SpaceX

[Shan Jan]

Hvala na odgovoru vlado. Sta ti predlazes kao realno zasnivanje samoodrzive kolonije na Marsu? I koliko mislis da je potrebno vremena i novca za to?

 

Jos se secam tvojih tekstova o pravljenju kuca od opeke na crvenoj planeti :)

[bigvlada]

Minimum minimuma za koloniju je 200 ljudi, radi normalnog ukrštanja potomstva. Dakle, pomnoži sa dva za svaki slučaj. Moj problem sa ovom prezentacijom je da olako prelaze preko problema ili ih uopšte ne spominju. Razuman plan bi bio da prvo pošalješ brod sa aparaturom koja će na licu mesta proizvesti dovoljnu količinu goriva za povratak pa da tek onda šalješ ljude. Oni žele da aparaturu za pravljenje goriva nose sa sobom. 

 

Cigle su najjednostavniji način. :)  Robote je mnogo lakše naučiti da pokupe prašinu, dodaju vodu, ispeku je i slože nego zezanje sa nečim komplikovanijim poput 3D printera. A ako se već pravi gorivo nema razloga da se ti bageri/roboti/dizalice ne snabdeju motorom sa unutrašnjim sagorevanjem umesto zezanja sa solarnim panelima ili radioaktivnim materijalima.

 

Knjiga The case for Mars opisuje kompletan proces planiranja, izgradnje i kao krajnji cilj samoodrživosti kolonije. Ideja sa ciglama je odatle. To je postepen i dug proces, jer i sama kolonija evoluira od podzemne nastambe preko kupole do teraformirane planete. Jedna mala kolonija ne može da sama teraformira celu planetu, tj. vekovima će joj trebati pomoć sa Zemlje. Može se napraviti potpuno zatvoren sistem koji bi bio samodovoljan ali ne bi imao resurse da se samostalno širi. 

 

Potrebno je 2500 godina da bi se oslobodio CO2 iz marsovog regolita sa dubine od 200m u cilju podizanja atmosferskog pritiska na 1000milibara. To ni kolonija sa 1000000 ljudi ne može sama.  

 

Ovde je ideja da se što brže prebaci milion ljudi sa svom potrebnom opremom i napravi grad. Koliko su to velike cifre se vidi kada se uporede sa skromnijim planovima, tj. onima koji se zasnivaju na poređenju sa kolonizacijom Severne Amerike. Takvi planovi počinju sa 100 ljudi godišnje, starosti 20-40 godina i rastu po stopi od 2% godišnje. Uzimajući brojku od 3,5 dece po familiji i smrtnost (od 0,1% u kategoriji 0-59 godina, 1% za 60-79 i 10% za one preko 80) posle 160 godina će populacija biti nešto preko 500.000 ljudi. Velik je znak pitanja da li infrastruktura i organizacija grada na drugoj planeti mogu da prate brz priliv stanovništva, pogotovo ako se želi da grad bude samodovoljan. 

 

Dubai je izgrađen za nekoliko decenija ali koliko je samodovoljan? Kina je puna gradova koji su izgrađeni na brzinu i u njih strpano stanovništvo. Da li su to gradovi ili samo grupa građana i grupa zgrada na istom mestu? 

 

Poenta je da prvo pripremiš ono osnovno za koloniste pre nego što bilo koga pošalješ tamo.  

[Time Crisis]

^^Čini mi se da ćemo pre stići na onu planetu što su otkrili kod Proksime Kentauri, nego što bi tako nešto uspelo... na Zemlji je prosek 2 dece po familiji ili manje, a na Marsu će biti 3,5? :)

[Shan Jan]

Pa ti prvi kolonijalisti nece ni moci nista drugo da rade na Marsu osim da se razmnozavaju :D

[Prokleto Djubre]

Posaljemo srednjoskolce i uskratimo kurtone, video igre, internet i tv. Prosek od 3.5 ce biti dostignut za 4 godine 

[Time Crisis]

Posaljemo srednjoskolce i uskratimo kurtone, video igre, internet i tv. Prosek od 3.5 ce biti dostignut za 4 godine 

 

Ne bih se kladio da bi poživeli 4 godine. :p

[zema]

nisam zna dje da turim

 

Zašto treba privatizovati Nasu

[Time Crisis]

 

nisam zna dje da turim

 

Zašto treba privatizovati Nasu

 

 

Privatizovanje NASA-e bi bio verovatno zadnji ekser u kovčeg istraživanja svemira, kakva glupost od teksta.

