Engineering topics

Ehrenfreund, P.

Publications and source records attributed to Ehrenfreund, P..

At least 19 records

NASA NTRS2019

Confirming Interstellar C60(+) Using the Hubble Space Telescope

Recent advances in laboratory spectroscopy lead to the claim of ionized Buckminsterfullerene (C60(+)) as the carrier of two diffuse interstellar bands (DIBs) in the near-infrared. However, irrefutable identiﬁcation of interstellar C60(+) requires a match between the wavelengths and the expected strengths of all absorption features detectable in the laboratory and in space. Here we present Hubble Space Telescope (HST) spectra of the region covering the C60(+) 9348, 9365, 9428, and 9577 Å absorption bands toward seven heavily reddened stars. We focus in particular on searching for the weaker laboratory C60(+) bands, the very presence of which has been a matter for recent debate. Using the novel STIS-scanning technique to obtain ultra-high signal-to-noise spectra without contamination from telluric absorption that afﬂicted previous ground-based observations, we obtained reliable detections of the (weak) 9365, 9428 Å and (strong) 9577 Å C60(+) bands. The band wavelengths and strength ratios are sufﬁciently similar to those determined in the latest laboratory experiments that we consider this the ﬁrst robust identiﬁcation of the 9428 Å band, and a conclusive conﬁrmation of interstellar C60(+).

Cordiner, M. A.↗

NASA NTRS2015

Organics in Space: Results from Space Exposure Platforms and Nanosatellites

A series of successful laboratory astrophysics experiments performed on International Space Station(ISS) external platforms such as EXPOSE have provided insights into the evolution of organic and biological materials in space and planetary environments. The study of the reactions, destruction, and longevity of organics in the space environment is of fundamental interest. To provide an accurate outer space environment for extended durations, exposure experiments in low Earth orbit have been conducted in the last decades in order to examine the consequences of actual space conditions including combinations of solar and cosmic radiation, space vacuum, and microgravity. The OOREOS (OrganismORganic Exposure to Orbital Stresses) nanosatellite studied in situ during the 6-month primary and 1-year extended mission the photochemical processing of selected PAHs in low Earth orbit (650 km altitude); results were autonomously telemetered to Earth. We report on the methods and flight preparation of samples for space exposure platforms and results on the stability of organic thin-films. The UV-vis degradation process of thin-films was recorded over time, which revealed intriguing and counter-intuitive photolytic kinetics that will be re-investigated on the ISS in a space environment.

Space weathering↗

NASA NTRS2014

Developing the “Lunar Vicinity” Scenario of the Global Exploration Roadmap

The Global Exploration Roadmap (GER) has been developed by the International Space Exploration Coordination Group (ISECG – comprised of 14 space agencies) to define various pathways to getting humans beyond low Earth orbit and eventually to Mars. Such pathways include visiting asteroids or the Moon before going on to Mars. This document has been written at a very high level and many details are still to be determined. However, a number of important papers regarding international space exploration can form a basis for this document.

Global↗

NASA NTRS2014

The O/OREOS Mission - Astrobiology in Low Earth Orbit

The O/OREOS (Organism/Organic Exposure to Orbital Stresses) nanosatellite is the first science demonstration spacecraft and flight mission of the NASA Astrobiology Small- Payloads Program (ASP). O/OREOS was launched successfully on November 19, 2010, to a high-inclination (72 deg), 650-km Earth orbit aboard a US Air Force Minotaur IV rocket from Kodiak, Alaska. O/OREOS consists of 3 conjoined cubesat (each 1000 cu cm) modules: (i) a control bus; (ii) the Space Environment Survivability of Living Organisms (SESLO) experiment; and (iii) the Space Environment Viability of Organics (SEVO) experiment. Among the innovative aspects of the O/OREOS mission are a real-time analysis of the photostability of organics and biomarkers and the collection of data on the survival and metabolic activity for microorganisms at 3 times during the 6-month mission. We report on the spacecraft characteristics, payload capabilities, and present operational phase and flight data from the O/OREOS mission. The science and technology rationale of O/OREOS supports NASA0s scientific exploration program by investigating the local space environment as well as space biology relevant to Moon and Mars missions. It also serves as a precursor for experiments on small satellites, the International Space Station (ISS), future free-flyers and lunar surface exposure facilities.

