text:
Mindstar Rising
- The Greg Mandel Trilogy, Book 1
- Narrated by: Toby Longworth
- Series: Greg Mandel, Book 1
- Length: 14 hrs and 52 mins
- Unabridged Audiobook
- Release date: 01-12-11
- Language: English
- Publisher: Audible Studios
- Whispersync for Voice-ready
Regular price: £18.99
It's the 21st century, and global warming is here to stay, so forget the way your country used to look. And get used to the free market, too – the companies possess all the best hardware, and they're calling the shots now. In a world like this, a man open to any offers can make out just fine.
A man like Greg Mandel for instance, who's psi-boosted, wired into the latest sensory equipment, carrying state-of-the-art weaponry – and late of the English Army's Mindstar Battalion. As the cartels battle for control of a revolutionary new power source, and corporate greed outstrips national security, tension is mounting to boiling point – and Greg Mandel is about to face the ultimate test.
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- Catherine
- 13-12-11
Given was written in the early 90s, the setting is eerily apt and poignant right now. Near future sci-fi, elements of cyberpunk, corporate scandal and detective story to boot and Toby Longworth's performance (because that's what it is) is first class. Highly recommended!
26 of 27 people found this review helpful
- Paul
- Oxford, United Kingdom
- 09-04-12
Intelligent, well crafted and absorbing spaceopera
I listen to audio books on long car journeys - if they are any good then the journey appears to take no time at all. Listening to this, the first of the Mindstar trilogy, caused me to enter a time-space vortex in which I was transported nearly 200 K without any sensation of movement, time or other reality. My esper sense clearly helped me to drive while the gland secretions enabled me to do so safely - either that or the other road users just gave me a wide berth. I cannot believe this was narrated by one person; awesome is the only real reaction. I particularly liked the evocation of one of the evil characters who sounded remarkably like a former UK prime minister!!! I think you either love sci-fi or just don't get it. If you love it - you will definitely get this. My feeling about what makes a really good audio book (or any book come to that) is - are the characters believable, do you care about the characters and what is/will happen to them, is the plot immersive and does it make you want to guess? I would answer yes to all those points and just say that the creation of England post global-warming is intelligent and very well articulated. I loved the idea of Peterborough becoming a major sea port and a kool place to live - now that really is science fantasy.
19 of 20 people found this review helpful
- Sean
- READING, United Kingdom
- 23-03-12
Brilliant Sci Fi Story & Setting
This is an excellent read if you are into "not too distant future" sci fi. Present day politics, companies etc, but with twists. The story doesn't hold you by the hand, from the get go it used terms (mimox crystals etc) I wasn't sure on, I thought had I missed something from another one of Peter Hamiltons books. But things are revealed bit by bit and I have to say, I rather liked it like that. Not explaining everything as soon as it appears, the story lets you piece this world together yourself, but does expand on it later. A great story, excellent world and Greg Mandel is now number 3 in my list of top main characters, after Jack Reacher (Lee Child) and John Clarke (Tom Clancy). I am definitely getting the second and third parts of the trilogy, and will probably get the rest of Peter Hamiltons books, on the back of this great story.
7 of 7 people found this review helpful
- jf101
- 11-01-12
Good book, excellent narration
Hamilton is always good value and the narration from Toby Longworth was top-notch and has prompted me to look for other books he has narrated.
10 of 11 people found this review helpful
- Banbury, United Kingdom
- 11-09-12
Didn't think I would like this
After listening to the void trilogy I was looking for something else from Peter Hamilton but these didn't appeal to me, I think the near future bit and name put me off. However when I decided to give this a go I was hooked. I still prefer the distant future novels but this was very enjoyable and have since purchased the remaining 2 books. Would definitely recommend no messing.
11 of 13 people found this review helpful
- Simon
- 31-08-15
Great start to a great series
Mindstar Rising is narrated excellently by Toby Longworth and sets the scene for a genuinely excellent sci-fi trilogy. I originally only got this as it was on special offer but I wouldn't have begrudged paying full price at all. The characters are very well detailed and the future Earth that they inhabit is given its own unique, thoroughly described reality.
The real key as to whether to start a series though is whether it delivers consistently and having read the other volumes in the trilogy it does. If you like this one I believe you'll like the rest.
6 of 7 people found this review helpful
- Mark
- BANCHORY, United Kingdom
- 23-02-12
Good PFH story
Well I did enjoy this and am going to listen to the rest of the trilogy. It is early work and quite amusing. By setting it in the near future - the future we are now in - he is very close to reality in some respects and miles away in others. His references to obsolete trade names for example is amusing but irritating. If we write a book now about 5 years in the future will we talk about Apple i products? I am sure there will be a icommunicator watch for example..... but do enjoy guys!
6 of 7 people found this review helpful
- Nick
- 28-01-12
Sixth Star for Toby Longworth.
I have had a print edition of this book since the late nineties. It is one of those books we all have that are the equivalent of comfort eating for the mind. I must admit I was sceptical about an audio edition as I had some definite ( or so I thought ) ideas as to how the characters sounded. These thoughts were blown away by Toby's performance. It is like listening to an ensemble reading but from one man. This should be a recording that they give to all budding readers and say .... Like That One Please.
13 of 16 people found this review helpful
- Kim-John
- southampton, United Kingdom
- 04-06-12
buy the follow on books
bought this as a reduced price audio book liking sci-fi detective/thriller type books, the narrator is absolutely brilliant with a great range of voices and great character portrayal the pace of the story is easy and i found myself stopping what i was doing to listen as this book totally absorbed me, I have bought books 2 and 3 and have enjoyed the whole series. this is the first time I have felt compelled to write a review
5 of 6 people found this review helpful
- William
- COLWYN BAY, United Kingdom
- 01-01-15
A Decent book and performance
Would you consider the audio edition of Mindstar Rising to be better than the print version?
Having not read the book i cannot say
Who was your favorite character and why?
Greg the main character, his history and traits make him a compelling listen.
Which character – as performed by Toby Longworth – was your favourite?
Umm very similar question to the above, Greg.
If you made a film of this book, what would be the tag line be?
I cant really think of one.
Any additional comments?
This sirs and ladys is a good book well performed and well read. I really enjoyed it and would highly recommend it. A quick summary its about a century in the future. glodal warming has happened forcing a population move in England . as this happened an extreme socialist nearly communist party comes into power and ran the country into the ground. using ever more extreme violence to maintain power. in this unstable country ex army veteran is unleashed to solve a corporate sabotage issue.
4 of 5 people found this review helpful
- Michael G Kurilla
- 13-01-12
Portrait of a SciFi master as a novice
Relative to Hamilton's more recent work (the Commonwealth Saga), Mindstar Rising is clearly not in the same league. That said, this 1st book of the Greg Mandel trilogy demonstrates the talent that has emerged as one of preeminent contemporary scifi authors. Mindstar is simply not as ambitious, nor as sweeping in scope as his later work, but the story is masterfully done and a thoroughly enjoyable listen.
We are presented with the limits of a near future tale (still near future due to the identifiability with the characters' daily routines), set late in the 21st century. Both environmental (in the form of global warming) and political (in the form of economic upheaval leading to vicious UK socialism) changes have occurred. Greg Mandel is a former UK soldier, discharged by the new, anti-military government. The Mindstar unit was a special ops group that received early experimental bioimplants. Mandel has an "esp" sense to detect mental states in others close by. He does not "read" minds, but can sense emotional reactions.
Greg is hired by a wealthy, elderly businessman and his granddaughter to track down what is thought to be sabotage within their manufacturing facilities (some of which are space based). What appears as straightforward corporate espionage and hardball takeover tactics gradually evolves into a life or death struggle with national political ramifications. For the major scifi elements, biology and cyber dominate along the lines of a William Gibson / Richard K Morgan love child.
The characters are wonderfully developed with vile villains and endearing supporting characters. The narrator performs an admirable rendition for the range of characters.
35 of 36 people found this review helpful
- Ralph
- 25-04-12
Early career but well written
Obviously an "early" Hamilton. It reads smoothly and the narrator is pleasant, but he's still learning to develop his plots. This isn't the epic thriller you will come to love in the star flyer wars in the Pandora's Star/Judas Unchained series or the Void Series but you'll grow to like the characters and there's pretty good action mixed in to keep action junkies like me happy. If you like his style in his later books read this series and if you give it time it will grow on you, if you're not sure or a new reader of Peter F Hamilton, his later books are his best and these are simply good so whatever you do don't put these down and leave Hamilton until you've tasted the good stuff.
6 of 6 people found this review helpful
- Sumit G.
- 17-12-11
Good Spy Thriller / Sci Fi
What did you love best about Mindstar Rising?
New sci fi approach, unconventional and dysotopian future world. Mixed genre of scifi and detective without one being more dominant.
What did you like best about this story?
The psi abilities opened quite a few possibilities strands. It was quite coherent and the narrative stayed true throughout. Despite being a triology, it could stand on itself as a single sci fi / detective novel.
What about Toby Longworth's performance did you like?
His standard voice can be a bit grating, but overall was OK.
If you were to make a film of this book, what would be the tag line be?
Psi mutant detective vs greed in a dysotopian world.
Any additional comments?
It's a good book, once you get past initial scene setting. The last 3rd of the book was stretched - but that's a minor fault, if at all.
