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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

The discovery of 1982 DB, the most accessible asteroid known

A small Apollo object was found while photographing the split comet DuToit 2-Hartley on February 27/28, 1982. Designated 1982 DB, this earth-crossing asteroid passed the earth at a distance of 4.08 million km about 1 month prior to its discovery. Asteroid 1982 DB has been determined to be the most accessible near-earth minor planet known. It provides many excellent opportunities for rendezvous and sample return missions, and a rare dual rendezvous mission with 1980 AA as the second target. For a mission to be realized, opportunities to observe 1982 DB during future apparitions must be taken.

Helin, E. F.↗
NASA NTRS2011

Near-Earth Asteroids Accessible to Human Exploration with High-Power Electric Propulsion

The diverse physical and orbital characteristics of near-Earth asteroids provide progressive stepping stones on a flexible path to Mars. Beginning with cislunar exploration capability, the variety of accessible targets steadily increases as technology is developed for eventual missions to Mars. Noting the potential for solar electric propulsion to dramatically reduce launch mass for Mars exploration, we apply this technology to expand the range of candidate asteroid missions. A robust and efficient exploration program emerges where a potential mission is available once per year (on average) with technology levels that span cis-lunar to Mars-orbital capabilities.

deep space exploration↗
NASA NTRS2017

NIAC Swarm Flyby Gravimetry Phase II Report

This NASA Innovative Advanced Concept (NIAC) grant has enabled the research and development of a method for conducting small body gravimetry from a spacecraft, using relative measurements to a set of deployed test-masses. The test-masses are tracked from a host spacecraft, which dispenses them near to the small body's surface. Thanks to this close proximity, the probes' orbits can be highly perturbed, which yields useful gravimetric measurements. The most readily achievable approach for tracking the probes is to use an optical instrument on- board the spacecraft. The probes then need only be reflective to sunlight. This implementation, called optical gravimetry (OpGrav), has the fewest requirements for the host spacecraft and probes.The results of this study indicate that OpGrav is feasible and offers meaningful improvement over existing methods. Parametric studies suggest roughly an order of magnitude improvement in accuracy or asteroid accessibility (how small an asteroid one can measure) over Earth-based Doppler-only mass estimation. This exponentially expands the number of potential near-Earth objects that one could study, which has implications for planetary defense.As a sample mission, we evaluated OpGrav as an added instrument on a main- belt asteroid tour mission. In this case, simulations show that OpGrav would increase the number of asteroid mass estimates from 3 of 9 to 7 of 9. That is, OpGrav has sufficient sensitivity to offer utility in missions for which it is not explicitly designed for.We designed and fabricated a prototype hardware implementation for this concept called the Small-body In-situ Multi-probe Mass Estimation Experiment (SIMMEE). This hardware provides a basis for many inputs into the simulations and grounds the models with physical values. The primary design driver for the hardware is a long life, on the order of five years prior to operation, and a need for high pointing accuracy to enable flybys of the smallest objects.The next steps include further hardware testing and extension of the concept to rendezvous cases. We believe that this concept offers planetary scientists a new and relevant means of better understanding small-bodies.

Atchison, Justin A.↗
NASA NTRS1994

Near-Earth Asteroid Returned Sample (NEARS)

The concept of the Near-Earth Asteroid Returned Sample (NEARS) mission is to return to Earth 10-100 g from each of four to six sites on a near-Earth asteroid and to perform global characterization of the asteroid and measure mass, volume, and density to ten percent. The target asteroid for the mission is 4660 Nereus, probably a primitive C-type asteroid, with the alternate target being 1989ML, an extremely accessible asteroid of unknown type. Launch dates will be 1998, 2000, 2002, and 2004 on the Delta II-7925 launch vehicle. The mission objectives are three-fold. (1) Provide first direct and detailed petrological, chemical, age, and isotopic characterization of a near-Earth asteroid and relate it to terrestrial, lunar, and meteoritic materials. (2) Sample the asteroid regolith and characterize any exotic fragments. (3) Identify heterogeneity in the asteroid's isotopic properties, age, and elemental chemistry.

Shoemaker, Eugene M.↗
NASA NTRS1984

Mission opportunity maps for rendezvous with earth-crossing asteroids

Rendezvous missions for earth-crossing asteroids are of interest to NASA, for scientific purposes as well as for technological applications and ecological implications. To provide a comprehensive data base for planners of such missions, a mission opportunity map (MOM) has been created for eight relatively easy-to-access asteroids. A MOM presents such mission data as launch dates, flight times, and launch and postlaunch delta-V requirements for all useful mission opportunities. The merits of a MOM are: (1) searches for all useful mission opportunities are completed in the process of generating a MOM, and (2) a clear view of good and bad opportunities, the extent of performance variations, and the repeatability of the missions.

