Analysis of the trajectory of spacecraft return from the lunar surface to a given region of the Earth

2021 ◽  
Author(s):  
M.S. Konstantinov ◽  
I.A. Nikolichev ◽  
Aung Myo Thant
Keyword(s):  
Lunar Surface ◽  
Auxiliary Problem ◽  
Initial Approximation ◽  
Single Pulse ◽  
Velocity Pulse ◽  
Reentry Vehicle ◽  
Earth’S Atmosphere ◽  
The Earth ◽  
Earth's Atmosphere ◽  
Flight Scheme

The paper describes a method developed for designing the trajectory of a spacecraft flight from the lunar surface to a given area of the Earth’s surface and analyzes a single-pulse flight scheme, in which the trajectory of a take-off lunar rocket is approximated by a single velocity pulse. The characteristics of the spacecraft entry into the Earth’s atmosphere are chosen so as to ensure that the conditions along the entry corridor during the ballistic entry are met and to ensure the landing of the reentry vehicle at a given point on the Earth’s surface. The criterion for optimizing the trajectory of the spacecraft return to the Earth is considered to be the value of the impulse that provides the spacecraft launch from the lunar surface. The method relies on the analysis of an auxiliary problem, the solution of which makes it possible to estimate the main properties of the investigated maneuver and find an initial approximation for the selected characteristics of the optimized trajectory.

scholarly journals In-Situ Cosmogenic 14C: Production and Examples of its Unique Applications in Studies of Terrestrial and Extraterrestrial Processes

Radiocarbon ◽  
2001 ◽  
Vol 43 (2B) ◽  
pp. 731-742 ◽  
Author(s):  
D Lal ◽  
A J T Jull
Keyword(s):  
Half Life ◽  
Earth Science ◽  
Chemical Properties ◽  
Radioactive Isotopes ◽  
Earth’S Atmosphere ◽  
The Earth ◽  
Wide Range ◽  
History Of ◽  
Earth's Atmosphere

Nuclear interactions of cosmic rays produce a number of stable and radioactive isotopes on the earth (Lai and Peters 1967). Two of these, 14C and 10Be, find applications as tracers in a wide variety of earth science problems by virtue of their special combination of attributes: 1) their source functions, 2) their half-lives, and 3) their chemical properties. The radioisotope, 14C (half-life = 5730 yr) produced in the earth's atmosphere was the first to be discovered (Anderson et al. 1947; Libby 1952). The next longer-lived isotope, also produced in the earth's atmosphere, 10Be (half-life = 1.5 myr) was discovered independently by two groups within a decade (Arnold 1956; Goel et al. 1957; Lal 1991a). Both the isotopes are produced efficiently in the earth's atmosphere, and also in solids on the earth's surface. Independently and jointly they serve as useful tracers for characterizing the evolutionary history of a wide range of materials and artifacts. Here, we specifically focus on the production of 14C in terrestrial solids, designated as in-situ-produced 14C (to differentiate it from atmospheric 14C, initially produced in the atmosphere). We also illustrate the application to several earth science problems. This is a relatively new area of investigations, using 14C as a tracer, which was made possible by the development of accelerator mass spectrometry (AMS). The availability of the in-situ 14C variety has enormously enhanced the overall scope of 14C as a tracer (singly or together with in-situ-produced 10Be), which eminently qualifies it as a unique tracer for studying earth sciences.

scholarly journals High-resolution spectroscopy and spectropolarimetry of the total lunar eclipse January 2019

2020 ◽  
Vol 635 ◽  
pp. A156
Author(s):  
K. G. Strassmeier ◽  
I. Ilyin ◽  
E. Keles ◽  
M. Mallonn ◽  
A. Järvinen ◽  
...  
Keyword(s):  
Large Scale ◽  
Solar Spectrum ◽  
High Resolution Spectroscopy ◽  
Strong Increase ◽  
Lunar Eclipse ◽  
The Sun ◽  
The Moon ◽  
Earth’S Atmosphere ◽  
The Earth ◽  
Earth's Atmosphere

