Ljudske posade u međuplanetarnim misijama - za i protiv

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godinu dana kasnije, 1978, više detalja o načinu gradnje orbitalnih struktura, elektromagnetnim topovima za transport rude sa meseca i dovlačenju asteroida u zemljinu orbitu radi eksploatacije

btw. pretpostavka da će šatl leteti jednom nedeljno. :0.6:

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mart 1979, konkretne mašine koje bi gradile platforme za solarne panele i fabrike

Za šta bi sve to moglo da se koristi? Recimo, jedna takva solarna centrala, kvadratnog oblika, sa stranicama dužine 370km bi mogla da se stavi u orbitu oko sunca, na razdaljini od 1.000.000 km. Takva centrala bi za godinu dana proizela dovoljno struje za stvaranje jedne crne rupe od recimo 1.350.000 tona, radijusa od 2 atometara (10^-18m) i životnog veka od četrdesetak godina. Takva crna rupa isijava oko 56 petavata energije.U studiji se pominje crna rupa od 1.820.000 tona, radijusa 2,7 am i životnog veka od oko 100 godina koja isijava 17 petavata energije. Njoj je potebno oko godinu i po da izrači dovoljno energije da ubrza masu od 1.820.000 tona do 10% brzine svetlosti. Manje rupe emituju više energije i kraće traju. Takve su dobre za putovanja u okviru sunčevog sistema, dok su one koje traju pedesetak godina sjajne za letove do drugih zvezda.

black hole starship.pdf

[mei]

Za šta bi sve to moglo da se koristi? Recimo, jedna takva solarna centrala, kvadratnog oblika, sa stranicama dužine 370km bi mogla da se stavi u orbitu oko sunca, na razdaljini od 1.000.000 km. Takva centrala bi za godinu dana proizela dovoljno struje za stvaranje jedne crne rupe od recimo 1.350.000 tona, radijusa od 2 atometara (10^-18m) i životnog veka od četrdesetak godina. Takva crna rupa isijava oko 56 petavata energije.

jedino što još uvek ne znamo da li crna rupa zrači, tj. hokingovo zračenje je još uvek nepotvrđena hipoteza. (mada navijam za postojanje! ;-))

Manje rupe emituju više energije i kraće traju. Takve su dobre za putovanja u okviru sunčevog sistema, dok su one koje traju pedesetak godina sjajne za letove do drugih zvezda.

tačno je da bi manje rupe trebalo da emituju više energije u jedinici vremena, tj. da brže isparavaju, ako ih poredimo u datom trenutku sa nekom većom crnom rupom. ali pošto se isparavanje ubrzava kako crna rupa gubi masu (obrnuto je proporcionalno kvadratu mase), zar ne bi trebalo da i veća crna rupa, kada isparavanjem dođe na masu manje crne rupe, postane dovoljno efikasna kao početno manja crna rupa? tj. veće rupe ne emituju manje energije u totalu, samo sporije isparavaju pa su u početnim fazama isparavanja "neefikasne".

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jedino što još uvek ne znamo da li crna rupa zrači, tj. hokingovo zračenje je još uvek nepotvrđena hipoteza. (mada navijam za postojanje! ;-))

Ma i postojanje planeta van sunčevog sistema je do pre neku deceniju bila samo hipoteza. :) Najbolji dokaz je napraviti je i proučavati. LHC bi mogao biti upotrebljen za to ali pošto je javnost toliko vrištala na sam pomen mogućnosti stvaranja crnih rupa, verovatnije je da će to biti rađeno u kosmosu. Još jedan razlog zašto nam trebaju solarne centrale (na zemlji će verovatno biti jeftinije koristiti fuziju).

zar ne bi trebalo da i veća crna rupa, kada isparavanjem dođe na masu manje crne rupe, postane dovoljno efikasna kao početno manja crna rupa? tj. veće rupe ne emituju manje energije u totalu, samo sporije isparavaju pa su u početnim fazama isparavanja "neefikasne".

