Studies of radio frequency interference at Parkes Observatory

During 16 weeks of continuous SETI observing at the Parkes Observatory in New South Wales, Australia, a set of time-averaged data with 643 Hz resolution were recorded and returned to the SETI Institute for post-processing. These data are the 14 second (10 frame) average powers in each of 15,552 “subband” channels covering 10 MHz of the spectrum in both right and left circular polarizations that were used by the signal detection hardware to baseline and threshold the 1 Hz high resolution SETI spectra. The observations covered frequencies from 1.2 to 3 GHz, tracking 209 stellar targets across the sky. The data at each frequency were averaged over all directions and then interrogated to attempt to determine the prevalence of radio frequency interference (RFI). Estimates were made for the probability of encountering RFI at a particular frequency. Particular attention has been paid to those portions of the spectrum that are allocated as primary use status, or footnote protection for radioastronomy. This sixteen-week snapshot of the RFI situation at Parkes is by now out of date. Unfortunately, a year later, the situation has undoubtedly worsened.     

Legal consequences of a SETI detection

If a detection of ETI takes place, this will in all probability be the result of either: (a) detecting and recognising a signal or other emission of ETI; or (b) the finding of an alien artifact (for instance on the Moon or other Celestial Body of our Solar System); or (c) the highly improbable event of an actual encounter. First and foremost, legal consequences regarding any of these contingencies will result from immediate consultations between nations on Earth. Understandings, memoranda and even agreements might be proposed and/or concluded. Such results within the field of terrestrial law will surely be a new branch of International Law, and particularly of International Space Law. At the same time, terrestrial nations will have to realize that any ETI will be self-determined intelligent individualities or organizations who might have their own understanding of “rules of behaviour” and thus, be legal subjects. Whether one calls such rules “law” or not: if two intelligent races—both of which have specific rules of behaviour—come into contact with each other, the basic understanding of such mutual rules will lead to a kind of “code of conduct”. This might be the starting point for a kind of Law—Metalaw—between different races in the Universe.     

The impact of launch vehicle type and size on development cost

The technical development trend of future launch vehicle systems is towards fully reusable systems, in order to reduce space transportation cost. However, different types of launch vehicles are feasible, as there are

• —winged two-stage systems (WTS)

• —ballistic single-stage vehicles (BSS)

• —ballistic two-stage vehicles (BTS)

The performance of those systems is compared according to the present state of the art as well as the development cost, based on the “TRANSCOST-Model”. The development costs are shown versus launch mass (GLOW) and pay-load for the three types of reusable systems mentioned above.It is shown that performance optimization and cost minimization lead to different results. It is more economic to increase the vehicle size for achieving higher performance, instead of increasing technical complexity.Finally it is described that due to the essentially lower launch cost of reusable vehicles it will be feasible to recover the development cost by an amortization charge on the launch cost. This possibility, however, would allow commercial funding of future launch vehicle developments.     

International coordination of space solar power related activities

Because the need for energy is global, and many energy networks are already interdependent, because no one country has sufficient technological capability or sufficient funds to provide a space solar powered solution on its own, and because any such solution will require international regulation, international coordination will be vital to any attempt to produce energy for Earth from space. This will be made easier by the fact that work on the subject has already been widely publicized and distributed and cooperative efforts have already been made. Various coordinating approaches are described and the need to forge partnerships between government, industry and academia — with greater involvement of all non-space groups concerned with energy — is emphasized. A “terracing approach” to the actual implementation of SPS is suggested and outlined.     

Legal analysis of Sea Launch license: National security and environmental concerns

This paper analyzes the national security and environmental concerns surrounding the Sea Launch consortium's international license from a legal perspective. The growing market demand for a more affordable, reliable, and convenient commercial satellite launching service has led to the idea of Sea Launch—launching satellites from the sea near the Equator. However, this can pose potential conflicts between national security and foreign policy interests, and between environmental conservation and economic growth because of the international technology development issues around launching from the sea. This paper illustrates a case for balancing such multiple constraints via legal interpretation. The analysis is conducted in reference to 49 U.S.C. § 70101–70119 Commercial Space Launch Activities and 42 U.S.C. § 4321–4345 National Environmental Policy Act (NEPA) of 1969. The paper also examines weather the United Nations Convention on the Law of the Sea is binding on Sea Launch operations. Although the scope of this paper is limited mostly to the US law and the national security and environmental aspects of Sea Launch, it provides a useful example for policy making of an international collaborative technology development project.     

