NASA's proposed lunar lander, Altair, will be exposed to vastly different external temperatures following launch till its final destination on the moon. In addition, the heat rejection is lowest at the lowest environmental temperatures (0.5 kW @ 4K) and highest at the highest environmental temperature (4.5 kW @ 215K). This places a severe demand on the radiator design to handle these extreme turn-down requirements. A radiator with digital turn-down capability is currently under study at JPL as a robust means to meet the heat rejection demands and provide freeze protection while minimizing mass and power consumption. Turndown is achieved by independent control of flow branches with isolating latch valves and a gear pump to evacuate the isolated branches. A bench-top test was conducted to characterize the digital radiator concept. Testing focused on the demonstration of proper valve sequencing to achieve turn-down and recharge of flow legs. Test results indicate the digital radiator concept to be feasible based on extrapolation to flight-like conditions.
Technical Paper
2009-07-12
Pradeep Bhandari, Gajanana Birur, Paul Karlmann, David Bame, Yuanming Liu, A. J. Mastropietro, Jennifer Miller, Michael Pauken, Gani Ganapathi, Robert Krylo, Brad Kinter
The Mars Science Laboratory (MSL) mission to land a large rover on Mars is being prepared for Launch in 2011. A Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) on the rover provides an electrical power of 110 W for use in the rover and the science payload. Unlike the solar arrays, MMRTG provides a constant electrical power during both day and night for all seasons (year around) and latitudes. The MMRTG dissipates about 2000 W of waste heat to produce the desired electrical power. One of the challenges for MSL Rover is the thermal management of the large amount of MMRTG waste heat. During operations on the surface of Mars this heat can be harnessed to maintain the rover and the science payload within their allowable limits during nights and winters without the use of electrical survival heaters. A mechanically pumped fluid loop heat rejection and recovery system (HRS) is used to pick up some of this waste heat and supply it to the rover and payload. During warm conditions, the same HRS works in reverse to pick up the heat dissipated by the rover electronics and payloads and reject it to the Martian environment via radiators.
Technical Paper
2009-07-12
Glenn T. Tsuyuki, Elisabeth L. Morse, Siu-Chun Lee, John D. Bernardin
The Mars Science Laboratory will be the next Martian mobility system that is scheduled to launch in the fall of 2011. The ChemCam Instrument is a part of the MSL science payload suite. It is innovative for planetary exploration in using a technique referred to as laser breakdown spectroscopy to determine the chemical composition of samples from distances of up to about 9 meters away. ChemCam is led by a team at the Los Alamos National Laboratory and the Centre d'Etude Spatiale des Rayonnements in Toulouse, France. The portion of ChemCam that is located inside the Rover, the ChemCam Body Unit contains the imaging charged-coupled device (CCD) detectors. Late in the design cycle, the ChemCam team explored alternate thermal design architectures to provide CCD operational overlap with the Rover's remote sensing instruments. This operational synergy is necessary to enable planning for subsequent laser firings and geological context. This paper will present the CCD thermal design trades that would increase the CCD operational window.
Technical Paper
2008-06-29
Anthony D. Paris, Melanie L. Fisher, Frank P. Kelly, Brenda J. Hernandez, Brenda A. Dudik, Robert J. Krylo, Pradeep Bhandari
NASA's Mars Science Laboratory mission will use a Powered Descent Vehicle to accurately and safely land a roving, robotic laboratory on the surface of Mars. The precision landing systems employed on this vehicle are exposed to a wide range of mission environments from deep space cruise to atmospheric descent and require a robust and adaptable thermal design. This paper discusses the overall thermal design philosophy of the MSL Powered Descent Vehicle and presents analysis of the active and passive elements comprising the Cruise, Entry, Descent, and Landing thermal control systems.