[namenski]

Zasto?
Sve ce to kapitalizam i slobodno preduzetnistvo da pozlate 

[Time Crisis]

Zasto?

Sve ce to kapitalizam i slobodno preduzetnistvo da pozlate 

 

Zato što veliki broj misija ima profit 0$, a troškove u milijardama, ko bi finansirao Mars Science Laboratory, Rosetta ili New Horizons misije? Tako nešto samo država može sebi da priušti. :)

[Prokleto Djubre]

http://www.popularmechanics.com/space/satellites/a23937/spacex-launch-4425-satellites/

[hazard]

 

nisam zna dje da turim

 

Zašto treba privatizovati Nasu

 

 

apsolutno retardiran tekst

[bigvlada]

http://www.popularmechanics.com/space/satellites/a23937/spacex-launch-4425-satellites/

 

U početku bijaše Iridium....

 

 

Iridium: If You Build It They Won't Necessarily Come

 

By Keith CowingPosted Tuesday, August 29, 2000

 Iridium Constellation Within the next few weeks a steady shower of human made meteorites - the Iridium family of satellites - will begin to strike the Earth. Bringing satellites back to Earth after their mission is complete is not new. However, bringing an entire constellation of more than 70 satellites back to Earth, years ahead of schedule because of financial failures is new - and unprecedented.

 

In the film "Field of Dreams" an Iowa corn farmer is compelled to build a baseball field amidst otherwise lucrative corn crop. A mysterious voice inside his head says "build it and they will come". He does - and they do. This makes a good Hollywood plot - but makes a horrible business plan.

 

Welcome to the unfulfilled promise of Iridium.

 

First 77 then 66

 

Iridium was initially envisaged as a constellation of 77 satellites oriented in 7 planes about the Earth with 7 satellites orbiting in each plane. The satellites would cover a set portion of the Earth with coverage overlapping with other satellites providing near continuous and nearly global coverage. It is from the number 77 that the name "Iridium" was chosen - element 77 on the periodic table. It was later decided to scale this constellation back to 66 satellites orbiting in 6 equally spaced orbital planes 421 miles high with 6 spacecraft in each group.

 

Curiously, element number 66 is named "Dysprosium". Motorola decided to stick with the more marketable name "Iridium" even if its applicability to the size of the operational satellite constellation was no longer accurate. Ironically "Dysprosium" is derived from the Greek word "dysprositos" meaning "hard to obtain" - the fate that soon faced Iridium's management.

 

Novel Concept

 

Iridium was launched with the benefit of many who saw global access as a concept whose time had long been predicted - indeed, one that had arrived at last. One could easily follow its core appeal back through the 1960's and Marshall McCluhan's concept of a global village, Star Trek's famous communicators, and even further to Arthur C. Clarke's first concepts of geostationary communications satellites in the 1940's and the ramifications of a world united by universal and affordable telecommunications.

 

It all began in 1987 when the Iridium concept was first envisioned by Motorola. Iridium became a business venture in 1990 and completed its first round of financing in 1993. A second round was completed in 1994. By the time investor funding was capped in 1996 a total of $1.9 billion had been raised. All told the venture would come to cost more than $5 billion. On 1 November 1998, Iridium premiered with formal service starting a few weeks later. Iridium seemed poised to be first out of the gate with other ventures still being organized and years behind Iridium.

 

 A product whose time had passed

 

Problems began almost at once and snowballed quickly thereafter. Iridium phones were late to ship, didn't work inside buildings or out of direct line of sight with a satellite, and cost far too much ($3,000). Call rates could easily reach $7 per minute. The phones were heavy and had very limited usage beyond basic telephony and were simply not designed to handle the demand for ubiquitous Internet access - something that was not a factor in the late 1980's and early 1990's when Iridium was being designed.

 

Other ventures, now nipping at Iridium's heels sought to provide these services - and would do so coupled with explosively popular ground-based cellular phone systems - another factor Iridium did not have the foresight to consider. Had Iridium appeared in the very early 1990's it might have had a better chance at success. Instead it arrived in the midst of a revolution no one foresaw barely a few years earlier - one able to run circles around Iridium's already stale technology.

 

The speed of Iridium's demise surprised many - especially given its solitary presence in the space-based telephone market. Iridium initially sought to play up the marvels of this access by a number of highly visible promotional ventures. One was Iridium Icetrek an Antarctic expedition where the son of Everest climber Sir Edmund Hillary and a small team took and overland route by skis from Scott Base to the South Pole in January 1999. They were airlifted out after successfully reaching their destination - giving live interviews via their Iridium phone all the while.