一种基于多层SOFM网络的星图识别方法

提出了一种基于自组织特征映射(SOFM)神经网络的星图识别算法。用基于支持向量机(SVM)的动态阈值选取算法选取导航星构建导航星库,将一多层多个并联SOFM子网的识别系统用于星图识别。给出了方法的流程。仿真结果表明,SOFM网络可提取星图中的复杂特征识别导航星。与传统三角形算法相比,该识别算法的识别准确率、鲁棒性和实时性更优,有一定的实用价值。     

Meeting the needs of the new millennium: passenger space travel and world economic growth

Without doubt, humans’ most urgent need at the start of the new millennium is the continuation of economic growth, which is the only means by which the great majority of the world population can lift themselves out of the poverty in which they live. A sine qua non for continuing economic growth is for the rich countries to continue to develop new industries—as they did throughout the 20th century, thereby creating high-productivity employment for hundreds of millions of people around the world. Arguably the most significant of these thus far is the development of passenger air travel from zero in 1900 to 1.5 billion passengers per year by 2000. It is becoming clear that passenger space travel could grow to reach a similar economic scale—and that no other space activity has comparable potential. The paper describes the potential contribution to world economic growth of passenger space travel; the failure of government space agencies either to aid its development or to make a contribution to economic growth commensurate to their cost; and the value for economic policy of prioritising the realisation of passenger space travel. The faster passenger space travel services grow, the more the space industry will contribute to “Meeting the Needs of the New Millennium”.     

Tracing the evolutionary path for space technologies

Proliferation and pace of advancing technologies warrant policy and strategic decision-making. Without thinking ahead, companies can loose marketshare and countries can yield comparative advantage. The rate at which burgeoning technologies progress, however, can make it difficult for corporations and governments alike to discern or better anticipate critical junctures in technology developments. This paper presents a conceptual, multidimensional framework, the “evolutionary path”, for understanding the stages of technological development in the civil space area. The analysis draws from three case studies — communications satellites, computers, and launch vehicles — and shows how the implications and developments of new, breakthrough technologies differ from the incremental technology upgrades or the later emergence of interconnected systems and infrastructures.     

ESDP and the space sector—defining the architecture and mechanisms for effective cooperation

This paper aims to identify and address key determinants of ESDP in space—political, industrial, research, technology and development (RTD) and procurement issues. It refers to different forms of cooperation serving the security and defence objectives of the EuropeanCommunity but organized beyond it (ESA, OCCAR, LoI, BOC, bi -or multilateral cooperation), attempting to define architecture and mechanisms for effective collaboration that could be applied between all members of the “EU 25”.     

Technology readiness and risk assessments: A new approach

Systems that depend upon the application of new technologies inevitably face three major challenges during development: performance, schedule and budget. Technology research and development (R&D) programs are typically advocated based on argument that these investments will substantially reduce the uncertainty in all three of these dimensions of project management. However, if early R&D is implemented poorly, then the new system developments that plan to employ the resulting advanced technologies will suffer from cost overruns, schedule delays and the steady erosion of initial performance objectives. It is often critical for senior management to be able to determine which of these two paths is more likely—and to respond accordingly. The challenge for system and technology managers is to be able to make clear, well-documented assessments of technology readiness and risks, and to do so at key points in the life cycle of the program.Several approaches have been used to evaluate technology maturity and risk in order to better anticipate later system development risks. The “technology readiness levels” (TRLs), developed by NASA, are one discipline-independent, programmatic figure of merit (FOM) that allows more effective assessment of, and communication regarding the maturity of new technologies. Another broadly used management tool is of the “risk matrix”, which depends upon a graphical representation of uncertainty and consequences. However, for the most part these various methodologies have had no explicit interrelationship.This paper will examine past uses of current methods to improve R&D outcomes and will highlight some of the limitations that can arise. In this context, a new concept for the integration of the TRL methodology, and the concept of the “risk matrix” will be described. The paper will conclude with observations concerning prospective future directions for the important new concept of integrated “technology readiness and risk assessments”.     

