Search NASA⌕ Search

SEARCH · Search NASA

Results for “habitable worlds”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

Planetary Protection Technologies for Planetary Science Instruments, Spacecraft, and Missions: Report of the NASA Planetary Protection Technology Definition Team (PPTDT)

Planetary bodies like Mars, Europa, and Enceladus pose the question, "How to study them without contaminating them and destroying future prospects to detect life, if it is there?" The natural trade-off, of course, is that the cleaner your spacecraft, the more you can explore such a body without risk of contaminating it. As chartered by NASA Headquarters, the Planetary Protection Technology Definition Team (PPTDT) was asked to provide a report covering six different areas related to the engineering and technology challenges of implementing planetary protection requirements on solar system exploration missions, including: Assessment of technical and engineering challenges to applying available microbial-reduction methods, including recontamination prevention, to spacecraft hardware and instruments, to meet current NASA requirements on preventing the forward contamination of potentially habitable worlds by future spacecraft missions (orbiters, atmospheric missions, landers, penetrators, and drills); Identification of spacecraft and instrument materials known to be compatible with existing planetary protection protocols; Planetary protection protocols/processes available or which appear promising, and areas ripe for technological development; The technical and engineering challenges in ensuring that spacecraft hardware and instruments can meet organic cleanliness requirements needed to ensure high confidence in differentiating Earth contamination from extraterrestrial signals to avoid false negative as well as false positive results; Approaches for mitigating the identified challenges that would allow instruments to be flown successfully at the required levels of cleanliness and microbial reduction, beginning with identification of commonly used materials and spacecraft hardware that are compatible (or particularly vulnerable) to planetary protection protocols; Engineering, technology, and scientific research and development that could be funded by NASA to provide future capabilities to field scientific instruments and spacecraft on missions that require either subsystem or system-level microbial reduction and recontamination prevention.

John D. Rummel↗
NASA NTRS2018

Environmental Requirements and Verification for NASA’s Planned Europa Clipper

NASA’s Jet Propulsion Laboratory (JPL) and its partner are planning a mission to explore an icy moon of Jupiter, Europa. The objective of the planned Europa Clipper mission is to gain insight into the key ingredients for this potentially habitable world. This mission will conduct investigations using a suite of instruments that includes a set of five remote sensing instruments, four in-situ fields and particles instruments, and a two-channel ice-penetrating radar. Among its science objectives are to produce high-resolution images of Europa's surface, determine its composition, look for signs of recent or ongoing activity, measure the thickness of the ice shell, search for subsurface lakes, and determine the depth and salinity of Europa's ocean. Europa Clipper is expected to encounter a very challenging environment, particularly in radiation. This paper provides a comprehensive description of the challenging environments and the environmental requirements that are levied onto the Europa Clipper system design. The mitigations activities being conducted or planned to ensure compliance with the severe environments will be described. Also discussed will be how the environmental requirements are verified and at which level of integration to ensure mission success.

Man, Kin F.↗
NASA NTRS2020

The First Habitable-zone Earth-sized Planet from TESS. III. Climate States and Characterization Prospects for TOI-700 d

We present self-consistent three-dimensional climate simulations of possible habitable states for the newly discovered habitable-zone Earth-sized planet TOI-700 d. We explore a variety of atmospheric compositions, pressures, and rotation states for both ocean-covered and completely desiccated planets in order to assess the planet's potential for habitability. For all 20 of our simulated cases, we use our climate model outputs to synthesize transmission spectra, combined-light spectra, and integrated broadband phase curves. These climatologically informed observables will help the community assess the technological capabilities necessary for future characterization of this planet—as well as similar transiting planets discovered in the future—and will provide a guide for distinguishing possible climate states if one day we do obtain sensitive spectral observations of a habitable planet around an M star. We find that TOI-700 d is a strong candidate for a habitable world and can potentially maintain temperate surface conditions under a wide variety of atmospheric compositions. Unfortunately, the spectral feature depths from the resulting transmission spectra and the peak flux and variations from our synthesized phase curves for TOI-700 d do not exceed 10 ppm. This will likely prohibit the James Webb Space Telescope from characterizing its atmosphere; however, this motivates the community to invest in future instrumentation that perhaps can one day reveal the true nature of TOI-700 d and to continue to search for similar planets around less distant stars.