Potpuno si u pravu, ovo sam govorio sa stanovišta upotrebljivosti. Ako ti treba onolika skalamerija za jednu malu, nećemo skoro imati dovoljno energije da pravimo veće a i ne bi bilo rentabilno. Ako se pravi jedna godišnje, tražiš nešto što će moći da se koristi u razumnom roku (pre će doći do zamora materijala broda (ovo nije baš najsrećniji izraz - posle par decenija u svemiru svaka struktura će imati neki stepen oštećenja mikrometeoritima - znam za jedan eksperiment na miru, početkom devedesetih gde su na spoljnoj strani stanice stavili nešto što liči na saće sa primercima materijala koji bi u budućnosti mogli da se koriste kao oplata)). One sa rokom od par decenija su idealne sa stanovišta energije koju izračuju, mase, veličine i roka trajanja.

[Roger Sanchez]

[mei]

LHC bi mogao biti upotrebljen za to ali pošto je javnost toliko vrištala na sam pomen mogućnosti stvaranja crnih rupa, verovatnije je da će to biti rađeno u kosmosu. Još jedan razlog zašto nam trebaju solarne centrale (na zemlji će verovatno biti jeftinije koristiti fuziju).

samo mali osvrt na LHC. na energijama dostupnim u LHC-iju (reda nekoliko TeV) se mogu stvarati mini crne rupe samo ako postoje dodatne prostorne dimenzije. nema dovoljno energije da se napravi mini crna rupa u tri dimenzije. ali ako dodatne dimenzije postoje, i ukoliko su pojedini modeli kvantih teorija gravitacije na pravom putu, onda je moguće da neka mini crna rupa nastane tamo, bez obzira da li mi to želimo ili ne.

Potpuno si u pravu, ovo sam govorio sa stanovišta upotrebljivosti. Ako ti treba onolika skalamerija za jednu malu, nećemo skoro imati dovoljno energije da pravimo veće a i ne bi bilo rentabilno. Ako se pravi jedna godišnje, tražiš nešto što će moći da se koristi u razumnom roku (pre će doći do zamora materijala broda (ovo nije baš najsrećniji izraz - posle par decenija u svemiru svaka struktura će imati neki stepen oštećenja mikrometeoritima - znam za jedan eksperiment na miru, početkom devedesetih gde su na spoljnoj strani stanice stavili nešto što liči na saće sa primercima materijala koji bi u budućnosti mogli da se koriste kao oplata)). One sa rokom od par decenija su idealne sa stanovišta energije koju izračuju, mase, veličine i roka trajanja.

da, naravno, manje su rentabilnije. (nisam pročitala rad koji si linkovao, izvinjence ako prokomentarišem još nešto što je očigledno :).)

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Ovo je dobar način, daju im tačno određenu svotu novca za tačno određeni deo projekta. Ako na kraju uspeju i samo dva od četiri opet su na dobitku, troškovi razvoja oriona i kasnije održavanje su mnogo veći. Izgleda da su konačno shvatili da je model po kome operiše Arijanaspejs za sada najbolji.

