Search NASA⌕ Search

SEARCH · Search NASA

Results for “Explore Earth”

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

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

At least 91 records · Page 5

Science Service Status 2019 World Radiocommunication Conference

Science missions such as Earth-exploration and remote sensing thatuse frequencies allocated for Earth Exploration-Satellite Service(EESS) provide valuable information about, for example: (1) Air quality monitoring (2) Soil moisture mapping (3) Sensing sea salinity (4) Weather forecasting and climate models (winds, storms, clouds).Another set of science missions use Space Research Service (SRS)allocations. These space research missions can support: (1) On orbit research that for example can help in the creation of new drugsor the impact of the space environment on satellites (2) Scientific information about the universe – stars, planetary science, solarsystem, and the future evolution of the universe.

Roura, Corali↗

Exploring Beyond Earth's Atmosphere with Human-Machine Teams

NASA's highly successful Kepler Mission has revolutionized our understanding of the Galaxy. We now know that planets, even Earth-size planets in the habitable zone, are common. With the end of the Kepler Mission we now look to the future with the Transiting Exoplanet Survey Satellite (TESS) which will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey, TESS will perform an all-sky search of more than 200,000 stars for temporary drops in brightness caused by planetary transits. With Kepler and TESS, humanity is finally at the verge of studying the masses, sizes, densities, orbits, and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars which may prove to host life. The massive data sets generated by Kepler and TESS must be meticulously combed for the weakest planetary signals every month. While a daunting and error-prone task for humans, this is an exciting opportunity for the breakthroughs recently seen in machine learning. Specifically, traditional methods for identifying planet transits require extensive data processing pipelines followed by extensive human vetting. This manual process risks loss of information due to the data processing and to inconsistency and biases due to individual human vetters. The latest advancements in machine learning will allow an objective classifier to minimize the losses of information and greatly lessen the burden on the human vetters, in addition to providing assessment of quality and score to each planet candidate, freeing the humans to concentrate on border cases and other more interesting investigations.

Smith, Jeffrey C.↗

Where Is the Upper Altitude Boundary of Earth's Biosphere? An Upcoming Stratosphere Exploration Mission

Earths atmosphere provides a relatively thin barrier to the severe conditions of space. Terrestrial microorganisms from our planets surface gets swept up into the atmosphere at rates which are influenced by meteorology, season, and variety of other regionally-dependent conditions. Residence time of microbes in the atmosphere, dispersal patterns, and metabolic activity in clouds are topics of special interest in tropospheric aerobiology. But what about even higher altitudes? A century of ocean exploration has allowed the scientific community to characterize marine life at every depth. Such knowledge was enabled by routine access, specifically, submersible vehicles with sample return systems. The outer reaches of Earth's atmosphere probably contain trace signatures of microbial life swept up from the surface, but high-altitude exploration (from 18-50 km above sea level) has been severely constrained by a shortage of reliable affordable sample acquisition systems. Thus, attempts to establish the upper altitude limits of Earths biosphere boundary remain unresolved. Previous conclusions based on observations of microbial growth and DNA signatures from samples collected in the upper atmosphere have resulted in extraordinary claims for the tenacity of life in the stratosphere. This altitude range can be regarded as a natural laboratory for examining the edge of habitability, a topic of central important to the field of astrobiology; in fact, stratosphere conditions (high UV light and low extremes of temperature, pressure, and relative humidity) closely resemble stressors associated with the surface of Mars. Moreover, low biomass detection instruments developed exploring Earths upper atmosphere can contribute to future strategies for life detection with spacecraft exploring other worlds. While pioneering, many past stratospheric microbiology studies have been qualitative in nature and lacking rigorous contamination control measurements to verify system sterility. We have designed, constructed, and recently flown a novel system for collecting upper atmosphere bioaerosols using the NASA C20A aircraft. We will report preliminary mission results from the lower stratosphere (characterizing abundance, diversity and survivability or airborne microorganisms), describe our methods for reducing false positives, and outline the open scientific engineering challenges in an ongoing effort to better establish Earths high-altitude biosphere boundary.

Smith, David J.↗

Solar activity and coronal mass ejections on the western hemisphere of the Sun in mid-August 1989: Association with interplanetary observations at the ICE and IMP 8 spacecraft