Spectroscopy↗

NASA NTRS2012

SEVO (Space Environment Viability of Organics) Preliminary Results from Orbit

SEVO (Space Environment Viability of Organics) is one of two astrobiology experiments onboard the NASA Organism/Organics Exposure to Orbital Stresses (O/OREOS) cubesat, launched in November 2010. The satellite is still operational with nominal performance and records data on a regular basis. In the SEVO experiment, four astrobiologically relevant organic thin films are exposed to radiation in low-earth orbit, including the unfiltered solar spectrum from approximately 120 - 2600 nm. The thin films are contained in each of four separate micro-environments: an atmosphere containing CO2, a low relative humidity (approximately 2%) atmosphere, an inert atmosphere representative of interstellar/interplanetary space, and a SiO2 mineral surface to measure the effects of surface catalysis. The UV/Vis spectrum of each sample is monitored in situ, with a spectrometer onboard the satellite.

Cook, A.↗

NASA NTRS2011

The O/OREOS Mission - Astrobiology in Low Earth Orbit

The O/OREOS (Organism/Organic Exposure to Orbital Stresses) nanosatellite is the first science demonstration spacecraft and flight mission of the NASA Astrobiology Small- Payloads Program (ASP). O/OREOS was launched successfully on November 19, 2010, to a high-inclination (72°), 650-km Earth orbit aboard a US Air Force Minotaur IV rocket from Kodiak, Alaska. O/OREOS consists of 3 conjoined cubesat (each 1000 cu.cm) modules: (i) a control bus, (ii) the Space Environment Survivability of Living Organisms (SESLO) experiment, and (iii) the Space Environment Viability of Organics (SEVO) experiment. Among the innovative aspects of the O/OREOS mission are a real-time analysis of the photostability of organics and biomarkers and the collection of data on the survival and metabolic activity for micro-organisms at 3 times during the 6-month mission. We will report on the spacecraft characteristics, payload capabilities and first operational phase of the O/OREOS mission. The science and technology rationale of O/OREOS supports NASA’s scientific exploration program by investigating the local space environment as well as space biology relevant to Moon and Mars missions. It also serves as precursor for experiments on small satellites, the International Space Station (ISS), future free-flyers and lunar surface exposure facilities.

Ehrenfreund, P.↗

NASA NTRS2011

The O/OREOS Mission - Astrobiology in Low Earth Orbit

The O/OREOS (Organism/Organic Exposure to Orbital Stresses) nanosatellite is the first science demonstration spacecraft and flight mission of the NASA Astrobiology Small- Payloads Program (ASP). O/OREOS was launched successfully on November 19, 2010, to a high-inclination (72°), 650-km Earth orbit aboard a US Air Force Minotaur IV rocket from Kodiak, Alaska. O/OREOS consists of 3 conjoined cubesat (each 1000 cu.cm) modules: (i) a control bus, (ii) the Space Environment Survivability of Living Organisms (SESLO) experiment, and (iii) the Space Environment Viability of Organics (SEVO) experiment. Among the innovative aspects of the O/OREOS mission are a real-time analysis of the photostability of organics and biomarkers and the collection of data on the survival and metabolic activity for micro-organisms at 3 times during the 6-month mission. We will report on the spacecraft characteristics, payload capabilities and first operational phase of the O/OREOS mission. The science and technology rationale of O/OREOS supports NASA’s scientific exploration program by investigating the local space environment as well as space biology relevant to Moon and Mars missions. It also serves as precursor for experiments on small satellites, the International Space Station (ISS), future free-flyers and lunar surface exposure facilities.

Ehrenfreund, P.↗

NASA NTRS2011

Astrobiology Field Research in Moon/Mars Analogue Environments: Preface

Extreme environments on Earth often provide similar terrain conditions to landing/operation sites on Moon and Mars. Several field campaigns (EuroGeoMars2009 and DOMMEX/ILEWG EuroMoonMars from November 2009 to March 2010) were conducted at the Mars Desert Research Station (MDRS) in Utah. Some of the key astrobiology results are presented in this special issue on Astrobiology field research in Moon/Mars analogue environments relevant to investigate the link between geology, minerals, organics and biota. Preliminary results from a multidisciplinary field campaign at Rio Tinto in Spain are presented.