Technical Paper
2008-06-29
Jose I. Rodriguez, Arthur Na-Nakornpanom, Jose G. Rivera, Virgil Mireles, Howard Tseng
Launched on NASA's Aura spacecraft on July 15, 2004, JPL's Tropospheric Emission Spectrometer (TES) has been operating successfully for over three years in space. TES is an infrared high resolution, imaging fourier transform spectrometer with spectral coverage of 3.3 to 15.4 μm to measure and profile essentially all infrared-active molecules present in the Earth's lower atmosphere. It measures the three-dimensional distribution of ozone and its precursors in the lower atmosphere on a global scale. The Aura spacecraft was successfully placed in a sun-synchronous near-circular polar orbit with a mean altitude of 705 km and 98.9 minute orbit period. The observatory is designed for a nominal 5 year mission lifetime. The instrument thermal design features include four temperature zones needed for efficient cryogenic staging to provide cooling at 65 K, 180 K, 230 K and 300 K. TES contains four infrared (IR) focal plane arrays (FPAs) in two separate housings that are cooled to 65 K by a pair of Northrop Grumman Space Technology (NGST) pulse tube cryocoolers.
Technical Paper
2008-06-29
Gani B. Ganapathi, Gajanana Birur, Eric Sunada, Jennifer Miller
NASA's Exploration Mission program is planning for a return to the Moon in 2020. The Exploration Systems Mission Directorate (ESMD)'s Lunar Architecture Team (LAT) is currently refining their lunar habitat architectures. The Advanced Thermal Control Project at the Johnson Space Center, as part of the Exploration Technology Development Program (ETDP) is developing technologies in support of the future lunar missions. In support of this project, a trade study was conducted at the Jet Propulsion Laboratory on the mechanically pumped two-phase and single-phase thermal loops for lunar habitats located at the South Pole for the LAT II architecture. This paper discusses the various trades and the results for a representative architecture which shares a common external loop for the single and two-phase system cases.
Technical Paper
2008-06-29
Jose G. Rivera, Arthur Na-Nakornpanom, Charles Phillips, Jose I. Rodriguez, Jason Zan, Howard Tseng, Jason Kempenaar
The Orbiting Carbon Observatory (OCO) instrument is scheduled for launch onboard an Orbital Sciences Corporation LEOStar-2 architecture spacecraft in December 2008. The instrument will collect data to identify CO2 sources and sinks and quantify their seasonal variability. OCO observations will permit the collection of spatially resolved, high resolution spectroscopic observations of CO2 and O2 absorption in reflected sunlight over both continents and oceans. OCO has three bore-sighted, high resolution, grating spectrometers which share a common telescope with similar optics and electronics. A 0.765 μm channel will be used for O2 observations, while the weak and strong CO2 bands will be observed with 1.61 μm and 2.06 μm channels, respectively. The OCO spacecraft circular polar orbit will be sun-synchronous with an inclination of 98.2 degrees, mean altitude of 705 km and 98.9 minute orbit period. The OCO mission forms part of NASA's A-Train and leads the afternoon constellation ahead of the Aqua spacecraft.
Technical Paper
2008-06-29
Jose I. Rodriguez, Howard Tseng, Burt Zhang, Arthur Na-Nakornpanom, Robert S. Leland
The Moon Mineralogy Mapper (M3) instrument is scheduled for launch in 2008 onboard the Indian Chandrayaan-1 spacecraft. The mission is managed by the Indian Space Research Organization (ISRO) in Bangalore, India and is India's first flight to the Moon. M3 is being developed for NASA by the Jet Propulsion Laboratory under the Discovery Program Office managed by Marshall Space Flight Center. M3 is a state-of-the-art instrument designed to fulfill science and exploratory objectives. Its primary science objective is to characterize and map the lunar surface composition to better understand its geologic evolution. M3's primary exploration goal is to assess and map the Moon mineral resources at high spatial resolution to support future targeted missions. M3 is a cryogenic near infrared imaging spectrometer with spectral coverage of 0.4 to 3.0 μm at 10 nm resolution with high signal to noise ratio, spatial and spectral uniformity. The mission lifetime is 2 years with 2 months of primary science imaging every 6 months.
