Do It Yourself Solar Energy

DIY 3D Solar Panels

Almost everyone in the United States is currently paying higher electricity bills. This usually eats deep into your salary. Fortunately, switching to solar energy is one way to save money and make your home eco-friendly. In DIY 3D Solar Panel, a pioneer in the field of solar panels known as Zak Bennet will teach you exactly how to set up a 3D Solar Panels in your home within 24 hours. You can be able to do this using tools you can easily find in your garage. He will also show you other tools you need to make this dream of living off-the-grid and saving money on electricity bill come true. This course contains an eBook and video guide. It is very affordable and you can get a refund if you don't like it. Read more here...

DIY 3D Solar Panels Summary


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My DIY 3D Solar Panels Review

Highly Recommended

I usually find books written on this category hard to understand and full of jargon. But the author was capable of presenting advanced techniques in an extremely easy to understand language.

My opinion on this e-book is, if you do not have this e-book in your collection, your collection is incomplete. I have no regrets for purchasing this.

Solar power satellites

Solar power satellites are space-based power supply systems. They are composed of arrays of solar panels that convert sunlight (or photons from other sources such as lasers) into power and then beam that power by microwave (or laser beam) to a distant site, such as a receiving station on Earth or Mars. Considerable literature has been written about solar power satellites they promise to deliver large amounts of electric power to distant sites at low cost. The lunar industrial base will be used to build the solar panels and other structural components of solar power satellites. The separate components of the solar power satellites will then be launched by mass driver from the Moon to their destination in space. They will be maneuvered into their final orbit (by tethers, rockets, etc.) and assembled by means of autonomous or tele-operated robotic devices. Large orbiting solar power satellites can then provide continuous power in the 100-200 (or more) megawatt range11 - for example, for...

Flux And Solar Panels

This calculation shows that solar power is a potentially potent power source on Earth. If it were possible to build a solar panel that could operate at 80 efficiency, then a 1-meter square panel would generate about 1000 watts of free electricity. In fact, solar cell engineers define a unit of illumination called the sun one sun is defined as 1000 watt m2. Since a single lamp is about 75 watts, the flux of one sun incident on a 1-meter square panel would power all of the lights in a house, together with an array of smaller appliances at the same time. Actual solar panels work at roughly 15 efficiency, and that's not even considering the difficulties of getting light to the panel. Our atmosphere is not transparent, there are frequent clouds, and it is night half the time. While these atmospheric factors will not go away, at least for Earth-based solar cells, it is possible that new advances in fundamental science could improve the efficiency of solar panels, which would be a great...

Dll Solar power cells for electricity

Moon Base Electricity

As discussed in Appendix A, concepts for paving the Moon with solar power cells are being developed, because most alternative sources of power are either more expensive, more complex, or both. Fuel cells are another emerging possibility, especially for rovers that must operate during the lunar night, but they require replenishment of their constituents - converting the output water back into oxygen and hydrogen. Solar power cells are likely to be the primary method of obtaining electrical power on the Moon. Electrical power can be used directly for many operations, and can be the power source for converting the output water of fuel cells back into hydrogen and oxygen. A solar cell (also referred to as a photovoltaic cell) is a device that converts photons from the Sun (solar radiation) into electricity. When they first became available, they were used in solar-powered calculators and other low-power applications. As their efficiency improved, they began to be used in remote areas...

Dl11 Lunar ilmenite for solar panels

As discussed above, most photovoltaic cells are made with silicon or gallium arsenide. However, ilmenite - particularly ilmenite which is formed in a reducing atmosphere such as the Moon's - has excellent potential as a material for photovoltaic cells. Ilmenite comprises up to 20 percent of the lunar regolith in its richest locations. It has been studied for use as a feedstock for the hydrogen reduction process to manufacture oxygen. However, its use as a semiconductor and for solar cell manufacture is a relatively new idea. Radiation damage is the major life-limiting factor for a photovoltaic array, especially in space. A typical silicon solar array may be oversized by as much as 40 percent to assure sufficient power over the life of the mission, whereas the large band gap of ilmenite makes it naturally radiation-resistant.

B2 Rationale For A Lunar Solar Power System Lsps

The advantages of this innovative solar energy system over conventional power are summarized in Exhibit 144. Looking along its last row, the case for lunar power is highlighted as follows 10 Exhibit 144. Comparison of 21st-century energy systems. This analysis shows the advantage of setting a goal by 2040 to obtain 20,000 GW of electricity from lunar solar power. Exhibit 144. Comparison of 21st-century energy systems. This analysis shows the advantage of setting a goal by 2040 to obtain 20,000 GW of electricity from lunar solar power. Terrestrial solar power Solar power satellites Exhibit 145. 21st-century power crisis. Further comparison of growing world population and the energy needs of individuals and how these could best be met by lunar solar power. Source David R. Criswell and Robert D. Waldron 12 . Exhibit 145. 21st-century power crisis. Further comparison of growing world population and the energy needs of individuals and how these could best be met by lunar solar power....

B3 Lunar Solar Power System Proposal

The Criswell Waldron concept as reviewed at numerous scientific gatherings worldwide utilizes solar power for the benefit of earthlings, as illustrated in Exhibit 148. A mature system would channel tens of terawatts of free and pure energy, using proven basic technology with passive and low-mass equipment. Further details are presented below in Exhibit 149 on lunar solar power in terms of the major elements involved, their function and advantages, as well as the specific challenges related to each. The transmissions would be at the speed of light over great distances for use where and when needed without physical connections. Essentially, the system involves the use of solar reflectors in lunar orbit to collect sunlight by thin-film photovoltaics which are then converted into thousands of low-intensity microwave beams at power stations on the Moon. From large-diameter, shared synthetic apertures on the lunar surface, these microwaves are beamed to receivers located anywhere on the...

Solar power

The design of solar power systems for landers has significantly different constraints from those for conventional satellites. First, environmental disturbances such as gravity mean the gossamer structures used on the large arrays (which often cannot bear their own weight), now common for satellites, cannot be used - there are therefore severe mass penalties for solar arrays with dimensions much larger than the body of the vehicle itself. Secondly, the orientation of the arrays with respect to the Sun is likely to be controlled by the Figure 9.4. Solar power available on an airless planet at 1 AU from the Sun (S 1340 Wm 2) as a function of time, spacecraft latitude (0) and solar declination (

Free Energy Methods

As noted in Section 13.6, it is difficult to calculate entropic quantities with any reasonable accuracy within a finite simulation time. It is, however, possible to calculate differences in such quantities.50 Of special importance is the Gibbs free energy, since it is the natural thermodynamic quantity under normal experimental conditions (constant temperature and pressure, Table 14.1), but we will illustrate the principle with Helmholtz free energy instead (constant temperature and volume). As indicated in eq. (13.6) the fundamental problem is the same. There are two commonly used methods for calculating differences in free energy Thermodynamic Perturbation and Thermo-dynamic Integration.51 Since the energy difference must be small compared with kT, the transformation from A to B must usually be broken into several intermediate steps described by a 1 parameter, and the total free energy change is given as the sum of changes in each step. statistically converged. It should be noted...

Photovoltaic Cell

Photovoltaic Cell Physics

A photovoltaic cell converts sunlight into direct current electricity. The PV effect was discovered in 1839 by the French physicist Antoine Henri Becquerel. It remained in the laboratory until 1954, when Bell Laboratories produced the first silicon solar cell. It powered the first Russian satellite in 1958, followed by applications in the U.S. space programs. Since then, it has been an important source of power for satellites because of its high power output per unit mass. Having developed maturity in space applications, PV technology is now spreading into terrestrial applications ranging from powering remote villages around the world to feeding power grids. The installed capacity of terrestrial PV systems worldwide in 2004 was over 3000 MW. Almost 40 of the PV panels installed in the world are produced in the U. S. Unlike the dynamic systems using turbine or engine driven generators, the PV array is static, produces no vibration or noise, and needs no active cooling. The photovoltaic...