Gabrielle Suissa↗
NASA NTRS2020

Environmental Verification of NASA’s Europa Clipper Mission

NASA’s Jet Propulsion Laboratory (JPL) and its partner are planning a mission to explore an icy moon of Jupiter, Europa. The objective of the planned Europa Clipper mission is to gain insight into the key ingredients for this potentially habitable world. This mission will conduct investigations using a suite of remote sensing and in-situ fields and particles instruments, and a two-channel ice-penetrating radar. Among its science objectives are to produce high-resolution images of Europa's surface, determine its composition, look for signs of recent or ongoing activity, measure the thickness of the ice shell, search for subsurface lakes, and determine the depth and salinity of Europa's ocean. Europa Clipper is expected to encounter very challenging environments. These environments include radiation, dynamics, thermal, and electromagnetics, which have been translated into a set of environmental requirements that are levied onto the Europa Clipper flight system design. This paper describes how the environmental requirements are specified and verified for each flight component and at which level of integration. A couple of examples will be provided to illustrate the process by which a comprehensive set of verification activities is specified and performed for individual subsystems and instruments to ensure mission success.

Man, Kin Fung↗
NASA NTRSDate not supplied

Laboratory Demonstration of High Contrast with the PIAACMC Coronagraph on an Obstructed and Segmented Aperture

Coronagraphs (together with starshades) are an important tool to directly image and characterize exoplanets, and enable the search for biomarkers in reflected light on potentially habitable worlds. Their performance and efficiency has steadily been improving over the past several decades, but has not yet reached performance limits. In particular, the expected exoplanet yield for missions such as the Astro2020-recommended “IR/O/UV Flagship” can still be improved by factors of at least 2-3, simply by continued improvements in coronagraph performance, before they plateau due to physics limits. One possible architecture that can enable at least a part of this improvement is the Phase-Induced Amplitude Apodization Complex Mask Coronagraph (PIAACMC). Itoffersthe advantages of high throughput, small inner working angle (IWA),and almost noloss inPSF sharpness, and natively supports obstructed and segmented apertures, which is essential to the Astro2020 “IR/O/UV Flagship”mission. Historically, key disadvantages of PIAA have been poor tolerance to stellar angular sizes and maturity, but latest designs and demonstrations have made significant strides in this respect.In this paper, we present the current status and overview of our program to mature the PIAACMC technology. We first review PIAACMC designs for LUVOIR-A and B, which resultedin improved expected yield of Exo-Earths relative tothe baselines for both mission concepts. In particular, for LUVOIR-B, the yield improves from 28 to 42due to improvedtolerance to stellar angular size in our design. The improvement in yield is marginal for LUVOIR-A, but our design enables detecting planets around smaller diameter stars (nearby K-dwarfs and/or farther FG stars). We also describe our modeling and vacuum demonstrationsfor the LUVOIR-A aperture(which is more challengingthan LUVOIR-B due to the central obstruction).The demonstration included a LUVOUR-A pupil mask, an on-axis PIAA set of 2 mirrors with central holes, a Boston Micromachines DM, a patterned CMC mask, Lyot stop, and supporting masks and optics. Demonstrations were conducted at JPL’s High Contrast Imaging Testbed (HCIT) using several characterization andwavefront control techniques (primarily standard EFC, several experimental techniques were attempted, as well as speckle nulling). So far, our results include 1.9e-8 raw contrast in 10% broadband light between 3.5 and 8 l/D; 4.1e-8 and 1.6e-9 coherent contrasts in monochromatic light between 2-4 and 4-8 l/D, respectively. We also present measurements and analysis of sensitivity to tip/tilt jitter and stellar angular size. Finally, we compare our test results to models, present an analysis of our limiting factors, and explorefuture prospectsfor improvement based on validated models.

Coronagraph↗
NASA NTRSDate not supplied

A New Linear Polarizer Design for Application in the Far-Ultraviolet Spectral Range