10 of 11 people found this review helpful
- Billy
- 04-02-12
The Psychic Detective of the Future
I remember reading an interview with Larry Niven where he explained that detective science fiction is hard to write due to how easy deus ex machina via technology is. When you consider this, Peter F. Hamilton does an incredible job. The main character has a gland that gives him a form of ESP, though it is more of an empathy enhancer that gives him insight into the emotional state of a person but also heightens his intuition. Another character can see the future. So the exploits are obvious but Hamilton does an incredible job of keeping these abilities realistic with clear boundaries so the story is not destroyed by technology. For instance, the character who can see into the future does not see future events but future possibilities. She determines likely outcomes by seeing how many versions of the future converge on a particular event.
This detective story focuses on industrial espionage and politics. There are some attempted murders with the most interesting attempt being on a computer that is essentially a downloaded human mind. The mystery, however, is a bit on the obvious side with me figuring out who the mole was long before the hero. Still, the future that is portrayed is very interesting and kind of scary when you look at the modern state of the world. Some people have described it as a dystopian future, but it is more of the beginning of a rebirth of the world after a dystopian age.
If you liked the other Peter F. Hamilton books available then you will probably enjoy this one, but I would recommend listening to Commonwealth series (Pandora's Star, Judas Unchained, and the Void trilogy) first if you have not already listened to them.
4 of 4 people found this review helpful
- Paul
- 14-01-12
Like Drinking From a Sci-Firehose
Peter F. Hamilton has more sci-fi imagination in his little typing finger than most authors have in their whole body! At times, it was all I could do to keep up with all the ideas and jargon he was throwing at me. Listening to the audio version makes it even more difficult to digest everything, so you'd better not try to listen to this book while operating heavy machinery.
Just listen to the first chapter and you will know that Mr. Hamilton is a certified sci-fi genius. He brings along some of the "inventions" from his previous books, but just enough to make you recognize his fingerprint. In this book, the scope is more narrowly contained to a single planet, which must have been like trying to keep Robin Williams on a single topic, but he does cover much of the planet (and the space above it, and below the surface of the water). This book pulls a few pages from The Windup Girl and Daemon, very smart. I can't wait for Book 2!
8 of 9 people found this review helpful
- Brian Rygaard Jensen
- 24-04-13
A pretty standard story with a predictable plot
Is there anything you would change about this book?
A lot of time was wasted listening to endless descriptions of the surroundings into minute detail. I found myself zoning out from boredom, and had to rewind a few times as something important was missed.
The stereo types were just too much. It was like reading a short story from a womans magazine. The rich beautiful is evil to the bone, the hero is a rightous guy and the game between them and their alles is predictable. I like a book where there are grays and surprises. None here.
Would you be willing to try another book from Peter F. Hamilton? Why or why not?
Perhaps. This is my first, and even though the story was easy to see through, it was still entertaining.
What did you like about the performance? What did you dislike?
The narrator was easy to understand. Sometimes when they have to portray a tough guy, he ends up sounding dumb as a door. I was left with that impression of the hero, even though he was quite smart.
Was Mindstar Rising worth the listening time?
I actually do not know. I would have listened to another more interesting story, but I still wanted to know how it ended.
3 of 3 people found this review helpful
- 15-04-13
Another great Hamilton listen!
Would you listen to Mindstar Rising again? Why?
I don't think so. The book is great, and the narration is excellent, but it isn't the sort of book that makes you THINK. Several of the authors' other stories are worth listening to several times, because they're complex and layered, and you always hear something a little different the second and third times you listen.
This book isn't like that; it's satisfying as it is, but not complex enough to require a second listen.
What did you like best about this story?
The fact that this book was released in 1993, right around the time that cell phones first hit the retail market, and yet the technology in it feels very "now".
What does Toby Longworth bring to the story that you wouldn't experience if you just read the book?
Being that I'm not British, I'm not sure how authentic any of his accents are, but to my Canadian ear, they SOUND perfect, and every character is distinguishable from the others.
3 of 3 people found this review helpful
- Sam
- 19-04-12
A post-climate change sci-fi detective thriller
All three of these stories are great, fast moving stories set in a world it is easy to believe in that still has plenty of surprises. Peter Hamilton is a master and it is great to have these three stories online now also. Highly recommended, although I think the first one was the best one.
3 of 3 people found this review helpful
- Mike.the.kraken
- 07-01-12
Near future scifi/spy intruige
Would you recommend this audiobook to a friend? If so, why?
Absolutely. I've been a fan of Peter F. Hamilton after going through his later works, and wanted more of his style - which is deceptively subtle, fast paced, and very engaging.
Who was your favorite character and why?
Greg Mandell - He's a few years removed from military service and while still retaining his edge, more human. He appreciates the way of soldiers without being reduced to a simpleton military mindset. Adding psi empathic abilities to a solider makes for really good reading.
What does Toby Longworth bring to the story that you wouldn't experience if you just read the book?
I had to look this book up again just to make sure Toby Longworth was the only narrator - he's simply fantastic! He gives each character not only a distinct voice, but also personality. He is smashing! One of the best readers I've ever come-across.
If you were to make a film of this book, what would be the tag line be?
You can't hide the truth from him...
3 of 3 people found this review helpful
- SciFi Kindle
- 17-02-14
Gritty Psy-cop takes on white collar CEO's
The key to my enjoying this PFH novel was to disassociate everything I'd previously read by the author in the Commonwealth Saga series. Here there are no alien threats or exotic stellar locations to explore. This story takes place in a far less optimistic, multi-point dystopian future where twin environmental and political disasters have stratified the class differences in society. The gritty tone is exemplified in the protagonist, psychic freelance mercenary Greg Mandel, a two-dimensional tough guy who uses the phrase "no messing" to end far too many sentences. The strength of this story is in the unraveling of a corporate mystery with turns and twists which explore most corners of Hamilton's dark future. It's a bit like watching a police procedural with psychic cops and some minor near-future SF tech peppered in. It compares quite similarly to Hamilton's other, separate, story- Great Northern Road- which features a similar investigation but has the added element of off world alien settings and more examples of action scenes. Much of the crime and conspiracy here are strictly white-collar, and it was hard to identify with the Mandel character or even sympathize with him during the only truly high-stakes, dangerous moments he endures in the climactic ten percent of the story, no messing.
2 of 2 people found this review helpful


text:
Rocket-propelled vehicles capable of travelling a kilometre or more in a ballistic 'hop' with propellants acquired from the Martian atmosphere offer the potential for increased mobility and planetary science return compared with conventional rovers. In concept, a radioisotope heat source heats a core or 'thermal capacitor', which in turn heats propellant exhausted through a rocket nozzle to provide thrust. A systematic study of the thermodynamics, heat transfer and selection of core materials for a Mars hopper was undertaken. The aim was to advance the motor design and assess technical risks and feasibility. Analytical and numerical motor models were developed; the former to generate thermodynamic performance limits, an ideal hop distance and plot a materials selection chart using simple explicit relations. The numerical model assessed the effect of core configuration and geometry. A hop coefficient Chop is shown to characterize the effect of core geometry independently of core material and temperature. The target hop distance of 1 km is shown to be robust. A moderate advantage to pebble-bed cores over a core consisting of straight channels was suggested. High-performance engineering ceramics such as boron carbide offer the longest hop providing the core temperature can be increased significantly above 1200 K.
1. Introduction
Exploration of the surface of Mars has been driven by a diverse but interlinked range of scientific objectives as wide ranging as geology, climate, radiation environment, the search for indications of biological life and identification of in situ resources to support future manned or long-duration missions. In addition to numerous static probes and orbital observations, mobile exploration conducted or proposed has used planetary rovers of generally increasing size, scientific payload and mission duration but no step change in raw speed or mobility (Zubrin et al. 2000; Shafirovich et al. 2006; Yu et al. 2010a,b). The European ExoMars rover (scheduled to commence surface operations in 2019) is expected to cover only 100 m d−1 on rough terrain (Grant et al. 2010). Among the most challenging of proposed future mission concepts are those aiming to collect and return a diverse range of material samples to earth for detailed analysis (Des Marais et al. 2008). Enhanced mobility therefore both is an enabling technology for Mars sample return (MSR) missions (Grant et al. 2010) and offers exciting new opportunities for scientific investigations. The Martian atmosphere is composed mainly of CO2 (Hunt 1974). Given this in situ resource, several authors have identified the potential for a ballistic 'hopping' vehicle using this CO2 as a propellant, proposing hop distances of 0.5–20 km (Zubrin et al. 2000; Landis & Linne 2001; Shafirovich et al. 2006; Yu et al. 2010a,b).
