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At least 1,621 records · Page 90
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NASA NTRS2019

Commercialization and Human Settlement of the Moon and Cislunar Space Using ISRU, Fission Surface Power, and Advanced In-Space Propulsion Systems

Over 50 years have passed since themovie 2001: A Space Odyssey debuted in April 1968. In the film, Dr. Heywood Floyd flies to a large artificial gravity space station orbiting Earth aboard a commercial space plane. He then embarks on a commuter flight to the Moon arriving there 25 hours later. Today, on the 50th anniversary of the Apollo 11lunar landing, the images portrayed in 2001 remain well beyond our capabilities and 2100: A Space Odyssey seems a more appropriate title for Kubrick and Clarke's film. This paper looks at the key technologies, systems, and supporting infrastructure (in-situ resource utilization (ISRU), fission surface power (FSP), nuclear thermal propulsion (NTP), andorbiting propellant depots), that could be developed by NASA and the private sector over the next 30years allowing the operational capabilities presented in 2001 to be achieved, albeit on a more spartan scale.

Borowski, Stan↗
NASA NTRS2019

NASA’s Galactic Cosmic Ray Simulator at Brookhaven National Laboratory: Enabling Human Exploration Missions to the Moon and Mars

With exciting new Agency plans for a sustainable return to the moon, astronauts will once again leave earth’s protective magnetosphere only to endure higher levels of radiation from galactic cosmic rays (GCR) and the possibility of a large solar particle event (SPE). Gateway, lunar landers, and surface habitats will be designed to protect crew against SPE’s with vehicle optimization, storm shelter concepts, and/or active dosimetry; however, the ever-penetrating GCR will continue to pose the most significant health risks especially as lunar missions increase in duration and as NASA sets its aspirations on Mars. The primary risks of concern include epithelial carcinogenesis and leukemia, central nervous system effects resulting in potential in-mission cognitive or behavioral impairment and/or late neurological disorders, degenerative tissue effects including cataracts, circulatory and heart disease, as well as, potential immune system decrements impacting multiple aspects of crew health. Characterization and mitigation of these risks requires a significant reduction in the large biological uncertainties of chronic (low-dose rate) heavy ion exposures and the validation of countermeasures in a relevant space environment. NASA has developed the “GCR Simulator” at Brookhaven National Laboratory to generate a spectrum of ion beams that approximates the primary and secondary GCR field experienced at human organ locations within a deep-space vehicle. The majority of the dose is delivered from protons (~65-75%) and alpha particles (~10-20%) with heavier ions (Z≤3) contributing the remainder. The “GCR Simulator” exposes state-of-the art cellular and animal model systems to 33 sequential beams including 4 proton energies plus degrader, 4 helium energies plus degrader, and the five heavy ions of C, O, Si, Ti, and Fe. A polyethylene degrader is used with the 100 MeV/n H and He beams to provide a nearly continuous distribution of low energy particles. A 500 mGy exposure, delivering doses from each of the 33 beams, requires 75-90 minutes. To more closely simulate the low dose rates found in space, sequential field exposures can be divided into daily fractions over 2-4 weeks, with individual fractions as low as 0.1-0.2 mGy. In the large beam configuration (60 x 60 cm(exp 2)), 54 special housing cages can accommodate 2-3 mice each for a 70-75 min duration or ~15 individually housed rats. Emerging research results from our 2018 runs utilizing mixed heavy ion fields and protracted space exposures are forthcoming and deepen our understanding of the numerous health risks faced by our astronauts. This paper discusses NASA’s innovative technology solution for a ground-based GCR simulator at the NASA Space Radiation Laboratory to enable future exploration missions.

Lisa C Simonsen↗
NASA NTRS2020

Lunar Technology with Roots in SBIR/STTR Will Reach the Moon in 2021

Astrobotic, a small business based in Pittsburgh, PA, received more than $80 million in contracts from NASA to support various aspects of the agency’s return to the Moon. The company’s compact lunar rover and precision lunar lander technology, which will deliver payloads to the lunar surface, were developed with funds from the NASA SBIR/STTR Program.

