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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.

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At least 469 records · Page 26

The Behavior of High-Velocity Dust Generated by Lander Plumes in the Lunar Environment

Lunar lander plumes are known to accelerate fine dust to speeds exceeding 2 km/s, and the resultant ejecta may remain in lunar orbit for extended periods of time. Such ejecta could become hazardous to objects in lunar orbit as well as systems on the surface. In order to understand the impact on orbiting lunar infrastructure such as Gateway, as well as assets on the lunar surface, here we consider the dynamics of the resultant high-velocity plume ejecta. Initial conditions were set by the expected near-term lunar activity and the known cone of accelerated dust generated by previous lunar landings. The effects of regular 3-body gravitation, solar radiation pressure, and electric field are included in the model. It is found that although the majority of sub-μm dust is carried away by solar wind and electric fields, about ~10% of the dust between 1.7 km/s and 2.3 km/s reimpacts the surface, much of it near the landing site. The hazard posed by that debris is a function of lander mass and distance from the landing site. The Gateway, when orbiting in the nominal NRHO at the time of a landing, is not expected to be significantly affected by the dust. However, other spacecraft in less elliptic orbits may be at greater risk.

Ejecta↗

Robust Trajectory Optimization for Guided Powered Descent and Landing

A robust trajectory optimization approach for guidance algorithm gain selection for powered descent and landing is developed. This approach uses a genetic algorithm to determine optimal guidance algorithm parameters while incorporating uncertainty information from linear covariance analysis. The optimal guidance algorithm parameters are determined while accounting for environment, navigation, and vehicle property uncertainty and sensor suite fidelity. As a demonstration of this method, the optimal gains for the fractional polynomial powered descent guidance are found for the braking phase of a robotic lunar landing mission. Scenarios with differing sensor suites and sensor qualities are considered, with objective functions to minimize variability in propellant usage or terminal position. Results show that the optimal guidance algorithm gains for a given trajectory differ based on the sensor suite, and optimal guidance algorithm gains may result in up to 20% performance improvements over the baseline in propellant usage and landed accuracy.

Grace E Calkins↗

The SPLICE Project: Continuing NASA Development of GN&C Technologies for Safe and Precise Landing

Guidance, Navigation and Control (GN&C) technologies for precise and safe landing are essential for future robotic science and human exploration missions to solar system destinations with targeted surface locations that pose a significant risk to successful landing and subsequent mission operations. These Entry, Descent and Landing (EDL) technologies are a part of the NASA domain called PL&HA (Precision Landing and Hazard Avoidance) and are considered high-priority capabilities within NASA space technology development roadmaps to promote and enable new mission concepts. The SPLICE (Safe & Precise Landing – Integrated Capabilities Evolution) project is a multi-center, multi-directorate NASA project focused on continuing the decade-plus of NASA investments and projects focused on PL&HA technology development and infusion. This paper highlights the GN&C technologies in development within SPLICE, along with the simulation and field test plans for validation of the capabilities and Technology Readiness Level (TRL) maturation toward infusion into potential near-term robotic lunar landing missions.

Tse, Teming↗

Search and Recovery Efforts for the ALSEP Data Tapes

On NASA's first human lunar landing on Apollo II in July 1969, the astronauts deployed a set of scientific instruments called Early Apollo Science Experiments Package (EASEP). It was powered by a solar panel and operated for -20 earth-days and transmitted data to the Earth. This paved a way for deployment of more expansive instrument packages, powered by radioisotope thermoelectric generators, on Apollo 12, 14, 15, 16, and 17 in November 1969 through December 1972. They were called Apollo Lunar Surface Experiments Packages (ALSEPs). Each ALSEP consisted of a variety of instruments such as seismometers, magnetometers, solar wind spectrometers, heat flow probes, etc. The majority of these instruments kept functioning long after their one-year design lifetime requirement, and they transmitted data to the Earth until September 1977, when the program ended. Over the three decades that followed, users of the NSSDC-archived data have learned that many of the ALSEP instrument data are not complete. The present work is a progress report on the authors' recent effort for restoring the entire raw ALSEP data that were received from the Moon,

