SEARCH · Engineering Papers

Results for “Planetary surface power”

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.

SourceResearch connectionFrom yearThrough year

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

At least 235 records · Page 13

All sources NASA NTRS DOE OSTI

NASA NTRS2005

Application of an Orbital GPR Model to Detecting Martian Polar Subsurface Features

There are numerous challenges in successfully implementing and interpreting planetary ground penetrating radar (GPR) measurements. Many are due to substantial uncertainties in the target ground parameters and the intervening medium (i.e., the ionosphere). These uncertainties generate a compelling need for meaningful quantitative simulation of the planetary GPR problem. An accurate numerical model would enable realistic numerical GPR simulations using parameter regimes much broader than are possible in laboratory or field experiments. Parameters such as source bandwidth and power, surface and subsurface features, and ionospheric profiles could be rapidly iterated to understand their impact on GPR performance and the reliable interpretation of GPR data.

Xu, Y.↗

NASA NTRS2005

Capabilities Roadmap Briefings to the National Research Council

High energy power and propulsion capability roadmap - general background and introduction. Advanced telescopes and observatories and scientific instruments and sensors capability roadmaps - general background and introduction. Space communications capability roadmap interim review. Robotic access to planetary surface capability roadmap. Human health and support systems capability roadmap progress review.

Source record↗

NASA NTRSDate not supplied

Capabilities for Long-Duration Landers on Mercury

Mercury surface assets will be exposed to extreme thermal swings over a Mercury day (-180 C to +430 C). Dayside operations, in particular, are challenging from a thermal control and power perspective. Consequently, the latest planetary decadal survey process included a Mercury lander concept that only operated during the night. Recent technology advancements in high and low temperature systems may enable new science over the entire Mercury day.

Mercury↗

NASA NTRSDate not supplied

Surface-Enhanced Raman Spectroscopy (SERS) for Venus Atmospheric Characterization and Trace Organics Identification

The chemical composition of Venus’ clouds has attracted considerable attention since the first atmospheric probes entered the planet in the early 1980s. We know from these early studies that cloud aerosols consist of micron and submicron droplets of sulfuric acid (~85%) and water (~15%), but outstanding questions still exist regarding their trace chemical composition, especially the identity of the unknown UV absorber(s) and the possible presence of organic material (Spacek & Benner, 2021). Veritas and DaVinci will launch at the end of the decade to advance our understanding of Venus’ surface and atmosphere, however these missions are not designed to sample and analyze cloud aerosols at trace levels. Raman spectroscopy is an ideal candidate for characterizing aerosols and has a track record in studies of Earth’s atmosphere. Raman provides broad chemical screening of organic and inorganic molecules within seconds, and Raman instrumentation can be miniaturized to meet the stringent size, weight, and power (SWaP) constraints of an atmospheric probe while retaining sensitivity and specificity that allow spectral fingerprinting of compounds and functional groups. Raman alone is insufficient to characterize trace constituents however, as limits of detection are typically in the 10s to 100s of ppm at best for planetary Raman spectrometers. Surface-Enhanced Raman Spectroscopy (SERS), a method that utilizes nanoscale materials interacting with a sample to enhance weak Raman signals by orders of magnitude when probed by a laser, has the potential to drastically improve the sensitivity of a Raman instrument while adding little-to-no SWaP nor complexity to a scientific payload. We aim to de-risk SERS technology for rapid infusion in future planetary science missions by developing custom SERS substrates tailored towards Venus atmospheric exploration. We have developed SERS substrates consisting of nanotextured silver films and tested them on potential Venus-relevant organic compounds, with preliminary results indicating sub-ppm sensitivity. Additionally, we have planned tests to investigate durability, longevity, and other key characteristics that impact SERS substrate performance to prepare SERS technology for flight.