SBIR/STTR, small business↗
NASA NTRSDate not supplied

Cost Breakeven Analysis of Lunar In-Situ Propellant Production for Human Missions to the Moon and Mars

NASA is preparing to return humans to the lunar surface as a first step to a human exploration campaign of Mars. Both a sustained lunar campaign and a campaign of missions to Mars will require tens to hundreds of tonnes of propellant. Although this propellant could be delivered from Earth, an alternative approach is to use the potentially vast quantities of lunar ice to enable in-situ propellant production on the lunar surface. This study evaluates the cost breakeven for using lunar-derived propellants, as opposed to those delivered from Earth, in support of an extended human exploration campaign with both a multi-year presence on the Moon as well as multiple crewed missions to Mars. In so doing, the value of lunar propellant production is considered in the context of future exploration priorities, addressing the question: over what range of human missions to the lunar surface and Mars does in-situ propellant production trade favorably with propellant delivery from Earth on the basis of cost? The results of this analysis show that the magnitude and duration of the lunar campaign, more so than the Mars campaign, drive the breakeven and that without long lifetime ISRU systems, with greater than 5 years of autonomous operation before replacement, the demand in cis-lunar space for a Mars campaign favors propellant delivery from Earth.

Christopher A Jones↗
NASA NTRSDate not supplied

Cost Breakeven Analysis of Lunar In-Situ Propellant Production for Human Missions to the Moon and Mars

NASA is preparing to return humans to the lunar surface as a first step to a human exploration campaign of Mars. Both a sustained lunar campaign and a campaign of missions to Mars will require tens to hundreds of tonnes of propellant. Although this propellant could be delivered from Earth, an alternative approach is to use the potentially vast quantities of lunar ice to enable in-situ propellant production on the lunar surface. This study evaluates the cost breakeven for using lunar-derived propellants, as opposed to those delivered from Earth, in support of an extended human exploration campaign with both a multi-year presence on the Moon as well as multiple crewed missions to Mars. In so doing, the value of lunar propellant production is considered in the context of future exploration priorities, addressing the question: over what range of human missions to the lunar surface and Mars does in-situ propellant production trade favorably with propellant delivery from Earth on the basis of cost? The results of this analysis show that the magnitude and duration of the lunar campaign, more so than the Mars campaign, drive the breakeven and that without long lifetime ISRU systems, with greater than 5 years of autonomous operation before replacement, the demand in cis-lunar space for a Mars campaign favors propellant delivery from Earth.

Christopher A. Jones↗
NASA NTRSDate not supplied

Space Settlement Should Use 1 g Shielded Space Platforms, Not the 1/6 or 1/3 g, Radiation Exposed Moon or Mars

Previous missions have subjected astronauts to confined space, weightlessness, and increased radiation. These impair astronaut comfort, performance, and future health. The exploration and future settlement of space will depend on the long term presence of individual humans. This requires the development of space platforms where humans can work and live in health for many years, perhaps generations. A livable space platform must provide adequate volume, gravity, and radiation shielding. This seems easier to do in deep space or Low Earth Orbit (LEO) than on the surface of the moon or Mars. Permanently habitable deep space platforms will enable scientific and technical research, space tourism, space mission preparation, space industry development, and military surveillance and operations. The first fully habitable space station would probably be located in LEO for convenience and lower cost.

Harry W Jones↗
NASA NTRSDate not supplied

Exploring Transfers Between Earth-Moon Halo Orbits via Multi-Objective Reinforcement Learning

Multi-Reward Proximal Policy Optimization, a multi-objective deep reinforcement learning algorithm, is used to examine the design space of low-thrust trajectories for a SmallSat transferring between two libration point orbits in the Earth-Moon system. Using Multi-Reward Proximal Policy Optimization, multiple policies are simultaneously and efficiently trained on three distinct trajectory design scenarios. Each policy is trained to create a unique control scheme based on the trajectory design scenario and assigned reward function: a unique combination of weights scaling competing objectives that guide the spacecraft to the target mission orbit, incentivize faster flight times, and penalize propellant mass usage. Then, the policies are evaluated on the same set of perturbed initial conditions in each scenario to generate the propellant mass usages, flight times, and state discontinuities from a reference trajectory for each control scheme. This solution space of low-thrust trajectories for a SmallSat is used to examine the multi-objective trade space for the trajectory design scenario. By autonomously constructing the solution space, insights into the required propellant mass, flight time, and transfer geometry are rapidly achieved.