Four firms plan to get the most out of NASA investmentBY STEPHEN CLARKSPACEFLIGHT NOWPosted: April 25, 2011The four companies granted almost $270 million by NASA last week face an orchestrated series of hardware tests, design milestones and government reviews of their privately-developed spacecraft over the next year, according to documents released by NASA. Artist's concept of Boeing's CST-100 spacecraft approaching the International Space Station. Credit: Boeing Each firm will receive their funding in payments at specific milestones set by the company and agreed to by NASA. The milestones include achievements like engineering reviews, propulsion testing and assembly of prototype hardware through May 2012. Boeing received the largest Commercial Crew Development award, an agreement valued at $92.3 million, to finish the preliminary design of the CST-100 capsule, a back-to-basics spacecraft solely designed for up-and-down trips to the International Space Station and other destinations in low Earth orbit. The aerospace giant plans to select a rocket to launch the capsule, which Boeing says will weigh up to 13 metric tons, or more than 28,000 pounds. Boeing will also test the craft's parachutes in an airborne drop and fire a lightweight abort engine built by Pratt & Whitney Rocketdyne. Engineers at the Langley Research Center in Virginia will drop a mock-up of the CST-100 into a landing pit to check the strength of the craft's airbags. Boeing and NASA already accomplished some drop testing, but engineers will add horizontal velocity this year to simulate windy landing conditions. A scale model of the spacecraft and launch vehicle will be put through wind tunnel testing to check aerodynamic characteristics, and a propellant tank will be fabricated and tested, according to Boeing. Other demos on tap soon include the construction of a CST-100 structural test article made of aluminum, testing pyrotechnics to sever connections between the crew and service modules, and evaluating a new thruster design fueled by non-toxic propellant. John Elbon, Boeing's commercial crew program manager, said he expects Boeing's workforce dedicated to the CST-100 development will increase to between 200 and 250 employees this year. Most of the workers will be based in Houston and Huntington Beach, Calif. Some employees will contribute from Florida and Alabama. With an early investment from NASA last year, Boeing built a CST-100 pressure shell, verified its weld-less manufacturing processes, constructed a mock-up to test human factors and crew accommodations, fired a prototype abort engine, and developed an automated rendezvous and docking simulator. "That's all behind us," Elbon said. "We accomplished that with $18 million of NASA investment. We put in a like amount. It was incredible the amount we were able to get done with that amount of money in the environment we're in today." Elbon said Boeing's $92.3 million CCDev 2 award was close to the company's request. With room for up to seven astronauts, the CST-100 has a diameter of nearly 15 feet and features just enough capability to deliver a crew to orbit and return them safely to Earth. The battery-powered capsule can only fly for about two days on its own, but it could stay plugged into the International Space Station's power for more than a half-year. The CST-100 is designed to be reusable for up to 10 missions. Boeing's yearlong agreement with NASA will conclude with a preliminary design review, a significant step in the development of any spacecraft where the tentative design is confirmed to meet requirements. If NASA provides more funding, a tall order in the current spending climate, Boeing could make headway toward the CST-100's critical design review, when the specifics of the spacecraft's components are typically frozen. On the current schedule, Boeing forecasts orbital flight tests by 2014 and an initial operational capability in 2015. Artist's concept of Sierra Nevada's Dream Chaser space plane launching on an Atlas 5 rocket. Credit: Sierra Nevada Sierra Nevada Corp., a Colorado-based firm, also plans to reach a preliminary design review for its reusable Dream Chaser space plane by May 2012. The company took the second-largest sum in NASA's commercial crew announcement, garnering $80 million to take the Dream Chaser from the drawing board to the cusp of flight testing. Sierra Nevada received $20 million in the first CCDev competition in February 2010, using that funding to develop manufacturing tooling, fire a Dream Chaser maneuvering engine and deliver parts of a structural mock-up of the spacecraft. Sierra Nevada also dropped a scale model of the Dream Chaser from an altitude of 14,000 feet. Engineers also made progress in the Dream Chaser's guidance, navigation and control system, along with significant aerodynamic analysis to reduce risk in the craft's development and performance. The Dream Chaser is based on the aerodynamic shape of NASA's HL-20 lifting body, a concept studied by the Langley Research Center as a safer, less expensive option for human space transportation. Although the HL-20 never flew, its design was borrowed from the Soviet Union's BOR-4 space plane that was tested in Earth orbit in the 1980s. Sierra Nevada updated the HL-20 concept with a composite structure and a hybrid rocket motor. Launching on an Atlas 5 rocket, the seven-person Dream Chaser