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In a recent paper (Maccone, 2011 [15]) and in a recent book (Maccone, 2012 [17]), this author proposed a new mathematical model capable of merging SETI and Darwinian Evolution into a single mathematical scheme. This model is based on exponentials and lognormal probability distributions, called “b-lognormals” if they start at any positive time b (“birth”) larger than zero. Indeed:
  • 1.Darwinian evolution theory may be regarded as a part of SETI theory in that the factor fl in the Drake equation represents the fraction of planets suitable for life on which life actually arose, as it happened on Earth.
  • 2.In 2008 (Maccone, 2008 [9]) this author firstly provided a statistical generalization of the Drake equation where the number N of communicating ET civilizations in the Galaxy was shown to follow the lognormal probability distribution. This fact is a consequence of the Central Limit Theorem (CLT) of Statistics, stating that the product of a number of independent random variables whose probability densities are unknown and independent of each other approached the lognormal distribution if the number of factors is increased at will, i.e. it approaches infinity.
  • 3.Also, in Maccone (2011 [15]), it was shown that the exponential growth of the number of species typical of Darwinian Evolution may be regarded as the geometric locus of the peaks of a one-parameter family of b-lognormal distributions constrained between the time axis and the exponential growth curve. This was a brand-new result. And one more new and far-reaching idea was to define Darwinian Evolution as a particular realization of a stochastic process called Geometric Brownian Motion (GBM) having the above exponential as its own mean value curve.
  • 4.The b-lognormals may be also be interpreted as the lifespan of any living being, let it be a cell, or an animal, a plant, a human, or even the historic lifetime of any civilization. In Maccone, (2012 [17, Chapters 6, 7, 8 and 11]), as well as in the present paper, we give important exact equations yielding the b-lognormal when its birth time, senility-time (descending inflexion point) and death time (where the tangent at senility intercepts the time axis) are known. These also are brand-new results. In particular, the σ=1 b-lognormals are shown to be related to the golden ratio, so famous in the arts and in architecture, and these special b-lognormals we call “golden b-lognormals”.
  • 5.Applying this new mathematical apparatus to Human History leads to the discovery of the exponential trend of progress between Ancient Greece and the current USA Empire as the envelope of the b-lognormals of all Western Civilizations over a period of 2500 years.
  • 6.We then invoke Shannon's Information Theory. The entropy of the obtained b-lognormals turns out to be the index of “development level” reached by each historic civilization. As a consequence, we get a numerical estimate of the entropy difference (i.e. the difference in the evolution levels) between any two civilizations. In particular, this was the case when Spaniards first met with Aztecs in 1519, and we find the relevant entropy difference between Spaniards an Aztecs to be 3.84 bits/individual over a period of about 50 centuries of technological difference. In a similar calculation, the entropy difference between the first living organism on Earth (RNA?) and Humans turns out to equal 25.57 bits/individual over a period of 3.5 billion years of Darwinian Evolution.
  • 7.Finally, we extrapolate our exponentials into the future, which is of course arbitrary, but is the best Humans can do before they get in touch with any alien civilization. The results are appalling: the entropy difference between aliens 1 million years more advanced than Humans is of the order of 1000 bits/individual, while 10,000 bits/individual would be requested to any Civilization wishing to colonize the whole Galaxy (Fermi Paradox).
  • 8.In conclusion, we have derived a mathematical model capable of estimating how much more advanced than humans an alien civilization will be when SETI succeeds.
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12.
The Drake equation, first proposed by Frank D. Drake in 1961, is the foundational equation of SETI. It yields an estimate of the number N of extraterrestrial communicating civilizations in the Galaxy given by the product N=Ns×fp×ne×fl×fi×fc×fL, where: Ns is the number of stars in the Milky Way Galaxy; fp is the fraction of stars that have planetary systems; ne is the number of planets in a given system that are ecologically suitable for life; fl is the fraction of otherwise suitable planets on which life actually arises; fi is the fraction of inhabited planets on which an intelligent form of life evolves; fc is the fraction of planets inhabited by intelligent beings on which a communicative technical civilization develops; and fL is the fraction of planetary lifetime graced by a technical civilization.The first three terms may be called “the astrophysical terms” in the Drake equation since their numerical value is provided by astrophysical considerations. The fourth term, fl, may be called “the origin-of-life term” and entails biology. The last three terms may be called “the societal terms” inasmuch as their respective numerical values are provided by anthropology, telecommunication science and “futuristic science”, respectively.In this paper, we seek to provide a statistical estimate of the three societal terms in the Drake equation basing our calculations on the Statistical Drake Equation first proposed by this author at the 2008 IAC. In that paper the author extended the simple 7-factor product so as to embody Statistics. He proved that, no matter which probability distribution may be assigned to each factor, if the number of factors tends to infinity, then the random variable N follows the lognormal distribution (central limit theorem of Statistics). This author also proved at the 2009 IAC that the Dole (1964) [7] equation, yielding the number of Habitable Planets for Man in the Galaxy, has the same mathematical structure as the Drake equation. So the number of Habitable Planets follows the lognormal distribution as well. But the Dole equation is described by the first FOUR factors of the Drake equation. Thus, we may “divide” the 7-factor Drake equation by the 4-factor Dole equation getting the probability distribution of the last-3-factor Drake equation, i.e. the probability distribution of the SOCIETAL TERMS ONLY. These we study in detail in this paper, achieving new statistical results about the SOCIETAL ASPECTS OF SETI.  相似文献   