Venus↗

NASA NTRS2011

ATHLETE: A Cargo-Handling Vehicle for Solar System Exploration

As part of the NASA Exploration Technology Development Program, the Jet Propulsion Laboratory is developing a vehicle called ATHLETE: the All-Terrain Hex-Limbed Extra-Terrestrial Explorer. Each vehicle is based on six wheels at the ends of six multi-degree-of-freedom limbs. Because each limb has enough degrees of freedom for use as a general-purpose leg, the wheels can be locked and used as feet to walk out of excessively soft or other extreme terrain. Since the vehicle has this alternative mode of traversing through or at least out of extreme terrain, the wheels and wheel actuators can be sized for nominal terrain. There are substantial mass savings in the wheel and wheel actuators associated with designing for nominal instead of extreme terrain. These mass savings are comparable-to or larger-than the extra mass associated with the articulated limbs. As a result, the entire mobility system, including wheels and limbs, can be about 25% lighter than a conventional mobility chassis. A side benefit of this approach is that each limb has sufficient degrees-of-freedom to use as a general-purpose manipulator (hence the name "limb" instead of "leg"). Our prototype ATHLETE vehicles have quick-disconnect tool adapters on the limbs that allow tools to be drawn out of a "tool belt" and maneuvered by the limb. A power-take-off from the wheel actuates the tools, so that they can take advantage of the 1+ horsepower motor in each wheel to enable drilling, gripping or other power-tool functions. Architectural studies have indicated that one useful role for ATHLETE in planetary (moon or Mars) exploration is to "walk" cargo off the payload deck of a lander and transport it across the surface. Recent architectural approaches are focused on the concept that the lander descent stage will use liquid hydrogen as a propellant. This is the highest performance chemical fuel, but it requires very large tanks. A natural geometry for the lander is to have a single throttleable rocket engine on the centerline at the bottom, and to have the propellant tanks arranged as compactly as possible around and above that engine, with nearly-straight structural load paths that carry the heavy LO2 tanks as well as the ascent stage or cargo on a top deck. (The requirement for exactly one descent engine stems from the need to avoid symmetry planes in the exhaust plume that can entrain surface particles and loft them up into the system at hypervelocity.) This geometry is especially attractive since abort considerations drive the ascent stage to have as much open space around it as possible, in case the ascent stage needs to fire away from an out-of-control descent stage. These considerations lead to a configuration where the cargo deck of the lander is relatively high off the ground (over 6 meters in current concepts, using a 10-meter diameter launch shroud). These considerations have led some observers to presume that there is a "lander offloading problem". ATHLETE has been demonstrated as a solution to this problem, walking cargo off the high deck. This paper describes the applicability of the ATHLETE concept to exploration of the moon, Mars and even to Near- Earth Objects. Recent field test results for long-range traverse are described, along with plans for testing in the simulated microgravity environment of a NEO.

Space Robotics↗

NASA NTRS2019

Experimental Forward Flight Rotor Performance Testing from Terrestrial to Martian Atmospheric Densities

With the recent interest in Martian exploration using Unmanned Aerial Vehicles (UAV), an experimental study was conducted to investigate rotor performance at Martian atmospheric conditions. Both simulation and testing of rotors is vital for the evaluation of performance and behavior of rotor, especially for operations at Martian atmospheric densities and pressures. Testing and measuring rotor forward flight performance at Martian atmospheric conditions is a relatively unexplored area. Therefore, an experimental study was performed in a wind tunnel to investigate helicopter forward flight performance and to demonstrate successful rotor operation at Martian atmospheric densities. This work was a continuation of the first ever wind tunnel test of a simulated rotorcraft in forward flight at Martian atmospheric densities. A test was conducted in a facility, which could be evacuated to the atmospheric pressure and density of Mars. A 40-in diameter rotor, roughly approximating the scale of the proposed Mars Helicopter design by the NASA Jet Propulsion Laboratory (JPL), was tested in forward flight at Mars atmospheric pressure at the NASA Ames Planetary Aeolian Laboratory (PAL). In this forward flight testing, the drive system of the Martian Surface Wind Tunnel (MARSWIT) was never turned on. The goal of this experiment was to collect rotor thrust, rotational speed, power, torque, and wind speed measurements. Subsequently, these results can be used for correlation with simulated cases using a mid-fidelity Computational Fluid Dynamics (CFD) simulation. Rotor thrust and power seem to decrease approximately proportional to the decrease in density. However, the Reynolds number has an effect on rotor performance that might also be contributing to the change in thrust and power. This effect plays a vital role in rotor performance at reduced pressure that cannot be neglected in the simulation. Despite the challenges involved in testing at a large difference of atmospheric densities between Earth and Mars, repeatable data is obtained in all the measurements at Martian atmospheric conditions.