Preface to the second edition

Astronomy is not an experimental science like physics it is a natural science like geology or meteorology. We must take the Universe as we find it, and deduce how the basic properties of matter have constrained the galaxies that happened to form. Sometimes our understanding is general but not detailed. We can estimate how much water the Sun's heat can evaporate from Earth's oceans, and indeed this is roughly the amount that falls as rain each day wind speeds are approximately what is required to dissipate the solar power absorbed by the ground and the air. But we cannot predict from physical principles when the wind will blow or the rain fall. Similarly, we know why stellar masses cannot be far larger or smaller than they are, but we cannot predict the relative numbers of stars that are born with each mass. Other obvious regularities, such as the rather tight relations between a galaxy's luminosity and the stellar orbital speeds within it, are not yet properly understood. But we trust...

Preface to the First Edition

Smaller, more frequent climate fluctuations are superimposed on the grand swings of the glacial interglacial cycles these minor ice ages may result from variations in the activity of the Sun itself. For instance, during the latter half of the seventeenth century the sunspot cycle effectively disappeared this long period of solar inactivity coincided with unusually cold spells in the Earth's northern hemisphere. Observations of Sunlike variable stars indicate that small, persistent variations in the solar energy output could produce extended periods of global cooling or warming. So, a prudent society will benefit by keeping a close watch on the Sun, the ultimate source of all light and heat on the Earth.

Availability of energy and material resources

The Moon, which lacks an atmosphere, receives abundant, energy from the Sun. Sunlight can be converted into electricity with lunar-made solar panels to supply the Moon with all of the power needed for global exploration and development. Sunlight could also be used for operating solar ovens, heat engines, and thermal management systems.

The Appearance Of Eclipses

The Sun is not simply a bright yellow disk in the sky. Actually, it is a hugely complicated heat-generating engine that solar physicists are still a long way from understanding completely. Car bumper stickers say Solar Power Not Nuclear Power, but solar power is nuclear power. The Sun is a gigantic nuclear reactor, fusing hydrogen nuclei together to produce helium and liberating vast amounts of energy in consequence.

The wind from the Sun an introduction

Not only does the Sun radiate the light we see - and that we do not see - but it also continually ejects into space 1 million tonnes of hydrogen per second. This wind is minute by astronomical standards it carries a very small fraction of the solar energy output, and compared to the violent explosions pervading the universe it blows rather gently. Yet it has amazing effects on the solar surroundings. It blows a huge bubble of supersonic plasma - the heliosphere - which engulfs the planets and a host of smaller bodies, shaping their environments. It also conveys perturbations that can be seen in our daily life.

Concept of Instability

In plasma physics the potential troughs and wells are replaced by sources of free energy, and the heavy sphere corresponds to a certain wave mode, in most cases an eigenmode of the plasma. There is a multitude of free energy sources in the Earth's environment. Neither the ionosphere nor the magnetosphere are closed systems in thermal equilibrium, but are driven by energy, momentum and mass input from outside, e.g., from the solar wind. On the macroscopic scale this input produces spatial gradients and inhomogeneities. On the microscopic scale it leads to deformation and distortions of the local distribution functions. The former free energy sources are the causes of the large-scale macroinstabilities, while the latter cause small-scale microinstabilities.

Space Processing Payloads

In the longer term, the high-energy aspects of the space environment may be as significant as the availability of hard vacuum and Og. The sun produces about 1400 W m2 at Earth, and this power is essentially uninterrupted for many orbits of possible future interest. The advance of solar energy collection and storage technology cannot fail to have an impact on the economic feasibility of orbital manufacturing operations. In this same vein, it is also clear that the requirement to supply raw material from Earth for space manufacturing processes is a tremendous economic burden on the viability of the total system. Again, it seems certain that, in the long term, development of unmanned freighter vehicles capable of returning lunar or asteroid materials to Earth orbit will be undertaken. With the advent of this technology, and the use of solar energy, the economic advantage in many manufacturing operations could fall to products manufactured in geosynchronous or other high Earth orbits.

The Mariner 10 Spacecraft

The Mariner 10 bus structure (Figure 2-2) was eight-sided and measured approximately 1.4 meters across and 0.5 meters in depth. The weight of the spacecraft was 504 kg, including 80 kg of scientific instrumentation (see Table 2.1) and 20 kg of hydrazine. With its two 2.7 meter by 1 meter solar panels deployed, the span of the spacecraft was 8.0 m. Each panel supported an area of 2.5 m2 of solar cells attached to the top of the octagonal bus. Figure 2-2. Mariner 10 spacecraft, illustrating the spacecraft design described in the text The instrument package, including cameras boom mounted instruments, including the magnetometer, can be seen, along with the solar panels, later used in the first demonstration of 'solar sailing'. Figure 2-2. Mariner 10 spacecraft, illustrating the spacecraft design described in the text The instrument package, including cameras boom mounted instruments, including the magnetometer, can be seen, along with the solar panels, later used in the first...

Basic solar properties

The solar distance is called the astronomical unit (AU) it is used as a basic unit in the Solar System and beyond. So is the solar mass, which is negligibly altered by the solar wind ejection. Indeed, the solar wind pours out in space roughly 109 kgs-1, which amounts to only 1O 4M0 over the Sun's age of a few 109 years. Note that the wind is not the only source of solar mass loss the mass-energy equivalence tells us that the luminosity L0 - the energy lost by the Sun per second via electromagnetic waves - yields a mass loss of L0 c2 4.3 x 109 kgs-1 this amounts to about four times the mass carried away by the solar wind, and thus barely alters the Sun's mass either we will return later to the solar energy source.

Electron Stream Modes

Let us construct the simplest electrostatic dispersion relation leading to instability. We consider a cold plasma in order to dismiss any complications due to thermal effects. And we assume sufficiently high frequencies so that ion effects can be neglected. To provide a free-energy source we assume that a cold electron beam of density nb and velocity vb streams across the electron background of density n0 and velocity v0 0. It is clear that this system is not at equilibrium and that the electrostatic interaction between the two plasmas should ultimately lead to dissipation of the extra energy stored in the streaming motion of the beam. The beam will be decelerated and the beam electrons will mix into the background plasma. During this process the plasma will be heated. The ignition of this complicated process leading to thermodynamic equilibrium will be caused by an instability.

Advanced Mission Concepts

This is not true of missions that are very advanced by today's standards. Such missions include the development of large structures for solar power satellites or antenna farms, construction of permanent space stations, lunar and asteroid mining, propellant manufacture on other planets, and many other activities that cannot be accurately envisioned at present. For these advanced concepts, the designer's imagination is still free to roam, limited only by established principles of sound engineering practice. In this section, we examine some of the possibilities for future space missions that have been advocated in recent years, with attention given to the mission and spacecraft design requirements they will pose.

Large Space Structures

Many of the advanced mission concepts that have surfaced have in common the element of requiring the deployment in Earth orbit of what are, by present standards, extremely large structures. Examples of such systems include solar power satellites, first conceived by Dr. Peter Glaser, and the large, centralized antenna platforms alluded to previously in connection with communications satellites. These structures will have one outstanding difference from Earth-based structures of similar size, and that is their extremely low mass. If erected in a 0-g environment, these platforms need not cope with the stresses of Earth's gravitational field, and need only be designed to offer sufficient rigidity for the task at hand. This fact alone will offer many opportunities for both success and failure in exploiting the capabilities of large space platforms. Other characteristics of expected large space systems have also received considerable analytical attention. As mentioned, structures such as...

Use of Lunar and Asteroid Materials

With the accumulation in orbit of sufficient capital equipment to allow large-scale use of lunar or other extraterrestrial materials, and the development of effective solar energy collection methods, the growth of heavy manufacturing must follow. As noted, the surface of the moon is much closer to either GEO or LEO in terms of energy expenditure than is the surface of Earth. Any really large projects will probably be more economical with lunar material, even considering the necessary investment in lunar mining bases. Further, some resources are more readily used than others even relatively modest traffic from LEO to GEO, the moon, or deep space will probably benefit from oxygen generated on the moon and sent down to Earth orbit.

Propellant Manufacturing

In all propellant manufacturing processes, the key is power. Regardless of the availability of raw materials, substantial energy is required to decompose the water or carbon dioxide. Compression and liquefaction of the products also require energy. The possible sources of energy are solar arrays, nuclear systems using radioisotopic decay, and critical assemblies (reactors). The use of solar energy is only practical in the inner solar system, and then probably only for small production rates.