would fly to the space station, deliver astronauts and supplies, and return to Earth for a gliding touchdown on a conventional runway. With the $80 million awarded last week, Sierra Nevada plans to conduct more detailed aerodynamic assessments to select the final shape of the Dream Chaser's air fins. Engineers will also build and activate a full cockpit flight simulator, a flight control integration laboratory and an avionics testbed. Sierra Nevada says it will finish construction of a full-scale engineering test article and verify the performance of the Dream Chaser's separation system. Company officials will also select several major subcontractors to provide software, a life support system and other components. With more money, Sierra Nevada says it can proceed toward landing gear drop testing, a piggyback test flight of the Dream Chaser test unit, and eventually a free flight ending with a runway landing by the spring of 2012. SpaceX, the growing space transportation firm started by Elon Musk, will invest its $75 million from NASA in the design and testing of a side-mounted launch abort system, a miniature rocket engine that would quickly carry a spacecraft away from a failing launch vehicle. The company's engineering team will also further development of cockpit controls and crew seating for the interior of the Dragon spacecraft, which has already been tested in orbit without passengers. The Dragon is being built first to resupply the space station starting next year. Artist's concept of SpaceX's Dragon spacecraft in orbit. Credit: SpaceX According to Musk, SpaceX can outfit the Dragon for crewed missions for $1 billion within three years if the project is given a steady stream of funding. SpaceX is the only company publicly disclosing total development cost projections for its reusable commercial crew system. SpaceX was not part of the first CCDev awards, partly because the Dragon and Falcon 9 rocket were already on the verge of unmanned flight tests, several years ahead of the other competitors. Last year's CCDev agreements focused on fundamental developments of technologies and processes that would lead to a piloted spacecraft. Ken Bowersox, SpaceX's vice president of astronaut safety and mission assurance, said much of the company's activity over the next year will be adding bells and whistles to the Dragon to make it safe for humans. "Our plan is to take the current cargo Dragon concept and then evolve it," Bowersox said. Bowersox said engineers have worked on cockpit designs in computers, but the NASA funding will accelerate translating that work into seat and control panel models for astronauts to get a feel for during visits to SpaceX headquarters in Hawthorne, Calif. The Dragon's side-mount launch abort system will be designed and built to the point of a full-duration engine firing on the ground by next May. SpaceX selected the novel side-mount design because the abort thrusters can be used in orbit and during landing if they are not needed to respond to a launch emergency. "The first thing we have to do is build the launch abort system, which we are currently envisioning as a system of thrusters on the side of the vehicle that uses the orbital maneuvering fuel to carry the vehicle away from the booster in the event of a problem," Bowersox said. SpaceX's ultimate objective is to use the abort engines for a rocket-assisted precision touchdown of the Dragon. Established by Jeff Bezos, the wealthy founder of Amazon.com, Blue Origin snatched $22 million from NASA last week to continue designing and testing systems for the company's New Shepard biconic spaceship. Blue Origin is also working on a concept for a reusable booster, but the firm plans its first orbital test flights to launch on Atlas 5 rockets. Blue Origin conducts much of its testing in secret at a sprawling West Texas ranch, but its proposal for government funding required the company to share its vision and development plans. Artist's concept of Blue Origin's New Shepard space capsule. Credit: Blue Origin The New Shepard's complement of up to seven crew members puts it on par with the other commercial crew winners. The craft can stay at the space station up to seven months at a time and serve as a lifeboat, according to Blue Origin's proposal. A fraction of Blue Origin's $22 million award will go toward settling on a basic design for the New Shepard, including picking its heat shield, defining its exact shape, and setting specific requirements. Blue Origin will spend the bulk of the government money on testing the company's unique pusher escape system, which has a similar purpose as a launch abort system, and advancing development of a cryogenic hydrogen-fueled engine capable of producing up to 100,000 pounds of thrust. The engine will help power Blue Origin's reusable booster into space, according to documents released by NASA. The hardware demos include a ground firing of the pusher escape system motor, then a test in which the system will simulate escaping a rocket on the launch pad. Blue Origin also plans to test the liquid-fueled cryogenic engine's thrust chamber assembly. The company foresees a series of incremental test flights, starting with suborbital missions to the edge of space before pressing on to more challenging ventures into low Earth orbit.izvor: Spaceflightnowhttp://spaceflightnow.com/news/n1104/25ccdevgoals/