Technical Paper
2008-06-29
A. Chutjian, M. R. Darrach, B. J. Bornstein, A. P. Croonquist, E. Edgu-Fry, D. J. Fry, V. Garkanian, M. A. Girard, V. R. Haemmerle, W. M. Heinrichs, R. D. Kidd, S. Lee, J. A. MacAskill, S. M. Madzunkov, L. Mandrake, T.M. Rust, R. T. Schaefer, J. L. Thomas, N. Toomarian, M. J. Walch, M. Christensen, A. Dawson, D. Demonbrun, R. Vanholden, P. M. Holland, B. J. Shortt
Progress on the delivery of the Vehicle Cabin Atmosphere Monitor (VCAM) is reported. VCAM is an autonomous trace-species detector to be used aboard the International Space Station (ISS) for atmospheric analysis. The instrument is based on a low-mass, low-power miniature preconcentrator, gas chromatograph, and Paul ion trap mass spectrometer (PCGC/MS) capable of measuring volatile constituents in a space vehicle or planetary outpost at sub-ppm levels. VCAM detects and quantifies 40 target compounds at their 180-day Spacecraft Maximum Allowable Concentration (SMAC) levels. It is designed to operate autonomously, maintenance-free, with a self-contained carrier and calibration gas supplies sufficient for a one-year lifetime. Two flight units will be delivered for operation in the ISS EXPRESS rack.
Technical Paper
2008-06-29
Eric Sunada, Jennifer Miller, Gani B. Ganapathi, Gajanana Birur, Chanwoo Park
Thermal characterization was performed on a vapor compression heat pump using a novel, hybrid two phase loop design. Previous work on this technology has demonstrated its ability to provide passive phase separation and flow control based on capillary action. This provides high quality vapor to the compressor without relying on gravity-based phase separation or other active devices. This paper describes the subsequent work done to characterize evaporator performance under various startup scenarios, tilt angles, and heat loads. The use of a thermal expansion valve as a method to regulate operation was investigated. The effect of past history of use on startup behavior was also studied. Testing under various tilt angles showed evaporator performance to be affected by both adverse and favorable tilts for the given compressor. And depending on the distribution of liquid in the system upon startup, markedly different performance can result for the same system settings and heat loads. In this sense, the specific configuration and settings of the system are not mutually exclusive to a given performance.
Technical Paper
2008-06-29
Wayne Schubert, Robert A. Beaudet
Bacillus sp. ATCC 29669 was isolated from microbial fallout in clean rooms during the assembly of the Viking Spacecraft missions to Mars, making it a potential contamination concern for outbound space missions. Spores from this bacterial strain were found to be thirty times more resistant to dry heat than B. atrophaeus. Spore inactivation rates under vacuum controlled humidity were faster than rates obtained under ambient humidity. Inactivation rates for these heat resistant spores are important considerations for planetary protection implementation where temperature, time and humidity conditions are used to estimate the effectiveness of dry heat microbial reduction (DHMR) procedures.
Technical Paper
2008-06-29
Gajanana Birur, Mauro Prina, Pradeep Bhandari, Paul Karlmann, Brenda Hernandez, Bradley Kinter, Phillip Wilson, David Bame, Gani Ganapathi
Passively activated thermal control valves were developed for use in a mechanically pumped single-phase fluid liquid loop (MPFL) of the Mars Science Laboratory (MSL) rover. A key approach to the thermal control of the rover with the fluid loop is to control the flow through the rover's heat generating or heat rejecting components. This is achieved by either splitting or mixing the fluid stream coming from different branches of the system at different temperatures; actively or passively controlled flow valves are typically used for such purposes. To meet the thermal control requirements of the Mars Science Laboratory (MSL) rover, a splitting and a mixing thermal control valves with gradual control capabilities using a linear thermal actuator and a spool was developed at Jet Propulsion Laboratory (JPL). The key feature of these control valves is the balancing of the flow through the various branches of the fluid loop in order to balance the heat loads of the whole thermal system. This paper describes the general design and testing used in the development of the valves.
Technical Paper
2008-06-29
M. A. Ryan, A. V. Shevade, A. K. Kisor, K. S. Manatt, M. L. Homer, L. M. Lara, H. Zhou
The Third Generation ENose is an air quality monitor designed to operate in the environment of the US Lab on the International Space Station. It detects a selected group of analytes at target concentrations in the ppm regime at an environmental temperature range of 18 - 30 °C, relative humidity from 25 - 75% and pressure from 530 to 760 torr. The abilities of the device to detect ten analytes, to reject confounders as “unknown” and to deconvolute mixtures of two analytes under varying environmental conditions has been tested extensively in the laboratory. Results of ground testing showed an overall success rate for detection, identification and quantification of analytes of 87% under nominal temperature and humidity conditions and 83% over all conditions.
