scholarly journals ChipSats for Planetary Exploration: Dynamics and Aerothermal Modeling of Atmospheric Entry and Dispersion

2021 ◽  
Vol 8 ◽  
Author(s):  
Joshua S. Umansky-Castro ◽  
Kimberly G. Yap ◽  
Mason A. Peck
Keyword(s):  
Planetary Exploration ◽  
Technology Readiness ◽  
Ground Model ◽  
Atmospheric Entry ◽  
Cornell University ◽  
The Earth ◽  
Mission Duration ◽  
Globally Distributed

This paper presents an orbit-to-ground model for the atmospheric entry of ChipSats, gram-scale spacecraft that offer unique advantages over their conventionally larger counterparts. ChipSats may prove particularly useful for in-situ measurements in the upper atmosphere, where spatially and temporally varying phenomena are especially difficult to characterize. Globally distributed ChipSats would enable datasets of unprecedented detail, assuming they could survive. The model presented is used to assess the survival and dispersion of a swarm of ChipSats when deployed over the Earth, Moon, Mars, and Titan. These planetary exploration case studies focus on the Monarch, the newest-generation ChipSat developed at Cornell University, in order to evaluate technology readiness for such missions. A parametric study is then conducted to inform future ChipSat design, highlighting the role of the ballistic coefficient in both peak entry temperature and mission duration.

A Discussion on the measurement and interpretation of changes of strain in the Earth - Role of pore fluids in faulting

1973 ◽  
Vol 274 (1239) ◽  
pp. 297-304 ◽  
Keyword(s):  
Pore Pressure ◽  
San Andreas Fault ◽  
Fault Creep ◽  
Time Constants ◽  
San Andreas ◽  
The Earth ◽  
Shallow Earthquakes ◽  
Pressure Changes

We consider three in situ processes which involve fluid flow in the crust: fault creep, aftershocks and dilatancy. Measurements of water level in wells suggest that creep events on the San Andreas fault are coupled with pore pressure changes. Readjustment of transient pore pressure, induced by large shallow earthquakes, possess the correct time constants and magnitudes to explain the occurrence of aftershocks. And finally, temporal changes of travel times in the Gram district (U.S.S.R.) imply that dilatancy may occur in situ.

Role of Satellite Technology in Oceanic Study

2018 ◽  
pp. 80-103
Author(s):  
Thomas Mathew
Keyword(s):  
Remote Sensing ◽  
Electromagnetic Radiation ◽  
Crucial Role ◽  
Near Infrared ◽  
Thermal Infrared ◽  
Microwave Region ◽  
Satellite Technology ◽  
The Earth

The three-fourth surface of the earth is covered with ocean. The study of the ocean is important for sustainable overall development of a nation and world at large in view of it being rich in resources and playing a crucial role in the climate of the region and changes associated with it. The space-based observations assume significance, as it provides synoptic and repetitive coverage of the ocean in contrast to the sparse and isolated in-situ buoy or ship observations. The remote sensing of the ocean with the help of satellite or satellite oceanography has many other applications also. The electromagnetic radiation in the visible, near infrared, thermal infrared, and microwave regions are used by the sensors on-board space platforms to measure the diverse physical, biological, and geological parameters of the ocean. Amongst the various electromagnetic regions, the microwave region plays an important role in the study of the ocean.

Role of asperities on the transition from seismic to aseismic slip using an experimental fault slip system

2021 ◽  
Author(s):  
Weiwei Shu ◽  
Olivier Lengliné ◽  
Jean Schmittbuhl
Keyword(s):  
Experimental Approach ◽  
Normal Load ◽  
Local Deformation ◽  
Local Dynamic ◽  
Aseismic Slip ◽  
The Earth ◽  
Internal Parameters ◽  
Interface Sliding

<p>Faults are common geological structures distributed at various depths within the Earth with different behaviors: from seismic to aseismic. The frictional stability of faults is linked to the properties of asperities that make the contact between fault surfaces. Investigating the interaction between asperities and its link with the frictional stability of faults aims at a better understanding of the intrinsic relationships between the observations of earthquake swarms and the slow local aseismic transient. Here we propose an experimental approach, which allows a customized interface sliding slowly under a well-controlled normal load, to study this problem. This interface consists of asperities modeled by poly-methyl-methacrylate (PMMA) balls in a softer, polymer base representing the parts of the fault that are easily deformed, facing a transparent flat PMMA plate. We employ a high-resolution camera for in-situ optical monitoring of the local deformation of the interface while loaded. We also attach acoustic sensors to capture the dynamics events attesting to local dynamic ruptures. We connect our observations with a mechanical model derived from a high-precision topography of the customized interface. We investigate the effects of various internal parameters of natural fault systems, including the density of asperities, their rigidity or the contrast of rigidity compared to the base, on the evolution of the frictional stability under variable normal load and of the behavior of the population of asperities at the transition between seismic and aseismic slip. Our results, bring new observations on the mechanics of swarm and fault transient.</p>

scholarly journals 2.1.1 In-Situ Records of Interplanetary Dust Particles - Methods and Results

