scholarly journals Contamination Control for Ultra-Sensitive Life-Detection Missions

2021 ◽  
Vol 2 ◽  
Author(s):  
Jennifer L. Eigenbrode ◽  
Robert Gold ◽  
John S. Canham ◽  
Erich Schulze ◽  
Alfonso F. Davila ◽  
...  
Keyword(s):  
Solar System ◽  
Contamination Control ◽  
Particulate Contamination ◽  
Science Operations ◽  
Monolayer Adsorption ◽  
Highly Sensitive ◽  
Life Detection ◽  
Low Probability ◽  
System Life ◽  
Adsorption Desorption

A key science priority for planetary exploration is to search for signs of life in our Solar System. Life-detection mission concepts aim to assess whether or not biomolecular signatures of life are present, which requires highly sensitive instrumentation. This introduces greater risk of false positives, and perhaps false negatives. Stringent science-derived contamination requirements for achieving science measurements on life-detection missions necessitate mitigation approaches that minimize, protect from, and prevent science-relevant contamination of critical surfaces of the science payload and provide high confidence to life-detection determinations. To this end, we report on technology advances that focus on understanding contamination transfer from pre-launch processing to end of mission using high-fidelity physics in the form of computational fluid dynamics and sorption physics for monolayer adsorption/desorption, and on developing a new full-spacecraft bio-molecular barrier design that restricts contamination of the spacecraft and instruments by the launch vehicle hardware. The bio-molecular barrier isolates the spacecraft from biological, molecular, and particulate contamination from the external environment. Models were used to evaluate contamination transport for a designs reference mission that utilizes the barrier. Results of the modeling verify the efficacy of the barrier and an in-cruise decontamination activity. Overall mission contamination tracking from launch to science operations demonstrated exceptionally low probability on contamination impacting science measurements, meeting the stringent contamination requirements of femtomolar levels of compounds. These advances will enable planetary missions that aim to detect and identify signatures of life in our Solar System.

scholarly journals Synergies between exoplanet and Solar System life detection efforts: Encouraging collaboration to enhance science return

2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Niki Parenteau ◽  
Shawn Domagal-Goldman ◽  
Nancy Y. Kiang ◽  
Edward Schwieterman ◽  
Victoria Meadows ◽  
...  
Keyword(s):  
Solar System ◽  
Life Detection ◽  
System Life

scholarly journals In-Situ Exploration of Dust in the Solar System and Initial Results from the Galileo Dust Detector

1991 ◽  
Vol 126 ◽  
pp. 21-28
Author(s):  
E. Grün ◽  
H. Fechtig ◽  
M. S. Hanner ◽  
J. Kissel ◽  
B.-A. Lindblad ◽  
...  
Keyword(s):  
Solar System ◽  
Impact Ionization ◽  
Interplanetary Space ◽  
Interplanetary Dust ◽  
High Mass ◽  
Large Area ◽  
Dust Flux ◽  
Highly Sensitive ◽  
Low Mass

AbstractIn-situ measurements of interplanetary dust have been performed in the heliocentric distance range from 0.3 AU out to 18 AU. Due to their small sensitive areas (typically 0.01 m2for the highly sensitive impact ionization sensors) or low mass sensitivities (≥10−9g of the large area penetration detectors) previous instruments recorded only a few 100 impacts during their lifetimes. Nevertheless, important information on the distribution of dust in interplanetary space has been obtained between 0.3 and 18 AU distance from the Sun. The Galileo dust detector combines the high mass sensitivity of impact ionization detectors (10−15g) together with a large sensitive area (0.1 m2). The Galileo spacecraft was launched on October 18, 1989 and is on its solar system cruise towards Jupiter. Initial measurements of the dust flux from 0.7 to 1.2 AU are presented.

scholarly journals Concerns of Organic Contamination for Sample Return Space Missions