Nagihara, S.↗

Use of Navigation Beacons to Support Lunar Vehicle Operations

To support a wide variety of lunar missions in a condensed regime, solutions are needed outside of the use of Earth-based orbit determination. This research presents an alternate approach to in-situ navigation through the use of beacons, similar to that used on Earth as well as under technology development efforts. An overview of the current state of navigation aids included as well as discussion of the Lunar Node – 1 payload being built at NASA/Marshall Space Flight Center. Expected navigation results of this beacon payload for planned operation from the lunar surface are provided. Applications of navigation beacons to multiple stages of the proposed human lunar landing architecture are given, with initial analysis showing performance gains from the use of this technology. This work provides a starting point for continued analysis and design, laying out the foundation of how navigation beacons can be incorporated into the architecture to enable continued analysis, design, and future expanded capability.

Lunar node-1↗

The Lunar Lab Initiative

Analogous to terrestrial Antarctic basecamps at our south pole, space exploration outposts will be a combination of habitation and science-focused assets. The Artemis Exploration Roadmap endeavors to establish a sustained human presence on the lunar south pole starting in 2028. Within the planned Artemis Base Camp, most efforts to date have focused on the habitation assets or a mixture of science and habitation assets . With the recent advent of commercial lunar landing capabilities, the trade space can be further expanded to include dedicated science focused assets that ensure adequate science capability. To that end, the Forge, an innovation team initiative created at the Johnson Space Center (JSC), explored alternative ways to increase the science capabilities within the basecamp. The Forge uses structured brainstorming and facilitation to increase innovation within the assigned team, while executing its process in a rapid turnaround fashion for ideation and design study. As a pilot study for the Forge, a multi-disciplinary team investigated a lunar lab module to augment the lunar surface plans for Artemis. This formulation study evaluated the scientific and operational considerations for this dedicated crew space that would increase the capabilities of lunar surface science operations. The trade space evaluated single lunar lander delivery versus multiple lunar lander delivery for module assembly, alternative structural designs, the science instrument outfitting with mapping to scientific goals to maximize lunar science objectives, and how the lab would be operated. The lab operations options explored a stand-alone facility, as well as a facility integrated into a larger lunar surface complex, while evaluating crew usage and habitability considerations. The resulting alternatives were evaluated by the Forge team with a set of metrics to determine their originality, feasibility, and science performance, and thereby provide a recommendation to the lunar architecture planning team. Lessons learned from the lunar lab study were compiled to improve the process and tools for future Forge studies. Forward work, open issues, and challenges to further refine the design of the various science-focused asset options were also documented. By providing a robust science capability at humanity’s furthest outpost, we can plan for a sustained human lunar presence once the initial lunar surface access capability is well established.

Lunar outpost↗

An assessment of technology alternatives for telecommunications and information management for the space exploration initiative

On the 20th anniversary of the Apollo 11 lunar landing, President Bush set forth ambitious goals for expanding human presence in the solar system. The Space Exploration Initiative (SEI) addresses these goals beginning with Space Station Freedom, followed by a permanent return to the Moon, and a manned mission to Mars. A well designed, adaptive Telecommunications, Navigation, and Information Management (TNIM) infrastructure is vital to the success of these missions. Utilizing initial projections of user requirements, a team under the direction of NASA's Office of Space Operations developed overall architectures and point designs to implement the TNIM functions for the Lunar and Mars mission scenarios. Based on these designs, an assessment of technology alternatives for the telecommunications and information management functions was performed. This technology assessment identifies technology developments necessary to meet the telecommunications and information management system requirements for SEI. Technology requirements, technology needs and alternatives, the present level of technology readiness in each area, and a schedule for development are presented.

Ponchak, Denise S.↗

The Mission Transcript Collection: U.S. Human Spaceflight Missions from Mercury Redstone 3 to Apollo 17

