The Impact of Mission Duration on a Mars Orbital Mission

2017 ◽  
Author(s):  
Dale C. Arney ◽  
Kevin D. Earle ◽  
William Cirillo ◽  
Christopher A. Jones ◽  
Jordan Klovstad ◽  
...  
Keyword(s):  
Mission Duration ◽  
The Impact ◽  
Orbital Mission

Human Factors Considerations for Enhancing Performance in the Naval Airship

1987 ◽  
Vol 31 (4) ◽  
pp. 410-413
Author(s):  
Lauren B. Leveton ◽  
Bethany H. Drum ◽  
Peter Engel ◽  
Timothy K. O'Donohue
Keyword(s):  
Human Performance ◽  
State Of The Art ◽  
Personal Hygiene ◽  
Medical Support ◽  
Mission Duration ◽  
Art Research ◽  
Leisure And Recreation ◽  
The Impact ◽  
Research Recommendations ◽  
The U.S

The purpose of this research and review effort was to make recommendations for enhancing human performance on a conceptual airship under consideration for maritime use by the U.S. Navy. The major intent was to determine an optimal work/rest schedule and corresponding crew size (See Figure 1). These recommendations assumed an inflight mission duration of 30 days with crew exchange after the mission is completed, continuous operations throughout the mission, and certain pre-determined crew positions. Based on an analysis of analogous systems and review of state-of-the-art research, recommendations for optimal and alternative work/rest cycles were made and the impact on crew size was identified. The authors concluded that a specifically sized crew can maintain acceptable levels of performance during airship missions of 30 to 60 days duration if an appropriate work/rest schedule is followed and minimum habitability requirements are met. Accordingly, recommendations for habitability requirements were made for the following areas: volume, temperature and humidity, lighting, noise and vibration, decor, privacy, personal hygiene and waste management, food, medical support, and leisure and recreation.

scholarly journals The effect of mission duration on LISA science objectives

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Pau Amaro Seoane ◽  
Manuel Arca Sedda ◽  
Stanislav Babak ◽  
Christopher P. L. Berry ◽  
Emanuele Berti ◽  
...  
Keyword(s):  
Black Holes ◽  
Duty Cycle ◽  
Data Stream ◽  
Continuous Data ◽  
Implicit Assumption ◽  
Mission Duration ◽  
Science Group ◽  
The Impact ◽  
Science Investigations ◽  
Mission Operations

AbstractThe science objectives of the LISA mission have been defined under the implicit assumption of a 4-years continuous data stream. Based on the performance of LISA Pathfinder, it is now expected that LISA will have a duty cycle of $$\approx 0.75$$ ≈ 0.75 , which would reduce the effective span of usable data to 3 years. This paper reports the results of a study by the LISA Science Group, which was charged with assessing the additional science return of increasing the mission lifetime. We explore various observational scenarios to assess the impact of mission duration on the main science objectives of the mission. We find that the science investigations most affected by mission duration concern the search for seed black holes at cosmic dawn, as well as the study of stellar-origin black holes and of their formation channels via multi-band and multi-messenger observations. We conclude that an extension to 6 years of mission operations is recommended.

scholarly journals The stellar variability noise floor for transiting exoplanet photometry with PLATO

2020 ◽  
Vol 493 (4) ◽  
pp. 5489-5498 ◽  
Author(s):  
Brett M Morris ◽  
Monica G Bobra ◽  
Eric Agol ◽  
Yu Jin Lee ◽  
Suzanne L Hawley
Keyword(s):  
Impact Parameter ◽  
Solar Dynamics Observatory ◽  
Depth Measurement ◽  
Stellar Oscillations ◽  
Mission Duration ◽  
Intensity Images ◽  
Solar Dynamics ◽  
In Transit ◽  
Limb Darkening ◽  
The Impact