 

Alas, little more than a year later in June 1999, Iridium's fortunes had faded such that another expedition - this one crossing the arctic icepack and relying upon Iridium phones - almost lost their service when Iridium began to shut down. A special service for expeditions such as the one in the arctic was established at the last minute. Meanwhile, all other Iridium phones on Earth were going silent.

 

Instead of becoming the global telecommunications preferred choice for users around the world, Iridium became as much a high tech toy for the rich and famous as it did a lesson in bad market research. By August 1999 Iridium declared bankruptcy. Given the amount of money invested and the looming failure that lay ahead, many financial publications and analysts referred to its failure as one of the largest and most significant in recent history.

 

 Rescue Attempts

 

A number of rescue attempts surfaced. The one given the most credence was that proposed by billionaire Craig McCaw which involved a purchase of the company for $6 billion. That offer was later withdrawn when it became clear that the purchase would not make economic sense. NASA even turned down a chance to take over the network citing no clear use to which they system could be put. The end is now abundantly near: another offer surfaced this summer offering a scant $30 million for the entire suite of ground and space-based assets - a capability worth more than $5 billion just a few years back.

 

The concept of a global telecommunications capability for consumers is not dead by any means. Despite Iridium's seemingly inevitable demise, one time Iridium White Knight Craig McCaw (with backing from Microsoft's Bill Gates) is building the $10 billion Teledesic system. Teledesic is scheduled to debut in 2005 and will use a swarm of 288 satellites to deliver high-speed video, data and telephone to anyone, anywhere on Earth. Teledesic is a true product of the Internet and wireless age and seeks to embrace and build upon this technology whereas Iridium was not designed - or able - to do so.

 

The Iridium satellites were initially launched by a combination of Boeing's Delta, Russia's Proton, and China's Long March launch vehicles. The first launch occurred in September 1997. The operational constellation was completed a year later. Deorbiting the Iridium fleet is now set to begin in the next few weeks and could cost $50 million or more to complete. In addition to the operational satellites (72 operational satellites were launched) a number of test, decommissioned, dead, or spare satellites were lofted bringing the total fleet to 88 - all of which need to be brought back to Earth in a controlled fashion.

 

Beauty in demise

 

One of the unexpected benefits of the Iridium project was catching "Iridium Flares". Each Iridium satellite has two Main Mission Antennas, long silver-coated teflon structures oriented 40 degrees from the axis of the satellite. As the satellite passes overhead and passes into the right configuration with respect to the sun and a viewer on the ground, a brief bright flash of light occurs. These flashes ("flares") last only a few seconds but can be brighter than the planet Venus. The prediction and observation of these flares has become a rather popular sport for amateur astronomers with a number of websites dedicated to published tables and instructions.

 

It is ironic that the only lasting visible legacy of Iridium over the next few years will be to serve as flashes in the sky as they orbit overhead and then crash back to Earth.

 

The next new thing

 

Teledesic is due to debut in 2005 and has set some rather lofty goals for itself: "On Day One of service, Teledesic will enable broadband connectivity for businesses, schools and individuals everywhere on the planet. The Teledesic Network will accelerate the spread of knowledge throughout the world and facilitate improvements in education, health care and other crucial global issues." This is eerily similar to some of the things Iridium had to say about itself on the eve of its launch.

 

Teledesic is by no means the only service under development - check out Wired Magazine's 1998 list of who's who (Space Jam). It will be just as crowded overhead - if not more so - in the years to come.

 

We all want to have a communicator like Captain Kirk had so we can call talk to anyone anywhere on this planet - at anytime. The real challenge is for the private sector to meet our demand - and adapt to it as our demand changes. Imposing a solution that doesn't meet actual demand (or the imminent prospect thereof) is doomed to failure.

 

As far as Iridium is concerned, the rocket science worked like a charm - its the underlying economics that failed.

 

http://www.spaceref.com/news/viewnews.html?id=208

 

 

Nakon kraha Disprozijuma, na svetlo pozornice stupi Teledesic sa svojih 288 satelita...

 

Teledesic Relinquishes License

 

By Staff Writer | July 14, 2003 | Feature

©       

Teledesic’s one-time plan of launching a $10 billion constellation of satellites to provide broadband services worldwide has been gradually scaled back over the years. But the company’s latest move of returning its Ka-band license to the Federal Communication Commission (FCC) stops just short of shutting the whole thing down.