New mission concepts that are under consideration by NASA (such as the Polstar MIDEX mission concept) call for the design and implementation of Far Ultraviolet (FUV) polarizer technologies that have not been developed yet. A team that includes members from the NASA Goddard Space Flight Center (GSFC), Arizona State University (ASU), and Woodruff Consulting, worked on the design and development of a polarizer design that may produce extinction ratios higher than have ever been reported before in the FUV spectral range (100-200 nm). This polarizer consists of transmitting linearly polarized light through a series of reflections from a combination of two silicon carbide (SiC) and two lithium fluoride (LiF) crystals positioned at angles of incidence (relative to surface normal) close to the LiF Brewster’s angle. The performance of this polarizer concept was fabricated and tested with an existing McPherson 225 Vacuum Ultraviolet (VUV) spectrometer located in the Optics Branch at NASA-GSFC. Initial testing has shown that in the FUV spectral range, this design can produce state-of-the-art extinction ratios at the Hydrogen Lyman-Alpha (Ly-α) wavelength of 121.6 nm. A polarizer with such a performance has never been reported and it signifies a breakthrough in FUV polarization technology. The levels of effectiveness paired with the design’s compact design allows for a new polarizer capability that would one day be implemented in a future spectropolarimetry space mission. In addition, this polarizer concept could potentially be used to characterize the optical properties of new mirror coatings that will be used in a future Habitable World Observatory (HWO) mission concept as proposed by the 2020 Decadal Survey.2

Far Ultraviolet (FUV), polarimetry, instrumentatio↗
NASA NTRSDate not supplied

Assessment of Near-Angle Scatter on Exo-Earth Coronagraphy

A first order single surface analysis indicates that, to enable coronagraphic detection and characterization of exo-Earth planets, near angle scatter must be considered when specifying optical surfaces for a potential Habitable World Observatory. Based on arbitrary error budget allocations and using Rayleigh-Rice Vector Scatter Theory, Generalized Harvey-Shack Scalar Scatter Theory, and Greynolds Approximation, ‘placeholder’ specifications for the primary mirror are derived: Static Surface Roughness < 1 nm rms, and Dynamic Surface Roughness < 1 pm PV. These specifications will change once error budget allocations are defined. Analysis does not include scatter from more than just the primary mirror, coating structure, edges, contamination, micrometeoroid impacts, etc.

H. Philip Stahl↗
NASA NTRSDate not supplied

Linear Polarizer Design for Application in the Far-Ultraviolet Spectral Range

New mission concepts that are under consideration by NASA (such as the Polstar MIDEX mission concept) call for the design and implementation of Far Ultraviolet (FUV) polarizer technologies that have not been developed yet. A team that includes members from the NASA Goddard Space Flight Center (GSFC), Arizona State University (ASU), and Woodruff Consulting, worked on the design and development of a polarizer design that may produce extinction ratios higher than have ever been reported before in the FUV spectral range (100-200 nm). This polarizer consists of transmitting linearly polarized light through a series of reflections from a combination of two silicon carbide (SiC) and two lithium fluoride (LiF) crystals positioned at angles of incidence (relative to surface normal) close to the LiF Brewster’s angle. The performance of this polarizer concept was fabricated and tested with an existing McPherson 225 Vacuum Ultraviolet (VUV) spectrometer located in the Optics Branch at NASA-GSFC. Initial testing has shown that in the FUV spectral range, this design can produce state-of-the-art extinction ratios at the Hydrogen Lyman-Alpha (Ly-α) wavelength of 121.6 nm. A polarizer with such a performance has never been reported and it signifies a breakthrough in FUV polarization technology. The levels of effectiveness paired with the design’s compact design allows for a new polarizer capability that would one day be implemented in a future spectropolarimetry space mission. In addition, this polarizer concept could potentially be used to characterize the optical properties of new mirror coatings that will be used in a future Habitable World Observatory (HWO) mission concept as proposed by the 2020 Decadal Survey.2

Far Ultraviolet (FUV), polarimetry, instrumentatio↗
NASA NTRSDate not supplied

Testing the Efficacy of Laser Sterilization as A Spacecraft Bioburden Reduction Alternative

As NASA continues to put forth efforts in seeking out life in the solar system with missions like Europa Clipper, Mars Sample Return, and Dragonfly, reducing the bioburden (number of living microbes) on spacecraft is required by NASA policy for the protection of potentially habitable worlds. In this project, we are testing the efficacy of a novel method for laser sterilization on stress tolerant bacterial spores (Bacillus subtilis) using a high energy femtosecond laser. To test the laser, we inoculate metal coupons with Bacillus subtilis spores. After laser treatment, we do a PVA (polyvinyl acetate) peel to recover the spores then we calculate to find the number of spores that survived the treatment. Our results show that within a certain pulse count range, increasing fluence increases sterilization effectiveness. We have demonstrated the ability to reduce viable microbial counts by at least 10-4. By studying laser sterilization, we could change the way spacecraft are sterilized by making the process more efficient and cost-effective.