Zubrin et al. (2000) conducted an experimental study including bench tests of cold gas and heated thrusters and both tethered and free flights of a simple demonstration vehicle. The thruster took the form of a pre-heated bed of high specific heat capacity material in pellet form. The bed was heated electrically in the tests reported. The thermal storage concept was selected on the grounds of simplicity and projected performance. A feasibility study was performed on the thermal insulation required to maintain the hot-bed at a useful temperature and a preliminary insulation design proposed. Alumina, graphite and steel hot-bed materials were tested following initial heating to 973 K. In all cases, the performance fell short of initial predictions. The authors attribute this to difficulties in achieving sufficient heat transfer between hot-bed and propellant. Fundamentally, this work was an important early experimental concept demonstration, and proposed that a mature 'gas hopper' concept could be expected to achieve a hopping range of over 10 km. A further proposed concept (Landis & Linne 2001) sees solar-generated electricity used to split CO2 into O2 oxidizer and CO fuel, which is then burnt in a conventional rocket motor. The design hop range was 0.5 km. The use of in situ acquired CO2 as the oxidizer for a magnesium powder-fuelled motor has also been proposed (Shafirovich et al. 2006; Yu et al. 2010a). Analytical studies assessed the required masses of propellant and CO2 acquisition systems under various constraints. Key variables considered were the number and distance of 'hops', total mission duration, time undertaking science and power to mass ratios for the CO2 acquisition systems. In the case presented, the total mission duration is limited by the mass of fuel (magnesium powder) carried. These studies show total ranges of around 10–15 km, using between five and 15 hops, i.e. with a hopping distance of the order of 1 km. Because of the finite fuel resource, the total number of hops is limited. A hopper propelled by heated CO2 has also been subject to further thermodynamic investigation (Yu et al. 2010b) focused on obtaining the overall thermodynamic performance (including propellant acquisition) in terms of specific thrust and thrust-specific power consumption. Design variables considered were ambient temperature and pressure, temperature and pressure at the entry to the rocket nozzle (representing the motor performance) and the flow rate and compression ratio of the coolant in the CO2 acquisition cycle. Detailed design of the rocket motor, in particular heat storage and transfer, was not within the scope of this study. The basic concept proposed battery-stored electrical heating of the propellant as it passes through the motor. This represents a significant challenge and technical risk for battery technology and heat transfer surface design. A common challenge for all hopper concepts is achieving adequate energy storage and heat transfer in a sufficiently small mass to allow a useful hopping distance.
Radioisotope heating and thermoelectric energy systems are a well-established space technology (Bennett 1990; Lenard 2008), with radioisotope selection and novel encapsulation being investigated for the next generation of space nuclear power systems (O'Brien et al. 2008). Such techniques offer significant potential for both heating the core and powering the CO2 compression. In a radioisotope thermal CO2 propelled hopper, the thermal capacitor, or 'core', must store thermal energy as sensible heat and transfer this to the propellant. The simplest method of heating this material is to disperse the radioisotope through it using advanced manufacturing techniques such as spark plasma sintering (SPS; O'Brien et al. 2009). This approach has the advantage of inherent simplicity, reliability and longevity. The particular challenges are in heat transfer surface design and material selection.
This aim of the work presented herein is to assess the fundamental feasibility and performance of the radioisotope thermal CO2 rocket motor itself, identifying key performance targets and technical risks. The objectives are:
— To develop a basic thermodynamic and heat transfer model for the 'heat capacitor' core, which takes the concept of a radioisotope dispersed throughout the heat storage material as a basis but would also be applicable to cores heated electrically or by a remote radioisotope source via heat pipes.
— To compare 'channel' and 'pebble-bed' core geometries.
— To perform preliminary geometric sizing of the core for a baseline hopper vehicle configuration and assess the sensitivity to geometric parameters.
— To conduct a systematic materials selection of candidate 'heat capacitor' materials and assess the effect on performance.
This paper will not consider the detailed trajectory of the hopper vehicle, the thermal management requirements for the vehicle or motor or the time taken to acquire propellant or reheat the core for the next hop. The effect of the heat capacitor material on the radiation dose to personnel and equipment will be considered only qualitatively as a basis for future work.
2. Method
A schematic of the motor concept is shown in figure 1, indicating the station numbering convention adopted in modelling the motor. Two core configurations are assessed within the same overall motor geometry.
The channel core consists of straight channels through the block of heat capacitor material. For manufacture, the core could be constructed from a number of short subassemblies of hexagonal form that could be mechanically fixed or brazed together, a configuration previously adopted in space nuclear reactor concept studies (Lawrence 2008). Overall mechanical constraint would require thermally insulating load-bearing connections to the pressure vessel with appropriate allowance for thermal expansion. The pebble-bed core is a collection of spherical pebbles of heat storage material with the flow path formed by the interstitial voids between spheres. This configuration has been previously investigated for space nuclear reactor concepts (Lawrence 2008). Pebbles may be stacked in an ordered arrangement or allowed to arrange themselves randomly. They will be subject to overall mechanical constraint by grids permitting fluid flow at the top and bottom, and by grids or a solid channel wall at the side. As for the channel core, insulated load transfer to the pressure vessel will be required. Additional mechanical constraint could be achieved by joining the pebbles by brazing or welding. Both core concepts will present significant challenges in detailed mechanical design and manufacture, but this is not expected to significantly influence a first-order thermofluid performance model.
(a) Fundamental performance relations for a baseline Mars hopper concept
Using the station numbering convention introduced in figure 1 and assuming steady, isentropic flow of a perfect gas, the exhaust velocity of a convergent–divergent rocket nozzle is given by (Moss 1995) 2.1 where γ is the isentropic index of the propellant, R0 is the universal gas constant (J K−1 mol−1), TP3.1 is the temperature of the propellant at entry to the nozzle (K) and M is the molecular mass (kg mol−1). The ratio of nozzle to core exit pressure p3.3/p3.1 is a function of the selected nozzle geometry. The resulting thrust F and specific impulse ISP are given by (Moss 1995) 2.2 and 2.3 where is the total propellant mass flow (kg s−1), Asect,3.3 is the cross-sectional area of the nozzle exit (m2), pambient is the ambient pressure (Pa) and g0 is the gravitational acceleration at the surface of the earth (m s−2). The specific impulse allows the overall performance of a rocket-propelled vehicle to be determined via the Tsiolkovsky equation (Moss 1995) 2.4where ΔV is the change in vehicle velocity and R is the ratio of mass at the start of discharge to the mass at the end. By neglecting drag and gravity losses, assuming a ballistic trajectory and a launch angle of 45° with motor discharges at the beginning and end of the flight (where half of the ΔV is used for take-off and half for landing), a simple explicit indication of hopping range xhop is obtained from (Yu et al. 2010a) 2.5where g is the local gravitational acceleration, taken as 3.711 m s−2 on the Martian surface.
A conservative baseline Mars hopper vehicle specification is detailed in table 1. It was generated as part of a broader mission and systems engineering activity by assembling a basic mass budget using conservative sizing assumptions, generous maturity margins and using proven technology and approaches. The nominal design target was 1 km hopping range—even this conservative initial target represents an enormous increase in mobility over current rovers if it can be repeated approximately every few days. Table 1 also illustrates the design approach adopted in this paper. The fixed parameters will not be altered during the analysis while the core mass, materials and configuration form the design variables. The resulting performance parameters will therefore vary from the baseline values quoted in table 1 as the effect of the design variables is explored.
(b) Performance limits for a hopper propelled by stored thermal energy
It is desirable to develop expressions for the thermodynamic performance limits, both for validation of the numerical model and to identify opportunities to maximize the available performance. The approach adopted was to develop bounding expressions for the temperature at core exit TP3.1 assuming ideal heat transfer. When related to hopper performance via equations (2.1)–(2.5), these allow the effects of the core mass and material properties to be assessed.
For convenience, the specific impulse can be related directly to the propellant velocity at the nozzle exit by combining equations (2.2) and (2.3) and introducing the approximation of a simplifying specific impulse coefficient CISP, 2.6Combining equations (2.1) and (2.4)–(2.6) yields the following expression for the hopping distance: 2.7Performance envelopes can be derived by assuming that TP3.1 is equal to the initial core temperature TCinitial throughout the burn or by assuming overall heat balance between the propellant and core. Derivation of these relations is described in the electronic supplementary material and ultimately allows an ideal core mass mcore,ideal to be calculated, 2.8where cPcore is the specific heat capacity of the core material (J kg−1 K−1, weighted to reflect the different specific heats of radioisotope and encapsulant), mp is the total propellant mass (kg), cPgas is the specific heat capacity of the propellant in the gas phase, TPinitial is the initial temperature of the gas (K) and hlat is the specific latent heat of vaporization of the propellant (J kg−1). This allows equation (2.7) to be solved for the ideal maximum hopping distance xhop,ideal using mcore,ideal in the mass ratio R. The simplest solution assumes that TP3.1 is equal to the initial core temperature TCinitial. The ideal hopping distance is therefore an explicit function of design parameters and independent of heat transfer effects, making it easy to calculate even at a concept design stage. Non-ideal heat transfer and other practical effects will reduce the achievable hopping distance, perhaps significantly, from this ideal value. A hopping coefficient Chop is therefore proposed to relate the results obtained from the full numerical model to the performance limit. This provides a unifying terminology and method for future hopper design studies, 2.9
(c) Bespoke core thermal–hydraulic numerical model
The bounding expressions developed above do not include the effect of heat transfer or the variation in thrust and specific impulse through the discharge as the core cools and the propellant tank empties. A numerical model is therefore developed to provide a more robust simulation of the performance, and ultimately to estimate the hopping coefficient Chop for various geometric variables. The calculation approach, verification and validation of the model are further described in the electronic supplementary material.