Yen, C.-W. L.↗
NASA NTRS1989

Mission opportunity maps for rendezvous with earth-crossing asteroids

Rendezvous missions to earth-crossing asteroids are of interest to NASA, for scientific purposes as well as for technological applications and ecological implications. To provide a comprehensive data base for planners of such missions, a mission opportunity map (MOM) has been created for eight relatively easy-to-access asteroids. A MOM presents such mission data as launch dates, flight times, and launch and postlaunch delta V requirements for all useful mission opportunities. The merits of a MOM are: (1) searches for all useful mission oportunities are completed in the process of generating a MOM, and (2) a MOM provides a clear view of good and bad opportunities, the extent of performance variations, and the repeatability of the missions.

Yen, Chen-Wan L.↗
NASA NTRS1998

Radar Studies in the Solar System

We aid in study of the solar system by means of ground-based radar. We have concentrated on: (1) developing the ephemerides needed to acquire radar data at Arecibo Observatory and (2) analyzing the resultant data to: test fundamental laws of gravitation; determine the size , shape, topography, and spin vectors of the targets; and study the surface properties of these objects, through their scattering law and polarization characteristics. We are engaged in radar observations of asteroids and comets, both as systematically planned targets and as "targets of opportunity." In the course of the program, we have prepared ephemerides for about 80 asteroids and three comets, and the radar observations have been made or attempted at the Arecibo Observatory, in most cases successfully, and in some cases on more than one apparition. The results of these observations have included echo spectra for the targets and, in some cases, delay - Doppler images and measurements of the total round-trip delay to the targets. Perhaps the most dramatic of these results are the images obtained for asteroids (4179) Toutatis and 1989PB (Castalia), which were revealed to be double-lobed objects by the radar images. Besides these direct results, the radar observations have furnished information on the sizes and shapes of the targets through analysis of the Doppler width of the echoes as a function of time, and on the surface properties (such as composition, bulk density, and roughness) through analysis of the reflectivity and of the polarization state of the echoes. We have also refined the orbits of the observed asteroids as a result of the Doppler (and in some cases delay) measurements from the radar observations. Although the orbits of main-belt asteroids accessible to ground-based radar are quite well known from the available optical data, some near-Earth objects have been seen by radar very soon after their optical discovery (for example, 199OMF, just eight days after discovery). In such cases. the radar results ensure that the object in question can be anticipated and identified at the next apparition. We have also participated in radar studies of the terrestrial planets. The results of these studies have included both planetary topography profiles from the analysis of round-trip delays to points along the target Doppler equator and determinations of the target spin state. The latter is of special interest in the case of Venus, which is very close to, but not on, a multi-body spin-orbit resonance such that Venus rotates 12 times for every 8 Earth orbits and 13 Venus orbits. As a result, Venus presents nearly the same face toward Earth at each inferior conjunction. Our latest results confirm that the spin state of Venus is slightly off the resonance. The delay measurements from planetary 2 ranging have also been used in combination with other types of range data in testing general relativity with increasing accuracy. We have also been engaged in radar studies of planetary satellites. Using our ephemerides, Arecibo made radar observations of the Galilean satellites of Jupiter and of Mars' satellite Phobos during the favorable opposition seasons (1988-1992 for Jupiter and 1990 for Mars). An attempt was also made to observe Deimos, but without detecting an echo. In 1997, an attempt was made to observe Saturn's satellite Titan, using the newly upgraded Arecibo radar system for transmitting and the Goldstone radar for receiving, but no echo was detected. The study of satellites by radar is in many ways similar to that of asteroids. The results from these observations have included characterization of the surface properties from the reflectivity and polarization ratio, as well as (in the case of the large satellites of Jupiter) the variation of reflectivity with incidence angle.

Shaprio, Irwin I.↗
NASA NTRS2011

Human Exploration of Near-Earth Asteroids via Solar Electric Propulsion

There have been many proposed technologies and architectures to extend a human presence beyond the Moon. Solar electric propulsion (SEP) provides the capability to implement a wide variety of missions with relatively low injected mass to low-Earth orbit. Because of its broad applicability this technology can enable progressively ambitious steps towards Mars by incrementally increasing power. The benefits of SEP are addressed for cis-lunar excursions, near-Earth asteroid exploration, and missions to Phobos and Deimos, and compared to chemical propulsion and nuclear thermal technologies. In particular, SEP expands the range of near-Earth asteroids accessible with a constrained launch capability (IMLEO).

exploration architectures↗
NASA NTRS1992

Mission options for rendezvous with the most accessible Near-Earth Asteroid - 1989 ML