Estimation of the Probability of Radiation Failures and Single Particle Upsets of Integrated Microcircuits onboard the <Emphasis Type="Italic">Fobos-Grunt</Emphasis> Spacecraft

When designing the radio-electronic equipment for long-term operation in a space environment, one of the most important problems is a correct estimation of radiation stability of its electric and radio components (ERC) against radiation-stimulated doze failures and one-particle effects (upsets). These problems are solved in this paper for the integrated microcircuits (IMC) of various types that are to be installed onboard the Fobos-Grunt spacecraft designed at the Federal State Unitary Enterprise “Lavochkin Research and Production Association.” The launching of this spacecraft is planned for 2009.__________Translated from Kosmicheskie Issledovaniya, Vol. 43, No. 3, 2005, pp. 237–239.Original Russian Text Copyright © 2005 by Kuznetsov, Popov, Khamidullina.     

25 YEARS OF SPACE AT SURREY—PIONEERING MODERN MICROSATELLITES

Space at Surrey has developed over 25 years from very modest beginnings in 1974 to an international space centre by 1998. It has pioneered small satellites and succeeded in launching 14 low cost but sophisticated microsatellites over the course of two decades. In the 1990s, small satellites have become fashionable—but this was not always so! This paper describes the 25 years history of “Space at Surrey”.     

Doppler Detection of Gravitational Bursts Using the Earth's Satellites

We discuss the possibility of detection of low-frequency gravitational waves by means of Doppler tracking of a relatively close satellite of the Earth. A detailed analysis is performed of electromagnetic fluctuations in the space communication channel and of the instrumental noise of receiving–transmitting systems. It is shown that when certain compensating procedures are used, one can detect gravitational radiation generated in star collapses and coalescences of binaries in our Galaxy in the frequency range from 2 × 10^–3 to 5 × 10^–1 Hz and with a metric variation amplitude of 10^–15 and higher.     

Optimization of the ion-propelled space tug

Optimization of ion-propelled space vehicles is a topic of many aspects. Well known is the Stuhlinger procedure, which results in maximum payload mass fraction, given some mission and vehicle characteristic data. This procedure determines all major vehicle data—specifically, the electric power level. It is described with some refinements in this paper. Furthermore, a novel problem is treated: What set of vehicular data leads to the shortest possible propulsive mission duration, for a given electric power level? This goes beyond the “classic” Stuhlinger treatment; but is built upon this fundament.     

Population inversion and gain distribution in supersonic mixed flow systems

Experimental results are reported for small signal gain distribution across a cavity of a mixed flow gasdynamic laser system at different turbulent supersonic mixing regimes. It is shown that the temperature range of the GDL generation regime can be extended up to 7000°K, and gain coefficients as high as 3.5 m⁻¹ be attained in a “double-freeze” supersonic gas flow. Basic advantages are discussed as well as the opportunity to obtain higher efficiencies in thermally pumped laser systems.     

Stepping stones to the future: Achieving a sustainable lunar outpost

The current emphasis in the US and internationally on lunar robotic missions is generally viewed as a precursor to possible future human missions to the Moon. As initially framed, the implementation of high level policies such as the US Vision for Space Exploration (VSE) might have been limited to either human lunar sortie missions, or to the testing at the Moon of concepts-of-operations and systems for eventual human missions to Mars [White House, Vision for Space Exploration, Washington, DC, 14 January, 2004. [1]]. However, recently announced (December 2006) US goals go much further: these plans now place at the center of future US—and perhaps international—human spaceflight activities a long-term commitment to an outpost on the Moon.Based on available documents, a human lunar outpost could be emplaced as early as the 2020–2025 timeframe, and would involve numerous novel systems, new technologies and unique operations requirements. As such, substantial investments in research and development (R&D) will be necessary prior to, during, and following the deployment of such an outpost. It seems possible that such an outpost will be an international endeavor, not just the undertaking of a single country—and the US has actively courted partners in the VSE. However, critical questions remain concerning an international lunar outpost. What might such an outpost accomplish? To what extent will “sustainability” be built into the outpost? And, most importantly, what will be the outpost's life cycle cost (LCC)?This paper will explore these issues with a view toward informing key policy and program decisions that must be made during the next several years. The paper will (1) describe a high-level analytical model of a modest lunar outpost, (2) examine (using this model) the parametric characteristics of the outpost in terms of the three critical questions indicated above, and (3) present rough estimates of the relationships of outpost goals and “sustainability” to LCC. The paper will also consider possible outpost requirements for near-term investments in enabling research in light of experiences in past advanced technology programs.     