 

The dream of telecommunications pioneer Craig McCaw to develop Teledesic into a “broadband in the sky” venture now appears to have ended. Originally licensed by the FCC to provide broadband satellite services in the 28.6-29.1 GHz and 18.8-19.3 GHz bands using a constellation of 840 non-geostationary satellites, Teledesic was considered impractical by many critics from the outset.

 

McCaw succeeded in recruiting Microsoft [NYSE: MSFT] Chairman Bill Gates and other well-heeled financial backers to support the development of Teledesic. However, not even McCaw and his “Who’s Who” of supporters could overcome doubters in the financial markets.

 

With billions of dollars needed, the cost was too high to convince Wall Street investors that they would get a payoff within a reasonable period of time. The financial markets had already seen three bankruptcies in the mobile satellite phone market – Iridium, ICO Global Communications and Globalstar. These companies were technologically successful but they never came close to recouping the billions of dollars invested to build and launch each company’s constellation.

 

Teledesic acknowledged last September that it was undergoing a reality check when it suspended work on two satellites that it had contracted to build under an agreement with Italian satellite manufacturer Alenia Spazio.

 

Also at that time, Teledesic significantly reduced its staff and announced plans to evaluate possible alternative approaches for its business. Company officials stayed low-key until Teledesic sent a June 27 letter to the FCC in which it surrendered its Ka-band license and asked the agency to dismiss a related modified application.

 

ITU Approval

 

Teledesic was also able to obtain approval from the International Telecommunication Union for its broadband satellite system. Teledesic managed to enlist the support of the U.S. government to advocate the company’s position to win an allocation for the system at a previous World Radiocommunication Conference (see related story about this year’s WRC). Those efforts now appear to be for naught.

 

Before Teledesic’s plans collapsed, the company had reduced the size of its massive constellation down to 30 medium-Earth-orbit satellites and ordered the construction of two of them from Alenia in February 2002. But company officials ultimately concluded it was not prudent to continue the substantial capital expenditures required to construct and launch the satellite system to meet FCC and ITU regulatory milestones “purely on speculation.”

 

That view was offered after company representatives assessed the financial markets and the commercial prospects for satellite broadband communications. Teledesic spent hundreds of millions of dollars to design and to develop its global broadband satellite system concept over the past decade, company officials said.

 

“Our decision to suspend our activities results from an unprecedented confluence of events in the telecommunications industry and financial markets,” Teledesic Chairman and Co- CEO McCaw said last September. “We do not presently see elements in place that would result in returns to our shareholders that are commensurate with the risk. We continue to believe that the Teledesic service would ultimately provide unique and measurable benefits to the world, and we are looking at scenarios to preserve the ability for that service to be realized,” he said.

 

The view from Teledesic management in September was that the scaled-back system could be useful to governments to aid with disaster relief, anti-terrorism, defense services and other critical government activities. The availability of ubiquitous, quality broadband service to the roughly three billion people who lack access to terrestrial capabilities was considered a worthy and potentially profitable mission, company officials said.

 

Impressive Investors

 

Aside from financial backing from McCaw and Gates, Teledesic’s strategic investors included Saudi Prince Alwaleed Bin Talal, Boeing [NYSE: BA] and The Abu Dhabi Investment Co.

 

McCaw and an investment group he headed spent $1.2 billion during May 2000 to acquire ICO from bankruptcy court protection. McCaw had originally planned to combine Teledesic and ICO in some fashion. With Teledesic’s demise, ICO faces a number of challenges to get its service up and running again. ICO is dependent on sorting through a number of regulatory matters, the raising of adequate financing, access to sufficient spectrum, and the operation of its technology without interference from other services, according to the company. ICO has an FCC license to use the 2 GHz band for its satellite and ancillary terrestrial services in the United States.

 

Perhaps McCaw can learn a few lessons from his Teledesic misstep. “The long story of the Teledesic system that never got built illustrates a common flaw in technology-driven business plans,” said D.K. Sachdev, who heads the Vienna, Va.-based SpaceTel Consultancy. “Very capable system designers develop a revolutionary system architecture and then try to force-fit whatever market data is available to justify the investment.”

 

The concept of using Teledesic to provide ubiquitous broadband access to fixed stations around the world is as technologically sound today as when “epic battles” were fought in the 1990s at the ITU to allocate the Ka-band for such a service, Sachdev said. However, the market justification was flawed then and did not improve in the interim, he added.

 

“It is true that billions of people around the world are without phone service,” Sachdev said. “But what they need is local phone service and not connectivity around the world. And they certainly are not going to pay even 50 cents per minute for a call, notwithstanding the revolutionary technology being offered.”