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Prvi potencijalni jugoslovenski astronaut

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Pre nekog vremena sam pominjao biosferu 2 kao projekat gde su hteli da testiraju kako bi izgledao potpuno funkcionalan habitat na nekoj planeti. Ovo ne treba brkati sa projektima uzgajanja raznih biljaka van saksija. Na orbitalnim stanicama je letelo sve i svašta, od meduza (kojima začudo odsustvo gravitacije uopšte ne smeta da se orijentišu u prostoru) i morskih prasića do drveta limuna. Na zemlji su rađeni i projekti bazena sa ribama za ishranu kosmonauta kao i biljaka koje bi visile a korenje bi bilo umakano u potocic hranljivih materija. Bosfera je bila pokušaj uspostavljanja više kompletnih ekosistema (sem većih živuljki) pod jednim krovom.

Dodatni problem (koji se na zemlji ne može testirati) je upravo gravitacija. Jedan opis toga kako izgledaju džinovski paradajz i ostalo voće i povrće je dat u čuvenom romanu Zvezda Kec (bilo u lektiri za osnovnu školu, sovjetski roman, kec je skraćenica od Konstantin Eduardovič Ciolkovski). Sledeći test je napraviti nešto slično ovome u orbiti. To su stotine tona materijala plus još komplikovanija pitanja izolacije, filtracije kosmičkih zraka, kondenzacije vode, kontrole kretanja insekata itd... Pravi habitati, u obliku cilindara koji se protežu stotinama kilometara u krug su još uvek jako daleko. heh, sada vidim da wikipedija ima članak, pa ako vas zanima kako se završilo i šta sada rade evo vam:http://en.wikipedia.org/wiki/Biosphere_2

[bigvlada]

Elem, svako zanimanje ima i svoju tamnu stranu medalje, pa pored gorenavadenih u vezi obuke, evo šta se sve dešavalo samo za vreme prvog leta ovog lekara. Poljakov je inače bio vođa jedne grupe kosmonauta, lekara (postoje i piloti i brodski inženjeri). Bivši rekorder po ukupnoj dužini boravka u kosmosu kao i važeći rekorder po dužini boravka tokom jedne misije (437 dana).

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Upgrade izvora energije, sličnog onom koji je pokretao Vojadžere, samo znatno unapređenom. NASA plans test of advanced nuclear power generatorBY STEPHEN CLARKSPACEFLIGHT NOWPosted: May 9, 2011 Two of the robotic missions NASA selected for further study last week would be powered by experimental nuclear generators, a new technology under development to boost the efficiency of electricity production in deep space. NASA's Cassini orbiter captured this image of sunlight glinting off a methane lake on Titan. Credit: NASA/JPL-Caltech NASA picked robotic missions to Mars, a comet and Saturn's moon Titan as finalists last week for a launch opportunity in 2016, and two of the probes would employ a cutting edge nuclear power source never tested in space. The space agency plans to settle on a single mission in June 2012, fully funding the winner for development and launch later this decade. Although NASA requires the missions to launch by the end of 2017, scientists in charge of all three probes target blastoff in 2015 or 2016. Probes to Titan and comet Wirtanen, a small object composed of a mix of rock and ice, would be powered by Advanced Stirling Radioisotope Generators on their journeys into the outer solar system. The nuclear power units, called ASRGs, use less plutonium than existing generators. NASA and the U.S. Department of Energy face a shortage of plutonium-238 nuclear fuel for robotic spacecraft, causing officials to turn to more efficient power generators. The Department of Energy is managing the ASRG's development, and NASA's Glenn Research Center in Ohio has conducted more than 14,000 hours of trouble-free endurance testing of a ground model, according to Lockheed Martin Corp., the prime contractor with the Energy Department for development, fabrication and testing of the ASRG. Diagram of an Advanced Stirling Radioisotope Generator. Credit: U.S. Department of Energy Plutonium is the best way to generate power on deep space probes because solar panels do not receive enough sunlight at such distances. But the U.S. no longer produces plutonium-238, the isotope best suited for space power, and Russia is charging higher prices for access to its stockpile. While scientists lobby to restart U.S. production of plutonium-238, federal agencies started developing a