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Just as you and John C. have indicated, the radioactive mess resulting from an NTR explosion in the atmosphere would be infinitely worse than the low level contamination of the exhaust plume from normal operations. I should have mentioned this in my earlier post. Soph was quite right to have questioned my remark on the exhaust issue.
You know, kneejerk anti-nuclear stuff like this simply HAS to stop.
<sigh>
First, what KIND of NTR did you discuss with your long list of smart people? Yes, they come in kinds.
Second, the idea of the tiny amount of D in normal LH2 being activated to T is simply laughable. The scattering MFP in liquid hydrogen is 48 cm. It takes at LEAST 5 scatters to thermalize a neutron, and the absorption cross-section of hydrogen or deuterium is miniscule. If you're REALLY worried about activating your fuel mass, add a couple of kilos of boron foil to the engine in strategic places, that'll mop up any thermal neutrons before they can affect the hydrogen.
In other words, NO, an NTR does NOT produce radioactive hydrogen exhaust, except in the minds of the most irrationally paranoid. You would be more at risk going into your basement and breathing the radon.
Now, as for your contention about how dirty an NTR would be in the case of a total loss of containment: If you choose the right launch site, this risk is easily mitigated. The "Castle" series of nuclear tests released thousands of times as much radiation as the "accident" at Chernobyl, and only two people died. The Soviet Union performed MUCH larger tests than Castle, and as far as I know, nobody at all died in those.
Radiation releases ARE NOT DANGEROUS, if the risk is mitigated. Mining coal is thousands of times as lethal as all of the accidental or deliberate releases of radiation throughout history, except for two.
Wow, that sounds crazy, doesn't it? Well, the facts bear me out. When I have a bit more time, I'll post some supporting links if you don't believe me.
Why, oh why, does everybody have this reflexive fear of nuclear? Doesn't anybody think anymore?
NTR's can achieve Isp's of AT LEAST 1000, and possibly as high as 5000, with technology available RIGHT NOW. If we would take the money we are dumping into HEDM research and move it to advanced NTR research, we could have a NTR HLV flying in 5 years, with performance dramatically better than anything we have ever seen.
<sigh> This FUD just makes me so nuts....
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I think you are seeing something where there is nothing, mauk2. We all seem to be taking a moderate position here, as we don't know that much about the whole thing itself.
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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I am the one who went into as much detail as I can to say that the low level of radiation from a Pluto nuclear jet engine will decay within 2 hours. Furthermore, what radiation that does exist is of a type that does not penetrate through skin. Extremely intense beta radiation can cause skin cancer, but I doubt you would get that intensity unless you stood directly in the exhaust of an operational nuclear jet engine for an extended period of time. I tried to say the quantity of tritium would be negligible and easily ignored, but if you are saying none would be generated at all, then so much the better.
Yes, catastrophic failure of a NTR or nuclear jet engine would produce a mess. Yes, any catastrophic failure would produce a mess, including a jet airliner falling out of the sky. I wouldn't want a 747 falling onto my house. Now how do we convince local yokels to say away from the debris of a crash? A rocket crash would have jagged metal shards as well as rocket fuel. Commercial communication satellites use hydrazine derivatives, such as UDMH, in the upper stages. That is toxic and hypergolic. These dangerous chemicals just scream "stay away". You could argue that encapsulated spent reactor fuel pellets are just the same; dangerous debris that should be collected with protective clothing by experts who know how to handle them. In fact, if the fuel capsules are large enough they would be easy to locate, especially with a Geiger counter.
Now comes the practicality. Politics is a strange thing. People have to become gradually used to an idea after an extended period of propaganda. It would be more effective to start with NTR upper stages and nuclear electric propulsion. After the public has come to think of use of this technology as routine, then we can consider nuclear launch vehicles. After all, we now have to deal with government officials and administrators who think the earliest they can send the initial manned mission to Mars is 2030. Apollo went from J.F.K.'s speech to men on the Moon in 8 years. Today we have much more advanced technology, and are debating how much is left of a launch vehicle that could do the job 15 years ago. I don't think we need to introduce something as politically controversial as a nuclear launch vehicle for the first manned mission.