Understanding the

This time span as well as the projected age for the Earth's existence of billions of years ascertained from geological formations, were in stark contrast with estimates of the Sun's age put forth by theories explaining the origins of solar energy. These theories evolved at a time when physicists like S. Carnot, R. Mayer, J.P. Joule, H. von Helmholtz, R. Clausius and W. Thomson formulated the laws of thermodynamics, and the concept of conservation of energy emerged 633 . Concepts like a meteoric bombardment or chemical reactions were dismissed on the basis of either problems with celestial mechanics or of the projection that the Sun could not have been radiating for more than 3,000 years. By the middle of the 19th century von Helmholtz suggested that the Sun's heat budget was derived from contraction of an originally larger cloud. This theory had two advantages. First, it would provide tens of millions of years of energy. Second, the contraction rate of the Sun would be too small to...

The Age Of Reusable Craft

As the Apollo Project wound down, NASA also turned to the development of a space station, quickly producing the prefabricated Skylab. The design utilized the empty upper stage of a Saturn rocket, a space more than 15 meters in length and 6 meters in diameter. Redesigned as the orbital workshop, the empty rocket tank was fitted with solar panels and divided into two compartments, a work area and living quarters for the crew, with an airlock for leaving and returning. NASA launched Skylab in May 1973 and sent three missions to the craft during 1973-1974. The missions, which lasted 28, 59, and 84 days respectively, studied the Sun and Earth as well as gathering invaluable information about human beings' ability to work in space. But due to declining budgets and a growing emphasis on the production of the space shuttle, NASA was quickly forced to abandon Skylab. It remained unused in orbit for six years. Unable to maintain its own orbit (a fatal design omission), the huge facility became...

Launch and Transfer Orbit Environment

High levels of acceleration, shock, and vibration are present during lift-off and during pyro-driven deployments at various stages. The resulting stress levels, varying with the launch vehicle, have effects on the power system design, particularly on the solar panels. For example, the solar panels are required to withstand the launch acceleration of about 3g on the space shuttle Orbiter, and about 10g on the launch vehicle Saturn, where g is the acceleration due to gravity on the Earth's surface. The pyro shock levels during deployments can be extremely high for a few milliseconds. The shock spectrum is generally characterized by high-frequency components. The peak shock level in Ariane during payload separation, for example, could be about 2000g at frequencies above 1.5 kHz. In transfer orbit, the solar panel is still folded, but must withstand the accelerating force at perigee and the braking force at apogee. Thermally, the outer solar panels must withstand the Earth's heat...

Can you See Any Detail on a Large Satellite in LEO

With practice, you should be able to change eyepieces from low to high magnification while a large low-orbiting satellite is traveling through your telescope's FOV Under good lighting conditions, you may be able to see the wings of a space shuttle or the solar panels of a space station.

Global sea surface temperature measurement

The ocean is a major component of the climate system (see Section 2.1.2), and ocean heat has an important role in the global climate. Most of the solar energy falling onto the Earth is absorbed in the ocean (which covers the majority of the surface) and the ocean is, therefore, the main source of heat, as well as moisture, for the atmosphere. Latitudinal variations in solar heating of the surface (and hence of the atmosphere) give rise to the general circulation of the atmosphere, and indirectly, via surface winds and thermohaline effects, of the ocean. By means of this circulation the ocean also acts as a major transporter of heat from low to high latitudes before release into the atmosphere. (In fact, roughly as much heat is transported polewards by the ocean as by the atmosphere itself.) This is because the solar energy, mainly in the form of visible light, is absorbed down to considerable depths in the ocean, and its transport back to the surface and release into the atmosphere...

Bootstrapping Lunar Development

Humankind presently has the means to develop lunar commerce with minimal modification or growth of existing technologies.7 Within a few years we could place solar panels, robots, scientific instruments and other enabling components at our preferred location on the Moon. In-situ experiments can begin that will enable mining, processing, and manufacturing. Robotic mobility systems are currently available that are capable of supporting the exploration of relatively flat areas of the Moon. It may not be necessary for rovers and instruments to be capable of working throughout the complete day night cycle -the rover could land at lunar dawn, shut down for a few tens of hours during the lunar midday for cooling, work through the lunar evening, then shut down again during the lunar night. One great benefit of a new rover mission would be that the mission could be viewed by millions of people in real time via the Internet. An example of such a system is the Mars Exploration Program. Two...

Redirecting Knowledge And Workforces Upward

Fields, such as in space medicine or psychology. For example, Dr. Stewart Johnson, a professional engineer in Albuquerque, New Mexico, has begun such a re-examination with his wife, Mary Anis Johnson. The Johnsons have jointly prepared a paper, The Civil Engineer and Space'', which they have permitted us to quote below. Their thesis, the effective use of Greater Earth resources (including the Moon and intervening space, particularly solar energy), is a subject of increasing importance to the nation, the world, and the engineer. Among trends cited by this professional couple are the following 21 . o The Civil Engineering Research Foundation will fund research related to space projects in robotic construction techniques, advanced material applications, computer-integrated manufacturing at construction sites. Space exploration and exploitation, especially at a lunar base, is dependent on such developments for habitats and facilities, resource and vehicle planning, and astronomical...

Lunar surface infrastructure requirements

Development of tele-operated devices on the lunar surface requires line-of-sight communications with Earth. Continuous power for solar cells will also help by alleviating the need for batteries while taking advantage of the abundant solar power.13 In Chapter 5, we explain why the summit of Mons Malapert, in the south polar region of the Moon, offers the optimum location for direct and continuous Earth-Moon communications, long periods of continuous sunlight, and proximity to regions of scientific interest. For the first robotic lander missions to the Moon, an area near Mons Malapert should be given consideration as the location of the first sunlight-dependent robotic base.

An example Partially ionized hydrogen plasma

The EOS of hydrogen in various physical conditions has been studied in many papers. Here we focus on the partially ionized atomic hydrogen at T 3 x 104 K, that is relevant to neutron star atmospheres. Let us employ the chemical picture of the plasma. A detailed model in the framework of the chemical picture of a plasma consisting of protons, electrons, H atoms, and H2 molecules (in all quantum-mechanical states) was developed by Saumon et al. (1995). A completely analytic version of the associated free-energy model, applicable to the case of weakly degenerate electrons in the absence of molecules, was presented by Potekhin (1996b) and extended to the case of arbitrary electron degeneracy by Potekhin et al. (1999b). In this model,

Solar activity and UV radiation

Most of the power is in the wavelength range of 400-700 nm, with very little power at wavelengths shorter than 300 nm (Figure 3.3). However, the proportional variation is highest for the shorter wavelengths. The solar energy output varies with the solar cycle, (a) because faculae, which radiate more energy, are more frequent during sunspot maximum and (b) because the sunspot areas are associated with a lower energy output. The faculae brightening is more dominant than the sunspot darkening and the Sun emits more energy at sunspot maximum than at sunspot minimum. Although the solar ultraviolet (UV) frequency band represents a small fraction of the radiative energy, the solar cycle variability in the UV band is of the order of 0.7 (Lean, 2000).

Coupling Between Thermal Convection and Surface Processes Volcanism and Tectonics

Finally, volcanism is a potential energy source that can be used by organisms to survive in extreme environments. This is the case at midocean ridges where life develops around and close to black smokers. When the geologists dived to study midocean ridges, they discovered that life can develop without solar energy. It does not mean that life can form at midocean ridges (or where there is submarine volcanism) but that life can evolve and adapt itself to difficult conditions.

Mysterious Flashing Satellite

More recently, it has come to light that STS-28's payload was most likely a member of the second-generation Satellite Data System (SDS)-B family of US Air Force military communications satellites. Doubts over whether it was a KH-12 were raised within weeks of its launch, when ground-based observers noted that it 'flashed' - as sunlight reflected from its solar panels - at regular intervals, a phenomenon not usually consistent with a spying platform.