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Liquid rocket engines for launch vehicles and space crafts as well as their subsystems need to be verified and qualified during hot-runs. A high test cadence combined with a flexible test team helps to reduce the cost for test verification during development/qualification as well as during acceptance testing for production. Test facility intelligence allows to test subsystems in the same manner as during complete engine system tests and will therefore reduce development time and cost.This paper gives an overview of the maturing of test engineering know how for rocket engine test stands as well as high altitude test stands for small propulsion thrusters at EADS-ST in Ottobrunn and Lampoldshausen and is split into two parts:
• Part 1 gives a historical overview of the EADS-ST test stands at Ottobrunn and Lampoldshausen since the beginning of Rocket propulsion activities in the 1960s.
• Part 2 gives an overview of the actual test capabilities and the test engineering know-how for test stand construction/adaptation and their use during running programs.
Examples of actual realised facility concepts are given to demonstrate cost saving potential for test programs in both cases for development/qualification issues as well as for production purposes.

Article Outline

1. Introduction
2. Historical overview
2.1. Ottobrunn
2.1.1. Air-breathing propulsion
2.2. Lampoldshausen
2.2.1. Attitude control systems
2.2.2. Launcher Propulsion
3. Today's status of hot firing test facilities at Lampoldshausen
4. Test facility engineering know how
5. Conclusion and outlook
References

1. Introduction

Test facilities are an indispensable element for the development and acceptance of space systems/subsystems and components. Hot-test facilities especially with environment simulation (e.g., altitude simulation) are very unique and are specifically designed to their needs.In Germany rocket propulsion developments were started during the 1950s in Ottobrunn near Munich. Beginning in the 1960s developments of attitude control engines and thruster for space crafts were started in Lampoldshausen. In addition to these two plants with test facilities and test capabilities, a third centre with test facilities operated by ERNO in Trauen was built up for the development of the ELDO Launcher (Europa III).In the frame of the consolidation of the different Space Propulsion activities within Dasa (Daimler-Benz Aerospace) in the 1990s as well as the creation of EADS-Space, all test activities were concentrated to the Lampoldshausen site, concluded in 2000.Main reasons for this concentration to one test site were:
• One EADS-ST test-centre in Germany.
• One EADS-ST Test and Engineering Team at one location.
• Multi-use of the three EADS test fields in Lampoldshausen instead of 10 facilities.
• Experts with test engineering know how for development and production programs at one location.
• Synergy effects for test facility modification/maintenance and field support together with DLR.
In addition, cost aspects, especially for test conductions have to be reduced. Therefore, the facility and test requirements have been changed by:
• Using more intelligence in the design and features of the facility (e.g., several test objectives to be tested during one hot-firing test).
• Use of test data for computer simulations as code calibration and therefore reduction of the total number of needed tests.
• Multi-function of test specialists with the main goal to reduce the test team size.
• Computer aided test set-up, firing sequencing and online documentation.

2. Historical overview

2.1. Ottobrunn

A complete overview of all technologies created since the mid of the 1950s is given by Hopmann in [1]. Within this chapter the focus was set on technologies and know how generated in the frame of the Ariane cyrogenic developments at P 59 and air-breathing propulsion [2] and [3].The start of the ARIANE 1 programme and the contract for the development of the HM7-A thrust chamber called for a new facility complex. The erection of the P 59 Test facility was the first high-pressure thrust chamber facility in Europe with a storage level of 800 bars. This high pressure gas was needed to feed the 400 bar LH2 and LOX vacuum insulated run-tanks. For this facility also a special valve test facility was erected in order to test the facility valves in advance to their integration into the test bench (Fig. 1).  相似文献   