Foing, B. H.↗

NASA NTRS2011

Analysis of Mars Analogue Soil Samples Using Solid-Phase Microextraction, Organic Solvent Extraction and Gas Chromatography/Mass Spectrometry

Polycyclic aromatic hydrocarbons (PAHs) are robust and abundant molecules in extraterrestrial environments. They are found ubiquitously in the interstellar medium and have been identified in extracts of meteorites collected on Earth. PAHs are important target molecules for planetary exploration missions that investigate the organic inventory of planets, moons and small bodies. This study is part of an interdisciplinary preparation phase to search for organic molecules and life on Mars. We have investigated PAH compounds in desert soils to determine their composition, distribution and stability. Soil samples (Mars analogue soils) were collected at desert areas of Utah in the vicinity of the Mars Desert Research Station (MDRS), in the Arequipa region in Peru and from the Jutland region of Denmark. The aim of this study was to optimize the solid-phase microextraction (SPME) method for fast screening and determination of PAHs in soil samples. This method minimizes sample handling and preserves the chemical integrity of the sample. Complementary liquid extraction was used to obtain information on five- and six-ring PAH compounds. The measured concentrations of PAHs are, in general, very low, ranging from 1 to 60 ng g(sup -1). The texture of soils is mostly sandy loam with few samples being 100% silt. Collected soils are moderately basic with pH values of 8-9 except for the Salten Skov soil, which is slightly acidic. Although the diverse and variable microbial populations of the samples at the sample sites might have affected the levels and variety of PAHs detected, SPME appears to be a rapid, viable field sampling technique with implications for use on planetary missions.

Orzechowska, G. E.↗

NASA NTRS2008

Triple F - A Comet Nucleus Sample Return Mission

The Triple F (Fresh From the Fridge) mission, a Comet Nucleus Sample Return, has been proposed to ESA's Cosmic Vision program. A sample return from a comet enables us to reach the ultimate goal of cometary research. Since comets are the least processed bodies in the solar system, the proposal goes far beyond cometary science topics (like the explanation of cometary activity) and delivers invaluable information about the formation of the solar system and the interstellar molecular cloud from which it formed. The proposed mission would extract three sample cores of the upper 50 cm from three locations on a cometary nucleus and return them cooled to Earth for analysis in the laboratory. The simple mission concept with a touch-andgo sampling by a single spacecraft was proposed as an M-class mission in collaboration with the Russian space agency ROSCOSMOS.

Kueppers, Michael↗

NASA NTRS2006

RTF+SpeX Near-IR Images and Spectra of the Moon Pre-impact and at Impact of SMART-1

We present SpeX 0.8-2.5 micron spectra and Br-gamma or J H or K-band images of the Moon on 2006 July 10 UT, 2006 Sep 1 UT, and 2006 Sep 3 UT. The first two dates are data taken in preparation (near Full Moon and 1 st quarter Moon) for observing the impact of ESA's SMART-1 Lunar satellite on 2006 Sep 3 UT. We hope to be presenting images (about 1 arc minute by 1 arc minute), and low resolution (Prism mode) spectra of the SMART-1 impact to be taken with the 60 arc second long slit.

Wooden, Diane H.↗

NASA NTRS2006

Is the tail of 73P-B/Schwassman-Wachman 1 chasing its Remnant Nucleus?

We report on imaging observations of comets 73P-B/Schwassmann-Wachmann 1 and 73P-C/Schwassmann-Wachmann 1 at the IRTF with SpeX (J, K) and MRSI (10 micron narrow band filter set) on 2006 Apr 17-19 UT and 2006 Jun 18-19, and at the VLT with VISIR (1 0 micron narrow band filters, 20 micron) on 2006 Apr 17 UT. Compared to when the comet was in the midst of breaking up in mid-April, in June the tail of 73P-B is much fainter and there is a compact coma detected well separated and ahead of its tail, and fainter than the tail. The width of the tail in J, K, and 10 micron images indicates that the pieces that were shed in April must still be outgassing and releasing small particles into the tail-shaped coma; small grains have relatively short lifetimes in the coma due to radiation pressure. The trailing tail is now well separated from the faint "leader of the pack" compact coma that we suppose is a remaining piece of the nucleus. It will be interesting to see post-perihelion if this "leading compact coma" object continues to gain distance on the debris and continues to weakly outgas and shed small grains. One wonders if it expended its volatiles (available to the surface) in breaking up; a short-lived release of volatiles occurred in the Deep Impact event with comet 9P/Tempel 1. 73P-C is extended with a more elongated coma structure closer to perihelion compared to 2006 Apr 18- 19 UT. The SEDs from 2006 Apr and Jun from SpeX-MIRSI (IRTF) are compared with VISIR (VLT) SEDs from 2006 Apr. Information on the heliocentric dependence of the activity and dust release yields insights into the origin of activity and the relationship between activity and grain size distribution/mineralogy.