During the 10-day period from August 12 to 21, 1989, a sequence of coronal mass ejections (CMEs) was observed above the west limb of the Sun by the Solar Maximum Mission (SMM) coronagraph. Most of these CMEs apparently originated in the vicinity of one particularly active region during its passage from near central meridian to behind the west limb of the Sun. We present observations made at 1 AU during this period by the International Cometary Explorer (ICE) (formerly International Sun Earth Explorer-3 (ISEE 3)) and Interplanetary Monitoring Platform (IMP 8) spacecraft which were separated by approximately 75 deg in heliolongitude. Following CMEs on August 12 associated with solar events at approximately W40 deg, IMP 8 (in Earth orbit) detected a strong shock followed by signatures in magnetic field, solar wind plasma, and energetic ion data which suggest that CME-related material ('ejecta') forming the shock driver engulfed the spacecraft. This spacecraft only observed weak shocks, and no ejecta, from later CMEs originating further west of the spacecraft. In contrast ICE, off the west limb at approximately W75 deg, observed the shock from the W40 deg event but failed to encounter the shock driver, whereas clear ejecta signatures were observed following events further west, closer to the spacecraft heliolongitude. The disappearance of these signatures (which include bidirectional energetic ion flows, bidirectional solar wind heat fluxes, quiet, enhanced magnetic fields and anomalously cool plasma) at IMP 8 and their emergence at ICE as the solar source region moved westward supports the association of such signatures with ejecta related to CMEs. The dual-spacecraft observations are also consistent with the conclusion of Richardson and Cane (1993) that ejecta at 1 AU typically extend approximately 50 degs in longitude from the solar source. Some plausible associations between particular intervals of ejecta signatures at ICE and individual CMEs are made. However, these associations are complicated by the large number of CMEs present, by intermittent ICE data coverage, and by uncertainties in the ejecta propagation speeds to the spacecraft.

Richardson, I. G.↗

Scientific Exploration of Near-Earth Objects via the Crew Exploration Vehicle

The concept of a crewed mission to a Near-Earth Object (NEO) has been analyzed in depth in 1989 as part of the Space Exploration Initiative. Since that time two other studies have investigated the possibility of sending similar missions to NEOs. A more recent study has been sponsored by the Advanced Programs Office within NASA's Constellation Program. This study team has representatives from across NASA and is currently examining the feasibility of sending a Crew Exploration Vehicle (CEV) to a near-Earth object (NEO). The ideal mission profile would involve a crew of 2 or 3 astronauts on a 90 to 120 day flight, which would include a 7 to 14 day stay for proximity operations at the target NEO. One of the significant advantages of this type of mission is that it strengthens and validates the foundational infrastructure for the Vision for Space Exploration (VSE) and Exploration Systems Architecture Study (ESAS) in the run up to the lunar sorties at the end of the next decade (approx.2020). Sending a human expedition to a NEO, within the context of the VSE and ESAS, demonstrates the broad utility of the Constellation Program s Orion (CEV) crew capsule and Ares (CLV) launch systems. This mission would be the first human expedition to an interplanetary body outside of the cislunar system. Also, it will help NASA regain crucial operational experience conducting human exploration missions outside of low Earth orbit, which humanity has not attempted in nearly 40 years.

Abell, Paul A.↗

Impacts on Explorer 46 from an Earth orbiting population

Explorer 46 was launched into Earth orbit in August 1972 to evaluate the effectiveness of using double-wall structures to protect against meteoroids. The data from the Meteoroid Bumper Experiment on Explorer 46 is reexamined and it is concluded that most of the impacts originated from an Earth orbiting population. The probable source of this orbiting population is solid rocket motors fired in Earth orbit.

Kessler, D. J.↗

Multimission spacecraft Dataplexer

The data multiplexing unit described is a low-power small-size building-block-type central data system designed for use on such spacecraft as the International Ultraviolet Explorer or the International Sun-Earth Explorer. Preprogrammed read-only memories are used to generate the telemetry format tailored to particular mission requirements. Low weight and low power dissipation are achieved with the aid of PMOS technology. The use of subcommutators in groups to meet particular spacecraft requirements allows low data rate experiments to be time-multiplexed into a single main input channel, to improve data collection and processing operations. The block diagram of the Dataplexer is discussed.

Cosme, R.↗

Scientific Exploration of Near-Earth Objects via the Crew Exploration Vehicle

The concept of a crewed mission to a near-Earth object (NEO) has been previously analyzed several times in the past. A more in depth feasibility study has been sponsored by the Advanced Projects Office within NASA's Constellation Program to examine the ability of a Crew Exploration Vehicle (CEV) to support a mission to a NEO. The national mission profile would involve a crew of 2 or 3 astronauts on a 90 to 120 day mission, which would include a 7 to 14 day stay for proximity operations at the target NEO.

Abell, P. A.↗

Exploring the Possibilities: Earth and Space Science Missions in the Context of Exploration

According to Dr. Edward J. Weiler, Director of the Goddard Space Flight Center, "Exploration without science is tourism". At the American Astronautical Society's 43rd Annual Robert H. Goddard Memorial Symposium it was quite apparent to all that NASA's current Exploration Initiative is tightly coupled to multiple scientific initiatives: exploration will enable new science and science will enable exploration. NASA's Science Mission Directorate plans to develop priority science missions that deliver science that is vital, compelling and urgent. This paper will discuss the theme of the Goddard Memorial Symposium that science plays a key role in exploration. It will summarize the key scientific questions and some of the space and Earth science missions proposed to answer them, including the Mars and Lunar Exploration Programs, the Beyond Einstein and Navigator Programs, and the Earth-Sun System missions. It will also discuss some of the key technologies that will enable these missions, including the latest in instruments and sensors, large space optical system technologies and optical communications, and briefly discuss developments and achievements since the Symposium. Throughout history, humans have made the biggest scientific discoveries by visiting unknown territories; by going to the Moon and other planets and by seeking out habitable words, NASA is continuing humanity's quest for scientific knowledge.