Context. Observations of the Earthshine off the Moon allow for the unique opportunity to measure the large-scale Earth atmosphere. Another opportunity is realized during a total lunar eclipse which, if seen from the Moon, is like a transit of the Earth in front of the Sun. Aims. We thus aim at transmission spectroscopy of an Earth transit by tracing the solar spectrum during the total lunar eclipse of January 21, 2019. Methods. Time series spectra of the Tycho crater were taken with the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope in its polarimetric mode in Stokes IQUV at a spectral resolution of 130 000 (0.06 Å). In particular, the spectra cover the red parts of the optical spectrum between 7419–9067 Å. The spectrograph’s exposure meter was used to obtain a light curve of the lunar eclipse. Results. The brightness of the Moon dimmed by 10.m75 during umbral eclipse. We found both branches of the O2 A-band almost completely saturated as well as a strong increase of H2O absorption during totality. A pseudo O2 emission feature remained at a wavelength of 7618 Å, but it is actually only a residual from different P-branch and R-branch absorptions. It nevertheless traces the eclipse. The deep penumbral spectra show significant excess absorption from the Na I 5890-Å doublet, the Ca II infrared triplet around 8600 Å, and the K I line at 7699 Å in addition to several hyper-fine-structure lines of Mn I and even from Ba II. The detections of the latter two elements are likely due to an untypical solar center-to-limb effect rather than Earth’s atmosphere. The absorption in Ca II and K I remained visible throughout umbral eclipse. Our radial velocities trace a wavelength dependent Rossiter-McLaughlin effect of the Earth eclipsing the Sun as seen from the Tycho crater and thereby confirm earlier observations. A small continuum polarization of the O2 A-band of 0.12% during umbral eclipse was detected at 6.3σ. No line polarization of the O2 A-band, or any other spectral-line feature, is detected outside nor inside eclipse. It places an upper limit of ≈0.2% on the degree of line polarization during transmission through Earth’s atmosphere and magnetosphere.

XXXIX.—Did the Tail of Halley's Comet affect the Earth's Atmosphere?

1910 ◽  
Vol 30 ◽  
pp. 529-550
Author(s):  
John Aitken
Keyword(s):  
The Sun ◽  
Earth’S Atmosphere ◽  
Magnetic Condition ◽  
The Earth ◽  
Electrical Condition ◽  
Halley's Comet ◽  
Earth's Atmosphere ◽  
Pass Through

The return of Halley's Comet in May of this year gave rise to much speculation as to its possible effects on the earth. As it was expected that the earth would pass through the tail of the comet when the comet passed between us and the sun, many observations were arranged for in order to see if the tail, whatever it was composed of, had any effect on the earth or on its atmosphere. If the tail was composed of matter in any form, gaseous, or fine solid or liquid particles, then it seemed possible to get some evidence of its presence in the atmosphere; or if the tail was composed of electrons, then these would disturb the electrical condition of the atmosphere, and also the magnetic condition of the earth.

Radio astronomical measurements from earth satellites

1959 ◽  
Vol 253 (1275) ◽  
pp. 494-500 ◽  
Keyword(s):  
Low Frequency ◽  
Radio Spectrum ◽  
Absorption Bands ◽  
Frequency Limit ◽  
Low Frequencies ◽  
Earth’S Atmosphere ◽  
Upper Limit ◽  
The Earth ◽  
Earth's Atmosphere

It may be thought that radio astronomical measurements made on the earth are not subject to the influence of the atmosphere and ionosphere to any great extent and that consequently there is no demand for measurements from earth satellites or other space stations. Unfortunately this is not the case and certain measurements from outside the earth’s atmosphere are very much desired. The radio spectrum so far explored extends from a low frequency limit in the 10 to 20 Mc/s band, to an upper limit in the millimetre waveband. In the millimetre band the limitation to the extension of the spectrum arises from absorption bands in the atmosphere, whereas at low frequencies the extension is limited by absorption and disturbances in the ionosphere. In this paper some examples will be given of the need to overcome these obstacles.

scholarly journals Quantifying drivers of chemical disequilibrium in the Earth's atmosphere

2012 ◽  
Vol 3 (2) ◽  
pp. 1287-1320
Author(s):  
E. Simoncini ◽  
N. Virgo ◽  
A. Kleidon
Keyword(s):  
Potential Role ◽  
Earth System ◽  
New Approach ◽  
Earth’S Atmosphere ◽  
Ch4 Production ◽  
The Earth ◽  
Thermochemical Equilibrium ◽  
Earth's Atmosphere ◽  
High Degree ◽  
Comparable Magnitude

Abstract. It has long been observed that Earth's atmosphere is uniquely far from its thermochemical equilibrium state in terms of its chemical composition. Studying this state of disequilibrium is important both for understanding the role that life plays in the Earth system, and for its potential role in the detection of life on exoplanets. Here we present a methodology for assessing the strength of the biogeochemical cycling processes that drive disequilibrium in planetary systems. We apply it to the simultaneous presence of CH4 and O2 in Earth's atmosphere, which has long been suggested as a sign of life that could be detected from far away. Using a simplified model, we identify that the most important property to quantify is not the distance from equilibrium, but the power required to drive it. A weak driving force can maintain a high degree of disequilibrium if the residence times of the compounds involved are long; but if the disequilibrium is high and the kinetics fast, we can conclude that the disequilibrium must be driven by a substantial source of energy. Applying this to Earth's atmosphere, we show that the biotically-generated portion of the power required to maintain the methane-oxygen disequilibrium is around 0.67 TW, although the uncertainty in this figure is about 50% due to uncertainty in the global CH4 production. Compared to the chemical energy generated by the biota by photosynthesis, 0.67 TW represents only a very small fraction and, perhaps surprisingly, is of a comparable magnitude to abiotically-driven geochemical processes at the Earth's surface. We discuss the implications of this new approach, both in terms of enhancing our understanding of the Earth system, and in terms of its impact on the possible detection of distant photosynthetic biospheres.