Technical Paper
2008-06-29
Jose G. Rivera, Jose I. Rodriguez, Dean L. Johnson
The Orbiting Carbon Observatory (OCO) will carry a single science instrument scheduled for launch on an Orbital Sciences Corporation LeoStar-2 architecture spacecraft bus in December 2008. The science objective of the OCO instrument is to collect spaced-based measurements of atmospheric CO2 with the precision, resolution, and coverage needed to identify CO2 sources and sinks and quantify their seasonal variability. The instrument will permit the collection of spatially resolved, high resolution spectroscopic observations of CO2 and O2 absorption in reflected sunlight over both continents and oceans. These measurements will improve our ability to forecast CO2 induced climate change. The instrument consists of three bore-sighted, high resolution grating spectrometers sharing a common telescope with similar optics and electronics. One spectrometer is used for O2 observations with a 0.765 urn channel, while the weak and strong CO2 bands are observed with 1.61 urn and 2.06 um channels, respectively.
Technical Paper
2008-06-29
A. V. Shevade, M. A. Ryan, A. K. Kisor, K. S. Manatt, M. L. Homer, L. M. Lara
Polymers are one of the major constituents in electrical components. A study investigating pre-combustion off-gassing and particle release by polymeric materials over a range of temperatures can provide an understanding of thermal degradation prior to failure which may result in a fire hazard. In this work, we report simultaneous measurements of pre-combustion vapor and particle release by heated polymeric materials. The polymer materials considered for the current study are silicone and Kapton. The polymer samples were heated over the range 20 to 400°C. Response to vapor releases were recorded using the JPL Electronic Nose (ENose) and Industrial Scientific's ITX gas monitor configured to detect hydrogen chloride (HCl), carbon monoxide (CO) and hydrogen cyanide (HCN). Particle release was monitored using a TSI P-TRAK particle counter.
Technical Paper
2008-06-29
Jose I. Rodriguez, Arthur Na-Nakornpanom, Jose G. Rivera, Virgil Mireles, Howard Tseng
The Tropospheric Emission Spectrometer (TES), launched on NASA's Earth Observing System Aura spacecraft on July 15, 2004 has successfully completed over three years in space and has captured a number of important lessons. The instrument primary science objective is the investigation and quantification of global climate change. TES measures the three-dimensional distribution of ozone and its precursors in the lower atmosphere on a global scale. It is an infrared (IR) high resolution, imaging Fourier Transform Spectrometer (FTS) with a 3.3 to 15.4 μm spectral coverage required for space-based measurements to profile essentially all infrared-active molecules present in the Earth's lower atmosphere. The nominal on-orbit mission lifetime is 5 years. The Aura spacecraft flies in a sun-synchronous near-circular polar orbit with 1:38 pm ascending node. The instrument uses four focal plane arrays in two separate housings cooled to 65 K by a pair of Northrop Grumman Space Technology (NGST) pulse tube cryocoolers.
Technical Paper
2008-06-29
Jose I. Rodriguez, Howard Tseng, Burt Zhang
The Moon Mineralogy Mapper (M3) instrument is one in a suite of twelve instruments which will fly onboard the Indian Chandrayaan-1 spacecraft scheduled for launch in 2008. Chandrayaan-1 is India's first mission to the Moon and is being managed by the Indian Space Research Organization (ISRO) in Bangalore, India. Chandrayaan-1 overall scientific objective is the photo-selenological and the chemical mapping of the Moon. The primary science objective of the M3 instrument is the characterization and mapping of the lunar surface composition in the context of its geologic evolution. Its primary exploration goal is to assess and map the Moon mineral resources at high spatial resolution to support future targeted missions. It is a “push-broom” near infrared (IR) imaging spectrometer with spectral coverage of 0.4 to 3.0 μm at 10 nm resolution with high signal to noise ratio, spatial and spectral uniformity. The nominal on-orbit mission lifetime for the instrument is 2 years with 2 months of primary science imaging every 6 months.