Pfarr, Barbara↗

ISECG Mission Scenarios and Their Role in Informing Next Steps for Human Exploration Beyond Low Earth Orbit

The International Space Exploration Coordination Group (ISECG) was established in response to The Global Exploration Strategy (GES): The Framework for Coordination developed by fourteen space agencies* and released in May 2007. This GES Framework Document recognizes that preparing for human space exploration is a stepwise process, starting with basic knowledge and culminating in a sustained human presence in deep space. ISECG has developed several optional global exploration mission scenarios enabling the phased transition from human operations in Low Earth Orbit (LEO) and utilization of the International Space Station (ISS) to human missions beyond LEO leading ultimately to human missions to cis-lunar space, the Moon, Near Earth Asteroids, Mars and its environs. Mission scenarios provide the opportunity for judging various exploration approaches in a manner consistent with agreed international goals and strategies. Each ISECG notional mission scenario reflects a series of coordinated human and robotic exploration missions over a 25-year horizon. Mission scenarios are intended to provide insights into next steps for agency investments, following on the success of the ISS. They also provide a framework for advancing the definition of Design Reference Missions (DRMs) and the concepts for capabilities contained within. Each of the human missions contained in the scenarios has been characterized by a DRM which is a top level definition of mission sequence and the capabilities needed to execute that mission. While DRMs are generally destination focused, they will comprise capabilities which are reused or evolved from capabilities used at other destinations. In this way, an evolutionary approach to developing a robust set of capabilities to sustainably explore our solar system is defined. Agencies also recognize that jointly planning for our next steps, building on the accomplishments of ISS, is important to ensuring the robustness and sustainability of any human exploration plan. Developing a shared long-term vision is important, but agencies recognize this is an evolutionary process and requires consideration of many strategic factors. Strategic factors such as the implications of an emerging commercial space industry in LEO, the opportunity provided by extending ISS lifetime to at least 2020, and the importance of defining a plan which is sustainable in light of inevitable domestic policy shifts are timely for agency consideration.

Culbert, Christopher J.↗

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↗

Modeling the data systems role of the scientist (for the NEEDS Command and Control Task)

Research was conducted into the command and control activities of the scientists for five space missions: International Ultraviolet Explorer, Solar Maximum Mission, International Sun-Earth Explorer, High-Energy Astronomy Observatory 1, and Atmospheric Explorer 5. A basis for developing a generalized description of the scientists' activities was obtained. Because of this characteristic, it was decided that a series of flowcharts would be used. This set of flowcharts constitutes a model of the scientists' activities within the total data system. The model was developed through three levels of detail. The first is general and provides a conceptual framework for discussing the system. The second identifies major functions and should provide a fundamental understanding of the scientists' command and control activities. The third level expands the major functions into a more detailed description.

Hei, D. J., Jr.↗

Simulation of interference between Earth stations and Earth-orbiting satellites

It is often desirable to determine the potential for radio frequency interference between earth stations and orbiting spacecraft. This information can be used to select frequencies for radio systems to avoid interference or it can be used to determine if coordination between radio systems is necessary. A model is developed that will determine the statistics of interference between earth stations and elliptical orbiting spacecraft. The model uses orbital dynamics, detailed antenna patterns, and spectral characteristics to obtain accurate levels of interference at the victim receiver. The model is programmed into a computer simulation to obtain long-term statistics of interference. Two specific examples are shown to demonstrate the model. The first example is a simulation of interference from a fixed-satellite earth station to an orbiting scatterometer receiver. The second example is a simulation of interference from earth-exploration satellites to a deep-space earth station.

Bishop, D. F.↗

Astrometric needs for the ISEE-3/ICE mission to Comet Giocobini-Zinner

The Third International Sun-Earth Explorer satellite (ISEE-3) was rechristened Internation Cometary Explorer (ICE) when the spacecraft left the Earth-Moon system after a close Lunar flyby on 1983 December 22. On 1985 September 11, ICE will pass through the inner parts of the tail of Comet Giacobini-Zinner to obtain the first in-situ measurements of any comet. Since the spacecraft has no cameras, its trajectory will be determined only from radio tracking. Astrometric updates of Comet Giacobini-Zinner will be critical for the final targeting of the spacecraft to achieve a successful encounter. ICE's flyby of Comet Giacobini-Zinner will provide valuable experience for the astrometry needed to target other spacecraft to encounter Hally's Comet six months later.

Dunham, D. W.↗