No single nation could undertake such an enormous project

Different mechanical and electrical components keep Hubble functioning. The power for Hubble comes from solar panels on the side that convert sunlight into electricity. Gyroscopes, star trackers and reaction wheels keep Hubble steady and pointing in the right direction for hours or days at a time not too close to the Sun, Moon or Earth as they would destroy the light-sensitive instruments and accurately towards the objects being studied. The Hubble pointing and tracking system is a triumph of engineering and relies on a complex hierarchy of systems that keep the entire spacecraft stable in space to an almost incredible precision. It can point to the same spot on the sky for weeks at a time without deviating by more than a few millionths of the Moon's diameter.

Lunar surface experiments

Mission using instruments that would be easier to deploy, with the duration of the outing being open ended. On 9 October the Manned Space Flight Management Council, chaired by Mueller, agreed to the development of three lightweight experiments for the first landing mission - a solar-powered passive seismometer, an unpowered laser reflector, and a solar wind composition experiment that would be deployed and later retrieved for return to Earth. It was decided to carry the erectable antenna for the television transmission in case the time of the moonwalk did not coincide with a line-of-sight to Goldstone. The mass saved by not carrying the ALSEP would allow more fuel to be carried, and thereby increase the time available for the hovering phase of the descent. In effect, the first landing was to be an 'operational pathfinder' for its successors. On 5 November Bendix was told to make the three-instrument Early Apollo Surface Experiments Package (EASEP), which was to be shipped by mid-May...

Superfluidity and Superconductivity in Neutron Stars

The minimum free energy state of any rotating system is the state of rigid body rotation. A charged superfluid - a superconductor - like the protons in the neutron star core achieves the state of rigid body rotation by setting up a magnetic field called the London field, of magnitude BLondon (2mc e)Q sustained by supercurrents at the boundaries of the superconducting region. The energy cost of the London field is negligible compared to the free energy gain of the rigid rotation state. A London field of only 10_4 G is needed for neutron star rotation rates Q 100 rad s_1. Magnetic free energy is minimized in the state with a uniform magnetic field distributing the total flux throughout the body of the system. For most observed stars the required magnetic field that corresponds to the dipole magnetic moment of the star is of the order of 1012 G, in the direction of the magnetic moment. (The magnetic moment constraint is distinct from the rotational constraint which, for the protons, is...

Work begins in earnest

The AOSO, 3.2m long by 1.5 m in diameter with eight fold-down solar panels, was originally devised as a free-flying, unmanned satellite system that would maintain a 300-mile high polar orbit, continually monitoring the sun and near solar environment through the use of an array of detectors and electronic imaging devices covering a broad frequency band. The array of instrumentation built into the AOSO would include a high-resolution X-ray telescope, a white light corona-graph, ultraviolet and hydrogen-alpha spectroheliographs and an ultraviolet scanning spectroheliometer.

Konstantin Eduardovich Tsiolkovsky 18571935

Because Tsiolkovsky was a village teacher in rural tsarist Russia, his important work went essentially unnoticed by the world. Few in Russia cared about space travel in those days, and he never received funding to pursue any type of practical demonstration of his innovative concepts. These suggestions included the space suit, space stations, multistage rockets, large habitats in space, the use of solar energy, and closed life-support systems.

Flux Tube Instabilities

Magnetohydrodynamic stability depends on the inhomogeneity of the plasma, because free energy in ideal magnetohydrodynamics can only be stored in inhomogeneous configurations. Good examples of such unstable situations are solar flares which are believed to evolve in so-called active magnetic configurations, which evolve dynamically and possibly explosively. The instability of these magnetic configurations leads to violent energy releases and causes the particle acceleration, matter ejection, optical flashes, and the various radiation processes observed in the optical, radio, x- and 7-ray energy ranges during solar Bares. Another instability of magnetohydrodynamic nature is the reconnection process, first introduced in Sec. 5.1 of our companion book. To study these instabilities, it is convenient to formulate an energy principle. Such a principle is a global measure of the tendency of a magnetohydrodynamic configuration to undergo instability. In short, when the total energy variation...

Massenergy Equivalence

But we must begin with the Special Theory. In 1905 Einstein published four papers on different topics, one of which presented the famous equation showing the equivalence of mass and energy (E mc2). Here E represents the energy (in Joules), m the mass (in kilograms), and c the speed of light (300 million meters per second). (Einstein actually got his Nobel Prize for one of the other papers, which explained the photoelectric effect his analysis showed that light is split into discrete packets, or photons.) Using that equation, and knowing the flux of solar energy at the Earth and our distance from the Sun, it is trivial to show that our local star is losing mass by conversion to energy at an astounding rate, about four million tons per second. Over millions and billions of years it is obvious that the total mass lost must have been enormous, but in terms of the entire bulk of the Sun it is a minor fraction. The problem of the solar power source was solved, and astronomers at last knew...

Nongravitational Perturbations Other

Satellite-dependent models have been developed to represent some nongrav-itational components. The GPS satellites experience a force parallel to the solar panel rotation axis, referred to as the y-bias force, thought to result from solar panel misalignment and or thermal force effects (Vigue, et al., 1994). in-dex aut Schutz, B. E.

Switchboard In The

With its communications gear folded up inside the large black solar panels, NASA's first Tracking and Data Relay Satellite is raised to its deployment position. Note the white Inertial Upper Stage mounted at its base and the 'tilt table' at the bottom of the frame. Already, by this time, it had supported data traffic on the first Spacelab mission, launched in November 1983. When fully deployed in orbit, the newly renumbered 'TDRS-1' resembled a colossal, 2,270kg windmill, measuring 17.4m across its fully unfurled solar panels, which extended from a hexagonal 'bus'. The dual panels generated 1,800 watts of electrical power, supplemented by onboard nickel-cadmium batteries when in Earth's shadow to support its decade-long life span. Inside the bus, the communications payload was capable of transmitting in a single second the entire contents of a 20-volume encyclopaedia.

Return of humans to the Moon

Autonomous and tele-operated robots will have prepared the way for the return of humans by installing navigation landing beacons, constructing the beginnings of communications and solar-powered electric networks, and by creating one or more underground shelters. Robotic geoscience expeditions in the south polar region will be routine and several large telescopes will be either operational or in the advanced planning stages, including infrared telescopes in permanently-shadowed craters.

Applications of Gyroresonance Emission 61 Coronal magnetic field measurement

One of the simplest uses of radio observations is the determination of magnetic field strengths at the base of the corona (e.g., Hurford 1986). The absolute value of the coronal magnetic field strength is important for understanding the energetics of the corona, and the availability of free energy stored in coronal magnetic fields which may be used in flares and coronal heating. Figs. 5.2-5.5 demonstrate that where the optically-thick GR layer corresponding to a given frequency and mode drops below the corona, the radio brightness temperature at that frequency and corresponding polarization shows a sharp drop from coronal to approximately chromospheric values. (Note that the transition region is not expected to be detected via gyroresonance emission if its thickness is less than 1 as energy balance models predict, because its signature would be confined to the line at the intersection of the 1 -thick surface of the transition region with the typically 0 2-thick GR surface, and the...

The Challenge of the Spaceplane

What if water is found on the Moon Of course, it would exist as ice, probably in the environs of the Lunar poles. If this ice could be melted and electrolyzed into its constituent elements of hydrogen and oxygen, the Moon itself could supply large quantities of propellant for future space infrastructure. This completely changes the picture. The story would now have its heroes picking up Lunar propellants and delivering them to the Earth-orbiting depot, rather than the other way around. As far as getting to the Moon is concerned, the spaceplane would need only a fraction of the fuel that it needed to get into orbit. So it would fill its tanks to about two fifths of their capacity, fly to the Moon with a much lighter load, and then return with a full load of water, not rocket propellants. This is because water takes up less volume than the same material in the form of liquid hydrogen and liquid oxygen. When it comes to utilizing propellants, it is mass that counts. Once the Lunar water...

Electric propulsion fundamentals

In view of the importance of the power plant to the rocket configuration, it is convenient to analyse the performance in terms of the component masses Mv, the power-plant mass Me, the expellant mass and Mp, the payload mass. The expellant storage and feed system may be assumed to be part of the power plant, while the power-plant fuel mass will be considered to be negligibly small (nuclear fuel) or inappropriate (solar powered). The configuration envisaged is shown schematically in Figure 6.23.