Technical Paper
2007-07-09
A. V. Shevade, M. L. Homer, H. Zhou, A. D. Jewell, A. K. Kisor, K.S. Manatt, J. Torres, J. Soler, S.-P.S. Yen, M. A. Ryan, M. Blanco, W. A. Goddard
The capabilities of the JPL Electronic Nose have been expanded to include characteristics required for a Technology Demonstration schedule on the International Space Station (ISS) in 2008-2009 [1,2]. Concurrently, to accommodate specific needs on ISS, the processes, tools and analyses which influence all aspects of development of the device have also been expanded. The Third Generation ENose developed for this program uses two types of sensor substrates, newly developed inorganic and organic sensor materials, redesigned electronics, onboard near real-time data analysis and power and data interfaces specifically for ISS. This paper will discuss the Third Generation ENose with a focus on detection of mercury in the parts-per-billion range.
Technical Paper
2007-07-09
Rui Q. Yang, Cory J. Hill, Kamjou Mansour, Yueming Qiu, Alex Soibel, Richard E. Muller, Pierre M. Echternach
The recent development of single-mode continuous wave distributed feedback mid-IR interband cascade lasers operating at thermoelectric cooler temperatures is presented. Also, latest progress of interband cascade lasers is reported.
Technical Paper
2007-07-09
A. Chutjian, B. J. Bornstein, D. G. Conroy, A. P. Croonquist, M. R. Darrach, E. Edgu-Fry, G. R. Francis, D. J. Fry, V. Garkanian, M. A. Girard, V. R. Haemmerle, W. M. Heinrichs, R. D. Kidd, J. A. MacAskill, T. M. Rust, R. T. Schaefer, J. L. Thomas, N. Toomarian, M. J. Walch, M. Christensen, D. Demonbrun, R. Vanholden, P. M. Holland, B. J. Shortt
Work is underway to deliver an instrument for analysis of the atmosphere aboard the International Space Station. The Vehicle Cabin Atmosphere Monitor (VCAM) is based on a low-mass, low-power miniature preconcentrator gas chromatograph/mass spectrometer (PCGC/MS) capable of providing sub-ppm measurements of volatile constituents in a space vehicle or outpost. VCAM is designed to operate autonomously, maintenance-free, once per day, with its own carrier and calibration gas supplies sufficient for a one-year lifetime. VCAM performance is sufficient to detect and identify 90% of the target compounds specified at their 180-day Spacecraft Maximum Allowable Concentration (SMAC) levels. The flight units will be delivered in mid-2008 and be operated in the ISS EXPRESS rack.
Technical Paper
2007-07-09
James Benardini, Erica Hagerman, Tonia Green, Ronald L. Crawford, Randall Sumner, Kasthuri Venkateswaran
The Internal Active Thermal Control System (IATCS) aboard the International Space Station (ISS) contains an aqueous, alkaline fluid (pH 9.5±0.5) that aids in maintaining a habitable environment for the crew. Because microbes have significant potential to cause disease, adverse effects on astronaut health, and microbe-induced corrosion, the presence of both bacteria and viruses within IATCS fluids is of concern. This study sought to detect and identify viral populations in IATCS samples obtained from the Kennedy Space Center as a first step towards characterizing and understanding potential risks associated with them. Samples were concentrated and viral nucleic acids (NA) extracted providing solutions containing 8.87-22.67 μg NA per mL of heat transfer fluid. After further amplification viral DNA and cDNA were then pooled, fluorescently labeled, and hybridized onto a Combimatrix panvira 12K microarray containing probes for ∼1,000 known human viruses. Positive hybridizations were observed for probes from the Adenoviridae, Mononegavirales, Poxovirade, Orthomyxoviridae, Flaviviridae, Herpesviridae, Papillomaviridae, Parvoviridae, and Reoviridae families.