Planetary protection↗
NASA NTRSDate not supplied

A New Integral Field Spectrograph for Broadband Coronagraph Demonstrations at the High Contrast Imaging Testbed Facility

An integral field spectrograph (IFS) camera may help fulfill the exoplanet characterization goals of a future Habitable Worlds Observatory. During the Nancy Grace Roman Space Telescope mission formulation phase, the Coronagraph Instrument Project established the laboratory performance baseline of a combined coronagraph and IFS system with the Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES; 1E-8 contrast over an 18% bandpass; 3--9 lambda/D bowtie-shaped control region). New laboratory demonstrations are needed to expand on this milestone in terms of contrast, bandpass, and field of view towards the requirements of a future mission capable of characterizing the atmospheres of Earth-like exoplanets. Here we present the design of a successor to PISCES that can observe a 20 lambda/D-diameter field of view with an instantaneous bandpass up to 30%, at a resolving power R > 70 at visible wavelengths. This instrument will interface with the existing coronagraph layout in the High Contrast Imaging Facility DST-2 vacuum chamber. The addition of a spectroscopic imaging camera at HCIT will benefit the wider coronagraph technology community by enabling other NASA-supported investigators to automatically obtain multi-wavelength measurements of speckles both inside and outside of their control region, and the instrument will support community-led demonstrations of high-order wavefront sensing and control techniques such as dark hole maintenance and linear dark field control.

coronagraph↗
NASA NTRSDate not supplied

The Hubble Space Telescope in a New Era of Astrophysics

The Hubble Space Telescope continues to achieve incredible scientific advances at the forefront of astrophysics after 33 years, thanks to 5 astronaut servicing missions, creative scientists, and an innovative technical ground team. What will Hubble’s role be in the new eras of the Webb, Roman, and Habitable Worlds space observatories? This talk will cover Hubble’s recent discoveries and future importance in realms ranging from the solar system and exoplanets to distant galaxies and cosmology. Hubble will play a key role for years to come in high priority science including Time Domain and Multi-Messenger Astrophysics (TDAMM), exoplanet characterization, and a full range of ultraviolet astronomy. Hubble’s unique capabilities complement those of Webb and future ground and space-based observatories and probes.

Jennifer J Wiseman↗
NASA NTRSDate not supplied

Photon Harvesting and Rocky Planet Biosignatures with 3D Climate Models

On the Earth solar photons are collected, sifted, and harvested by life at a scale that has transformed and defined the planet and continues to do so. That transformation is considered to be a key biosignature to look for in the rocky exoplanet population of our galaxy. However, the availability of photons on planetary surfaces depends on orbital and spin configuration as well as shadowing and scattering by clouds and other atmospheric phenomena. We are using a state-of-the-art 3D climate model (ROCKE-3D, Way et al. 2017) to study rocky planet surface irradiances and the implications for biosignatures and future missions such as the Habitable Worlds Observatory.

exoplanets↗
NASA NTRS2024

Stress Control of Multilayer Suspended MEMS Structures In High Contrast Microshutters

The microshutter array (MSA) is a programmable field mask (Fig. 1) that enables large-format multi-object spectroscopy at extremely high contrast ratios of over 105 in space [1]. Assessment of the first generation MSAs used on the James Webb Space Telescope (JWST) revealed light leakage and stuck shutters due to warping (Fig. 2) [2]. Such leakage is partially reduced with appropriate light shields and mitigation strategies. Anticipation of stricter performance requirements for the upcoming Habitable Worlds Observatory Flagship [3] motivates the study. In this paper, we present the systematic study of film stress effects using finite element modeling (FEM) and analysis of newly fabricated MSAs. We present structural designs to mitigate stress effects and improve flatness of suspended structures in micro-electromechanical systems (MEMS). Our study aims to provide a comprehensive view of film-to-film interaction, mechanical, and structural considerations in design and process definition that goes beyond NGMSA devices. The presented findings can be of value to the stress and morphology control in any suspended MEMS membranes.