The recent discovery of the Amor-class 1989 ML, the most accessible known asteroid for minimum-energy rendezvous missions, has expedited the search for frequent, low-cost Near-Earth Asteroid rendezvous and round-trip missions. This paper identifies trajectory characteristics and assesses mass performance for low Delta V ballistic rendezvous opportunities to 1989 ML during the period 1996-2010. This asteroid also offers occasional unique extended mission opportunities, such as the lowest known Delta V requirement for any asteroid sample return mission as well as pre-rendezvous asteroid flyby and post-rendezvous comet flyby opportunities requiring less than 5.25 km/sec total Delta V. This paper also briefly comments concerning mission opportunities for asteroid 1991 JW, which recently replaced other known asteroids as the most accessible Near-Earth Asteroid for fast rendezvous and round-trip missions.

Mcadams, Jim V.↗
NASA NTRS1991

Accessibility of near-Earth asteroids, 1990

Previous research which analyzed the accessibility of all known near-Earth asteroids is updated. Since then, many new near-Earth asteroids have been discovered, and 1928 DB, the most accessible asteroid at that time, has been recovered. Many of these recently discovered near-Earth asteroids have promising orbital characteristics. In addition to accessibility (as defined by minimum global delta v), ideal rendezvous opportunities are identified.

Hulkower, Neal D.↗
NASA NTRS2015

The Mission Accessibility of Near-Earth Asteroids

The population of near-Earth asteroids (NEAs) that may be accessible for human space flight missions is defined by the Near-Earth Object Human Space Flight Accessible Targets Study (NHATS). The NHATS is an automated system designed to monitor the accessibility of, and particular mission opportunities offered by, the NEA population. This is analogous to systems that automatically monitor the impact risk posed to Earth by the NEA population. The NHATS system identifies NEAs that are potentially accessible for future round-trip human space flight missions and provides rapid notification to asteroid observers so that crucial follow-up observations can be obtained following discovery of accessible NEAs. The NHATS was developed in 2010 and was automated by early 2012. NHATS data are provided via an interactive web-site, and daily NHATS notification emails are transmitted to a mailing list; both resources are available to the public.

Mission Design↗
NASA NTRS1987

Accessibility of near-earth asteroids

Missions to near-earth asteroids are of interest to both scientists and prospectors in search of extraterrestrial materials. The primary consideration in selecting the object to explore is accessibility, or the global minimum total Delta-V for a two-impulse transfer or less than 360 deg from standard Shuttle orbit to rendezvous with the asteroid. A ranking by accessibility of all known near-earth asteroids is presented. In addition, actual mission opportunities with launch dates between 1990 and 2010 for the most accessible are listed and compared with the optimal rendezvous. Actual sample return opportunities are investigated for the best candidates.

Lau, C. O.↗
NASA NTRS2012

The Osiris-Rex Mission - Sample Acquisitions Strategy and Evidence for the Nature of Regolith on Asteroid (101955) 1999 RQ36

NASA selected the OSIRIS-REx Asteroid Sample Return Mission as the third New Frontiers mission in May 2011 [I]. The mission name is an acronym that captures the scientific objectives: Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer. OSIRIS-REx will characterize near-Earth asteroid (101955) 1999 RQ36, which is both the most accessible carbonaceous asteroid [2,3] and one of the most potentially hazardous asteroids known [4]. The primary objective of the mission is to return a pristine sample from this bod, to advance our understanding of the generation, evolution, and maturation of regolith on small bodies.

Lauretta, D. S.↗
NASA NTRS1990

Search techniques for near-earth asteroids

Knowledge of the near-earth asteroids (Apollo, Amor, and Aten groups) has increased enormously over the last 10 to 15 years. This has been due in large part to the success of programs that have systematically searched for these objects. These programs have been motivated by the apparent relationships of the near-earth asteroids to terrestrial impact cratering, meteorites, and comets, and their relative accessibility for asteroid missions. Discovery of new near-earth asteroids is fundamental to all other studies, from theoretical modeling of their populations to the determination of their physical characteristics by various remote-sensing techniques. The methods that have been used to find these objects are reviewed, and ways in which the search for near-earth asteroids can be expanded are discussed.