 

In that light, McCaw and the other Teledesic backers deserve credit for not building even the scaled-down version, Sachdev said. Others are not so wise. Misguided efforts are now underway to salvage the Astrolink broadband satellite system, he added.

 

At the same time, there have been some encouraging signs from regional systems, such as AceS, Thuraya and iPStar. They are test marketing broadband satellite service in limited environments, Sachdev said. If the business models of the regional systems are validated, one day a case also might be made for the more ambitious, costly and risky global systems, he added.

 

Roger Rusch, a satellite consultant who heads the Palos Verdes, Calif.-based TelAstra consulting firm, described Teledesic as a pioneering effort that deserves to be recognized as a worthy attempt to provide broadband by satellite using the latest technology.

 

“In the long run, we expect these services to be provided by geostationary satellites that will be more economical to build and operate,” Rusch said. “The dream of providing broadband services by satellite is still alive with projects like WildBlue and [Hughes Network Systems’] SpaceWay. The goal of providing these services worldwide has merit and will be realized in the near future.”

 

‘Tremendous Impact’

 

Teledesic should be acknowledged for making a “tremendous impact” on the satellite industry when it proposed to offer broadband data services worldwide, Rusch said. “The concept of a major switchboard in the sky had been a theoretical dream until it was embraced by McCaw and Gates. Teledesic electrified interest in high-speed Internet services by satellite,” he added.

 

“Unfortunately, the extensive Teledesic network was extremely complex and expensive,” Rusch said. “After years of study and refinements by several major manufacturers, the cost was still prohibitive. It was not possible to find sufficient financial backing to fund the large capital cost,” he concluded.

 

–Paul Dykewicz

 

(William Owens, Teledesic, 425/602-0000; D.K. Sachdev, SpaceTel Consultancy, 703/757-5880; Roger Rusch, TelAstra, 310/373-1925)

 

http://www.satellitetoday.com/publications/st/feature/2003/07/14/teledesic-relinquishes-license/

 

Danas Google, FB i SpaceX pokušavaju da urade istu stvar, na isti način i nadaju se drugačijem ishodu.  

[Prokleto Djubre]

 

Danas Google, FB i SpaceX pokušavaju da urade istu stvar, na isti način i nadaju se drugačijem ishodu.  

 

 

Znam da ovaj argument u osnovi gusi raspravu, ali ne mogu da ne podsetim na to da se ne radi o grupi maloumnika koji su bezali sa casa pa nisu svesni problema koji ih cekaju niti onih koji su slicnu stvar pokusali pre njih. Istorija tehnologije je prepuna primera kako se izmenom stanja neka ideja koja je pokusana puno puta i od vecine smatrana nemogucom u novonastalim uslovima odjednom postaje uspeh. Ja bih sacekao da vidim barem pocetak USA faze, a najveci problem koji mi je ocigledan je brzina odziva i zanimljivo ce mi biti da vidim da li ce to moci da se resi (i cak pitanje da li ce morati).

[bigvlada]

Da pokriješ celu kuglu potrebna su ti minimum tri satelita. Što ideš niže treba ti sve više. 4000+ komada u orbiti košta više od većeg broja balona, dirižabla ili aviona na solarni pogon koji mogu da obave istu stvar. Logistika održavanja i praćenja tolikog broja satelita je monstruozna. Šta se dešava kada im istekne (kratki) životni vek? Šta se dešava kada crkne 30 komada na različitim mestima u mreži? Da li će čekati da crkne još 20 pre nego što pošalju raketu sa novih 50 komada? Šta se dešava ako raketa sa 50 novih satelita eksplodira na rampi? Nose li sateliti dovoljno goriva za drastične promene orbite jer neće sve rupe na mreži biti jedna blizu druge? 

 

Poluskuvana ideja, kao i ona sa gradom na Marsu od milion ljudi (deo gde govori da će im trebati državne pare za to ga trpa u isti koš sa ostalim sličnim predlozima koje NASA (po rečima Čarls Boldena) dobija jednom nedeljno).

 

Istorija tehnologije je i puna аviona sa 10+ krila gde se svaki sledeći nadao da će baš njegov dizajn biti onaj pravi. Jedina razlika u odnosu na Iridijum je što su povećali broj satelita sa 66 na 4000+ i smanjili im visinu orbite. Veći broj krila satelita ne umanjuje probleme već ih uvećava. 

 

edit: SpaceX je pre nekog vremena rekao da im se ne isplati da lansiraju satelite mase nešto manje od tone sa cenom u rasponu od valjda 7-11 miliona dolara. 

Edited November 21, 2016 by bigvlada