The model uses a simple finite-element approach whereby liquid CO2 enters the core at vapour-line conditions from the tank. A stepwise integration of propellant enthalpy through the core length (z-direction) is performed using simple but appropriate heat transfer, friction factor and pressure-loss assumptions and correlations (Moody 1944; Gnielinski 1976; Swamee & Jain 1976; KTA 1981, 1983; Ozisik 1985; Incropera et al. 2007). Variations of core temperature are calculated in finite steps in the time domain using heat balance. The aim of the model is to provide a good system-level representation of the performance appropriate for early-stage conceptual design. The solution is iterative to allow for variations of material and propellant properties with mean temperatures and the variation in mass flow rate during the discharge. The overall specific impulse of the motor is used to determine hopper performance via equations (2.4) and (2.5). It is given by a sum of the impulse over each time step (Moss 1995) 2.10
(d) Material properties
Materials property expressions suitable for application at the relatively high temperatures of interest were collated from a variety of sources including the literature and supplier datasheets. Polynomial expressions describing property variation with temperature were either obtained directly from the literature or generated by a least-squares fit to tabulated data. Primary data sources suitable for concept studies were obtained from the open literature for the CO2 propellant (Kaye & Laby 1995; Union Engineering 2007; National Institute of Standards and Technology 2008) and encapsulant materials (Neely et al. 1950; Roth 1982; Karditsas & Baptiste 1995; International Nuclear Safety Centre 1997; Basak et al. 2003; National Institute of Standards and Technology 2008; Dorn et al. 2009).
3. Initial heat capacitor material selection
(a) Thermal energy storage
Material property charts can be plotted for a very wide range of mechanical, thermal and other material properties (Ashby 1992). Their value stems not only from selecting and comparing a database of material properties for a given duty, but also from identifying strategies for expanding the range of properties by modifying the chemistry, microstructure or architecture of a material (Fleck et al. 2010). The aim of the current study is to undertake preliminary materials selection based on the requirement for storage of sensible heat. There is a wealth of potential for extending this approach to encompass mechanical properties, and to guide extending the property space through a number of materials engineering techniques (including composite materials) should the hopper concept progress.
Meaningful material property selection requires an appropriate understanding of the influence of materials properties on system-level performance (Ashby 1992). The explicit thermodynamic performance boundaries generated above can provide this direct input via solutions of equations (2.7) and (2.8). The key variables that will be intimately linked with properties of the core material are TCinitial and cPcore. The ideal maximum hopping distance xhop,ideal was calculated for a range of values of these variables and found to be a close approximation to 3.1where A and B are constants, functions of the propellant and baseline hopper properties. For a CO2 propellant and the hopper properties in table 1, a least-squares fit gives A=0.840, B=−1.46. Intuitively, the energy limit on hopper performance is maximized by selecting a material with both a high specific heat capacity and a high melting point. The latter allows an increase in TCinitial up to some limit that, in practice, must be some way below the melting point of both radioisotope fuel and encapsulating heat capacitor material. A selection criterion S can be derived directly from equation (2.1) by incorporating representative temperature constraints 3.2where cP is the specific heat capacity of the material (J kg−1 K−1), TEmelt is the melting temperature of the encapsulating thermal capacitor material (K), TEmeltmargin is a margin applied to this melting temperature (K), TFmelt is the melting temperature of the radioisotope fuel (K) and TFmeltmargin is the corresponding margin (K). An alternative practical constraint could readily be substituted for the fuel limit term if required. Figure 2 shows contours of increasing S plotted by rearranging equation (3.2).
Beryllium, its nitride, oxide and carbide compounds, boron carbide and nitride and graphite are the group of materials offering generally the highest performance in figure 2. The shape of the contours is due to the temperature constraints imposed—in the left-hand region of the plot, the performance is limited by encapsulant melting, and in the right-hand region, fuel melting provides the limitation. As a result, increases in encapsulant melting temperature do not offer improved energy storage above the limit represented by the flattening of the S-contours.
A notable conclusion from figure 2 is that high-performance metal alloys—with the exception of beryllium—and refractory metals offer generally very poor thermal storage performance compared with high-performance engineering ceramics.
(b) Mechanical requirements
The core material is not required to carry primary spacecraft or motor loads or form part of the pressure vessel. The major load case for the core is expected to be thermal shock as a result of rapid temperature changes during the discharge. Thermal shock resistance is a function of material and component geometry, thermal conductivity and coefficient of linear expansion (Katz 2002). A thermal–mechanical materials selection may be pursued in a later phase of work. The approach adopted in this paper is to evaluate a wide range of candidate materials to mitigate the risk of any one factor, including thermal shock resistance, affecting the feasibility of the hopper concept.
The principal safety requirement for deployment of a radioisotope power source in space is containment of the radioisotope under heating and impact loads associated with launch vehicle failure, inadvertent spacecraft re-entry and consequent ground impact (Bennett 1990; Lenard 2008). To date, radioisotope thermal generators have used multi-layered configurations consisting of carbon/graphite ceramic matrix composite ablative 'aeroshells' and refractory metal containment shells. Iridium-alloy-welded vessels have been successfully applied in this role (Lynch 1998), while encapsulating the isotope in a tungsten matrix was evaluated at laboratory scales as an alternative approach (O'Brien et al. 2009). The encapsulating thermal capacitor material could form part of the containment system. Equally, the multi-layered configuration adopted to date provides sufficient design flexibility that this is not an essential feature of the initial material selection. The approach adopted was to operate all thermal capacitor materials at a nominal margin (TEmeltmargin=350 K) below their melting temperatures and assess the sensitivity of performance to larger margins. Refractory metals and metal alloys may also have a significant role as surface coatings to manage corrosion and reactions with the CO2 propellant. In these contexts, their contribution to the overall thermal storage capability will be negligible.
(c) Nuclear property requirements
A further desirable feature of the encapsulating material is that it should not increase the overall radiation dose to vehicle instrumentation or assembly and integration staff by releasing neutrons in response to alpha-particle flux (α,n reaction) from the radioisotope (O'Brien et al. 2008). Furthermore, an encapsulant that is a strong neutron absorber may provide more flexibility in selection of radioisotopes previously discounted on account of higher neutron emission fluxes owing to (α,n) reactions or spontaneous fission, e.g. curium-244.
(d) Material design cases
In order to assess Mars hopper vehicle performance, assess sensitivity to enforced selection of a non-optimum material and validate the materials selection approach, four material design cases were selected based on figure 2 and the general requirements of §3b,c above.
(i) Beryllium
Beryllium, or its alloys, offers the highest specific heat capacity at the expense of relatively low melting temperature and significant health, safety and environmental concerns. Exposure limits, focused on inhalation of dust or machining debris, are in place for workers exposed during manufacturing (Fulton & Goldberg 2009). The European Space Agency explicitly lists beryllium as a safety hazard and prohibits its use without prior approval on low-gravity platforms (Ceglia et al. 2005). To perform a role as a thermal capacitor, significant quantities of material will probably be required, so selection of this material could be considered a significant technical risk. A further disadvantage of beryllium is the characteristic (α,n) reaction in response to flux from the radioisotope and small neutron absorbance cross section: the very effect from which the neutron itself was discovered (Chadwick 1932; Martin 2006; Goldberg 2009). Additional shielding or an interface material between the dispersed radioisotope particles and the encapsulant would, therefore, be required to reduce radiation dose to instruments or assembly staff. Beryllium has nevertheless been proposed in previous hopper studies (Zubrin et al. 2000) and is included as a reference case for motor sizing.
(ii) Boron carbide
Boron carbide is representative of a number of high-performance ceramics that achieve the highest value of S based on the assumptions used in plotting figure 2, i.e. providing the thermal capacitor can be operated up to around 1800 K. Boron carbide is an established high-performance ceramic in relatively widespread use. Of notable interest is that boron carbide sees widespread application in nuclear reactor control rods owing to its large neutron absorption cross section (Thevenot 1990). Boron carbide is also compatible with advanced manufacturing techniques such as SPS (Hayun et al. 2010), which has been proposed as a particularly promising manufacturing process for encapsulated radioisotope fuel (O'Brien et al. 2009).
Boron nitride, graphite and beryllium compounds have broadly comparable thermal storage performance, with advantages and disadvantages in each case. The overall hopper performance for this group of core materials will be well represented by boron carbide.
(iii) Silicon carbide
Silicon carbide is broadly representative of a number of engineering ceramics that do not achieve quite the thermal performance as the options above, but could nevertheless provide a viable solution. This group includes alumina and silicon nitride, and more exotic options such as beryllide and diboride compounds. The diborides are likely to have the advantage of neutron absorption common to compounds containing boron. Owing, in part, to good thermal shock resistance, silicon nitride has been applied for complex, load-bearing components in automotive turbocharger and aerospace auxiliary power units with temperatures exceeding 1100 K (Katz 2002): up to 1580 K has been reported in a small-scale rocket nozzle test (Eckel 2000). Silicon carbide is selected to represent this group of materials as a design case to provide a quantification of the impact of the risk that boron carbide or an equivalent is unsuitable and to validate the materials selection technique.
(iv) Titanium alloy (6Al/4V)
Aerospace-grade titanium alloy is relatively inexpensive and representative of the highest value of S achieved by the conventional high-performance metal alloys. It is included as a design reference case and to validate the materials selection technique.