Technical Paper
2007-07-09
Glenn T. Tsuyuki, Deborah I. Hernandez, Daniel H. Nguyen, Henry A. Rotter, Ryan A. Stephan, James R. Yuko
The NASA-wide CEV Smart Buyer Team (SBT) was assembled in January 2006 and was tasked with the development of a NASA in-house design for the CEV Crew Module (CM), Service Module (SM), and Launch Abort System (LAS). This effort drew upon over 250 engineers from all of the 10 NASA Centers. In 6 weeks, this in-house design was developed. The Thermal Systems Team was responsible for the definition of the active and passive design architecture. The SBT effort for Thermal Systems can be best characterized as a design architecting activity. Proof-of-concepts were assessed through system-level trade studies and analyses using simplified modeling. This nimble design approach permitted definition of a point design and assessing its design robustness in a timely fashion. This paper will describe the architecting process and present trade studies and proposed thermal designs
Technical Paper
2007-07-09
Glenn T. Tsuyuki, Leslie K. Tamppari, Terry Z. Martin, James R. Murphy
Phoenix is NASA's first Mars Scouts Mission that will place a soft-lander on the Martian surface at a high northern latitude. Much of the Mars surface environmental flight data from landed missions pertains to the near-equatorial regions. However, orbital observations have yielded very useful data about the surface environment. These data along with a simple, but highly effective one-dimensional atmospheric model was used to develop the Phoenix surface thermal environment. As candidate landing sites were identified, parametric studies including statistical variations were conducted to prescribe minimum nighttime and maximum daytime temperature design Sols (a Martian day). Atmospheric effects such as clouds and ice were considered. Finally, recent candidate landing site imaging conducted by the Mars Reconnaissance Orbiter revealed that the prime site contained a much higher rock density than first thought. Candidate landing sites were reprioritized and thus the surface thermal environment required re-characterization.
Technical Paper
2006-07-17
M. A. Ryan, A. V. Shevade, C. J. Taylor, M. L. Homer, A. D. Jewell, A. Kisor, K. S. Manatt, S. P. S. Yen, M. Blanco, W. A. Goddard
An array-based sensing system based on polymer-carbon composite conductometric sensors is under development at JPL for use as an environmental monitor in the International Space Station. Sulfur dioxide has been added to the analyte set for this phase of development. Using molecular modeling techniques, the interaction energy between SO2 and polymer functional groups has been calculated, and polymers selected as potential SO2 sensors. Experiment has validated the model and two selected polymers have been shown to be promising materials for SO2 detection.
Technical Paper
2006-07-17
R. E. Freeland, R. G. Helms, M. M. Mikulas
Early development of concepts for space structures up to 1000 meters in size was initiated in the early 1960's and carried through the 1970's. The enabling technologies were self-deployables, on-orbit assembly, and on-orbit manufacturing. Because of the lack of interest due to the astronomical cost associated with advancing the on-orbit assembly and manufacturing technologies, only self-deployable concepts were subsequently pursued. However, for over 50 years, potential users of deployable antennas for radar, radiometers, planar arrays, VLBF and others, are still interested and constantly revising the requirements for larger and higher precision structures. This trend persists today. An excellent example of this trend is the current DARPA/SPO ISAT Program that applies self-deployable structures technology to a 300 meter long active planar array radar antenna. This ongoing program has created a rare opportunity for innovative advancement of state-of-the-art concepts. The current DARPA program plan is dependent on a successful Critical Design Review (CDR) in June 2006, tentatively followed by a 90-100 meter orbital demonstration in 2009, and, if successful, a full-scale operational system on orbit in 2012.
Technical Paper
2006-07-17
Paul M. McElroy, Andrea E. Hoyt Haight, Peter B. Rand, Tanya Shkindel, Ronald E. Allred, Paul B. Willis
The overall goal of this program was the development of a 10 m. diameter, self-deployable antenna based on an open-celled rigid polyurethane foam system. Advantages of such a system relative to current inflatable or self-deploying systems include high volumetric efficiency of packing, high restoring force, low (or no) outgassing, low thermal conductivity, high dynamic damping, mechanical isotropy, infinite shelf life, and easy fabrication with methods amenable to construction of large structures (i.e., spraying). As part of a NASA Phase II SBIR, Adherent Technologies and its research partners, Temeku Technologies, and NASA JPL/Caltech, conducted activities in foam formulation, interdisciplinary analysis, and RF testing to assess the viability of using open cell polyurethane foams for self-deploying antenna applications.
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