Electrostatic Instabilities

While macroinstabilities are caused by configuration space accumulations of free energy in spatial inhomogeneities and affect the bulk or even global plasma properties, the effects of instabilities fed by velocity space inhomogeneities, i.e., microinstabilities, are observed on smaller and sometimes microscopic scales. Free energy can be easily stored in deviations of the velocity distribution from its thermal equilibrium shape. As a rule the equilibrium distributions are Maxwellian distribution functions (see Sec. 6.3 of our companion book, Basic Space Plasma Physics). In an open system, like in space plasmas, a slight deformation of the Maxwellian distribution can be readily produced and there are many possibilities of such deviations from equilibrium. Correspondingly, a very large number of microinstabilities can arise in a plasma. The present chapter selects those which have been detected in space plasmas. We, however, restrict to electrostatic instabilities only leaving...

Speed Fuel And Plants

If that were possible, says the first officer, there would be hundreds of robotic MUVs roving Mars right now. It might someday be possible to get oxygen from subsurface water ice on Mars by melting it and elec-trolyzing it using solar energy, but that is not a convenient way to obtain oxygen for a moving vehicle run by a combustion engine.

Circumferential lunar utilities

The highest priority of the Planet Moon Project will be given to creating the means to support exploration and development projects. During the first phases, greater emphasis will be placed on constructing the lunar electric power and transportation systems, rather than conducting scientific experiments. The rationale for this approach is simple first build the laboratory, then conduct the experiments. Once the laboratory has been built, virtually unlimited energy and material resources will become available, and global scientific and other human activities on the Moon will be possible on a large scale. There are two principal options for providing electric power on the Moon nuclear reactors and photovoltaic (solar) cells. Both of these sources of power have been deemed to have limitations that will delay large-scale lunar missions well into the future. However, solar cells will be the likely source of electric power for both near- and long-term lunar exploration and development...

Power Systems for Spaceflight

A spacecraft must be powered, otherwise it can't accelerate or is useless. Electromagnetically driven propulsion systems require a reliable power supply. The ion rocket and VASIMR are likely to be employed over the direct nuclear rocket for reasons of radiation safety. Large spacecraft sent to deep space this will require a power source that is considerably superior to what currently exists. Current power systems are solar photovoltaic generators and weak decay reactors that are not true nuclear reactors. Photovoltaic systems work well for small craft that travel close enough to the sun. The RTG radioactive type of decay reactors have been employed on craft sent to the outer gas giant planets. It is likely that some form of nuclear energy will have to be used to send spacecraft by propulsive means to speeds of 100 km sec or higher to the outer planets. Solar energy may work well for the inner planets. However, the energy requirements for reaching Mercury are comparatively high and a...

Circumferential Electric Grid

The LPS is intended to satisfy the future energy needs of the consumers of electric power on Earth, but it would also, be the source of electric power for all future lunar missions. For the first permanent lunar base, the LPS concept could be modified by creating a solar-powered electric grid that courses around the circumference of the Moon. If solar panels were placed at regular intervals along a given circumference of the Moon, then 50 percent of the panels would be powered at any one time, and continuous4 electric power would be available in the grid for all lunar operations (Figure 7.2). Earth to the first lunar base. Solar cells can be fabricated from lunar regolith feedstock (using autonomous and tele-operated robots) and then connected to the lunar electric grid. As more solar cells are added, the grid would grow in east and west directions from the first lunar base until a solar-powered electric grid is constructed around the circumference of the Moon. When the solar-powered...

Looking to the Future

Neither NASA nor the DOD was anchored solely in the contemporary realities of pursuing Mercury and Dynasoar and dealing with the numerous associated challenges. Both organizations looked to future and follow-on human-spaceflight projects such as space stations and lunar landings. As early as 10 July 1959, NASA held a conference to study the various aspects of placing a manned space laboratory in operation. . . . This project is envisioned as one of the initial steps in the actual landing of a man on the moon in 10-15 years. The participants at this conference even reached preliminary design decisions such as that the station should have a one-year life, incorporate a two-person crew, have a near-equatorial 400-mile altitude orbit, be comprised of a rigid cylinder with a parabolic solar energy collector, and weigh 7,000 lbs.124 NASA's Langley Laboratory continued to study the space station concept and produce preliminary designs throughout the Eisenhower and Kennedy administrations....

Lake Vostok and Ice Core Data in a Nutshell 711 Generalities

The recently discovered subglacial lakes in Antarctica are icy-water-geologic complex systems with unique characteristics. More than 100 lakes have been detected (Siegert et al., 1996, 2001), some of which are very large (up to 14 000km2). The high pressure, excess gas, low temperature, absence of solar energy and isolation of subglacial lakes from surface biota for thousands and perhaps millions of years make them extreme environments that may host life different from that found on the Earth's surface.

Mars Observer Surveyor and Pathfinder

Launched on November 7, 1996, and is continuing a long project of (among other things) detailed low-altitude mapping of the Martian surface. Unexpected oscillations in its solar panels while coming into a circular orbit around the planet caused the start of the major surface mapping program to be delayed by almost a year.

Understanding The Corona

Nineteenth-century astrophysicists were much confused about the source of the Sun's power. They did not understand this until nuclear reactions were discovered, as discussed in Chapter 4. This had major ramifications for other areas of science because the origin of solar energy affected estimates of the age of the Earth, and hence studies of geological and biological evolution. In this earlier

The RNA world and the origin of the genetic code

Early versions of the code probably used a smaller repertoire of amino acids, each with a larger number of codons. The codon table was divided up into progressively smaller blocks as successive amino acids were added. This idea goes as far back as Crick (1968). Each addition would have opened up a whole new world of protein possibilities. Thus, there is a selective drive for adding new amino acids in the early stages of code development. This brings us back to question of the order of addition of amino acids to the genetic code. We have shown above that the early group of amino acids can be identified based on their appearance in meteorites, the Miller-Urey experiment, and a variety of other chemical syntheses designed to simulate prebiotic conditions. The strong correlation between the ranking, Robs, that we derive and the free energy of formation, AGsurf, suggests that this ranking is a meaningful prediction of the relative frequencies of abiotically synthesized amino acids that...

International Space Station The Latest

After years of planning and design, the largest, most expensive international collaboration in space is now under construction. As of early 2001, the heart of the International Space Station (ISS) had been assembled, and the first crew exchange had taken place after four and a half months. The international effort now includes the United States, Canada, Japan, Russia, Belgium, Denmark, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and the United Kingdom. As expected, the project has experienced growing pains. There were concerns early on when the power-generating solar panels failed to deploy properly, but with some human intervention, they were coaxed into place.

Image not available

Is solar energy generated by thermonuclear conversion of hydrogen to helium. A beautiful theory had been constructed to describe this process, but although the theory accounted successfully for the Sun's luminosity, it predicted less than half of the observed flux of neutrinos (we will discuss all this in detail in chapter 7). Was the nuclear theory that far off Or was something wrong with our ideas about the core of the Sun It was a critical question for astrophysicists. Helio-seismologists were therefore eager to pin down the properties of the core.

Surface investigations

As the mechanical properties of the lunar surface would influence the design of the LM the Apollo planners said, in October 1962, that the development of JPL's 'soft landing' spacecraft should receive a higher priority than the orbital spacecraft. However, the development of the Centaur stage was so protracted that the surface investigations could not start until 1966. The planners for these Surveyor missions were faced with the same dilemma as their Apollo counterparts where should they send their first mission Although safety issues obliged them to select one of the dark plains, this was consistent with characterising the surface in the equatorial zone in which the Apollo targets were located. When Surveyor 1 was launched on 30 May 1966, the 'old hands' at JPL might well have wondered whether they were in for a rerun of the teething troubles that had plagued Ranger, but on 2 June the spacecraft landed safely near Flamsteed, in a crater that appeared to have been breached by the...

Palaeo data proxy data 5251 Biological proxies

It is sometimes possible to learn about past climate by examining elements that one way or another have been exposed to the climate and bear an imprint of the past climatic conditions. Such data records, which themselves are not direct measurements of the climate elements, but are witnesses of the past, are called proxy data. One common type of proxy data is tree rings from old trees and fossilised wood. Tree rings provide two types of information by counting the rings that show faster growth during summer and slower growth during winter, it is possible to date events in chronological order. The width of the rings gives an indication of how warm and wet the summer has been. The tree ring chronology can be used for calibrating carbon dating methods and vice versa. The proxy data do not give a direct measure of the conditions, but one must use empirical models to relate the tree ring characteristics to the climate elements. It is possible to develop statistical relations (empirical...