基于导航星域和K矢量的快速星图识别算法

星图识别算法是星敏感器的关键技术,快速性和可靠性一直是对其评价的重要指标。提出了基于K矢量查找表和导航星域联合进行超快速星图识别的方法。首先根据星敏感器视场和所能敏感的星等建立全天球导航星表;再依据K矢量的原则对全天的导航星按照星对角距进行分类,建立星对角距所对应导航星的K矢量和K矢量查找表。利用星敏感器视场中的4颗星构成6组星对角距,将其中的5组星对角距所对应K矢量查找表域的星对组进行导航星表域（简称导航星域）的变换,根据另外一组星对角距所对应的K矢量查找表域的值对前面5组导航星域的值同时进行索引比较,直接找到了满足条件的4颗导航星,即完成全天的星图识别。最后,通过计算机仿真,实验室模拟和真实星空实验三个层次验证了此方法的可靠性和快速性。     

The putative mechanical strength of comet surface material applied to landing on a comet

The comet lander PHILAE (part of the ESA mission ROSETTA) is going to touch down on comet 67P/Churyumov–Gerasimenko in 2014. Landing dynamics depend on the mechanical strength of the surface material: in an extremely soft material, the lander (100 kg, 1 m/s touch-down velocity) may sink in too deep for successful operation while on a very hard surface the probability for bouncing and overturning increases. It is shown that direct knowledge on the strength of cometary surface material is very limited. In our view, even the Deep Impact experiment could not provide a reliable value of the mechanical strength of comet Tempel 1. We discuss the definition of “strength” and revise the ideas on cometary surface strength and theories that describe the low-velocity (≈1 m/s) impact of blunt bodies into dust-rich, fluffy cometary materials. Available direct and indirect measurements and data are critically reviewed. Lessons learnt from laboratory measurements to verify our equations of motion are presented as well. Conclusions for Philae are drawn: most likely, the soft landing will lead to a typical penetration of the lander's feet of up to 20 cm.     

Technology readiness assessments: A retrospective

The development of new system capabilities typically depends upon the prior success of advanced technology research and development efforts. These systems developments inevitably face the three major challenges of any project: performance, schedule and budget. Done well, advanced technology programs can substantially reduce the uncertainty in all three of these dimensions of project management. Done poorly, or not at all, and new system developments suffer from cost overruns, schedule delays and the steady erosion of initial performance objectives. It is often critical for senior management to be able to determine which of these two paths is more likely—and to respond accordingly. The challenge for system and technology managers is to be able to make clear, well-documented assessments of technology readiness and risks, and to do so at key points in the life cycle of the program.In the mid 1970s, the National Aeronautics and Space Administration (NASA) introduced the concept of “technology readiness levels” (TRLs) as a discipline-independent, programmatic figure of merit (FOM) to allow more effective assessment of, and communication regarding the maturity of new technologies. In 1995, the TRL scale was further strengthened by the articulation of the first definitions of each level, along with examples (J. Mankins, Technology readiness levels, A White Paper, NASA, Washington, DC, 1995. [1]). Since then, TRLs have been embraced by the U.S. Congress’ General Accountability Office (GAO), adopted by the U.S. Department of Defense (DOD), and are being considered for use by numerous other organizations. Overall, the TRLs have proved to be highly effective in communicating the status of new technologies among sometimes diverse organizations.This paper will review the concept of “technology readiness assessments”, and provide a retrospective on the history of “TRLs” during the past 30 years. The paper will conclude with observations concerning prospective future directions for the important discipline of technology readiness assessments.