Martian↗

NASA NTRS2014

Development of a Linear Ion Trap Mass Spectrometer (LITMS) Investigation for Future Planetary Surface Missions

Future surface missions to Mars and other planetary bodies will benefit from continued advances in miniature sensor and sample handling technologies that enable high-performance chemical analyses of natural samples. Fine-scale (approx.1 mm and below) analyses of rock surfaces and interiors, such as exposed on a drill core, will permit (1) the detection of habitability markers including complex organics in association with their original depositional environment, and (2) the characterization of successive layers and gradients that can reveal the time-evolution of those environments. In particular, if broad-based and highly-sensitive mass spectrometry techniques could be brought to such scales, the resulting planetary science capability would be truly powerful. The Linear Ion Trap Mass Spectrometer (LITMS) investigation is designed to conduct fine-scale organic and inorganic analyses of short (approx.5-10 cm) rock cores such as could be acquired by a planetary lander or rover arm-based drill. LITMS combines both pyrolysis/gas chromatograph mass spectrometry (GCMS) of sub-sampled core fines, and laser desorption mass spectrometry (LDMS) of the intact core surface, using a common mass analyzer, enhanced from the design used in the Mars Organic Molecule Analyzer (MOMA) instrument on the 2018 ExoMars rover. LITMS additionally features developments based on the Sample Analysis at Mars (SAM) investigation on MSL and recent NASA-funded prototype efforts in laser mass spectrometry, pyrolysis, and precision subsampling. LITMS brings these combined capabilities to achieve its four measurement objectives: (1) Organics: Broad Survey Detect organic molecules over a wide range of molecular weight, volatility, electronegativity, concentration, and host mineralogy. (2) Organic: Molecular Structure Characterize internal molecular structure to identify individual compounds, and reveal functionalization and processing. (3) Inorganic Host Environment Assess the local chemical/mineralogical makeup of organic host phases to help determine deposition and preservation factors. (4) Chemical Stratigraphy Analyze the fine spatial distribution and variation of key species with depth.

Mars↗

NASA NTRS2016

New Approaches to Inferences for Steep-Sided Domes on Venus

New mathematical approaches for the relaxation and emplacement of viscous lava domes are presented and applied to steep-sided domes on Venus. A similarity solution approach is applied to the governing equation for fluid flow in a cylindrical geometry for two distinct scenarios. In the first scenario, dome relaxation is explored assuming a constant volume of fluid (i.e. lava) has been rapidly emplaced onto the surface. Cooling of lava is represented by a time-variable viscosity and singularities inherent in previous models for dome relaxation have been eliminated. At the onset of relaxation, bulk dynamic viscosities lie in the range between 10(exp 10) - 10(exp 16) Pa s, consistent with basaltic-andesite to rhyolitic compositions. Plausible relaxation times range from 5 to 5000 years, depending on initial lava viscosity. The first scenario, however, is only valid during the final stages of dome relaxation and does not consider the time taken for lava to be extruded onto the surface. In the second scenario, emplacement and growth of a steep-sided dome is considered when the volume of lava on the surface increases over time (i.e. time-variable volume approach). The volumetric flow rate may depend on an arbitrary power of the dome thickness, thus embracing Newtonian as well as other rheologies for describing terrestrial and planetary mass flows. The approach can be used to distinguish between basic flow rate models for fluid emplacement. The formalism results in radial expansion of a dome proportional to t(sup 1/2), consistent with the diffusive nature of the governing equation. The flow at the front is shown to thicken as the front advances for a constant rate of lava supply. Emplacement times are intimately correlated with the bulk rheology. Comparison of the theoretical profiles with the shape of a typical dome on Venus indicates that a Newtonian bulk rheology is most appropriate, consistent with prior studies. However, results here suggest a bulk dynamic viscosity of 10(exp 12) - 10(exp 13) Pa s and emplacement times of approximately 2-16 years. Both scenarios investigated give emplacement times significantly less than prior estimates and compositions consistent with basaltic andesite.