Nuclear Thermoelectric

Interplanetary and deep space missions far away from the sun cannot be effectively designed using photovoltaic power generation because of weak solar flux. The spacecraft must therefore carry on board a primary energy source, such as a radioactive isotope or a nuclear reactor. In the first alternative, the radioisotope heats a thermoelectric (TE) material such as lead telluride, which generates electrical potential (Figure 3.10). The principle is similar to that in a thermocouple, only with higher conversion efficiency. The radioisotope thermoelectric generator (RTG) is being routinely used for interplanetary missions requiring power levels of several hundred watts. The reactor, on the other hand, has been considered for high power in the 30 to 300 kW range. Both power sources have the advantage of supplying power all the time, thus eliminating the need for a battery in base load systems having no peak power requirement. The obvious disadvantage is the heavy radiation shielding...

Composition Atmosphere And Weather

The climatic system that governs the temperatures on Uranus might be called the great thermal equalizer. If Earth were tilted on its axis as much as is Uranus, the weather on our planet would be incredibly severe. Winters would be brutal everywhere except at the very lowest latitudes. The prevailing winds would be fierce as they attempted to equalize the radical annual seesaw of solar energy received at most points on the surface. Hurricanes of unimaginable size would prowl the seas and slam into land masses. The whole course of the evolution of life on our planet would be much different from what it was. We cannot be certain that intelligent life would have evolved at all.

Launch Vehicle Environment and Its Effects on Spacecraft Design

For launch spectators, one overriding impression is the wall of sound that hits them a few seconds after they see the rocket engines ignite, despite the fact that they are kept at a safe distance from the launch complex. Launch is a very noisy affair, and even more so for the satellite payload sitting on top of the rocket. The acoustic field encountered by the satellite is harsh, despite the satellite being contained within the launcher fairing. Large amplitude and damaging vibrations can be excited in flexible structures, such as solar panels or large antennas, by this level of noise.

Magnetic Fields in Prominences

The physics of prominences plays an important role in modern understanding of all types of solar activity because they reflect the position of the neutral lines of the photospheric magnetic field, both in its global and local AR structures. In the latter case it represents the location of the highest flare activity. The complicated plasma and magnetic structure of the surrounding regions is of great interest for studying the nature of the solar flares and other processes of the solar energy release.

Weakly nonideal Coulomb plasma

According to the Bohr-van Leeuwen theorem (p. 54) the magnetic field does not affect thermodynamics of classical charged particles. Thus the excess free energy F (r) for a classical OCP of ions is independent of B at any ion coupling parameter r (defined by Eq. (2.22)). The classical regime for an electron-ion plasma corresponds to rs 1 and r 1 in the absence of electron degeneracy. In this case the excess Coulomb free energy is given by the Debye-H ckel formula FeC -N T Z J(1 + Z) 3 r3 2 (compare to Eq. (2.73)). Indeed, it is easy to check that for classical plasma particles this law holds independently of B (Abrahams & Shapiro, 1991a Cornu, 1998). The magnetic field, however, affects quantum contributions to F . These effects have been studied either in the regime of low T and high p (considered in the following section), or at low densities. In the latter case, a general power-series expansion for the free energy of a Coulomb plasma in an arbitrary magnetic field (up to the terms a...

Softlanders and orbiters

Solar batteries solar panel Ranger was the first NASA spaceprobe to be stabilized on oil three axes, instead of spinning to remain stable. This was achieved by importing small amounts of thrust from nitrogen gas jets. This allowed the use of large flat solar panels tilted toward the Sun, insteod of the earlier spinning drum design, and produced a large increase in electrical power to the probe.

Results And Discussion

We analyzed helicity injection in active region NOAA 8100 from November 1 to 4, 1997. As shown in Figure 1(b), the helicity injection caused by flux emerging first starts on November 2 at 3 00 UT. This process continues at least until November 4, supplying a positive helicity of about 5 x 1042 Mx2. On the other hand, the photospheric shear motion injects negative helicity from November 3 to 4. Note that the helicity injected by the two processes has opposite sign, but a similar absolute value. Furthermore we point out that X-ray activity increases and a series of flares begins with a delay of about a day after the start of the helicity injection. This suggests a relationship between helicity injection and the activation of the flares. We also integrated the energy supplied into the coronal field by interpolating the data gap in SFT observations. Figure 1(c) shows that the supplied energy has an excess of 5 x 1032 erg above the potential field energy. Since energy release is not taken...

St century starflight

As it happens, there is one star-travelling approach that may become feasible by the middle of the century. Figure 7.1 presents the various aspects of this approach -beamed-energy sailing. A solar powered station is located closer to the Sun than the starship. Solar collectors focus sunlight on a solar pumped beam projector attached to the solar collector array. A laser beam or particle beam is generated by the power station. This is directed at the distant starship with the beam divergence angle shown. The starship, which consists of payload attached to a sailcraft, accelerates to its cruise velocity by the exchange of momentum with the impinging beam.

Crewtraining strategies

Orbital team satellite repairs. The historic first salvage mission of a satellite into the payload of the Shuttle Discovery the first of two such recoveries on mission 51-A. During the 8-day mission beginning on November 8,1984, two astronauts demonstrated superb teamwork by retrieving two communications satellites for repair. Again in 2007, the continuing teamwork between astronauts was evident in difficult and delicate repairs made to ISS solar panels. Source NASA Johnson Space Center.

Energy Budgets from Field Measurements

The release of the non-potential magnetic energy required to drive transient activity must be accompanied by a change in the magnetic field topology as it relaxes to a more potential state. One major reconfiguration frequently invoked to describe CMEs is the opening of previously closed field lines. It has been conjectured that, for simple geometries, the energy stored in pre-eruption closed force-free fields can never exceed that of a fully open coronal magnetic field with the same boundary conditions (Aly, 1991 Sturrock, 1991). This has been confirmed by numerical experiments (e.g. Mikic and Linker, 1994). Thus, if a CME was required to open all of the field then the energy source could not be solely magnetic in nature. The Aly-Sturrock conjecture has also been found to apply to more complex magnetic topologies, most notably ones which contain a current-carrying fluxrope of the type often used to model filaments (e.g. Lin et al., 1998). The impact of the Aly-Sturrock conjecture has...

Interstellar probe Mission

With the successful flight of the solar-powered ion propulsion system on the Deep Space 1 mission, and the numerous electric propulsion systems in use by Earth-orbiting spacecraft, it was now possible to consider the use of electric propulsion for more ambitious deep-space applications.4 However, solar power is not a feasible option for an electric propulsion system on a fast mission into interstellar space the spacecraft does not spend enough time close to the Sun to build up adequate velocity and the farther you get from the Sun, the less power you can generate to drive your propulsion system. The Interstellar Probe study team estimated that a mission to the outer solar system would require a solar collector with a mass estimated to be in the order of 50,000 kilograms in order to collect enough power for an 11-year trip time with electric propulsion. Given the relatively high power levels required to achieve fast trip times, a small fission reactor capable of producing tens of...

Al11 Exploration for waterice

Extremely robust mobility will not be required at first. The lander must have a smooth surface to land on, and the smoothest surfaces are often found in the floors of large craters. The robot would then deploy from the lander and explore within the confines of that single crater. Because continuous solar power will not be available when the first robots arrive (the infrastructure needed will not yet be in place), they will use batteries or fuel cells. The instruments and tools will be based on flight-proven or commercial systems. A six-degree-of-freedom manipulator arm with stereo vision, onboard lighting, and an end effector will allow multiple views at varying distances. Additional instrumentation might include color cameras with filter wheels to provide spectral information for geologic interpretation. The first robotic explorer might have a capability of handling 10 kg of regolith over a one-month time period, representing up to 100 individual samples.

Space Weather Effects On Soho

SOHO is designed to withstand the effects of the varying flux of high energy particles encountered in its L1 Halo orbit. These effects can be separated at least into three classes. First we will discuss the effects on the spacecraft (service module and solar panels) and then the effects on the different scientific instruments. A brief summary of efforts to prevent interruptions to the daily operation of the spacecraft is also discussed.