Microshutters↗
NASA NTRSDate not supplied

Experimental Verification of the Parabolic Deformable Mirror for the ExoSpec Project

For the Habitable Worlds Observatory, it is essential to broaden the controllable wavelength bandwidth for high-contrast imaging and spectroscopy to increase the exoEarth yield and characterization. The Parabolic Deformable Mirrors (PDM) under the NASA Headquarters directed ExoSpec Work package is specifically tailored to do so. We have successfully procured a generation 1 (Gen 1) PDM device and completed in-depth characterization of the device. This robust evaluation has become instrumental in informing subsequent stages of development, particularly in shaping the design and specifying requirements for the next generation, Gen2, PDM device. We have built a testbed in an environmentally controlled cleanroom to experimentally demonstrate the use of a parabolic DM in a coronagraph instrument as well an integral field spectrograph (IFS). This versatile testbed is designed to test different DM architectures, various low-order wavefront schemes, and a lenslet based IFS. This provides us with a basis for comparison with different DM configurations – 1) flat DM, 2) parabolic DMs, and 3) a flat DM and parabolic DMs. In this communication, we will discuss the testbed design and updates, parabolic DM characterization, Gen 2 requirement definitions, and different tests planned for the testbed.

Hari Subedi↗
NASA NTRSDate not supplied

Deformable Mirror Technology Roadmap: Architecting A Path to TRL5 for Future Exoplanet Direct Imaging Space Missions

The Deformable Mirror Technology Roadmap (DMTR) is a working group tasked by NASA’s Exoplanet Program Office to study the path to bring deformable mirror (DM) systems to a Technology Readiness Level 5. DMs, and their drive electronics and harnessing, are the critical component of any exoplanet direct imaging coronagraph, and there is no device that exists today which can meet the ambitious performance goals expected for NASA’s Habitable Worlds Observatory (HWO). Here we present progress on surveying the field of DM technologies, defining a first cut set of device requirements, and recommending a development and verification maturation program.

Tyler D. Groff↗
NASA NTRS2023

Mitigating Worst-Case Exozodiacal Dust Structure in High-Contrast Images of Earth-Like Exoplanets

Detecting Earth-like exoplanets in direct images of nearby Sun-like systems brings a unique set of challenges that must be addressed in the early phases of designing a space-based direct imaging mission. In particular, these systems may contain exozodiacal dust, which is expected to be the dominant source of astrophysical noise. Previous work has shown that it may be feasible to subtract smooth, symmetric dust from observations; however, we do not expect exozodiacal dust to be perfectly smooth. Exozodiacal dust can be trapped into mean-motion resonances with planetary bodies, producing large-scale structures that orbit in lock with the planet. This dust can obscure the planet, complicate noise estimation, or be mistaken for a planetary body. Our ability to subtract these structures from high-contrast images of Earth-like exoplanets is not well understood. In this work, we investigate exozodi mitigation for Earth–Sun-like systems with significant mean-motion resonant disk structures. We find that applying a simple high-pass filter allows us to remove structured exozodi to the Poisson noise limit for systems with inclinations <60° and up to 100 zodis. However, subtracting exozodiacal disk structures from edge-on systems may be challenging, except for cases with densities <5 zodis. For systems with three times the dust of the solar system, which is the median of the best fit to survey data in the habitable zones of nearby Sun-like stars, this method shows promising results for mitigating exozodiacal dust in future Habitable Worlds Observatory observations, even if the dust exhibits significant mean-motion resonance structure.

Miles H. Currie↗
NASA NTRSDate not supplied

Leveraging the Roman Coronagraph Approach for the HWO Error Budget

The Habitable Worlds Observatory (HWO) is currently being considered as a future, coronagraph-equipped space telescope that would fulfill the top priority of Astro-2020. The top priority stated is the building of a telescope capable of detecting and characterizing exoplanets with sensitivity down to Earth-like planets. In a coronagraph approach, the methodology for setting up the error budget and performance model can benefit directly from the Nancy Grace Roman Space Telescope (RST) experience. RST’s Coronagraph Instrument (CGI) is a direct precursor to the HWO coronagraph, with performance reaching below 10 −7 in contrast demonstrated in very recent thermal-vac testing, and the possibility that it will perform better with more time on orbit. The RST CGI development benefited significantly from an error budget approach and analytical model focused on the noise incurred in measuring a planet’s flux ratio. In this brief paper we outline the current state of the application of the Roman approach to an HWO flux ratio noise error budget, including reasonable allocations informed by the Roman experience, and recent studies of narrow angle scatter done independently.

Bijan Nemati↗