new power generator built around Stirling engines and linear alternators. The new device is called an Advanced Stirling Convertor because it transforms the decay heat of the plutonium-238 fuel into electricity. The Stirling convertor is being developed by Sunpower Inc. of Ohio. Unlike Radioisotope Thermoelectric Generators, which have powered satellites and probes for nearly 50 years, the ASRG has the added complexity of moving parts. But each ASRG creates between 130 and 140 watts of electricity with 1 kilogram, or about 2.2 pounds, of plutonium-238. More than four times more plutonium would be required to generate the same power in an existing RTG, according to the Energy Department. Officials want to complete extensive ground testing and a low-cost flight demonstration before flying ASRGs on a multi-billion dollar flagship mission. NASA tapped the Discovery program, the agency's line of frequent, relatively inexpensive planetary probes, to test the ASRG system in space for the first time. The mission costs are capped at $425 million, not including the launch vehicle. NASA will also provide two ASRGs at a value of $54 million as government-furnished equipment. Sketch of the Comet Hopper spacecraft. Credit: NASA/UMD The Titan Mare Explorer, a proposed craft that would study a methane-ethane sea, would carry two ASRG units to produce electricity. After launching in January 2016, the probe would cruise through space for more than seven years before reaching Titan in 2023, said Ellen Stofan, TiME's principal investigator at Proxemy Research Inc. "We will use two ASRGs and have a 96-day mission in which we accomplish our science goals of characterizing the Titan sea and its environment," Stofan told Spaceflight Now. "The ASRGs last years and years beyond that, of course." The TiME capsule would plunge into Titan's thick atmosphere, parachute through blustery clouds and touch down in a hydrocarbon ocean rich in organic molecules, the building blocks of life. The craft would float in Ligeia Mare, a large sea in Titan's northern hemisphere, and search for complex organic chemistry while studying the ocean's interaction with the moon's robust atmosphere. Lockheed Martin would build the TiME spacecraft and the Johns Hopkins University Applied Physics Laboratory would manage the mission for NASA. Another Discovery mission candidate named Comet Hopper would also rely on two ASRG units on its journey to Wirtanen, a small comet about 0.7 miles in diameter, according to Jessica Sunshine, the project's principal investigator from the University of Maryland in College Park. Built by Lockheed Martin and managed by NASA's Goddard Space Flight Center, Comet Hopper would blast off in late 2015 and reach Wirtanen in 2022 nearly 500 million miles from the sun, nearly the distance of Jupiter's orbit. Wirtanen's orbit brings it within 100 million miles of the sun every five-and-a-half years, and the Comet Hopper probe would land on the icy rock up to four times over two years as the objects fall back toward the sun. The craft would measure changes in the comet as sunlight and heat trigger eruptions of dust and gas. Artist's concept of the Phoenix lander, the basis for the GEMS mission proposal. Credit: NASA/JPL-Caltech NASA's third finalist for the next Discovery program mission is the Geophysical Monitoring Station, or GEMS. GEMS would launch in early 2016 and begin an eight-month journey to Mars, where it would parachute into the atmosphere and conduct a rocket-powered landing. The mission would reuse Lockheed Martin's successful Phoenix lander design. The mission would probe the interior of Mars with a seismometer, a penetrating mole instrument to measure subsurface heat, and an experiment to monitor the planet's wobble and dynamic motion. GEMS would be powered with solar arrays like Phoenix and not carry nuclear generators, according to Bruce Banerdt, the mission's chief scientist from the Jet Propulsion Laboratory. All three proposals will receive $3 million from NASA to continue concept studies before another review next year to select a mission for flight.btw. Ja bih glasao za Titan. Njegova atmosfera podseća na našu od pre par milijardi godina a i nikada do sada nije detaljno istraživano more ili jezero na nekom drugom svetu.