ABSTRACT One of the main science motivations for the ESA PLAnetary Transit and Oscillations (PLATO) mission is to measure exoplanet transit radii with 3 per cent precision. In addition to flares and starspots, stellar oscillations and granulation will enforce fundamental noise floors for transiting exoplanet radius measurements. We simulate light curves of Earth-sized exoplanets transiting continuum intensity images of the Sun taken by the Helioseismic and Magnetic Imager (HMI) instrument aboard the Solar Dynamics Observatory (SDO) to investigate the uncertainties introduced on the exoplanet radius measurements by stellar granulation and oscillations. After modelling the solar variability with a Gaussian process, we find that the amplitude of solar oscillations and granulation is of order 100 ppm – similar to the depth of an Earth transit – and introduces a fractional uncertainty on the depth of transit of 0.73 per cent assuming four transits are observed over the mission duration. However, when we translate the depth measurement into a radius measurement of the planet, we find a much larger radius uncertainty of 3.6 per cent. This is due to a degeneracy between the transit radius ratio, the limb darkening, and the impact parameter caused by the inability to constrain the transit impact parameter in the presence of stellar variability. We find that surface brightness inhomogeneity due to photospheric granulation contributes a lower limit of only 2 ppm to the photometry in-transit. The radius uncertainty due to granulation and oscillations, combined with the degeneracy with the transit impact parameter, accounts for a significant fraction of the error budget of the PLATO mission, before detector or observational noise is introduced to the light curve. If it is possible to constrain the impact parameter or to obtain follow-up observations at longer wavelengths where limb darkening is less significant, this may enable higher precision radius measurements.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Organic Syntheses During the Impact of a Comet with a Gaseous Planet

1997 ◽  
Vol 161 ◽  
pp. 189-195
Author(s):  
Cesare Guaita ◽  
Roberto Crippa ◽  
Federico Manzini
Keyword(s):  
Polymeric Material ◽  
Molecular Form ◽  
Parent Compound ◽  
Blue Filter ◽  
Organic Syntheses ◽  
The Impact

AbstractA large amount of CO has been detected above many SL9/Jupiter impacts. This gas was never detected before the collision. So, in our opinion, CO was released from a parent compound during the collision. We identify this compound as POM (polyoxymethylene), a formaldehyde (HCHO) polymer that, when suddenly heated, reformes monomeric HCHO. At temperatures higher than 1200°K HCHO cannot exist in molecular form and the most probable result of its decomposition is the formation of CO. At lower temperatures, HCHO can react with NH3 and/or HCN to form high UV-absorbing polymeric material. In our opinion, this kind of material has also to be taken in to account to explain the complex evolution of some SL9 impacts that we observed in CCD images taken with a blue filter.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Unusual Microstructure in Shock-Compacted Graphite

1970 ◽  
Vol 28 ◽  
pp. 474-475
Author(s):  
Lucien F. Trueb
Keyword(s):  
Mechanical Characteristic ◽  
Compression Wave ◽  
Gray Zone ◽  
Flyer Plate ◽  
Compacted Graphite ◽  
The Impact

Crushed and statically compressed Madagascar graphite that was explosively shocked at 425 kb by means of a planar flyer-plate is characterized by a black zone extending for 2 to 3 nun below the impact plane of the driver. Beyond this point, the material assumes the normal gray color of graphite. The thickness of the black zone is identical with the distance taken by the relaxation wave to overtake the compression wave.The main mechanical characteristic of the black material is its great hardness; steel scalpels and razor blades are readily blunted during attempts to cut it. An average microhardness value of 95-3 DPHN was obtained with a 10 kg load. This figure is a minimum because the indentations were usually cracked; 14.8 DPHN was measured in the gray zone.

Drug Induced Changes in Cell Organelles

1968 ◽  
Vol 26 ◽  
pp. 110-111
Author(s):  
Sarah A. Luse
Keyword(s):  
Clinical Medicine ◽  
Cell Organelles ◽  
Riboflavin Deficiency ◽  
Drug Induced ◽  
New Era ◽  
Health And Disease ◽  
In The Beginning ◽  
Cellular Pathology ◽  
Induced Changes ◽  
The Impact

In the mid-nineteenth century Virchow revolutionized pathology by introduction of the concept of “cellular pathology”. Today, a century later, this term has increasing significance in health and disease. We now are in the beginning of a new era in pathology, one which might well be termed “organelle pathology” or “subcellular pathology”. The impact of lysosomal diseases on clinical medicine exemplifies this role of pathology of organelles in elucidation of disease today.Another aspect of cell organelles of prime importance is their pathologic alteration by drugs, toxins, hormones and malnutrition. The sensitivity of cell organelles to minute alterations in their environment offers an accurate evaluation of the site of action of drugs in the study of both function and toxicity. Examples of mitochondrial lesions include the effect of DDD on the adrenal cortex, riboflavin deficiency on liver cells, elevated blood ammonia on the neuron and some 8-aminoquinolines on myocardium.

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