steep-sided domes↗

NASA NTRS1999

MABVAP: One Step Closer to an Aerobot Mission to Mars

Lighter-than-air planetary missions continued attract growing interest in Mars exploration due to unique combination of proximity to the surface and mobility that far surpasses capability of surface vehicles. Following the experience with the Sojourner rover and subsequent development of powerful rovers for Mars 2003 and 2005 missions it became clear that on Mars surface rover mobility is quite restricted. Realistic travel distances may be limited to tens of kilometers per year on relatively obstacle-free plains and a few kilometers or less on the more rugged terrains. Many areas on Mars will be inaccessible to rovers. Several concepts for a Mars aerobot (robotic balloon) mission have been pursued in the last decade. Additional information is contained in the original extended abstract.

Kerzhanovich, V. V.↗

NASA NTRSDate not supplied

Automation and AI in Space Drilling

Future planetary surface sampling missions, such as delving past the near-surface ice layers on Mars in search of organics and possibly signs of past/extant life, will require lightweight, low-mass planetary drilling and sample handling. Unlike terrestrial drills, these exploration drills must work dry (without drilling muds or gas), blind (no prior local or regional seismic or other surveys), and light (very low downward force or weight on bit, and perhaps 100 W available from solar power or batteries). Given the lightspeed transmission delays to Mars and outward, an exploratory planetary drill cannot be controlled directly from Earth. Drills that penetrate deeper than a few centimeters are likely to get stuck if operated open-loop (the MSL drill only penetrates 5 cm, and the MER Rock Abrasion Tools 5 mm by comparison), so some form of local drill control is required. In the relatively near-term, human crews cannot be presumed to be available for surface instrument teleoperation. Therefore highly automated drill and sample-transfer operations will be required, to explore the subsurface with the ability to safe robotic drilling systems and recover and continue on from the most probable fault conditions. Current automation, scheduling and diagnostic approaches will be discussed that roughly track the actions and roles of humans in terrestrial manual drilling operations.

drill automation↗

NASA NTRS1994

Remote geochemical experiment package for Discovery class missions

Remote sensing x-ray and gamma-ray spectrometers can be used to infer elemental composition on atmosphereless bodies, such as asteroids, the moon, and Mercury. The composition of the planetary body and variations in its surface chemistry are of fundamental importance in understanding the formation and dynamics of that body. Thus, for Discovery class missions, x-ray fluorescence (XRF), gamma-ray spectrometer (GRS), or a combined Geochemical Experiment Package (GEP) have been proposed. These instruments can meet the mission science objectives, while still meeting the weight, power, and cost constraints. These missions include the Near Earth Asteroid Rendezvous, the Main-belt Asteroid Rendezvous, and others such as HERMES (Mercury Orbiter). This paper presents the results of calculations done to assess the sensitivity of a combined instrument to obtain elemental compositions of planetary bodies with an uncertainty small enough to be scientifically useful.

Clark, Pamela E.↗

NASA NTRS2001

An Analysis and Procedure for Determining Space Environmental Sink Temperatures With Selected Computational Results

The purpose of this report was to analyze the heat-transfer problem posed by the determination of spacecraft temperatures and to incorporate the theoretically derived relationships in the computational code TSCALC. The basis for the code was a theoretical analysis of the thermal radiative equilibrium in space, particularly in the Solar System. Beginning with the solar luminosity, the code takes into account these key variables: (1) the spacecraft-to-Sun distance expressed in astronomical units (AU), where 1 AU represents the average Sun-to-Earth distance of 149.6 million km; (2) the angle (arc degrees) at which solar radiation is incident upon a spacecraft surface (ILUMANG); (3) the spacecraft surface temperature (a radiator or photovoltaic array) in kelvin, the surface absorptivity-to-emissivity ratio alpha/epsilon with respect to the solar radiation and (alpha/epsilon)(sub 2) with respect to planetary radiation; and (4) the surface view factor to space F. Outputs from the code have been used to determine environmental temperatures in various Earth orbits. The code was also utilized as a subprogram in the design of power system radiators for deep-space probes.