Aboard every U.S. piloted spacecraft, from Mercury through Apollo, NASA installed tape recorders that captured nearly every word spoken by the astronauts during their history-making flights into space. For the first time ever, NASA has digitally scanned all of the transcripts made from both the onboard tapes and those tape recordings made on the ground from the air-to-ground transmissions and placed them on this two CD-ROM set. Gathered in this special collection are 80 transcripts totaling nearly 45,000 pages of text that cover every US human spaceflight from the first human Mercury mission through the last lunar landing flight of Apollo 17. Users of this CD will note that the quantity and type of transcripts made for each mission vary. For example, the Mercury flights each had one transcript whereas the Gemini missions produced several. Starting with the Gemini flights, NASA produced a Public Affairs Office (PAO) commentary version, as well as at least one "technical" air-to-ground transcript version, per mission. Most of the Apollo missions produced four transcripts per flight. These included the onboard voice data recorder transcripts made from the Data Storage Equipment (DSE) on the Command Module (CM), and the Data Storage Electronics Assembly (DSEA) onboard the Lunar Module (LM), in addition to the PAO commentary and air-to-ground technical transcripts. The CD set includes an index listing each transcript file by name. Some of the transcripts include a detailed explanation of their contents and how they were made. Also included in this collection is a listing of all the original air-to-ground audiotapes housed in NASA's archives from which many of these transcripts were made. We hope you find this collection of transcripts interesting and useful.

Source record↗

Lunar Receiving Laboratory Project History

As early as 1959, the Working Group on Lunar Exploration within NASA advocated that 'one of the prime objectives of the first lunar landing mission should be the collection of samples for return to Earth, where they could be subjected to detailed study and analysis.' Within NASA, neither this group nor any other scientists working with the Agency were concerned about back contamination issues. Outside of NASA, back contamination concerns had been raised as early as 1960. Although NASA did not seem to pay any attention to the concerns at that time, the scientific community continued to be interested in the topic. In 1962 and again in 1963, as the Apollo Program loomed large, further discussions were held. These early discussions of back contamination did not make their way into NASA's administration, however, and when Manned Spacecraft Center personnel began to articulate early concepts for the Lunar Receiving Laboratory (LRL), the back contamination issue was not considered. Once this concern became a major focus, however, the LRL's development became increasingly complex. This is the history of that development.

Mangus, Susan↗

Preliminary geologic map of the region around the candidate Proclus Apollo landing site, part J

The Proclus Crater region was mapped to test the value, for photogeologic mapping purposes, of Apollo 15 metric photographs and to estimate the scientific value of the area as a potential landing site. Adjacent frames of the metric photography were overlapped with the base frame to provide stereographic images. Because of the high quality of the photographs, it was found that the geologic units could be more definitely interpreted and dated than those of earlier maps. The photographs tend to confirm the earlier interpretation of the rugged area as composed of bedrock uplifted when the Crisium basin formed. They also suggest that an earlier predominantly volcanic interpretation of the terra in this area might be replaced by an interpretation in which mass wasting and fracturing play the major roles in producing different terrain types. It was concluded that because of apparent lithologic homogeneity, the terra of the Proclus region is an undesirable objective for an extensive manned lunar landing mission.

Wilhelms, D. E.↗

Analytical Dimensional Reduction of a Fuel Optimal Powered Descent Subproblem

Current renewed interest in exploration of the moon, Mars, and other planetary objects is driving technology development in many fields of space system design. In particular, there is a desire to land both robotic and human missions on the moon and elsewhere. The landing guidance system must be able to deliver the vehicle to a desired soft landing while meeting several constraints necessary for the safety of the vehicle. Due to performance limitations of current launch vehicles, it is desired to minimize the amount of fuel used. In addition, the landing site may change in real-time in order to avoid previously undetected hazards which become apparent during the landing maneuver. This complicated maneuver can be broken into simpler subproblems that bound the full problem. One such subproblem is to find a minimum-fuel landing solution that meets constraints on the initial state, final state, and bounded thrust acceleration magnitude. With the assumptions of constant gravity and negligible atmosphere, the form of the optimal steering law is known, and the equations of motion can be integrated analytically, resulting in a system of five equations in five unknowns. It is shown that this system of equations can be reduced analytically to two equations in two unknowns. With an additional assumption of constant thrust acceleration magnitude, this system can be reduced further to one equation in one unknown. It is shown that these unknowns can be bounded analytically. An algorithm is developed to quickly and reliably solve the resulting one-dimensional bounded search, and it is used as a real-time guidance applied to a lunar landing test case.