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Otvorio se bezdan, zvezda pun,zvezdama broja nema, bezdanu - dna....Mihail Ljermontov

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Posle više od 25 godina, došlo je vreme da se napravi SABRE motor u punoj veličini. Radi se o tehnologiji koja je pravljena za projekat Hotol a kasnije razvijana nižim intezitetom. To je motor za SSTO letelice (Single stage to orbit) koji u sebi kombinuje mlazni i raketni motor (koji se razlikuje od klasično raketnog motora jer umesto da nosi tečni kiseonik, kupi ga iz atmosfere). Sa uspešnim testiranjem ovog motora, ESA bi dobila jedan izuzetno važan motor, osnovu budućih hipersoničnih putničkih aviona, kosmičkih kargo letelica i šatlova za transfer posade do orbitalne stanice. 24 May 2011 Last updated at 07:04 GMT UK Skylon spaceplane passes key reviewBy Jonathan AmosScience correspondent, BBC News A revolutionary UK spaceplane concept has been boosted by the conclusions of an important technical review.The proposed Skylon vehicle would do the job of a big rocket but operate like an airliner, taking off and landing at a conventional runway.The European Space Agency's propulsion experts have assessed the details of the concept and found no showstoppers.They want the next phase of development to include a ground demonstration of its key innovation - its Sabre engine.This power unit is designed to breathe oxygen from the air in the early phases of flight - just like jet engines - before switching to full rocket mode as the Skylon vehicle climbs out of the atmosphere.It is the spaceplane's "single-stage-to-orbit" operation and its re-usability that makes Skylon such an enticing prospect and one that could substantially reduce the cost of space activity, say its proponents.Mature conceptThe UK Space Agency (UKSA) had commissioned Esa to evaluate the design, and the European organisation's staff reported on Tuesday that they had not seen any obvious flaws."Esa has not identified any critical topics that would prevent a successful development of the engine," they write in their review.Skylon has been in development in the UK in various guises for nearly 30 years. It is an evolution of an idea first pursued by British Aerospace and Rolls Royce in the 1980s. From what we've seen so far, we can't identify any showstoppers”Dr Mark FordEsa's head of propulsion engineeringThat concept, known as Hotol, did have technical weaknesses that eventually led the aerospace companies to end their involvement. But the engineers behind the project continued to refine their thinking and they are now working independently on a much-updated vehicle in a company called Reaction Engines Limited (REL). Realising the Sabre propulsion system is essential to the success of the project. The engine would burn hydrogen and oxygen to provide thrust - but in the lower atmosphere this oxygen would be taken directly from the air.This means the 84m-long spaceplane can fly lighter from the outset with a higher thrust-to-weight ratio, enabling it to make a single leap to orbit, rather than using and dumping propellant stages on the ascent - as is the case with current expendable rockets.But flying an integrated air-breathing and rocket engine brings unique challenges.At high speeds, Sabre would have to manage 1,000-degree gasses entering its intake. This hot air would need to be cooled prior to being compressed and burnt with hydrogen. Reaction Engines' answer is a novel precooler heat-exchanger.This would incorporate arrays of extremely fine piping to extract the heat and plunge the intake gases to minus 130C in just 1/100th of a second.Ordinarily, the moisture in the air would be expected to freeze out rapidly, covering the network of fine piping in a blanket of frost and dislocating its operation.Regulatory supportBut REL says it has developed an anti-frost solution that will allow the heat exchanger to run and run. Esa's technical staff have witnessed this "secret technology" on the lab bench and can confirm it works. The agency's experts say they also fully expect a scaled up version of the precooler technology to function properly this summer when it is tested in conjunction with a standard jet engine."We've not looked at everything; we've focussed on the engine and the [skylon's] structure," explained Dr Mark Ford, Esa's head of propulsion engineering. "But from what we've seen so far, we can't identify any showstoppers. It's quite an innovative technology if it works." Assuming, this summer's test programme does indeed achieve its goals, Reaction Engines says private investors will release £220m ($350m) of funds to take Skylon into the next phase of its development.This would include the production of a ground demonstrator that would show off Sabre's full engine cycle - its air-breathing and rocket modes and the transition between the two. Sabre's precooler technology will be put through its paces on a test rig this summerThe price for launching a kilogram of payload into a geostationary orbit - the location for today's big telecoms satellites - is currently more than $15,000 (£9,000). Skylon's re-usability could bring that down to less than $1,000, claims REL.If the vehicle ever does go into full production, the investment required will probably be in the region of $9-12bn (£5.5-7.5bn), but the company will not be looking to government for that money."The government hasn't got that sort of money and we want this project to be a privately financed one," said Alan Bond, the managing director of REL. "What government can do for us however is deal with the legislation that surrounds the eventual introduction of a spaceplane - how it is certified and how it conforms to certain aspects of international space law. And the government has already indicated its willingness to do all this in the recent budget."http://www.bbc.co.uk/news/science-environment-13506289

[bigvlada]