Juhasz, Albert J.↗

NASA NTRSDate not supplied

NASA's Habitation Development Status: Current Concepts and ISRU Opportunities

Introduction: The National Aeronautics and Space Administration (NASA) is embarking on a bold journey to return humankind to the Moon and onward to Mars with innovative commercial, international, and academic partnerships. Under the Artemis series of missions, NASA seeks to establish sustained human exploration of deep space through an objectives-based approach. This approach drives the identification of needed system functionality and the current and future capabilities which will eventually allow humanity to sustainably live beyond Earth. Providing evolvable and scalable habitation is a cornerstone function that calls for the collection and integration of current, developmental, and future technologies that can meet near-term exploration needs while growing into long-term sustained presence. NASA is advancing in-space habitation through its Next Space Technologies for Exploration Partnerships (NextSTEP) model while designing lunar, Mars transit, and Mars surface habitat government reference concepts for Artemis missions. These efforts have unveiled possible near-term opportunities for the in-space resource utilization community if human habitation is considered a future customer of space resources. NextSTEP Habitation Development: NASA is closely working with commercial partners under its NextSTEP Appendix A model to advance habitation systems in the arena of inflatable and composite habitation structures. Such efforts promise efficiencies in volumetric packaging and overall spacecraft mass respectively. Recent testing by commercial partners have helped to quantify possible failure mechanisms for inflatable structures while advancing their technology towards eventual flight certification. The advancement of such Class II habitation structures, in which the habitat is only fully deployed once in-space or on a planetary surface, is critical to providing increased habitable volume for long-duration missions with no additional mass penalties. The progression of such technology is infused into NASA’s government reference concepts for notional deep space habitation concepts. Current Government Reference Concepts: To best inform the formulation of future collaborative solicitations, NASA employs the practice of internally developing reference concepts for future exploration elements. These concepts aid in identifying the functions and capabilities needed to complete NASA missions as well as feasible solutions within the timeframe needed. Government reference concepts for a lunar Surface Habitat, Mars Transit Habitat, and Mars Sur-face Habitat are continuously being developed and updated to better guide the Agency’s overall exploration architecture. Lunar Surface Habitat. As NASA returns to the Moon, it is evaluating possible lunar surface habitation concepts. The Surface Habitat (SH) reference concept entails a hybrid metallic-inflatable structure capable of initially housing two crew for surface stays of up to 30 days in duration. While initial missions may span ~7 days in duration, consideration is being given to expanding SH’s capability to support a crew of four for up to 60 days over its 15-year design life. Functionally, the SH serves as a ‘hub’ for all Artemis crewed surface operations, providing internal volume for maintenance, medical, logistics, science utilization, and extravehicular activity (EVA) support in addition to core habitation functionality such as environmental control and life support (ECLS) and power generation and distribution among many others. Additionally, NASA has entered a study agreement with the Italian Space Agency (Agenzia Spaziale Italiana – ASI) to investigation a possible Multi-Purpose Habitat (MPH) as an additional or augmenting habit-able element for the lunar surface. Mars Transit Habitat. NASA’s current architectural concept for initial human missions to Mars entails the utilization of a transit habitat (TH) to transport a four-person crew to and from Mars orbit, departing from and returning to a lunar near-rectilinear halo orbit (NRHO), over the course of a ~1,200-day mission. While holding a similar 15-year design lifetime, TH will also support a series of analog mission activities in NRHO to gradually test the systems and interaction with lunar surface elements, some of which may be adapted for Mars surface exploration. Holding similar functional capabilities as SH, TH is sized to support much longer durations in space and greater logistical independence. Mars Surface Habitat. NASA is still exploring the concept of operations for initial crewed missions to Mars. As such, the Mars Surface Habitat (MSH) concept is still in its infancy as options for mobile, pressurized habitation and stationary habitats are being explored. It is expected MSH will leverage heavily from the lunar SH and possible lunar pressurized rover, however the very different Martian environment will likely necessitate modifications. ISRU Opportunities: Despite the advancements under NASA’s NextSTEP habitation work and continually optimized reference concepts, NASA is facing near-term mass and power challenges that may create opportunities to the ISRU community by providing yet another possible customer for space resources. While NASA desires to use regenerative ECLS systems (ECLSS) for all habitation concepts, their operation comes with initial mass penalties and maintenance overheads when compared to simpler open-loop architectures. Because of this, NASA is currently pro-posing an open-loop, consumables-based architecture for its surface habitats to achieve initial launch and delivery lander mass targets while scarring for the in-corporation of regenerative ECLSS to meet longer mission durations and sustained presence. With such an architecture, oxygen and potable water are needed consumables, which initial ISRU systems may be able to provide in a pilot capacity. Although the TH is expecting to utilize regenerative ECLSS, advancements in lunar surface-based ISRU and possible re-supply of spacecraft in lunar or Mars orbit could significantly reduce the logistical need for ECLSS related spares on TH and possibly allow a similar open-loop and consumables-based architecture. In addition to ECLSS mass concerns, the SH is facing challenges with energy storage to support operations over periods of darkness exceeding 100 hours. Both battery and fuel cell-based power architectures are being traded, opening options for external power generation and energy storage. One possibility is ISRU-produced H2 and O2 feeding external primary fuel cell systems which could supplement habitation power generation while reducing initial mass and volume until much more powerful fission power systems might be deployed. Conclusion: Significant advancements are being made in evolvable habitation concepts that span from near-term technologies, such as inflatable structures under NextSTEP, to potentially revolutionary capabilities like the lunar surface construction as funded through the Moon-to-Mars Planetary Autonomous Construction Technologies (MMPACT) project. As NASA investigates both heritage capabilities and rap-idly advancing, disruptive technologies, there are likely many near-term opportunities for initial ISRU capabilities to significantly aid human habitation and increase self-sufficiency beyond Earth.