2020 ◽  
Vol 216 (4) ◽  
Author(s):  
Queenie Hoi Shan Chan ◽  
Rhonda Stroud ◽  
Zita Martins ◽  
Hikaru Yabuta
Keyword(s):  
Organic Matter ◽  
Solar System ◽  
Analytical Techniques ◽  
Lessons Learned ◽  
Organic Analysis ◽  
Terrestrial Organic Matter ◽  
Organic Contamination ◽  
Sample Return ◽  
Contamination Control ◽  
Solar System Exploration

Abstract Analysis of organic matter has been one of the major motivations behind solar system exploration missions. It addresses questions related to the organic inventory of our solar system and its implication for the origin of life on Earth. Sample return missions aim at returning scientifically valuable samples from target celestial bodies to Earth. By analysing the samples with the use of state-of-the-art analytical techniques in laboratories here on Earth, researchers can address extremely complicated aspects of extra-terrestrial organic matter. This level of detailed sample characterisation provides the range and depth in organic analysis that are restricted in spacecraft-based exploration missions, due to the limitations of the on-board in-situ instrumentation capabilities. So far, there are four completed and in-process sample return missions with an explicit mandate to collect organic matter: Stardust and OSIRIS-REx missions of NASA, and Hayabusa and Hayabusa2 missions of JAXA. Regardless of the target body, all sample return missions dedicate to minimise terrestrial organic contamination of the returned samples, by applying various degrees or strategies of organic contamination mitigation methods. Despite the dedicated efforts in the design and execution of contamination control, it is impossible to completely eliminate sources of organic contamination. This paper aims at providing an overview of the successes and lessons learned with regards to the identification of indigenous organic matter of the returned samples vs terrestrial contamination.

Evaluating Clean Room Products for Aerospace Applications

1986 ◽  
Vol 29 (4) ◽  
pp. 19-22
Author(s):  
Suzanne Keilson
Keyword(s):  
Hubble Space Telescope ◽  
Selection Process ◽  
Clean Room ◽  
Optical Telescope ◽  
Unique Challenge ◽  
Contamination Control ◽  
Particulate Contamination ◽  
Aerospace Applications ◽  
Final Selection ◽  
Plastic Products

Large aerospace assemblies, such as the Optical Telescope Assembly (OTA) for the Hubble Space Telescope built by Perkin-Elmer, present a unique challenge to anyone evaluating clean room products for use on these programs. Very stringent requirements for molecular and particulate contamination control are often not taken into account by the manufacturers of clean room products. The realization that extractables of plastic products pose a serious contamination threat to optical assemblies is gaining wider recognition, but even so-called "solvent compatible" products may not meet the requirements of all sensitive payloads. A process is described for evaluating, selecting and monitoring products in the most widespread use—garments, gloves, and wipers. Notwithstanding well-trained, conscientious personnel, items such as garments, gloves and wipers can be used in such a variety of ways that their tolerance for misuse without untoward consequences must be considered. The final selection process must therefore consider both compatibility and durability and, as was discovered, a unique choice is not always possible for all applications.

scholarly journals Contamination Control Technology Study for Achieving the Science Objectives of Life-Detection Missions

2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Christopher McKay ◽  
Alfonso Davila ◽  
Jennifer Eigenbrode ◽  
Chris Lorentson ◽  
Rob Gold ◽  
...  
Keyword(s):  
Control Technology ◽  
Technology Study ◽  
Contamination Control ◽  
Life Detection

scholarly journals In-situ synthesis of poly(m-phenylenediamine) on chitin bead for Cr(VI) removal

2020 ◽  
Author(s):  
Jinyu Wei ◽  
Huayu Hu ◽  
Yanjuan Zhang ◽  
Zuqiang Huang ◽  
Xingtang Liang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
In Situ Polymerization ◽  
High Adsorption ◽  
Adsorption Temperature ◽  
Monolayer Adsorption ◽  
Ft Ir ◽  
High Adsorption Capacity ◽  
User Friendly ◽  
Adsorption Desorption