4. Results and discussion
(a) Channel core geometry
The key overall geometric design variables for any core configuration are the overall diameter D and length Lcore of the core. This study is confined to cores of cylindrical form. For the channel configuration core, the channel diameter d and surface roughness δ are the key design variables. A series of solutions of the bespoke model were undertaken to explore the effect of these variables on the baseline hopper vehicle detailed in table 1. The channel spacing was nominally set at 2d, which is a physically realistic limit (illustrated in finite-element models presented in the electronic supplementary material). Material properties were determined for a core material consisting of a fixed mass of the dispersed radioisotope giving a power output of 1 kW encapsulated in a varying mass of beryllium. The initial mass flow rate was selected to achieve a constant thrust-to-weight ratio at the start of discharge (i.e. for take-off) as a representative system-imposed constraint. The varying core mass was used in determining ΔV and, therefore, the estimated hop distance, xhop. These assumptions are intended to ensure that the optimization is, as far as possible, representative of the overall vehicle system. An initial core temperature of 1200 K was assumed, some 350 K below the melting point of beryllium in accordance with the assumptions used in plotting figure 2.
Figure 3a shows solutions of the numerical model for various combinations of core diameter and length. The agreement with the trends represented by the performance envelope is good at higher core mass where the core is sufficiently massive to ensure that the specific impulse through the burn is relatively constant. At low masses, however, the performance drops below the lower performance boundary. Small-diameter cores offer a longer hop for a given core mass. A reasonable hypothesis is that the greater length of small-diameter cores gives greater length for heat transfer to the propellant, resulting in higher nozzle entry temperatures and, therefore, overall specific impulse. It is important to note that a long, thin configuration for the core would result in disadvantages in thermal insulation design and practicality of integration.
The effect of a range of channel diameters and surface roughness is shown in figure 3b. The roughened tubes are assumed to incorporate a relative roughness δ/d=0.01. This is the limit of applicability of the correlation applied (Swamee & Jain 1976). The effect of channel diameter and roughness on heat transfer is clearly indicated as the curves approach the upper thermodynamic performance limits. The improved heat transfer also shifts the optimum geometry to a shorter core, which would be expected to ease integration. Rough surface results for a larger 10 mm channel are included, and show comparable, or better, performance to a smooth-walled 6 mm channel. The significance of these data is that manufacturing or vehicle integration constraints imposed on channel diameter or overall core length can be offset with the addition of surface texture. The roughness added in these calculations is a conservative first estimate limited by the surface friction relationship selected for the model (Swamee & Jain 1976). In the rough-wall data presented in figure 3b, the surface friction factor f is between 1.38 and 1.83 times the smooth-wall value. Incropera et al. (2007, p. 485) quote that, in practice, and given an appropriate correlation, f can be increased to four times the smooth-wall value in any given condition to further improve the heat transfer coefficient. This is significant because it suggests that heat transfer enhancement by surface texture changes offers further potential for improving performance in light of practical constraints likely to be imposed on the motor design. Heat transfer enhancement options for a straight channel include machined grooves, rifling, fins and coil inserts. Many of these approaches have been characterized in detail and further analysis approaches and experimental data are available (Incropera et al. 2007, pp. 491–494).
(b) Pebble-bed core geometry
For the pebble-bed core, the key geometric design variables are the overall diameter D, length of the core Lcore and pebble diameter d. The sensitivity to these variables was explored in a very similar manner to the investigations undertaken on the channel core, using a beryllium heat capacitor material initially at 1200 K. The pebble diameter d is limited by the validity of the heat transfer and pressure-loss correlations (KTA 1981, 1983) to be less than approximately D/20. The total number of pebbles was selected to achieve a bed porosity (void fraction) of 0.39. This is in the middle of a correlation validity of 0.36–0.42 (KTA 1983), which is itself in good agreement with studies on porosity limits for beds of randomly stacked spheres (Song et al. 2008). The sensitivity of the hopping distance to porosities of 0.36 and 0.42 was assessed using the model. There was negligible difference in performance to assuming a fixed porosity of 0.39.
Figure 4a shows the influence of core size on the hopping performance for the baseline design. The performance of a core formed of 10 mm diameter pebbles is similar to one with 2 mm diameter channels. The latter would be expected to represent a more significant manufacturing challenge. The drive for a thin, long core remains, but is a weaker design driver than in the channel core configuration. Importantly, a compact pebble-bed core 0.35 m in diameter and length still offers Chop=0.85, a significant improvement on the trends shown in figure 3. The effect of pebble diameter is examined in figure 4b, with smaller pebbles offering longer hop distances. Higher values of heat transfer coefficient were noted and account for this improvement. The practical limits to the utility of this conclusion include the manufacturing of such pebbles, but perhaps more significantly the difficulties in accurately accounting for the total inventory of the radioisotope during manufacture and assembly. The effect of surface roughness was not considered as this effect is not included in the correlation selected, but may provide further increases in heat transfer coefficient for a given pebble diameter.
(c) Core and propellant temperature distributions
The variation in core and propellant temperatures for the pebble-bed motor with overall diameter D=0.2 m and pebble diameter d=10 mm is discussed in detail in the electronic supplementary material. Achieving maximum values of hop distance requires a core with sufficient mass and length to achieve sufficient energy storage and heat transfer to maintain a consistently high propellant temperature at core exit. Figures 3 and 4 show some configurations where xhop drops below the lower performance boundary; this is on account of inadequate heat transfer.
(d) Effect of material and initial core temperature
To assess the effect of different materials, two geometric design cases representative of channel and pebbled bed geometries with relatively low manufacturing risk were used. Both cases featured a core of overall diameter D=0.2 m. Rough-wall channels of diameter d=6 mm and pebble diameter d=10 mm were assumed for the channel and pebble configurations, respectively. The four material design cases identified in §3d were assessed at a number of temperatures up to the limiting temperatures determined in equation (3.2). The pebble-bed configuration was evaluated only with the beryllium and boron carbide encapsulants.
Figure 5a shows a number of performance curves and the corresponding upper performance envelopes for the channel core configuration. The materials are operated at their limiting temperatures as defined by the first term of equation (3.2). The pebble-bed core results show a very similar trend. The numerical results show excellent agreement with the materials selection chart of figure 2, with the relative hop performance closely matching the relative values of selection metric S. Figure 5a also shows that titanium alloy and silicon carbide require a notably larger core mass (approaching twice that of beryllium and boron carbide) for maximum hop distance. It is important to reiterate that this mass is already incorporated within the maximization of hop distance. The analysis has not, however, considered the second-order effect of a large increase in core mass on other items in the hopper vehicle mass budget—for example, the structural mass could increase to support higher inertia loading from a heavier core. Additional mass constraints are also likely to be imposed by the Earth launch, Mars transfer and atmospheric entry systems.
Figure 5b shows the predicted performance for all material and temperature data points generated using the two geometries. It is shown that Chop can, for practical engineering design purposes, be considered independent of material and initial core temperature, and a function of the core configuration and geometry. This is an important simplification that has significant utility for conceptual design, material selection and in the preparation of a structured programme to experimentally validate designs and methods in the future.
Figure 5c effectively draws together all the results presented to explore the effect of initial core temperature in more detail. The materials selection approach described in §3 and figure 2 incorporated assumed temperature constraints; these are extremely difficult, if not impossible, to define with confidence at an early stage of concept development. It is reasonable to consider that the core temperature may be limited by any one of a number of additional factors. For example, assume a pebble-bed core of Chop=0.90, the baseline hopper configuration in table 1 and an initial core temperature limited to 1000 K, similar to that already experimentally demonstrated at the laboratory scale (Zubrin et al. 2000). In this case, beryllium offers the longest hop at 1.04 km while an enforced change to boron carbide only reduces the hopping distance to 0.96 km—a fairly modest impact. If the limitation is related to the encapsulant material itself, some increase in design temperature is likely to be possible with boron carbide, which has a much higher melting point than beryllium. It is interesting to note that a boron carbide core requires an increase in temperature to only 1075 K to match the performance of the beryllium core at 1000 K. Refined temperature constraints could readily be used to replot the S-contours to repeat the materials selection.
(e) Impact of simplifying assumptions
The analysis in this paper assumes no gravity losses, and optimizes hop distance without considering external mass constraints such as those imposed by initial launch. Based on the current hopper vehicle parameters, it was estimated that gravity losses could reduce the hop distance by up to 0.2–0.5 km. However, the potential for minimizing this effect via increasing motor thrust and optimizing vehicle trajectory was not within the scope of the studies conducted to date. The main objectives of this work relate to comparative studies of motor design details and confirm, in broad terms, that the target hop distance of 1 km is feasible. Future work will refine the estimates of vehicle performance by incorporating these effects.
5. Conclusions
This study has systematically considered geometry design variables and materials selection for the stored thermal rocket motor propelling a ballistic Mars hopping vehicle. The study was based on a conservative baseline vehicle specification with a target hopping distance of 1 km, but the models developed are sufficiently general to have wide applicability.
Analytical expressions have been developed to describe an ideal thermodynamic performance envelope for the combined system of a Mars hopper and a stored thermal rocket motor. An ideal hopping distance was determined from simple vehicle and material properties using explicit relations (equations (2.7) and (2.8)). These should prove useful engineering design tools for future hopper concept development.
A bespoke numerical model based on proved and/or conservative correlations and assumptions was developed to investigate the combined system performance of motor and hopper in more detail and demonstrated adequate heat transfer between the core and propellant in practically realizable configurations.
A hopping coefficient Chop was proposed to link the maximum hopping distance determined from the numerical model with the analytical ideal (equation (2.9)). This coefficient was shown to be effectively independent of core material and initial core temperature in the range of interest. It is therefore primarily a function of heat transfer efficiency and can be used to compare the effect of core configurations and geometry.