habitation↗

NASA NTRS2017

Feasibility of Passive Cryogenic Cooling for Solar Powered Outer Planetary Missions

Spacescience instruments with cooled detectors require innovative thermal cooling solutions to meet science objectives. Detector sensitivity increases with decreasing temperature and low optics temperatures are often needed to reduce background photon noise. As the detector spectral range coverage increases from the visible to far infrared also requires lower detector temperatures. Increasing demands on detector performance lead to larger format detectors and higher refresh rates resulting in significant increases in power dissipation. Passive coolers rely on emissive power of radiating surfaces to reject heat to space. As the operating temperature requirements of detectors and optics decreases, the ability to reject heat to space becomes increasingly more difficult. Reducing both cooler internal parasitic and external environmental heat loads and maximizing the passive cooler field of view to space will enhance performance. While instrument heat loads and passive cooler parasitic heat loads are controlled by instrument designers, the external environmental heat loads and cooler views to space are governed by spacecraft and mission designers. Solar powered planetary missions require large arrays to generate sufficient power for spacecraft subsystems and payloads. Two or more solar array wings with cell coverage of the order of 40-80 m2 are often needed to generate sufficient power at 3-6 AU. These large arrays are typically symmetrically configured and can extend tens of meters. The arrays along with spacecraft attitude requirements near the target planetary bodies pose significant challenges for passive cooling at large AU. It is very difficult to provide a clear field of view to space for the cooler with large articulating arrays while keeping solar loads from impinging the cooler and meeting the spacecraft attitude science pointing requirements. This is counter intuitive because of the decreasing solar flux and colder planetary body temperatures at large AU. This paper presents the challenges and opportunities of passive cryogenic cooling versus active cooling for solar powered planetary missions.