Christopher J Sullivan↗
NASA NTRS2006

Integrated human-robotic missions to the Moon and Mars : mission operations design implications

For most of the history of space exploration, human and robotic programs have been independent, and have responded to distinct requirements. The NASA Vision for Space Exploration calls for the return of humans to the Moon, and the eventual human exploration of Mars; the complexity of this range of missions will require an unprecedented use of automation and robotics in support of human crews. The challenges of human Mars missions, including roundtrip communications time delays of 6 to 40 minutes, interplanetary transit times of many months, and the need to manage lifecycle costs, will require the evolution of a new mission operations paradigm far less dependent on real-time monitoring and response by an Earthbound operations team. Robotic systems and automation will augment human capability, increase human safety by providing means to perform many tasks without requiring immediate human presence, and enable the transfer of traditional mission control tasks from the ground to crews. Developing and validating the new paradigm and its associated infrastructure may place requirements on operations design for nearer-term lunar missions. The authors, representing both the human and robotic mission operations communities, assess human lunar and Mars mission challenges, and consider how human-robot operations may be integrated to enable efficient joint operations, with the eventual emergence of a unified exploration operations culture.

Lee, Young↗
NASA NTRS2000

The Galileo mission to Jupiter and its moons

Since 1995, the Galileo mission, despite all the technical troubles, has provided a detailed view of the Jovian system, revealed only fleetingly in the Pioneer and Voyager flybys of the 1970s. The atmospheric probe penetrated the clouds and conducted the first in situ sampling of an outer planet's atmosphere, transmitting data for an hour before it was lost in the gaseous depths. The orbiter, which is still going strong, has photographed and analyzed the planet, its rings, and its diverse moons. Some of the results obtained so far are reviewed.

Jupiter↗
NASA NTRS1996

The Moon is not Space

The Moon as a venue for remote sensing has certain geometrically-based advantages over free flyers that facilitate reuse of assets: lack of dispersion of emplaced facilities; reduction (compared to space) of the dimension of mobility space from 3 to 2; repetitive lunar-station to Earth-station communications geometry.

assets↗
NASA NTRS2022

Moon: Origin, Alternative Theories

The Moon’s origin and formation should be able to explain the current physical, dynamical, chemical, and internal thermal states. While the Giant Impactor Theory is the leading theory, we must also look into the earlier variations of lunar origins. This includes variants on three main possible scenarios: capture, rotational disruption, and co-accretion.

Caitlin Ahrens↗
NASA NTRS2021

Erosion of Volatiles by Micro-Meteoroid Bombardment on Ceres, and Comparison to the Moon and Mercury

Ceres, the largest reservoir of water in the main-belt, was recently visited by the Dawn spacecraft that revealed several areas bearing H2O-ice features. Independent telescopic observations showed a water exosphere of currently unknown origin. We explore the effects of meteoroid impacts on Ceres considering the topography obtained from the Dawn mission using a (Replaced: full-fledged replaced with: widely-used) micro-meteoroid model and ray-tracing techniques. Meteoroid populations with 0.01-2 mm diameters are considered. We analyze the short-term effects Ceres experiences during its current orbit as well as long-term effects over the entire precession cycle. We find the entire surface is subject to meteoroid bombardment leaving no areas in permanent shadow with respect to meteoroid influx. The equatorial parts of Ceres produce 80% more ejecta than the polar regions due to the large impact velocity of long-period comets. Mass flux, energy flux, and ejecta production vary seasonally by a factor of (Replaced: a few replaced with: 3–7) due to the inclined eccentric orbit. Compared to Mercury and the Moon, Ceres experiences significantly smaller effects of micro-meteoroid bombardment, with a total mass flux of 4.5±1.2×10(exp −17)kg m(exp −2)s(exp −1). On average Mercury is subjected to a 50× larger mass flux and generates 700× more ejecta than Ceres, while the lunar mass flux is 10× larger, and the ejecta generation is 30× larger than on Ceres. For these reasons, we find that meteoroid impacts are an unlikely candidate for the production of a water exosphere or significant excavation of surface features. The surface turnover rate from the micro-meteoroid populations considered is estimated to be 1.25 Myr on Ceres.