The hopping coefficient of vehicles with channel configuration cores is increased by smaller channel diameters (where the spacing between channels scales with channel diameter) and surface roughening. There is further scope for enhancing performance using greater relative surface roughness or surface features such as rifling. Manufacturing complexity will impose a practical limit.
The hopping coefficient of vehicles with pebble-bed configuration cores is increased by smaller pebbles (where the overall porosity of the bed is constant). Manufacturing complexity and nuclear material accounting requirements for radioisotope material when encapsulated into numerous small pebbles may impose a practical limit.
Within the assumptions of this work, practical pebble-bed configurations yield values of Chop approximately 10 per cent higher than practical channel configurations, owing mainly to better heat transfer. Both configurations are viable from the thermofluid viewpoint. Optimum cores in both configurations are significantly longer than their diameter, i.e. with L/D≈4. The pebble-bed configuration is more tolerant to reductions in this value, which may give more flexibility for vehicle integration.
A materials property chart was plotted from the explicit performance expressions and used for preliminary core material selection. There was excellent agreement with the results of the full numerical modelling. The selection metric incorporated practical temperature constraints, and, while the assumptions are relatively arbitrary at this stage, entering new constraints and assessing the effect on materials selection will be relatively trivial as the concept matures.
Boron carbide and a number of alternative engineering ceramics with comparable thermal properties provide a range of viable alternatives to beryllium for the heat capacitor material. If the initial design temperature of the motor core can be increased significantly above 1200 K, the predicted hopping distance is significantly increased with the use of boron carbide compared with beryllium. Several other advanced engineering ceramics would be expected to offer similar performance to boron carbide, which should be seen as a significant reduction of technical risk.
Overall, achieving the hopping range target of 1 km is not critically dependent on a single motor configuration, core material or geometric parameter. A radioisotope thermal thruster represents one of the most novel aspects of the Mars hopper concept, and will rightly be regarded as a technical risk during development. That the thermofluid design appears relatively robust is an important conclusion, albeit one that will require much further work as the concept develops.
The authors gratefully acknowledge the funding provided by EPSRC via grant EP/D030277/1, the input of overall system parameters by M.-C. Perkinson, J. Reed & L. Waugh (EADS Astrium) as part of the Mars hopper system studies and S. Howe and R. O'Brien (Centre for Space Nuclear Research, Idaho National Laboratory) for useful discussions. Thanks also to P. Samara-Ratna for assistance with finite-element modelling. The authors would also like to express their thanks to the reviewers for their suggested improvements.
- Received August 20, 2010.
- Accepted October 11, 2010.
- This journal is © 2010 The Royal Society

subset: commoncrawl


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After completing her residency, Dr. Petersen spent several years with the Indian Health Service. She was based out of Shiprock, NM, on the Navajo Nation. She then returned to Minnesota and has been engaged in providing healthcare for diverse populations, including Hmong, Somali, and Hispanics.
Dr. Petersen is an Assistant Professor of Family Medicine and Community Health at the University of Minnesota School of Medicine.
Medical School
- University of Wisconsin Madison, Madison, WI, USA
- Family Medicine, Hennepin Healthcare, Minneapolis, MN, USA


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New John Lennon film to premiere at Abbey Road on the River
Louisville, KY (May 11, 2010) -- "Let Him Be," a film written, directed and composed by Peter McNamee, will make its U.S. premiere at this year's WHAS-11 Abbey Road on the River in Louisville, Kentucky on Friday, May 28th at 11:00am at the Galt House Hotel. This intriguing new, critically acclaimed Canadian film will also be shown during the festival on Saturday, May 29th at 11:00am and Sunday, May 30th at 4:00pm. There will be a Q&A session with the director after each screening.
In "Let Him Be", two film students discover something uncanny on a tape found inside an old video camera bought at a garage sale in a remote northern Canadian town. It contains a brief clip of an old man who bears more than a passing resemblance to an older John Lennon. Is Lennon alive and living? The two become fixated. Could it be him? It's an absurd idea that they might have passed off if it were not for the fact that the man also sounds so much like Lennon.
Did John Lennon stage his own death to live a life of anonymity in his second-favorite nation? The filmmakers decide to uncover the truth. With hidden body cameras, wireless cameras and surveillance cameras, the viewer gets to experience first-hand the possibility that history deceived us. Illusion and reality tangle and swirl on this remarkable journey of discovery.
The documentary film "The Mayor of Strawberry Fields," a chronicle of the quirky life of a homeless man named Ayrton "Gary" Ferreria dos Santos Jr. who has been decorating John Lennon's "Imagine" memorial in Central Park for the past 15 years, will also be shown at this year's WHAS-11 Abbey Road on the River. Gary's work has been documented in the New York Post, and his income comes from the tips he receives from tourists as a result of his work, and the three-minute monologue he delivers to tourists that describes his work and the life of John Lennon and his family. Produced and written by Buffalo, NY born filmmaker Torre Catalano, the film will be shown on Friday, May 28th at 3:00pm and on Saturday, May 29th at 2:15pm.
WHAS-11 Abbey Road on the River, a five day music festival celebrating the greatest rock band of all time, will be held at the Belvedere and Galt House Hotel in Louisville, Kentucky from May 27th to May 31st. Tickets for the world's largest Beatles tribute festival are currently on sale at www.abbeyroadontheriver.com or at three Louisville retailers - The Louisville Visitor Center, 301 S. 4th Street, The Great Escape, 2433 Bardstown Road, and Hard Rock Caf'e, 424 S. 4th Street. Families who want to take advantage of a money saving incentive need to purchase tickets in advance in order to receive free admission for one 21 and under guest with each regular ticketholder.
WHAS-11 Abbey Road on the River, a Kentucky Tourism Council Top 10 Spring Festival, is sponsored by WHAS-11 TV, The Galt House Hotel, the Louisville Convention & Visitors Bureau, 107.7 SFR Classic Rock, The Courier-Journal and www.courier-journal.com, with additional support from Republic Bank, Gretsch Guitars, Magic Hat #9 Brewing Company, WFPK 91.9, Hard Days' Night Hotel Liverpool, Metro Louisville, Hard Days' Night Shop Liverpool, DuPont Manual High School, Sivori Catering, Brightside, and Go Green Louisville.
Published May 11, 2010
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Westcott 2006-WESTCOTT
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The MERET project, run by the Ethiopian government and WFP, helps poor farmers manage land better, so that it becomes more productive and does not become desert. Hiwot Gebre-Tsadkan, one of MERET's beneficiaries, explains how it changed her life. Watch video
ADDIS ABEBA -- Hiwot, who lives in the Abraha Atsbaha region in Northern Ethiopia, says she realized what the MERET project could do when the local community helped her build a well outside her house.
"It gave me access to water, changed my life," says the 35-year-old single mother of three as she prepares cabbage with tomatoes from her garden for breakfast. "The money I received from selling guava and lemon allowed me not only to send my children to school but also to build a house," she added.
Until a few years ago, most people in Abraha Atsbaha were not able to produce enough to survive. The land was degraded, covered by sand and full of gullies. Many people simply left.
Rewriting the book
"Ethiopia has rewritten the book on successful climate adaptation with the MERET project," said WFP Executive Director Josette Sheeran during a presentation of MERET at the COP15 Climate Change Conference in Copenhagen. Watch video
Private sector support
WFP's first Asian corporate partner, LG Electronics, supports WFP's work in Ethiopia via a number of communities called "LGE Hope Villages". Read more
Improve land
But when the MERET project (Managing Environmental Resources to Enable Transition) took off, offering people food assistance and a way to improve their land, they started to come back.
Working with local administration and development agents, the community started the MERET interventions by building terraces and check dams in the surrounding hills to stop water from carrying away soil and to increase the level of the water table.
As the ground water level rose, the community built shallow wells near their homes which allowed them to grow different fruits and vegetables. The land productivity improved steadily and the community decided to use Food for Work activities to construct roads to transport their yields to the markets in surrounding villages to increase their income.
Production increased
With the well in place, Hiwot's fruit and vegetable production increased year by year and so did her income. In the meantime she bought several cows, pays for her brother's university education and she covers all of her mother's expenses.
Hiwot participated in many of the MERET activities and she recalls suffering a lot from carrying the stones from the surrounding hills to the gully to construct the check-dam but back then it was only thanks to the food rations she received as a compensation for her work that she and her family had something to eat.
"I don't know where my children and I would be without MERET," Hiwot declares. "If the children are smart enough, they are going to make good use of their education and get a better life, if they are not able to make it, they can come back here and expand the farm I have and improve it. They won't suffer like I did."


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On July 2, 2010, Lee Jenkins left this life. In his 65 years he worked hard and traveled and explored extensively. He made friends everywhere he went. He did more than just create a comfortable and homey bed and breakfast; he truly enjoyed the many people who came as guests and left as friends.
A talented and creative photographer and avid gardener, his photos are often sold as greeting cards and his flower garden will always inspire awe. He had a broad knowledge of geologic history and a passion for collecting rocks and fossils. He grew up in Canby, Ore., and came to Hood River in the 1960s.
Lee was always kind and generous with everyone. His boundless joy for life included a love of nature and above all, the deep and abiding love for his wife, Linda, his many friends and his children, Warren and Molly. His spirit will live on in the memories of all those who knew him. He will be missed by many.
In lieu of flowers, please send a contribution to the American Cancer Society.