15.
This work is a continuation of investigation [1] of the behavior of the solar wind’s and interplanetary magnetic field’s parameters near the onset of geomagnetic storms for various types of solar wind streams. The data of the OMNI base for the 1976–2000 period are used in the analysis. The types of solar wind streams were determined, and the times of beginning (onsets) of magnetic storms were distributed in solar wind types as follows: CIR (121 storms), Sheath (22 storms), MC (113 storms), and “uncertain type” (367 storms). The growth of variations (hourly standard deviations) of the density and IMF magnitude was observed 5–10 hours before the onset only in the Sheath. For the CIR-, Sheath-and MC-induced storms the dependence between the minimum of the IMF B z-component and the minimum of the D st -index, as well as the dependence between the electric field E y of solar wind and the minimum of the D st -index are steeper than those for the “uncertain” solar wind type. The steepest D st vs. B z dependence is observed in the Sheath, and the steepest D st vs. E y dependence is observed in the MC.  相似文献   

16.
Planar orbits of three-dimensional restricted circular three-body problem are considered as a special case of three-dimensional orbits, and the second-order monodromy matrices M (in coordinate z and velocity v z ) are calculated for them. Semi-trace s of matrix M determines vertical stability of an orbit. If |s| ≤ 1, then transformation of the subspace (z, v z ) in the neighborhood of solution for the period is reduced to deformation and a rotation through angle φ, cosφ = s. If the angle ? can be rationally expressed through 2π,φ = 2π·p/q, where p and q are integer, then a planar orbit generates the families of three-dimensional periodic solutions that have a period larger by a factor of q (second kind Poincareé periodic solutions). Directions of continuation in the subspace (z, v z ) are determined by matrix M. If |s| < 1, we have two new families, while only one exists at resonances 1: 1 (s = 1) and 2: 1 (s = ?1). In the course of motion along the family of three-dimensional periodic solutions, a transition is possible from one family of planar solutions to another one, sometimes previously unknown family of planar solutions.  相似文献   

17.
Based on the comparison of solar activity indices (annual average values of the relative number of sunspots Rz12 and solar radio emission flux at a wavelength of 10.7 cm F12) with the ionospheric index of solar activity IG12 for 1954–2013, we have found that the index F12 is a more accurate (than Rz12) indicator of solar activity for the long-term forecast of foF2 (the critical frequency of the F2-layer). This advantage of the F12 index becomes especially significant after 2000 if the specific features of extreme ultraviolet radiation of the Sun are additionally taken into account in the minima of solar cycles, using an appropriate correction to F12. Qualitative arguments are given in favor of the use of F12 for the long-term forecast of both foF2 and other ionospheric parameters.  相似文献   

18.
Significant advances have been made during the last decade in several fields of solid propulsion: the advances have enabled new savings in the motor development phase and recurring costs, because they help limit the number of prototypes and tests.The purpose of the paper is to describe the improvements achieved by SNPE in solid grain technologies, making these technologies available for new developments in more efficient and reliable future SRMs: new energetic molecules, new solid propellants, new processes for grain manufacturing, quick response grain design tools associated with advanced models for grain performance predictions.Using its expertise in chemical synthesis, SNPE develops new molecules to fit new energetic material requirements.Tests based on new propellant formulations have produced good results in the propellant performance/safety behavior ratio. New processes have been developed simultaneously to reduce the manufacturing costs of the new propellants.In addition, the grain design has been optimized by using the latest generation of predictive theoretical tools supported by a large data bank of experimental parameters resulting from over 30 years' experience in solid propulsion:
• Computer-aided method for the preliminary grain design
• Advanced models for SRM operating and performance predictions