Helin, E. F.↗
NASA NTRS2015

The Mission Accessibility of Near-Earth Asteroids

Astrodynamical Earth departure dates; mission v; mission duration; stay time; etc. Physical I NEO size(?); rotation rate; dust satellites environment; chemistry; etc. Architectural Launch vehicle(s); crew vehicle(s); habitat module(s); budget; etc. Operational Operations experience; abort options profiles; etc. Astrodynamical Accessibility is the starting point for understanding the options and opportunities available to us. Here we shall focus on. Astrodynamical Accessibility.2 Earth departure date between 2015-01-01 and 2040-12-31 Earth departure C3 60 km2s2. Total mission v 12 kms. The total v includes (1) the Earth departure maneuver from a 400 km altitude circular parking orbit, (2) the maneuver to match the NEAs velocity at arrival, (3) the maneuver to depart the NEA and, (4) if necessary, a maneuver to control the atmospheric re-entry speed during Earth return. Total round trip mission duration 450 days. Stay time at the NEA 8 days Earth atmospheric entry speed 12 kms at an altitude of 125 km. A near-Earth asteroid (NEA) that offers at least one trajectory solution meeting those criteria is classified as NHATS-compliant.

Trajectory Optimization↗
NASA NTRS2015

OSIRIS-REx, Returning the Asteroid Sample

This paper addresses the technical aspects of the sample return system for the upcoming Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) asteroid sample return mission. The overall mission design and current implementation are presented as an overview to establish a context for the technical description of the reentry and landing segment of the mission.The prime objective of the OSIRIS-REx mission is to sample a primitive, carbonaceous asteroid and to return that sample to Earth in pristine condition for detailed laboratory analysis. Targeting the near-Earth asteroid Bennu, the mission launches in September 2016 with an Earth reentry date of September 24, 2023.OSIRIS-REx will thoroughly characterize asteroid Bennu providing knowledge of the nature of near-Earth asteroids that is fundamental to understanding planet formation and the origin of life. The return to Earth of pristine samples with known geologic context will enable precise analyses that cannot be duplicated by spacecraft-based instruments, revolutionizing our understanding of the early Solar System. Bennu is both the most accessible carbonaceous asteroid and one of the most potentially Earth-hazardous asteroids known. Study of Bennu addresses multiple NASA objectives to understand the origin of the Solar System and the origin of life and will provide a greater understanding of both the hazards and resources in near-Earth space, serving as a precursor to future human missions to asteroids.This paper focuses on the technical aspects of the Sample Return Capsule (SRC) design and concept of operations, including trajectory design and reentry retrieval. Highlights of the mission are included below.The OSIRIS-REx spacecraft provides the essential functions for an asteroid characterization and sample return mission: attitude control propulsion power thermal control telecommunications command and data handling structural support to ensure successful rendezvous with Bennu characterization of Bennus properties delivery of the sampler to the surface, and return of the spacecraft to the vicinity of the Earth sample collection, performed by the Touch-and-Go Sample Acquisition Mechanism (TAGSAM), to acquire a regolith sample from the surface Earth re-entry and SRC recovery. Following sample collection, OSIRIS-REx drifts away from Bennu until the Asteroid Departure Maneuver is commanded on March 4, 2021, sending OSIRIS-REx on a ballistic return cruise to Earth. No additional large deterministic maneuvers are required to return the SRC to Earth. During the cruise, tracking and trajectory correction maneuvers (TCMs) are performed as necessary to precisely target the entry corridor. As OSIRIS-REx approaches Earth, the reentry plans are reviewed starting about a year before arrival, and preparations begin. The spacecraft is targeted away from the Earth until 7 days before entry. The final two trajectory correction maneuvers bring the spacecraft on target toward the Utah Test and Training Range (UTTR), with sufficient time for contingency resolution. The SRC releases 4 hours prior to atmospheric entry interface and, using the Stardust capsule heritage design, employs a traditional drogue and main parachute descent system for a soft touchdown.

reentry↗
NASA NTRS1990

Momentum harvesting techniques for solar system travel

Astronomers are lately estimating there are 400,000 Earth visiting asteroids larger than 100 meters in diameter. These asteroids are accessible sources of building materials, propellants, oxygen, water, and minerals which also constitute a huge momentum reserve, potentially usable for travel throughout the solar system. To use this momentum, these stealthy objects must be tracked and the extraction of the momentum wanted must be learned. Momentum harvesting by momentum transfer from asteroid to spacecraft, and by using the momentum of the extraterrestrial material to help deliver itself to the destination are discussed. A net and tether concept is the suggested means of asteroid capture, the basic momentum exchange process. The energy damping characteristics of the tether will determine the velocity mismatch that can be tolerated, and hence the amount of momentum that can be harvested per capture. As it plays out of its reel, drag on the tether steadily accelerates the spacecraft. A variety of concepts for riding and using the asteroid after capture are discussed. The hitchhiker uses momentum transfer only. The beachcomber, the caveman, the swinger, the prospector, and the rock wrecker also take advantage of raw asteroidal materials. The chemist and the hijacker go further, they process the asteroid into propellant. Or, an 'asteroid railway system' could evolve with each hijacked asteroid becoming a scheduled train. Travelers could board the space railway system assured that water, oxygen, and propellants await them.

Willoughby, Alan J.↗