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What is From Around The Web:
Threat Classification: PUP/adware
If your web browser start showing you lots of unwanted web Ads by From Around The Web, our security research team strongly recommends you to run a malware system scan using an up-to-date, reputable & reliable anti-malware software like SpyHunter 4. Our malware research experts found out that these From Around The Web Ads are caused by a malicious browser extension called From Around The Web, that is capable of infiltrating various computers without asking for user's permission or any consent. After performing multiple experiments and tests, our security researchers concluded that this malware infection has been designed and developed to earn revenue for its developers by directly injecting the html code (sponsor ads/links) into the requested websites, which basically will lead to website look & feel alteration. After performing further tests, our security researchers discovered that the adware collects various private information from the victim's computer including Web Searches, Browsing History & Information, Usernames & Passwords, E-mail addresses, Cookies, Location History, Names, SSN, Credit Card information and/or other private financial information and even online banking accounts information, which later will be either sold or shared with some 3rd party company, that will use your private data for their own marketing purposes. Our security experts warned us, that even though From Around The Web claims to provide many useful & handy features, however it has been classified as a dangerous adware and/or a Potentially Unwanted Program (PUP) by the majority of the reputable malware researchers. It seems that the adware contains a malicious browser extension, distributed mainly via suspicious or even questionable software bundles, often configured to install the From Around The Web by default using silent or stealth mode, hiding it from the users. This kind of adware has been used by malware developers to generate income by showing sponsor links or ads on almost every web page, requested by the victim. If your display starts getting overflown by these annoying ads "by From Around The Web" , "Ads by From Around The Web", "From Around The Web Ads", "Ad by From Around The Web", "Powered by From Around The Web", "Brought by From Around The Web", "Optimized by From Around The Web" or "Brought to you by From Around The Web" – you should consider your computer infected by the From Around The Web adware. Please note, that all of these ads, shown by the From Around The Web extension should NOT BE considered SAFE and we strongly advise you to avoid interacting and/or clicking on them! After performing multiple tests and experiments, our malware researchers came to the conclusion that From Around The Web works fine with all the well-known web browsers like Internet Explorer, Mozilla Firefox and Google Chrome.
Generally, users that have it installed on their computers might experience various pop-up or pop-under ads, coupon boxes, banners, search suggestion windows, sponsored link advertisements or other commercials, displayed on almost all requested web pages. Please note, that the search results should be considered compromised as well, usually filled with 3rd party advertising and SPAM.
From Around The Web is usually bundled with some other free ad-supported software products and is being installed by default while performing an express/default installation, right after the user accepts the EULA. That's why we strongly advise you to always opt-out and use custom installation if possible and if it's available, you should always deselect/exclude all of the unwanted software programs from the bundle installation process. You should leave selected (included) for installation only the initially requested software. The possible distribution of From Around The Web varies but is not limited to – installing 3rd party toolbars, free software products, video editing software, various multimedia codecs, downloading e-mail attachments, clicking suspicious ads or banners etc.
The main goal of From Around The Web is to generate as much web traffic as possible, that could easily be monetized via one of the many online marketing platforms. Please note, that the creators of that or similar adware will collect private information from your computer, that might be used to track your browsing habits, IP addresses, Bookmarks, Usernames, Passwords and even financial information, however often they collect much more than just that. That's why this infection should not be left unattended, and needs to be terminated immediately, as it presents a serious threat to your online, personal and financial safety.
!!! Please note, that these infections could potentially bring up other malware to your computer and even cause data loss. Please, do not underestimate such threats!!!
Removal Process:
There are two ways to remove this infection. It is totally up to you to decide which way you want to go:
1. Automatic Removal Method (recommended for ALL users) using the SpyHunter Malware Security Suite.
2. Manual Removal Method (recommended ONLY for PC Experts or Enthusiasts).
Automatic From Around The Web Removal:
We recommend using SpyHunter Malware Security Suite.
You can download and install SpyHunter in order to detect From Around The Web and remove it, by clicking the download button below. Once installed, SpyHunter will automatically initiate a malware scan, that will detect all present threats on your system, but to unlock the full potential of the SpyHunter Anti-Malware Security Suite and use it as a removal tool, you need to have an active subscription.
SpyHunter will automatically scan and detect all the present threats on your computer.
Learn more about SpyHunter (EULA). You can find more about the SpyHunter Installation Process. SpyHunter`s free diagnosis offers unlimited free scans and detections. You can remove the detected files and registry entries manually, by yourself, however we strongly advise you to purchase a subscription that will allow you to use the automatic removal feature and to get unlimited one-on-one professional phone or remote support for any malware related issues by an expert technician.
Manual From Around The Web Removal:
!!! Please note: You can remove From Around The Web Adware manually, although you should proceed at your own risk. Any of the below-mentioned interventions might render your system inoperable. Therefore the Manual Removal Method is recommended ONLY for PC Experts or Enthusiasts. For all the other users, MalwareKillers.com recommends using SpyHunter.
1. Remove From Around The Web Uninstall Entry:
First, you can try to go to Control panel and click on Programs and Features (Windows Vista/7/8/10) or Add/Remove Programs (Windows XP) and check the Uninstall Programs` List for all entries related to From Around The Web, StartNewTab.com, NewPopTab.com, Shopperz, MPC Cleaner, Sonic Train, BrowseAir, Bestadblocker, CheDotGame.com Hijacker, Magical Find, Space Sound Pro, DNS Unlocker, High Stair, Coupon Time, CutThePrice, FunDay24.ru, Smartsputnik.ru, iReview, Obrona Blockads, GamesFlight, Facts Right, YoutubeAdBlocker, 1ClickDownload, Yontoo, Space Sound Pro, Video Converter Toolbar, SafeSurfs.com, SafeSaver, BetterSurf, PassShow, Feven Pro, Couponpeak or any third-party add-on, extension and toolbar. We strongly advise you to look for any suspicious programs, installed on the same date as the infection, because most likely they came together via some software bundle. If you find something – right-click on it and try to uninstall it. Although, please mind that these are actual infections and you might not be able to remove them directly from the list.
*(Start -> Control Panel -> Programs and Features or Add/Remove Programs) or "Win + R" keys to open "Run" and type in "control", then hit Enter.
2. Remove From Around The Web from your browser:
Internet Explorer:
Go to Tools -> Internet options -> Advanced Tab and click the Reset button (make sure to select the Delete Personal Settings checkbox).
*please note that in order to save your favorites, you need to export them before resetting the browser as you will lose all personal settings.
After Internet Explorer completes the operation, click the close button and then restart browser it for the new changes to take effect.
Google Chrome:
Go to the following path (you can copy-paste it) and delete the entire "Chrome" folder with all its content – including all the files and all the subfolders.
For Windows XP: %USERPROFILE%\Local Settings\Application Data\Google\
For Windows Vista/7/8/10: %USERPROFILE%\AppData\Local\Google\
Alternatively, you can navigate to these folders by following these steps:
For Windows XP:
1. Click on "Start" in the bottom-left part of the screen.
2. Choose "Run".
3. Type %USERPROFILE%\Local Settings\Application Data\Google\ and hit Enter.
For Windows Vista/7/8/10:
1. Click on the Windows logo in the bottom-left part of the screen.
2. Type %USERPROFILE%\AppData\Local\Google\ and hit Enter.
Mozilla Firefox:
1. At the top of the Firefox Main window (top-right corner), click the Firefox Menu button, go over to the Help sub-menu and select Troubleshooting Information.
2. Click the Refresh / Reset Firefox button in the top-right corner of the Troubleshooting Information page.
3. To continue, click Refresh / Reset Firefox in the confirmation window that opens.
4. Firefox will close and be reset. When it's done, a window will list the information that was imported. Click Finish and Firefox will reopen.
3. Delete any files or folders related to From Around The Web by checking the following locations:


text:
Earlier this week, I bought a Treasury bill.
Everybody calls Treasury bills T-bills, and they work like this: The government promises to pay holders of T-bills a specific amount on a specific day in the near future. For the T-bill I bought, the government promised to pay $1,000 on Oct. 31.
I bought the T-bill on Tuesday, before Congress had made the debt-ceiling deal, so it was unclear whether I would get paid back on time.
If people are worried about a bond, the price tends to fall. But, despite all the news about about possible default, my T-bill — which promises to pay a total of $1,000 — was selling for $999.78 on Tuesday. I stood to make exactly 22 cents on my big investment.
The immediate default danger has now passed, of course. But one of the fears was that the mere fact that the U.S. was flirting with default would drive up the interest rates the government had to pay to borrow money.
Default fears did drive up interest rates a little — and those higher rates probably cost the government somewhere around $50 million, and possibly as much as $100 million, according to Francis Longstaff, a finance professor at UCLA. In the context of the U.S. debt, that's a small number, he says.
Since Congress passed the debt-ceiling deal, investors' small fear of default seems to have gone away. That boring T-bill I bought has become even more boring. At the end of the day Thursday, it was selling for $999.99. If you bought it at that price, your profit in two weeks would be one penny.
*Technically, I didn't lend money directly to the government. I bought the T-bill from someone else. The person who bought the T-bill when it was first issued was the one who actually loaned the money to the government.
This is MORNING EDITION from NPR News. Good morning. I'm Renee Montagne.
And I'm David Greene. Earlier this week, David Kestenbaum with our Planet Money team did something that seemed a little risky. He called up a broker and made an investment.