1976 ◽  
Vol 31 ◽  
pp. 143-158 ◽  
Author(s):  
H. Fechtig
Keyword(s):  
Interplanetary Dust ◽  
Space Missions ◽  
Dust Particles ◽  
Measure Data ◽  
Interplanetary Dust Particles ◽  
Detection Techniques ◽  
The Earth ◽  
Future Space

AbstractA review is given on the techniques used to record and to quantitatively measure data of individual interplanetary dust particles. New developments in detection techniques are briefly discussed.The main results from recent space missions at about 1 AU and in the earth-moon neighborhood are discussed and compared with the flux results from lunar microcrater studies. Spatial anisotropies and time fluctuations are found indicating that the earth is exposed to two main micrometeoroid dust populations: the “apex”-population and the B-meteoroids. The near planet-dust enrichments measured by HEOS 2 near the earth and by the Pioneer 10/11 near Jupiter are emphasized. The experimental data strongly suggest a fragmentation process associated with the earth. The role of the moon as a dust source is discussed. The important problems in the dust field for future space missions are summarized.

scholarly journals Joint Discussion 10 Progress in planetary exploration missions

2006 ◽  
Vol 2 (14) ◽  
pp. 319-320
Author(s):  
Guy Consolmagno
Keyword(s):  
Solar System ◽  
Planetary Exploration ◽  
Research Projects ◽  
Laboratory Studies ◽  
The Earth ◽  
Space Age ◽  
New Research ◽  
First Time

The astronomical study of planets is as old as Galileo's telescope, but in a profound way it was reborn with the advent of the Space Age. By constructing probes capable of leaving the surface of the Earth and traveling to other places in our solar system, sending back data collected from the very places that the astronomers wished to study, for the first time we were freed from the restrictions of observing astronomical objects from afar. These in-situ measurements, in their turn, have inspired countless new research projects back on Earth, from laboratory studies of materials to telescopic observations, of objects and in wavelengths now known to be of astronomical interest, thanks to those probes.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

Beyond the Social Determinants of Health

2020 ◽  
Vol 3 ◽  
pp. 1-11
Author(s):  
Laura Hall ◽  
Urpi Pine ◽  
Tanya Shute
Keyword(s):  
Labour Force ◽  
Methodological Approach ◽  
Active Role ◽  
Indigenous Women ◽  
Economic Activities ◽  
The Earth ◽  
The Social ◽  
Weather Changes ◽  
People First

Abstract This paper will reflect on key findings from a Summer 2017 initiative entitled The Role of Culture and Land-Based Healing in Addressing and Ending Violence against Indigenous Women and Two-Spirited People. The Indigenist and decolonizing methodological approach of this work ensured that all research was grounded in experiential and reciprocal ways of learning. Two major findings guide the next phase of this research, complicating the premise that traditional economic activities are healing for Indigenous women and Two-Spirit people. First, the complexities of the mainstream labour force were raised numerous times. Traditional economies are pressured in ongoing ways through exploitative labour practices. Secondly, participants emphasized the importance of attending to the responsibility of nurturing, enriching, and sustaining the wellbeing of soil, water, and original seeds in the process of creating renewal gardens as a healing endeavour. In other words, we have an active role to play in healing the environment and not merely using the environment to heal ourselves. Gardening as research and embodied knowledge was stressed by extreme weather changes including hail in June, 2018, which meant that participants spent as much time talking about the healing of the earth and her systems as the healing of Indigenous women in a context of ongoing colonialism.

“Eternal Bodies”: images of archangels in the upper parts of Nubian buildings

2020 ◽  
pp. 713-736
Author(s):  
Magdalena Łaptaś
Keyword(s):  
Near East ◽  
Structural Elements ◽  
Christian Art ◽  
The Earth ◽  
Cosmic Space

Images of archangels and angels, which were painted on the walls, in the upper parts of the buildings and, on their structural elements, were very popular in Christian Nubian painting as attested by the discoveries from Church SWN.BV on the citadel in Old Dongola. These images, which derive from pre-Christian art, depict the eternal nature of the archangels and angels. Presenting this group of representations, the author traces the origins of these images to highlight the role of these spiritual beings as intermediaries between God and humankind. As such, they move freely between the Heavens and the Earth, so the air and cosmic space are their natural surroundings. Moreover, archangels govern the forces of nature, the planets, and the seven skies. Therefore, their sanctuaries were located on hill summits, in the upper chapels, on structural elements of ecclesiastical buildings, etc. The Nubian tradition is therefore part of a broader Mediterranean tradition, the roots of which should be sought in the Near East.

{10-12} Twinning Mechanism During In Situ Micro-Tensile Loading of Pure Mg: Role of Basal Slip and Twin-Twin Boundary Interaction

2020 ◽  
Author(s):  
Nicolò Maria della Ventura ◽  
Szilvia Kalácska ◽  
Daniele Casari ◽  
Thomas Edward James Edwards ◽  
Johann Michler ◽  
...  
Keyword(s):  
Twin Boundary ◽  
Basal Slip ◽  
Tensile Loading ◽  
Boundary Interaction
Sign in / Sign up

Export Citation Format

Share Document