References

A Davenas, D Boury, M Calabro, B D'Andrea and A Mc Donald, Solid Propulsion for Space Applications: A Roadmap, 51st IAF Congress, Rio de Janeiro, Brazil (2000).
H Austruy, M Biagioni and Y Pelipenko, Improvement in Propellant and Process for Ariane 5 Boosters (1998) AIAA 98-35588.
Y Longevialle, M Golfier, H Graindorge and G Jacob, The use of new molecules in high performances energetic materials, NDIA Insensible munitions and energetic materials technology symposium, Tampa, Florida (1999).
A.T. Nielsen, J. Org. Chem. 55 (1990), pp. 1459–1466 US Patent 5 693 794, 30/09/1998. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (58)
Bescond P, Graindorge H, Mace H, EP 913374, 6/05/1999.
G Jacob, G Lacroix and V Destombes, Identification and analysis of impurities of HNIW, 31st Annual Conference of ICT (2000).
B D'Andrea, F Lillo, A Faure and C Perut, A New Generation of Solid Propellants for Space Launchers, 50th IAF Congress, Amsterdam, The Netherlands (1999).
D.W. Doll and G.K. Lund, Magnesium neutralized clean propellant (1991) AIAA 91-2560.
C. Beckman, Clean propellants for space launch boosters, Propulsion and Energetic Panel, 84th Symposium held in Aalesund, Norway (2921994).
B. D'Andrea, B. Lillo, A. Volpi, C. Zanotti and P. Giuliani, Advanced solid propellant composition for low environmental impact and negligible erosive effect, ISTS (1998) 98-a-1-12.
J.C Chastenet and A Mobuchon, Prediction of Air Bag Performance, 5 ISCP, Stresa, Italy (2000).
J. Thépénier, D. Ribereau and E. Giraud, Grain Design for thrust trace shaping in segmented solids for the SRBs IAF-99-S.2.09, 50th IAF Congress, Amsterdam, The Netherlands (1999).
J. Thépénier, D. Ribereau and E. Giraud, Application of advanced computational softwares in propellant grain analysis : a major contribution to future SRM development for space application IAF-97-S.4.06, 48th IAF Congress, Torino, Italy (97).
A. Davenas and J. Thépénier, Recent Progress in the prediction and analysis of the operation of Solid Rocket Motors IAF-98-S2.06, 49th IAF Congress, Melbourne, Australia (1998).
D. Ribéreau, P. Le Breton and E. Giraud, SRM 3D surface burnback computation using mixes stratification deduced from 3D grain filling simulation, AIAA 99-2802, 35th AIAA JPC Conference, Los Angeles, USA (1999).
Mary. Y; “Simulation de coulée gravitaire, validation du code MONTREAL.”, DEA mechanics report, 1995.
P. Le Breton, D. Ribéreau, F. Godfroy, R. Abgrall and S. Augoula, SRM Performance Analysis by coupling bidimensional surface burnback and Pressure field computations AIAA 98-3968, 34th AIAA JPC Conference, Cleveland, USA (1998).
P. Durand, B. Vieille, H. Lambare, P. Vuillermoz, G. Bourit and P. Steinfeld, A three dimensional CFD numerical Code dedicated to space propulsive flows AIAA 00-3864, 36th AIAA JPC Conference, Huntsville, USA (2000).
  相似文献   

19.
In the implementation of the space projects Rosetta and Mars Express, a large-scale series of experiments has been carried out on radio sounding circumsolar plasma by decimeter (S-band) and centimeter (X-band) signals of the Rosetta comet probe (from October 3 to October 31, 2010) and the Mars Express satellite of Mars (from December 25, 2010 to March 27, 2011). It was found that in the phase of ingress the spacecraft behind the Sun, the intensity of the frequency fluctuations increases in accordance with a power function whose argument is the solar offset distance of radio ray path, and when the spacecraft is removed from the Sun (the egress phase), frequency fluctuations are reduced. Periodic strong increases in the fluctuation level, exceeding by a factor of 3–12 the background values of this value determined by the regular radial dependences, are imposed on the regular dependences. It was found that increasing the fluctuations of radio waves alternates with the periodicity m × T or n × T, where m = 1/2, n = 1, аnd T is the synodic period of the Sun’s rotation (T ≈ 27 days). It was shown that the corotating structures associated with the interaction regions of different speed fluxes are formed in the area of solar wind acceleration and at distances of 6–20 solar radii already have a quasi-stationary character.  相似文献   

20.
In this paper, we analyzed the thermal and energy characteristics of the plasma components observed during the magnetic dipolarizations in the near tail by the Cluster satellites. It was previously found that the first dipolarization the ratio of proton and electron temperatures (T p/T e) was ~6–7. At the time of the observation of the first dipolarization front T p/T e decreases by up to ~3–4. The minimum value T p/T e (~2.0) is observed behind the front during the turbulent dipolarization phase. Decreases in T p/T e observed at this time are associated with an increase in T e, whereas the proton temperature either decreases or remains unchanged. Decreases of the value T p/T e during the magnetic dipolarizations coincide with increase in wave activity in the wide frequency band up to electron gyrofrequency f ce. High-frequency modes can resonantly interact with electrons causing their heating. The acceleration of ions with different masses up to energies of several hundred kiloelectron-volts is also observed during dipolarizations. In this case, the index of the energy spectrum decreases (a fraction of energetic ions increases) during the enhancement of low-frequency electromagnetic fluctuations at frequencies that correspond to the gyrofrequency of this ion component. Thus, we can conclude that the processes of the interaction between waves and particles play an important role in increasing the energy of plasma particles during magnetic dipolarizations.  相似文献   

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