Abstract In this work, a user-friendly chitin-based adsorbent (CT-PmPD) was synthesized by in-situ polymerization of m-phenylenediamine on chitin bead, which could effectively remove Cr(VI) from water. The structure and morphology of the CT-PmPD were characterized by FT-IR, XRD, SEM, zeta potential and XPS. Specifically, the effect of adsorbed dosage, pH, contact time, adsorption temperature and coexisting salt on the adsorption of Cr(VI) were studied. Besides, the adsorption mechanism of CT-PmPD toward Cr(VI) were also analyzed. Consequenlty, CT-PmPD exhibited a monolayer adsorption and the Langmuir model fitted a Cr(VI) adsorption capacity reaching 185.4 mg/g at 298 K. The high adsorption capacity was attributed to the abundant amino groups of CT-PmPD, which could be protonated to boost the electrostatic attraction of Cr(VI) oxyanions, thus providing electron to reduce Cr(VI). Additionally, the CT-PmPD revealed a good regeneration and reusability capacity, maintaining most of its adsorption capacity even after five cycles of adsorption-desorption. This high adsorption capacity and excellent regeneration performance highlighted the great potential of CT-PmPD for the removal of Cr(VI).

scholarly journals Gas adsorption and desorption effects on cylinders and their importance for long-term gas records

2015 ◽  
Vol 8 (12) ◽  
pp. 5289-5299 ◽  
Author(s):  
M. C. Leuenberger ◽  
M. F. Schibig ◽  
P. Nyfeler
Keyword(s):  
Mole Fraction ◽  
Pressure Dependence ◽  
Gas Adsorption ◽  
Binding Energies ◽  
Adsorption Model ◽  
Climate Chamber ◽  
Temperature Coefficients ◽  
Monolayer Adsorption ◽  
Pressure Changes ◽  
Adsorption Desorption

Abstract. It is well known that gases adsorb on many surfaces, in particular metal surfaces. There are two main forms responsible for these effects (i) physisorption and (ii) chemisorption. Physisorption is associated with lower binding energies in the order of 1–10 kJ mol−1, compared to chemisorption which ranges from 100 to 1000 kJ mol−1. Furthermore, chemisorption only forms monolayers, contrasting physisorption that can form multilayer adsorption. The reverse process is called desorption and follows similar mathematical laws; however, it can be influenced by hysteresis effects. In the present experiment, we investigated the adsorption/desorption phenomena on three steel and three aluminium cylinders containing compressed air in our laboratory and under controlled conditions in a climate chamber, respectively. Our observations from completely decanting one steel and two aluminium cylinders are in agreement with the pressure dependence of physisorption for CO2, CH4, and H2O. The CO2 results for both cylinder types are in excellent agreement with the pressure dependence of a monolayer adsorption model. However, mole fraction changes due to adsorption on aluminium (< 0.05 and 0 ppm for CO2 and H2O) were significantly lower than on steel (< 0.41 ppm and about < 2.5 ppm, respectively). The CO2 amount adsorbed (5.8 × 1019 CO2 molecules) corresponds to about the fivefold monolayer adsorption, indicating that the effective surface exposed for adsorption is significantly larger than the geometric surface area. Adsorption/desorption effects were minimal for CH4 and for CO but require further attention since they were only studied on one aluminium cylinder with a very low mole fraction. In the climate chamber, the cylinders were exposed to temperatures between −10 and +50 °C to determine the corresponding temperature coefficients of adsorption. Again, we found distinctly different values for CO2, ranging from 0.0014 to 0.0184 ppm °C−1 for steel cylinders and −0.0002 to −0.0003 ppm °C−1 for aluminium cylinders. The reversed temperature dependence for aluminium cylinders points to significantly lower desorption energies than for steel cylinders and due to the small values, they might at least partly be influenced by temperature, permeation from/to sealing materials, and gas-consumption-induced pressure changes. Temperature coefficients for CH4, CO, and H2O adsorption were, within their error bands, insignificant. These results do indicate the need for careful selection and usage of gas cylinders for high-precision calibration purposes such as requested in trace gas applications.

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