GREENE: That's David talking with an employee at the online brokerage firm Etrade. Now, the reason buying a treasury bond might have seemed dicey is that at the time it looked like the government might default on its debt, which meant people who owned Treasury bonds might not get paid back. David now has the story of what happened to that bond and what it tells us about our brush with default.
: The thing I bought is technically called a T-bill. It's a short term loan to the U.S. government. The way T-bills work is that if you have one, the government is supposed to pay you a specific amount of money on a specific day. If you own this Tbill the government is promising to give you $1000 in a couple weeks, on October 31st. I told the guy at Etrade - his name is Peter - that's the one I want.
: We're going to preview the order. We are going to buy one $1000 face value of...
: If people are worried about a bond. You see it reflected in the price. If, for instance, people are really worried they might not get that $1000 on the 31st of October they won't pay as much for the bond. And the price will drop. So with all the fear about U.S. default - what was this $1000 bond selling for -- $800, $900? Nope. I had to pay I had to pay $999.78.
Meaning I stood to make exactly 22 cents on my big investment. This had to be the most boring thing Peter had helped anyone buy all day.
: Does that all sound good to you, the one you wanted?
: I'm not going to make a lot of money on this.
: Definitely not.
: What this means is yes, some investors were worried that the U.S. might not be able to pay this thing on time, but not that many.
: All right. I'm putting the order through for you right now. You'll see it in your account shortly.
: The immediate danger of default has now passed, of course. But one of the fears was that the mere fact that the U.S. was flirting with default might cost the U.S. and taxpayers money. Francis Longstaff is a finance professor at UCLA. I asked him to calculate how much the standoff in Congress had cost the U.S. and taxpayers through higher interest rates on our debt.
He looked at all the treasury bills the government issued since the beginning of October. And the answer? The additional damage from our flirting with default?
FRANCIS LONGSTAFF: A very wide upper bound on the potential impact is going to be on range of $75 to $100 million.
: In the scheme of things, he says, that is a very small number. The U.S. debt is trillions of dollars. Since the debt ceiling deal that small fear investors apparently had about certain treasury bonds seems to have gone away. That boring bond that I bought has become even more boring. At the end of the day yesterday it was selling for $999.99 Meaning your profit in two weeks' time would be one penny. David Kestenbaum, NPR News. Transcript provided by NPR, Copyright NPR.


text:
NEW YORK (AP) — From the tragic to the downright silly, millions of people searched the Web in 2012 to find out about a royal princess, the latest iPad, a record-breaking skydiver and the death of a pop star.
Google released its 12th annual "zeitgeist" report on Wednesday. The company calls it "an in-depth look at the spirit of the times as seen through the billions of searches on Google over the past year."
Here's an Associated Press photo gallery of the top ten trending searches of 2012.


text:
Email: email@example.com
Dr. Luder G. Whitlock, Jr., a Presbyterian minister, has spent much of his life in education, including 27 years at Reformed Theological Seminary (RTS). Dr. Whitlock joined the faculty of RTS in 1975, and, at the age of 37, was appointed president, a position he held for 23 years. Under his leadership, RTS grew from a small regional school to one of the most innovative as well as one of the 10 largest seminaries in North America.
Dr. Whitlock's years of ministry have been marked by an effort to bring mutual understanding and cooperation within the worldwide evangelical community, which led him to serve on the boards of the National Association of Evangelicals (NAE), the World Evangelical Fellowship (North America region), Mission America, the Lausanne Committee for World Evangelization, and Greater Europe Mission. He was co‐founder and co‐president of the International Reformed Fellowship, and later assumed a major role in the establishment of the World Reformed Fellowship. Dr. Whitlock has contributed to more than 20 books and 20 periodicals. He is author of The Spiritual Quest and served as executive director for The Spirit of The Reformation Study Bible.
Dr. Whitlock currently serves as President of Excelsis and as Executive Director of the CNL Charitable Foundation and the Seneff Family Foundation in Orlando, Florida. He is a graduate of the University of Florida, Westminster Theological Seminary, and Vanderbilt University. He and his wife, Mary Lou, have three grown children and eleven grandchildren.
Whether you're a prospective student, current student, alumnus, donor, or friend of RTS, we would love to hear from you.


text:
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While Unionville men and women in Unionville might find dating to be more annoying than nice, it'simportant to get past this by breaking the ice. Write an introductory email that's worthy of a response, you probably find that it's easier than delivering a tired line in a darkened bar. After taking a good look at a number of local Unionville guys, you'll know that the person you are attempting to get to know will have plenty in common with you.


text:
Nearly everywhere on the internet and on your computer you use passwords to protect all sorts of accounts and data
example user account(s) online banking, Etc from people that shouldnt have access to them
Your password is the key that unlocks the information that is locked behind the door. Not using a password would make all of your data out in the open and anyone could take a peek at it and do malicious things with it if they choose to do so.
A user name with a password is the most common way of securing data there are other methods being used today such as fingerprints, retina readers and smartcards with out passwords and these devices any person could pretend to be you in chat rooms ,your credit cards web site Etc
For system administration your user name and password are very important the system uses that information to identify you from all the other users that may have accounts on the system and to give you the proper system access and permissions As a example you wouldnt want a guest on your network to have Administrator privileges if they make one mistake they can really mess things up
What not to do when creating passwords
Don't use passwords that are names of children, pets, favorite sports teams and movies These are considered to be weak passwords because password crackers can very quickly generate countless words, names and variations of those words and names
Avoid using consecutive patterns on your keyboard example abcd,123 zxcv or uiop
Never tape a list of your passwords to your monitor or type them in to wordpad or notepad anyone that has physical access to your computer can use this to get into your data
Don't use use any word or name for your root passwords
Don't reuse old parts of previous passwords
Don't use passwords that are written in different languages
Don't use any part of your login name in your password(s)
Now since you now know what not to do it is time to show you what you should do
Create passwords
When creating a random password use Mnemonics( this is a rhyme or a phrase that you can use to help yourself to rember the password)
example of mnemonics "The cat in the hat comes back" in password form and using special characters the password would look like this
Create different passwords for each account that has access to data that you consider to be sensitive such as credit card web site(s) the admin and your user account on your computer Etc
For sites that contain nonsensitive data such as online news sites etc you can use a one word password
Do change your password every three to six months or sooner ( if you feel it is nessary to do so)
Make the password at least 8 or more characters in length
Create single password for access to nonsensitive data
Different versions of windows comes with various levels of password protection they range from somewhat secure to very secure
Windows 95/98 and Me
Offer low end password protection because it lets you create profiles so you can have your own settings such as wallpaper screen saver Etc
So if you don't know the users password you can't access these features but if you fail to input a password you can still access the programs and harddrive
Windows 2000
Has the option to have users enter a user name and a password before they can use the computer there are three types of group membership that can be granted to a user
1. standard user(poweruser group): Users can modify the computer and install programs but can not read files that belong to other users
2. Restricted user( users group)Users can operate the computer and save documents but can not install programs or make changes to the system files and settings
3. Administrators :Admin have complete and unrestricted access to the system
windows 2000 also has the following options
Enforce password history
Maximum password age
Minimum password age
Minimum password length
Passwords must meet Complexity requirements
Store password using reversible encryption for all users in the domain
Windows xp
is on the very secure end because any person that wishes to use the desktop or computer has to have a user account, password protecting your user account and admin account will prevent anyone from using it intill they input the correct password
Windows Xp provides two types of accounts Admin and user
The admin account can install programs access all files and folders add and delete accounts
the Limited user account(s) are limited account(s) they can't install programs or make system changes unless they have the permission to do so and have access to fewer files
There are software programs that will help you create and manage your passwords
Freeware programs
Descriptions are available on the web site these programs work with 98/Me/NT/200 and XP
www.romanlab.com/apw/index.html for any password
www.webattack.com/get/passafe.html for the password safe
www.webattack.com/get/didentity.html digital identity is not only a password manager it also uses steganography
Programs that cost money
has a program called Personal passworder this program costs $14.99 this program offers a number of features such as a personal passworder that lets you create seperate password protected accounts for multiple users, organize passwords into groups, search your list of passwords and has a customizable password generator with a password expiration
L0pht crack
LC4 is used to check the strength of users passwords by using different types of cracking methods: dictionary, hybrid, and brute force analysis
15 day trial
cost 1 upgrade License $95.00
1 license $350.00


text:
A member of the Post War World Council, an ardent pacifist, and anti-imperialist, Stephen Siteman was a long-time member of the Socialist Party of America, serving for seventeen years as secretary to the party's leader Norman Thomas. In his late teens, Siteman was imprisoned as a conscientious objector during World War II. Although he was later pardoned, his time as a prisoner led him into active involvement in prison reform and the peace movement.
During his long involvement in the Socialist Party, Siteman collected a large quantity of material relating to important socialist issues, including Socialist Reform, the peace movement, conscientious objection, and prison reform. The collection also includes a small selection of Siteman's personal correspondence with Frank Zeidler, former Socialist mayor of Milwaukee, and the novelist Mark Harris.
- Conscientious objectors
- Democratic Socialists of America
- Pacifists--United States
- Peace movements--United States
- Prison reformers
- Prisons--United States
- Socialists--United States
- Thomas, Norman, 1884-1968
- War Resisters League of America
- World War, 1939-1945
- Harris, Mark, 1922-2007
- Siteman, Stephen
- Zeidler, Frank P