Wooden, D. H.↗

NASA NTRS2003

Radioastronomical Searches for Instellar Biomolecules

Impacts of comets and asteroids could have delivered large amounts of organic matter to the early Earth. to retain a significant interstellar signature; observations of recent bright comets indicate that they have a molecular inventory consistent with their ices being largely unmodified interstellar material. Many simple organic molecules with biochemical significance observed in circumstellar envelopes and in molecular clouds, similar to that from which the Solar System formed, may have acted as the precursors of the more complex organics found in meteorites. Therefore, there is potentially a strong link between interstellar organics and prebiotic chemical evolution. Radioastronomical observations, particularly at millimeter wavelengths, allow us to determine the chemical composition and characteristics of the molecular inventory in interstellar space. Here we report some of our recent results from extensive astronomical searches for astrobiologically-important interstellar organics.

Kuan, Y.-J.↗

NASA NTRS2003

Chemistry and Evolution of Interstellar Clouds

In this chapter we describe how elements have been and are still being formed in the galaxy and how they are transformed into the reservoir of materials present at the time of formation of our protosolar nebula. We discuss the global cycle of matter, beginning at its formation site in stars, where it is ejected through winds and explosions into the diffuse interstellar medium. In the next stage of the global cycle occurs in cold, dense molecular clouds, where the complexity of molecules and ices increases relative to the diffuse ISM.. When a protostar forms in a dense core within a molecular cloud, it heats the surrounding infalling matter warms and releases molecules from the solid phase into the gas phase in a warm, dense core, sponsoring a rich gas-phase chemistry. Some material from the cold and warm regions within molecular clouds probably survives as interstellar matter in the protostellar disk. For the diffuse ISM, for cold, dense clouds, and for dense-warm cores, the physio-chemical processes that occur within the gas and solid phases are discussed in detail.

Wooden, D. H.↗

NASA NTRS2002

Laboratory Calibration Studies in Support of ORGANICS on the International Space Station: Evolution of Organic Matter in Space

This paper describes the scientific overview and current status of ORGANICS an exposure experiment performed on the International Space Station (ISS) to study the evolution of organic matter in space (PI: P. Ehrenfreund), with supporting laboratory experiments performed at NASA Ames. ORGANICS investigates the chemical evolution of samples submitted to long-duration exposure to space environment in near-Earth orbit. This experiment will provide information on the nature, evolution, and survival of carbon species in the interstellar medium (ISM) and in solar system targets.

Ruiterkamp, R.↗

NASA NTRS2001

Spectroscopic diagnostics of organic chemistry in the protostellar environment

A combination of astronomical observations, laboratory studies, and theoretical modelling is necessary to determine the organic chemistry of dense molecular clouds. We present spectroscopic evidence for the composition and evolution of organic molecules in protostellar environments. The principal reaction pathways to complex molecule formation by catalysis on dust grains and by reactions in the interstellar gas are described. Protostellar cores, where warming of dust has induced evaporation of icy grain mantles, are excellent sites in which to study the interaction between gas phase and grain-surface chemistries. We investigate the link between organics that are observed as direct products of grain surface reactions and those which are formed by secondary gas phase reactions of evaporated surface products. Theory predicts observable correlations between specific interstellar molecules, and also which new organics are viable for detection. We discuss recent infrared observations obtained with the Infrared Space Observatory, laboratory studies of organic molecules, theories of molecule formation, and summarise recent radioastronomical searches for various complex molecules such as ethers, azaheterocyclic compounds, and amino acids.

Ethers/analysis/chemical synthesis/chemistry↗

NASA NTRS2000

A Cometary Origin of the Amino Acids in the Orgueil Meteorite?

A reexamination of a piece of the Orgueil meteorite revealed that its amino acid composition is strikingly different to two other carbonaceous chondrites, suggesting different parent bodies. A cometary origin for Orgueil would be one possibility.

Botta, O.↗

NASA NTRS1995

Analytical pyrolysis experiments of Titan aerosol analogues in preparation for the Cassini Huygens mission

Comparative pyrolysis mass spectrometric data of Titan aerosol analogs, called 'tholins', are presented. The Titan tholins were produced in the laboratory at Cornell by irradiation of simulated Titan atmospheres with high energy electrons in plasma discharge. Mass-spectrometry measurements were performed at FOM of the solid phase of various tholins by Curie-point pyrolysis Gas-Chromatography/Mass-Spectrometry (GCMS) and by temperature resolved in-source Pyrolysis Mass-Spectrometry to reveal the composition and evolution temperature of the dissociation products. The results presented here are used to further define the ACP (Aerosol Collector Pyrolyser)-GCMS experiment and provide a basis for modelling of aerosol composition on Titan and for the iterpretation of Titan atmosphere data from the Huygens probe in the future.

Ehrenfreund, P.↗