Lasermaser Sailing Fundamentals

Perhaps because particle-beam techniques are of military significance in missile defence schemes, more research has been published on optical laser or microwave laser (maser) application to spacecraft acceleration. This work leans heavily upon studies of solar power stations (SPS) in space that beam energy to Earth by

Al31 Automated solar cell production

A mobile robotic system is envisioned (Figure A.4) that would have a launch mass of between 150 and 200 kg. Solar thermal collectors will provide energy of evaporation, and photovoltaic panels will provide power for mobility and control. As the robot moves along, it creates a continuous layout of solar cells that lie directly on the lunar surface.

A14 Robotic explorations of the lower latitudes

Robotic rovers that operate with a combination of supervisory and autonomous control will begin to explore the lower latitudes (closer to the equator) on Magellan routes - paths that remain in sunlight at all times - so that solar power can be used as the principal power source. They would require more autonomy than past rovers, due to the 14-day traverse of the lunar far side (Teti et al., 2005). Their autonomous system software will include guidance algorithms for long-range route planning (based on LRO data) as well as short-range planning to avoid obstacles detected by sensors. They will be able to recognize features to determine their current position, in a method that may be similar to the way that Clementine's StarTracker cameras provided navigation guidance by recognizing constellations. The software must also manage strategies for re-planning routes when necessary, and for continuously pointing its solar panels towards the Sun.

Electromagnetic Radiation

Most of the energy in the Sun's electromagnetic spectrum is contained within wavelengths ranging from about 0.2 to 3 m (see Figure 6.2), ranging from short wavelength ultraviolet radiation, through visible light, to longer wavelength infrared (heat) radiation. The most obvious effect of this radiation on an orbiting spacecraft is the thermal heating that it causes. For an Earth-orbiting spacecraft, the solar power falling on every square meter of surface presented to the Sun is about 1.4 kilowatts, so that the heat input to the spacecraft surfaces is substantial. By contrast, a spacecraft in a LEO usually enters Earth's shadow on each orbit, and when this happens the vehicle's surface temperature drops drastically. Management of this thermal cycling is a critical job to be done by the thermal control subsystem engineer (see Chapter 9) to ensure that the equipment inside the spacecraft does not suffer a damaging level of temperature variation.

The Anatomy of a Critical System

Need to be able to operate for up to 20 months and traverse thousands of kilometers over the life of the mission. Tens of kilowatts of power might be required to accomplish these goals, and it would most likely not be practical to use solar photovoltaic systems given the relatively large size of those systems.

A233 Picking up rocks

Although it is not useful for cleaning spacesuits, brushing (perhaps using an electrostatic or magnetic brush) may be effective for cleaning other items, such as tools and equipment (e.g., solar power cells or other hard, smooth surfaces). Dust was a serious problem during the Apollo missions (Sullivan, 1994). Dust got into areas where the release bolts were located and made it difficult to deploy some experiments. It is likely that dust caused some of the equipment to fail early, and it is known that the accumulated dust on surfaces caused a gradual increase in the operating temperatures of the instruments (Bates et al., 1979). A brush end effector mounted on a mobile robot would be able to clean equipment on the lunar surface when dust has built up on the equipment to the point that its effectiveness is compromised. Trade studies are needed to determine the efficiency of brushing away dust from surfaces as opposed to making all of the surfaces dust-repellant.

Calculating Orbital Parameters

The solar energy received at the top of the atmosphere in one true solar day is a function of the total solar irradiance (S), the latitude the tilt of the Earth's orbit on the ecliptic (e) and the Earth-Sun distance (r). This distance is known from the length of the semi-major axis (a) of the Earth's orbit, its eccentricity (e) and the true anomaly (v) giving the position of the Earth on its orbit. Figure 1 and the key to symbols at the end of this chapter may be referred to for a definition of the various angles. Given that the seasons are defined by reference to the vernal equinox (V.E.), v is expressed as the difference between the longitude of the Earth (X) to the vernal equinox, and that of the perihelion (ro). An astronomical theory of palsoclimates is built on the hypothesis that the evolution of climate is somehow determined by the seasonal and spatial distribution of insolation. This distribution is a functional of a, e, e and ro. It therefore links the evolution of climate...

Trapped Particle Radiation

Solar panels suffer radiation damage, which causes the amount of power they produce from sunlight to decrease with time. A spacecraft in this type of orbit for many years may suffer a power loss up to 50 of the solar panel's original output. However, the power subsystem engineer is able to predict the likely deterioration for the particular type of orbit flown, and make due allowance in the spacecraft's design. Other electronic components onboard are also subject to radiation damage, but unlike solar panels, they can be shielded to some degree from the energetic particles by increasing the thickness of the walls of the metal boxes (typically made of aluminium) in which they are usually mounted. However, this needs to be done carefully as it will increase the spacecraft's mass, and as we have seen in Chapter 5, an increase in mass means a larger, more expensive launch vehicle. Another way of providing radiation protection, which goes some way toward solving this mass-growth problem, is...

Oast2 A Technology Testbed

The TES experiment consisted of two GAS canisters affixed to the Hitchhiker bridge, one of which contained a 'salt' of lithium fluoride and the other of lithium fluoride and calcium difluoride eutectic. After activation by Mission Specialist Pierre Thuot early on 5 March, TES collected and stored solar energy which was converted into electricity while in Earth's shadow. As the salts in the GAS canisters absorbed thermal energy, they slowly melted and expanded by up to 30 . Then, when cooled, they solidified and shrank, creating 'voids' in the salts which affected their heat-absorption rates.

The Other Planets In Our Solar System 571 The signature of solar variability from other planets

Variations in Venus's brightness temperature should in principle be coherent with Earth's temperatures if they both are driven by changes in the solar energy output. A strong coherent signal may furthermore be indicative of common feedback mechanisms on Earth and Venus responsible for amplifying the effect. But it is also possible that a feedback mechanism only takes place on one planet. Hence, one question is does the surface brightness temperature of other planets vary, and is it coherent with the temperature fluctuations on Earth For such studies, one needs long, high-quality time-series to reduce the risk of coincidence.23

Representative Space Transfer Vehicles

Each OMV has approximately the same OEW as indicated in Figures 5.6, 5.7 and 5.9. But each has a different configuration that is determined by the characteristics of the individual propulsion system, as depicted in Figure 5.18. The two chemical rocket-powered OMVs are similar and conventional. Although having different gross weights, they are similarly sized. The satellite attaches to an equipment module mounted on the front end of the propellant tank, where the guidance and control systems and all subsystems are housed. There would be a stowed communications antenna and solar panels for power in the equipment module (not shown). The solar electric propulsion system would require much larger solar panels than shown. Current communications satellites have solar panels in the 25 to 30 m (82 to 98 ft) total span for thrusters with less than one-tenth the thrust required for the solar electric OMV. Some of the limitations of this system are the current low thrust levels the continuously...

Power System Elements

The majority of present-day spacecraft use a solar array as the primary energy source. The 'fuel' in this case is solar radiant energy, which is converted via the photovoltaic effect (see Section 10.3.1) into electrical energy. On manned missions of short duration, fuel cells have been used most frequently as the primary source for longer duration flights associated with space stations such as Mir and ISS, the combination of solar arrays and fuel cells has been adopted. These electrochemical devices perform a controlled chemical reaction, in such a way that electrical energy may be derived rather than heat energy. The fuels used for space operation are hydrogen and oxygen yielding water as the reaction product this may then be drunk by astronauts. Nuclear systems utilize either a radioactive decay process (RTG uses this) or a nuclear fission process as the energy source. RTG makes use of the thermoelectric effect, whereas fission reactors operate in a manner similar to terrestrial...

Far Ultraviolet Spectroscopic Explorer

The FUSE satellite consists of two primary sections the spacecraft and the science instrument. The spacecraft contains all of the elements necessary for powering and pointing the satellite, including the attitude-control system, the solar panels, and communications electronics and antennae. The observatory is approximately 25 feet (7.6 m) long with baffle fully deployed.