minor planets↗
NASA NTRS2019

The Lunar IceCube EM-1 Mission: Prospecting the Moon for Water Ice

Lunar IceCube is a NASA nanosatellite mission designed to prospect, locate, and measure volumes and composition of water ice deposits and other volatiles on the Moon in support of future exploitation by robots and human explorers. Lunar IceCube is one of several public -private partnerships selected under NASA's Next Space Technologies for Exploration Partnerships Broad Agency Announcement for the development of advanced exploration systems. Among the first small satellites planned to explore deep space, Lunar IceCube, along with the 12 other Exploration Mission One (EM -1) missions will help lay a foundation for future small-scale planetary missions. In addition to providing useful scientific data, Lunar IceCube will help inform NASA's strategy for sending humans farther into the solar system.

Benjamin K. Malphrus↗
NASA NTRSDate not supplied

NASA's Watts on the Moon Challenge

This is a presentation to an LSIC workshop on lunar surface power describing the formulation of the Phase Two Watts on the Moon Centennial Challenge

lunar surface power↗
NASA NTRS2021

Framework for Coordinated Efforts in the Exploration of Volatiles in the South Polar Region of the Moon

The exploration of the lunar south polar region and the ground truthing of polar volatiles is one of the top priorities for several space agencies and private partners. Here we use Moon Mineralogy Mapper surficial water ice detections to investigate the location of water ice-bearing permanently shaded regions near the south pole. We extract a variety of parameters such as their temperature regime, slope, hydrogen content, number of ice detections, depth stability for water ice and dry ice, and mobility aspects. We identify 169 water ice-bearing PSRs and use their characteristics to identify sites that allow to access the highest abundances of volatiles, sites that can be visited to characterize the lateral or vertical distribution of volatiles (water ice and dry ice), and sites that allow for the fastest recovery of a scientifically interesting sample. Collectively, 37 PSRs are identified as sites of interest, including 11 that would address more than one mission objective and may be, for that reason, higher priority targets of exploration. These PSRs are found in Shoemaker, Faustini, Cabeus, Malapert, Nobile, Sverdrup, Wiechert J and Haworth craters, as well as 3 unnamed craters (PSRs 57, 120, 89). These sites are all located within 6 degrees of the south pole. We present case studies for a relatively short traverse mission (20 to 50 km) to PSR 89, a medium length traverse (~100 km) to Sverdrup 1, and a longer traverse (~300 km) to Cabeus that can serve as a guide in planning upcoming exploration missions.

Myriam Lemelin↗
NASA NTRSDate not supplied

Should Oxygen, Hydrogen, and Water on the Moon Be Provided by Earth Supply, Life Support Recycling, or Regolith Mining?

The water needed for space life support has so far been provided by either direct supply from Earth on most missions or by life support wastewater recycling on the International Space Station (ISS). With the recent large reduction in launch cost, Earth resupply has become more attractive, but recycling always costs less than resupply for a large enough crew on a long enough mission. Water is also needed to make up recycling losses and oxygen and hydrogen are needed for propulsion fuel. This paper compares the costs of oxygen, hydrogen, and water on the moon for Earth supply, lunar recycling, and lunar mining. While Earth supply is the most expensive by far, lunar recycling and mining costs are not much different. Life support wastewater provides a large but limited supply, so lunar mining will always be needed. Minor cost reductions may make mining less expensive than recycling.

Harry W Jones↗