Rodriguez, Jose I.↗

NASA NTRSDate not supplied

NASA's Habitation Development Status: Current Concepts and ISRU Opportunities

Introduction: The National Aeronautics and Space Administration (NASA) is embarking on a bold journey to return humankind to the Moon and onward to Mars with innovative commercial, international, and academic partnerships [1]. Under the Artemis series of missions, NASA seeks to establish sustained human exploration of deep space through an objectives-based approach [2]. This approach drives the identification of needed system functionality and the current and future capabilities which will eventually allow humanity to sustainably live beyond Earth. Providing evolvable and scalable habitation is a cornerstone function that calls for the collection and integration of current, developmental, and future technologies that can meet near-term exploration needs while growing into long-term sustained presence. NASA is advancing in-space habitation through its Next Space Technologies for Exploration Partnerships (NextSTEP) model while designing lunar, Mars transit, and Mars surface habitat government reference concepts for Artemis missions. These efforts have unveiled possible near-term opportunities for the in-space resource utilization community if human habitation is considered a future customer of space resources. NextSTEP Habitation Development: NASA is closely working with commercial partners under its NextSTEP Appendix A model to advance habitation systems in the arena of inflatable and composite habitation structures. Such efforts promise efficiencies in volumetric packaging and overall spacecraft mass respectively. Recent testing by commercial partners have helped to quantify possible failure mechanisms for inflatable structures while advancing their technology towards eventual flight certification. The advancement of such Class II habitation structures, in which the habitat is only fully deployed once in-space or on a planetary surface [3], is critical to providing increased habitable volume for long-duration missions with no additional mass penalties. The progression of such technology is infused into NASA’s government reference concepts for notional deep space habitation concepts. Current Government Reference Concepts: To best inform the formulation of future collaborative solicitations, NASA employs the practice of internally developing reference concepts for future exploration elements. These concepts aid in identifying the functions and capabilities needed to complete NASA missions as well as feasible solutions within the timeframe needed. Government reference concepts for a lunar Surface Habitat, Mars Transit Habitat, and Mars Sur-face Habitat are continuously being developed and updated to better guide the Agency’s overall exploration architecture. Lunar Surface Habitat. As NASA returns to the Moon, it is evaluating possible lunar surface habitation concepts. The Surface Habitat (SH) reference concept entails a hybrid metallic-inflatable structure capable of initially housing two crew for surface stays of up to 30 days in duration [4]. While initial missions may span ~7 days in duration, consideration is being given to expanding SH’s capability to support a crew of four for up to 60 days over its 15-year design life [5]. Functionally, the SH serves as a ‘hub’ for all Artemis crewed surface operations, providing internal volume for maintenance, medical, logistics, science utilization, and extravehicular activity (EVA) support in addition to core habitation functionality such as environmental control and life support (ECLS) and power generation and distribution among many others. Additionally, NASA has entered a study agreement with the Italian Space Agency (Agenzia Spaziale Italiana – ASI) to investigation a possible Multi-Purpose Habitat (MPH) as an additional or augmenting habit-able element for the lunar surface [6]. Mars Transit Habitat. NASA’s current architectural concept for initial human missions to Mars entails the utilization of a transit habitat (TH) to transport a four-person crew to and from Mars orbit, departing from and returning to a lunar near-rectilinear halo orbit (NRHO), over the course of a ~1,200-day mission [5]. While holding a similar 15-year design lifetime, TH will also support a series of analog mission activities in NRHO to gradually test the systems and interaction with lunar surface elements, some of which may be adapted for Mars surface exploration. Holding similar functional capabilities as SH, TH is sized to support much longer durations in space and greater logistical independence. Mars Surface Habitat. NASA is still exploring the concept of operations for initial crewed missions to Mars. As such, the Mars Surface Habitat (MSH) concept is still in its infancy as options for mobile, pressurized habitation and stationary habitats are being explored. It is expected MSH will leverage heavily from the lunar SH and possible lunar pressurized rover, however the very different Martian environment will likely necessitate modifications. ISRU Opportunities: Despite the advancements under NASA’s NextSTEP habitation work and continually optimized reference concepts, NASA is facing near-term mass and power challenges that may create opportunities to the ISRU community by providing yet another possible customer for space resources. While NASA desires to use regenerative ECLS systems (ECLSS) for all habitation concepts, their operation comes with initial mass penalties and maintenance overheads when compared to simpler open-loop architectures. Because of this, NASA is currently pro-posing an open-loop, consumables-based architecture for its surface habitats to achieve initial launch and delivery lander mass targets while scarring for the in-corporation of regenerative ECLSS to meet longer mission durations and sustained presence. With such an architecture, oxygen and potable water are needed consumables, which initial ISRU systems may be able to provide in a pilot capacity. Although the TH is expecting to utilize regenerative ECLSS, advancements in lunar surface-based ISRU and possible re-supply of spacecraft in lunar or Mars orbit could significantly reduce the logistical need for ECLSS related spares on TH and possibly allow a similar open-loop and consumables-based architecture. Table 1 Notional ECLSS consumables per mission use for SH and TH [5]. SH (28-day) Open Loop: Water (kg) 288 | Oxygen (kg) 30 TH (1110-day) Closed-Loop: Water (kg) 182 | Oxygen (kg) 123 In addition to ECLSS mass concerns, the SH is facing challenges with energy storage to support operations over periods of darkness exceeding 100 hours. Both battery and fuel cell-based power architectures are being traded, opening options for external power generation and energy storage. One possibility is ISRU-produced H2 and O2 feeding external primary fuel cell systems which could supplement habitation power generation while reducing initial mass and volume until much more powerful fission power systems might be deployed. Conclusion: Significant advancements are being made in evolvable habitation concepts that span from near-term technologies, such as inflatable structures under NextSTEP, to potentially revolutionary capabilities like the lunar surface construction as funded through the Moon-to-Mars Planetary Autonomous Construction Technologies (MMPACT) project [7]. As NASA investigates both heritage capabilities and rap-idly advancing, disruptive technologies, there are likely many near-term opportunities for initial ISRU capabilities to significantly aid human habitation and increase self-sufficiency beyond Earth.