Increasing Complexity Capability And Creativity

Future missions to the martian surface are also planned to have greater longevity and mobility. The Mars rovers Spirit and Opportunity rely on battery and solar power sources that were designed for 3-month operation, though their lifetime has proven to be much longer under martian conditions than anticipated, and both rovers were functioning more than 1 year after their landings. The 2009 Mars Science Laboratory, a mission designed to explore potential habitats, will use a radioactive thermal generator as a power source, giving the rover the capability to roam distances of 20 km and to visit multiple sites that may include diverse martian environments.

The Messenger of the Gods

Since Mercury is so close to the Sun, it receives about nine times as much solar energy as Earth does. Daytime high temperatures at Mercury are nearly as hot as they are at Venus, over 500 degrees Celsius. Since the planet has no appreciable atmosphere to retain heat, when the long Mercury night sets in, the temperature falls more than 700 degrees Celsius. This makes Mercury not only one of the hottest places in the solar system, but one of the coldest too. Mercury's axis also has just about no tilt so the planet's poles never view the Sun at a very steep angle and certain crater bottoms, like on the Moon are never exposed to sunlight. Scientists speculate that these permanently shadowed craters might also contain deposits of water ice from primeval comets. One of MESSENGER's most important assignments will be to use a spectrometer to check for the presence of hydrogen emission lines at Mercury's poles as Lunar Prospector did in the late 1990s. Also because the planet's solar period...

C2 Types Of Simulants

Simulants are needed for two general categories of research. One of these is engineering (designing robotic rovers, building roads, digging trenches, drilling holes, site preparation, and so on). Another need is for simulants than can be used to test resource extraction and processing schemes. Other proposals, such as building solar power cells using lunar regolith for both substrate and components, may require a simulant that meets both civil engineering and resource extraction requirements.

Mini Case Studies Of Macrothinking

Macrothinking space-based energy from the Moon. An artist's depiction of a future major base on the surface of the Moon. One aspect of such a base might be the construction of large solar energy collectors on the lunar surface, to convert the collected solar power into usable energy, and then transmit the energy as low intensity microwave beams to receivers on Earth, thereby helping to satisfy rising global energy needs. The system could be built on the Moon from lunar materials and operated on the Moon and on Earth using existing technologies. Source Original painting by Dennis M. Davidson for Space Resources (NASA SP-509), Washington D.C., U.S. Government Printing office, 1992.

Planetary Energy Sources

The major electromagnetic energy source comes from the solar irradiation. The solar luminosity, 4 x 1026 W, constitutes the dominant energy source for all inner planets. For the Earth, the solar power input amounts to some 1.8 x 1017 W, which represents more than 1000 times the total internal power produced (see below). However, while the solar energy is key to controlling the surface and atmospheric properties and evolution, it does not contribute to the internal activity, as it is absorbed in the very shallow surface layers the internal evolution of the planets does not depend in any essential way on their being planets, that is objects subjected to the solar radiation (and gravitational) field. As an example, the energy Q released by the transformation of 238U into 208 Pb is 52 MeV. For a typical inner planet material, given its content in the three long-lived elements, P is of the order of a few 10-8 Wm-3. For the global Earth, the total power released is thus 4 x 1013 W. This...

Insitu resource utilization ISRU

Living off the land'' is the principle of in-situ resource utilization (ISRU). On the Moon, this means using lunar resources for the production of everything that is needed for human settlement. The history of human migration shows that the settlers of a new land brought their essential tools and seed corn'' with them, but they otherwise relied upon the natural resources of the new land for their survival and growth. The migration of humanity to the Moon will be no different the first human settlers on the Moon will bring their tools and survival equipment with them, but they will use lunar resources and solar energy for long-term development and colonization (see Figure D-1).

Possible ion propulsion technology application to Solar System development

So how will ion propulsion help us to live off the land'' and explore the solar system Because of their inherently high efficiency, 10 times greater than their chemical propulsion cousins, they will allow more complex, propulsion-intense missions than would be otherwise possible. They are powered by the Sun, through the conversion of sunlight into electricity via their photovoltaic arrays. Lastly, their propellant should be able to be extracted from the atmospheres of many planets and moons throughout the solar system. Noble gases, which are the propellants of choice for ion drives, are not uncommon in the solar system. Comets, once thought to be devoid of argon and other noble gases, were found in the year 2000 to contain them by a team from the Southwest Research Institute using sounding rockets to study the comet Hale-Bopp. Argon, krypton, and xenon all being potential fuel for ion drives were also found at jupiter by NASA's Galileo mission in 1996. (Actually, the data was...

System Design Considerations

Furthermore, if the spacecraft has a very flexible operating profile, with more than one intended target of observation (such as would be the case, for example, with an astronomical telescope), then the designer's goal must include the ability to execute an equally flexible set of attitude maneuvers. The attitude-maneuver design must consider other spacecraft subsystems as well as the attitude system. A solar power system may need to have the arrays pointed toward the sun, and the arrays may need articulation individually to compensate for spacecraft maneuvers. Thermal radiators may need to be oriented toward dark space, or at least not toward the sun, while antennas may be required to point continuously toward Earth. As an excellent example of Murphy's Law, ground controllers want uninterrupted communication with the spacecraft at the exact time, during an attitude maneuver, when it is most difficult to achieve.

D12 Mirrors and solar concentrators Dl21 Mirrors

There are three kinds of concentrating solar power systems - troughs, dish engines, and power towers. The dish (concentrator) is the primary solar component of the system. It collects the solar energy and focuses it on a small area. The resultant solar beam has all of the power of the sunlight hitting the dish, but is concentrated in a small area so that it can be more efficiently used. The dish structure must track the Sun continuously to reflect the beam into the thermal receiver. The power conversion unit includes the thermal receiver and the engine generator. The thermal receiver absorbs the concentrated beam of solar energy, converts it to heat, and transfers the heat to the engine generator. A thermal receiver can be a bank of tubes with a cooling fluid (usually hydrogen or helium), which is the heat transfer medium and also the working fluid for an engine. Alternate thermal receivers are heat pipes, in which the boiling and condensing of an intermediate fluid is used to...

Comparative simulation studies

The final configurations are qualitatively similar in all cases, an example is shown in the upper panel of Fig. 11.17. Interestingly, the final state resembles an equilibrium solution (lower panel) obtained by solving the Grad-Shafranov equation for the boundary conditions reached after the flux inflow was shut off and for fixed pressure function p(A) (see Section 6.2.2). This problem generally has more than one solution, the figure shows the one that minimizes free energy (Chapter 12). A substantial amount of the initial magnetic energy has been released.

B Photoconductors and photodiodes

Photon detectors can be classified as either photoconductive (PC) or photovoltaic (PV) devices. In photoconductors the resistance of the material is lowered when impinging photons generate free charge carriers. The signal is measured as a change in voltage across the detector when it is connected to a constant current source or as a change in current when it is connected to a constant voltage source. Photoconductors In photovoltaic detectors, also called photodiodes, electrons and holes generated by photons are separated by an electric field formed at a potential barrier within the device. This field is formed at a specifically introduced interface in the material, for instance a p-n junction. Photodiodes used in astronomy are almost always made of intrinsic material. When an electron-hole pair is created at the junction by a photon the electron drifts to the -region and the hole to the p-region. The separation of charge causes a voltage to be generated across the detector terminals,...

Advanced Modelling for Radiation Pressure

Apart from the discussion of the effect of light aberration in the previous paragraph we assumed so far that radiation pressure acts along the line Sun satellite and that the area-to-mass ratio A m is constant. Both assumptions are only crude approximations in the case of active satellites like GPS satellites, TOPEX Poseidon, etc. Such satellites have a relatively complex shape and the satellites' attitude is dictated by their mission. Usually, the Earth-observing sensors (altimeter antenna for TOPEX, transmission antennas for GPS satellites) have to point to the center of the Earth, and the solar panels' axes have to be perpendicular to the unit vector Sun satellite (to optimize the energy absorbed by the panels). Figure I- 3.5 illustrates the body-fixed coordinate system for a GPS satellite. The satellite's antenna axis (the z-axis) for obvious reasons always should point to the center of the Earth, whereas the solar panels axis (the y-axis) always should be perpendicular to the...

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Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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