scholarly journals Die Hubble-Ruimteteleskoop: ’n Kort Oorsig

1999 ◽  
Vol 18 (3) ◽  
pp. 97-100
Author(s):  
C. Koen
Keyword(s):  
Outer Space ◽  
Earth’S Atmosphere ◽  
The Earth ◽  
Earth's Atmosphere ◽  
Adverse Influence

Telescopes are placed in orbit around the earth in order to avoid the adverse influence of the earth's atmosphere on radiation from outer space.

Oxygen

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Scientific Evidence ◽  
Earth’S Atmosphere ◽  
The Earth ◽  
Evolution Of Life ◽  
History Of ◽  
Earth's Atmosphere ◽  
Book Covers ◽  
Over Time ◽  
The Way

The air we breathe is 21 percent oxygen, an amount higher than on any other known world. While we may take our air for granted, Earth was not always an oxygenated planet. How did it become this way? This book covers this vast history, emphasizing its relationship to the evolution of life and the evolving chemistry of the Earth. The book guides readers through the various lines of scientific evidence, considers some of the wrong turns and dead ends along the way, and highlights the scientists and researchers who have made key discoveries in the field. Showing how Earth's atmosphere developed over time, the book takes readers on a remarkable journey through the history of the oxygenation of our planet.

Observational evidence of the meteoritic bombardment

1967 ◽  
Vol 296 (1446) ◽  
pp. 316-319
Keyword(s):  
Surface Layer ◽  
Lunar Surface ◽  
Prima Facie ◽  
Observational Evidence ◽  
The Moon ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere ◽  
The Impact

Prima facie evidence for the meteoritic bombardment of the Moon is given by the known meteoritic environment of the Earth’s atmosphere. The impact by particles of different sizes and the likely damage to the lunar surface are discussed, reference being made to terrestrial craters and experiments with hypervelocity projectiles. An attempt is made to reconcile the formation and distribution of certain features with the results of meteoritic bombard­ment. In a number of instances the reconciliation is unsatisfactory and it is likely that the cause may be internal. It is pointed out that once a surface layer of dust has been formed, the effect of subsequent impacts by the smaller particles will only very slowly increase the depth.

scholarly journals Resolution of the Faint Young Sun Paradox via the Expanding Earth and Radiation Balance Equilibrium Hypothesis

2021 ◽  
Author(s):  
Golden Gadzirayi Nyambuya
Keyword(s):  
State Of The Art ◽  
Radiation Balance ◽  
Radial Expansion ◽  
Earth System ◽  
Earth’S Atmosphere ◽  
Current State ◽  
The Earth ◽  
The Face ◽  
Earth's Atmosphere ◽  
Vertical Height

We present a plausible solution to the now forty seven year old paleoclimatology riddle of the so-called Faint Young Sun Paradox via the combined hypothesis of the conservation of the state of radiation balance between the Earth and Sun and that of an expanding Earth, where, in the face of a changing (increasing) Solar luminosity, the Earth would maintain steady temperatures by re-adjusting the height of its atmosphere. That is to say, depending on whether or not the radius of the solid Earth is changing, this re-adjustment of the height of the Earth’s atmosphere would mean two things — i.e.: (1) either the height increases — in which event the Earth accretes matter from its immediate surroundings (i.e., the obvious pool formed by the Solar wind) thereby increasing the mass of the Earth’s atmosphere, or: (2) the height decreases — in which event the Earth naturally expels matter from its atmosphere, thereby decreasing the effective mass of the Earth. We demonstrate that if –- as the current state of the art ITRF observations seem to indicate, namely that — the Earth’s landmass is steadily expanding globally at a paltry rate of ∼+0.45±0.05mm·yr−1, and, that the Earth’s atmosphere is to have a present radial vertical height of about one third of the Earth’s radius (∼2860km) from the Earth’s surface, then, one can (might) with relative ease, explain not only the presence of liquid water on the Earth’s surface some ∼3.20±0.70Gyr ago during the Archaean eon when the Sun was about 75% of its current luminosity, but also the present radial expansion rate of the Earth. When all is said and done, the Earth system is herein cast as an auto-self-regulating incubator where the auto-self-regulating mechanism is as a result of the Earth’s atmosphere responding by automatically re-adjusting its height.

Sign in / Sign up

Export Citation Format

Share Document