Još jedno razmišljanje na temu o kolonizaciji Marsa.To Boldly Go: A One-Way Human Mission to MarsOctober 20, 2010 by EditorThe planet Mars, like Earth, has clouds in its atmosphere, a deposit of ice at its north pole, and caves, probably with water. (NASA/JPL/Malin Space Science)Paul Davies, a physicist and cosmologist from Arizona State University, and Dirk Schulze-Makuch, a Washington State University associate professor, argue for a one-way manned mission to Mars.In an article, “To Boldly Go: A One-Way Human Mission to Mars,” published in Volume 12 of the Journal of Cosmology, the authors write that while technically feasible, a manned mission to Mars and back is unlikely to lift off anytime soon, largely because it is a hugely expensive proposition, both in terms of financial resources and political will.And because the greatest portion of the expense is tied up in safely returning the crew and spacecraft to earth, they reason that a manned one-way mission would not only cut the costs by several fold, but also mark the beginning of long-term human colonization of the planet.“One approach could be to send four astronauts initially, two on each of two space craft, each with a lander and sufficient supplies, to stake a single outpost on Mars. A one-way human mission to Mars would be the first step in establishing a permanent human presence on the planet.”While acknowledging that the mission would necessarily be crewed by volunteers, Schulze-Makuch and Davies stress that they aren’t suggesting that astronauts simply be abandoned on the Red Planet for the sake of science. Unlike the Apollo moon missions, they propose a series of missions over time, sufficient to support long-term colonization.“It would really be little different from the first white settlers of the North American continent, who left Europe with little expectation of return,” Davies said of the proposed one-way Martian mission. “Explorers such as Columbus, Frobisher, Scott and Amundsen, while not embarking on their voyages with the intention of staying at their destination, nevertheless took huge personal risks to explore new lands, in the knowledge that there was a significant likelihood that they would perish in the attempt.”The authors propose the astronauts would be re-supplied on a periodic basis from Earth with basic necessities, but otherwise would be expected to become increasingly proficient at harvesting and utilizing resources available on Mars. Eventually they envision that outpost would reach self-sufficiency, and then it could serve as a hub for a greatly expanded colonization program.The proposed project would begin with the selection of an appropriate site for the colony, preferentially associated with a cave or some other natural shelter, as well as other nearby resources, such as water, minerals and nutrients.“Mars has natural and quite large lava caves, and some of them are located at a low elevation in close proximity to the former northern ocean, which means that they could harbor ice deposits inside similar to many ice-containing caves on Earth,” said Schulze-Makuch.“Ice caves would go a long way to solving the needs of a settlement for water and oxygen. Mars has no ozone shield and no magnetospheric shielding, and ice caves would also provide shelter from ionizing and ultraviolet radiation.”The ultimate adventureThe article suggests that, in addition to offering humanity a “lifeboat” in the event of a mega-catastrophe on Earth, a Mars colony would provide a platform for further scientific research. Astrobiologists agree that there is a fair probability that Mars hosts, or once hosted, microbial life, perhaps deep beneath the surface and Davies and Schulze-Makuch suggest a scientific facility on Mars might therefore be a unique opportunity to study an alien life form and a second evolutionary record.“Mars also conceals a wealth of geological and astronomical data that is almost impossible to access from Earth using robotic probes,” the authors write. “A permanent human presence on Mars would open the way to comparative planetology on a scale unimagined by any former generation… A Mars base would offer a springboard for human/robotic exploration of the outer solar system and the asteroid belt. And establishing a permanent multicultural and multinational human presence on another world would have major beneficial political and social implications for Earth, and serve as a strong unifying and uplifting theme for all humanity.”Although they believe the strategy of colonizing Mars with one-way missions brings the goal of colonizing another planet technologically and financially within our reach, Schulze-Makuch and Davies acknowledge that such a project would require not only major international cooperation, but a return to the exploration spirit and risk-taking ethos of the great period of the Earth’s exploration.They write that when they raise the idea of a one-way Mars colonization mission among their scientific colleagues, a number express an interest in making the trip. “Informal surveys conducted after lectures and conference presentations on our proposal have repeatedly shown that many people are willing to volunteer for a one-way mission, both for reasons of scientific curiosity and in a spirit of adventure and human destiny,” they write.And yes, Schulze-Makuch offered that he too would be prepared to “boldly go” on a one-way mission to the Red Planet. But he hedges just a bit, holding out the single caveat that he would want the launch to wait until his young children have all grown into adults.Adapted from materials provided by Washington State University.http://www.kurzweilai.net/to-boldly-go-a-one-way-human-mission-to-mars

[noskich]

Zanimljiv tekst sa dosta nepoznanica.Nije mi jasno sta se podrazumeva pod `nutrients`, sta to ocekuju da nadju na Marsu sto moze biti hranljivo?Slanje kolonizatora samo u jednom pravcu povlaci sa sobom veliku moralnu dilemu. Ma kolikih celicnih nerava ti volonteri bili ovo bi definitivno bio najveci izazov za psihu bilo kog coveka ikada. Ko garantuje da oni tamo ne bi potpuno poludeli nakon nekog vremena.I na kraju - tehnicka izvodljivost, kako proizvoditi kiseonik? Zdravstvena nega?I da dodam jos jednu stvar - to sto su ljudi potvrdjivali da bi se dobrovoljno prijavili za ovu ekspediciju nakon predavanja treba okaciti macku o rep. To je isto kao kada na kraju fokus grupe pitaju prisutne da li bi kupili proizvod o kome se razgovaralo. Naravno da ce odgovoriti potvrdno, dosli su na sat vremena, malo lagano popricali uz sok, kafu i sendvice i dobili lepu svoticu za to da se pojave.

Edited June 27, 2011 by noskich