Rea, Jeremy R.↗

Blue Origin De-orbit Descent and Landing Tipping Point: Program Final Report

The purpose of this document is to provide a final report on the Deorbit, Descent, and Landing (DDL) Tipping Point program, a public-private partnership between Blue Origin and NASA that is partially funded by NASA contract 80LARC19C0005. In this report we summarize the results of the entire contract, including recommendations and conclusions based on the experience and results obtained. Only the portions funded by the government with associated unlimited rights are documented in detail in this report. For the work funded by Blue Origin, summaries with unlimited rights are provided for context and completeness. The Blue Origin funded work exceeded 25% of the originally proposed total program cost and included a mixture of hardware procurement and critical technology maturation. The scope of this document is a discussion of all the major tasks performed under the contract including the sensor flight demonstrations on New Shepard, the hardware in the loop lunar landing navigator demonstration, and the ground testing of the Flash LiDAR hazard sensor. The contributions from the multiple NASA teams – Johnson Space Center, Langley Research Center, Goddard Space Flight Center, and Jet Propulsion Laboratory – are described along with the contributions from Blue Origin. This document is the Final Report for statement of work item 4.1.2.10 as Deliverable 5.8.

Stefan Bieniawski↗

Rocket Exhaust Cratering: Lessons Learned from Viking and Apollo

During the Apollo and Viking programs NASA expended considerable effort to study the cratering of the regolith when a rocket launches or lands on it. That research ensured the success of those programs but also demonstrated that cratering will be a serious challenge for other mission scenarios. Unfortunately, because three decades have elapsed since NASA last performed a successful retro-rocket landing on a large planetary body - and ironically because Apollo and Viking were successful at minimizing the cratering effects - the space agency has a minimized sense of the seriousness of the issue. The most violent phase of a cratering event is when the static overpressure of the rocket exhaust exceeds the bearing capacity of the soil. This bearing capacity failure (BCF) punches a small and highly concave cup into the surface. The shape of the cup then redirects the supersonic jet - along with a large flux of high-velocity debris - directly toward the spacecraft. This has been observed in terrestrial experiments but never quantified analytically. The blast from such an event will be more than just quantitatively greater than the cratering that occurred in the Apollo and Viking programs. It will be qualitatively different, because BCF had been successfully avoided in all those missions. In fact, the Viking program undertook a significant research and development effort and redesigned the spacecraft specifically for the purpose of avoiding BCF [1]. (See Figure 1.) Because the Apollo and Viking spacecraft were successful at avoiding those cratering effects, it was unnecessary to understand them. As a result, the physics of a BCF-driven cratering event have never been well understood. This is a critical gap in our knowledge because BCF is unavoidable in the Martian environment with the large landers necessary for human exploration, and in Lunar landings it must also be addressed because it may occur depending upon the design specifics of the spacecraft and the weakening of the regolity by gas diffusion.

Metzger, Philip T.↗

SOME FOREIGN POLICY IMPLICATIONS OF SPACE SCIENCE

The startling developments in space science of the past few years which are already affecting the everyday conduct of our lives have introduced problems of new concepts and dimensions into the formulation and conduct of United States foreign affairs. We in the foreign policy field are now forced to speak matter-of-factly, and we hope confidently, of boosters, synchronous orbits, lunar landings, and meteorological satellites--terms which still seem slightly unusual in the diplomatic vocabulary. These developments have not only changed our vocabulary, however, they have forced upon us a whole new way of looking at the rest of the world and at the role which the United States must play in the international community.

United States↗

Development of the Saturn Space Vehicle

The Saturn launch vehicle program has become a major element in our national space effort within little more than 3 years. At the beginning of the program, in 1958, various Saturn configurations were planned to lift instrumented payloads of 20,000 to 40,000 lb. into Earth orbit. As research and development progressed, it became apparent that the vehicle design approach had far more potential than anticipated that it was, in fact, a breakthrough into a new class of heavy launch vehicles. Thus, within the space of a few years, it was possible to consider even more advanced missions. In addition to placing multiton payloads in orbit, we can seriously conceive sending over 90,000 lb. of instruments on escape missions, using advanced Saturn-class vehicles. With these vehicles, we plan to accomplish lunar reconnaissance and manned lunar landings scheduled for the latter part of this decade. Likewise, these vehicles will permit flight tests of advanced nuclear power plants and stages.

SATURN LAUNCH VEHICLE↗

SYSTEMS CHECKOUT FOR APOLLO

Discussion of the checkout procedure for the equipment associated with the manned lunar landing program

GROUND SUPPORT SYSTEM↗