habitation↗

NASA NTRS2015

Scalable Lunar Surface Networks and Adaptive Orbit Access

Teranovi Technologies, Inc., has developed innovative network architecture, protocols, and algorithms for both lunar surface and orbit access networks. A key component of the overall architecture is a medium access control (MAC) protocol that includes a novel mechanism of overlaying time division multiple access (TDMA) and carrier sense multiple access with collision avoidance (CSMA/CA), ensuring scalable throughput and quality of service. The new MAC protocol is compatible with legacy Institute of Electrical and Electronics Engineers (IEEE) 802.11 networks. Advanced features include efficiency power management, adaptive channel width adjustment, and error control capability. A hybrid routing protocol combines the advantages of ad hoc on-demand distance vector (AODV) routing and disruption/delay-tolerant network (DTN) routing. Performance is significantly better than AODV or DTN and will be particularly effective for wireless networks with intermittent links, such as lunar and planetary surface networks and orbit access networks.

Wang, Xudong↗

NASA NTRS1976

Possibility of detecting magnetospheric radio bursts from Uranus and Neptune

The intensity of magnetospheric radio bursts (MRBs) is scaled to solar-wind input into planetary magnetospheres and the frequency of emission is scaled to polar surface magnetic-field strength in order to estimate the possibility of detecting MRBs from Uranus and Neptune. A scaling law is derived which relates the ratio of power radiated in MRBs to the solar-wind input for earth, Jupiter, and Saturn. Power-flux spectra of MRBs from these three planets are plotted, and it is shown that Jupiter and Saturn may radiate 1% to 5% of the solar-wind energy input into their magnetospheres. The properties of MRBs from Uranus and Neptune are estimated by assuming a conversion efficiency of 1% to 5%, a bandwidth of half the peak frequency, and conformity of Uranus' and Neptune's dipole moments with the magnetic Bode's law. Based on the results, it is suggested that detection of MRBs from these two planets may be a reasonable cruise-mode radio-astronomy objective on future missions to the outer solar system.

Kennel, C. F.↗

NASA NTRS2000

Nanotechnology at NASA Ames

Advanced miniaturization, a key thrust area to enable new science and exploration missions, provides ultrasmall sensors, power sources, communication, navigation, and propulsion systems with very low mass, volume, and power consumption. Revolutions in electronics and computing will allow reconfigurable, autonomous, 'thinking' spacecraft. Nanotechnology presents a whole new spectrum of opportunities to build device components and systems for entirely new space architectures: (1) networks of ultrasmall probes on planetary surfaces; (2) micro-rovers that drive, hop, fly, and burrow; and (3) collections of microspacecraft making a variety of measurements.

Srivastava, Deepak↗