I did mention Janyce's idea. That is using a Pluto derived nuclear jet engine, but configuring it to operate as Nuclear Thermal Rocket to get up to speed where the ramjet can ignite, then functioning as an air breathing jet engine as long as practical, then transition back to NTR for the final push to space. Notice I said "practical", not "possible". She believes it costs 20% to get 80% performance out of any theoretical aerospace technology. That means it would be much more cost effective to develop a nuclear jet engine to operate to high supersonic speed, rather than trying to operate as a ramjet to extreme hypersonic speed in extremely thin atmosphere. However, I don't think it is necessary for the first manned mission.
By the way, I also know Chris Hirata.
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muak2,
Your knee-jerk attacks on anyone who dares mention environmental concerns have to stop. Sorry, I did not realize that Chernobyl had no negative health effects on anyone. Good thing we have someone as smart as you to point these things out to us. Perhaps you can offer the French military the use of your basement for H bomb tests, so they won't have to worry about all those pesky Pacific Islanders anymore.
Do you deny that the same Soviet technical community that was willing to undertake the kind of nuclear tests you describe, felt obliged to cancell NTR HLLV research out of environmental concerns over the possibility of catasrophic launch failures? I guess you must be much smarter than they were.
In previous posts I have repeatedly stated my support of NTRs for TMI applications, stressed the superiority of nuclear-electric over solar-electric propulsion, and always recognized small "slow poke" type reactors as by far the best near term source for Mars surface power. I also advocate the use of thermo-nuclear explosivesives to help spread volcanic ash over the Martian polar caps as part of a Terra-forming plan. Is this what you call "reflexive fear of nuclear"?
Seeing as you have obviously given this a lot of thought, how do you propose to get around the U.S. sponsored international agreements that ban the use of NTRs in the atmosphere? Where exactly is the "right" launch site? Who will pay for this new facility? Kindly provide a detail outline of the technical and performance specifications of this amazing new NTR HLLV you propose have flying "within 5 years." How much will it cost? How do you arrive at this cost? Who do you expect to pay for it? Do you seriously think that diverting every cent of public money away from HEDM will cover even five percent of what it will take to bring it into full scale production and operational service? Perhaps diverting the HEDM research money in question to help build Transhabs and ERVs would be a better use of the funds.
Maybe you and your friends have the money to develop and build your proposal. The public certainly won't be willing to pay for it, least of all the ESA, RKA, JSA, CSA etc., etc.
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rob:
a lot of people at several forums have been keen on the idea of, if the space elevator is completed, or we have cheaper RLVs, sending a NPP or NTR ship up to orbit piecemeal, avoiding an earth launch.
this is especially attractive with the elevator, because its cheap, and easy to get to a central location. If you assemble it in orbit, and launch from there, you avoid the political implications of an earth launch, and are far more likely to receive political support.
I've been thinking of combining Orion-style pulse propulsion with an ion drive, for short bursts of acceleration combined with long distance cruising-its a great combination, i think. And ion sounds nice to the public. People will like the idea.
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I like what you guys have said about the Energia and using Khouro. Seems to me it could be done. Get an assembly line going and maybe we'd have a relatively cheap RHLLV system. The Ares would take a fair amount of development and then there's those SRBs. How about using Zenit boosters on an Ares instead of SRBs?? Here's a good one if you haven't seen it already: http://www.russianspaceweb.com/energia.html
I read Robert Dyk's letters to Russia and translations. Don't remember exactly how I found them, Robert!!! One thing bothers me-LH2 is just fine for launching small numbers of payloads to Mars, but what about routine space flight?? What if we fueled up the Energia core with liquid methane and LOX instead of LH2?? It would cut the payload mass down but it could allow more routine launching. LCH4 might be cheaper than LH2 also. And what about recovery of the four core engines? Is recovery of the core tank possible? I imagine an inflatable heat shield in the nose of the core tank might make it recoverable. If we can just get the main engines back and use the Energia core or ET for the Ares in space for stations, ship hulls, surface hab, storage tank, scrap metal even grind it up for rocket fuel (Al powder+LOX) we might have an excellent system. See http://www.space-rockets.com/Wickmans.html and http://www.spaceislandgroup.com
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LCH4 is, indeed, the cheapest high-performance rocket propellant, according to "Case For Mars." However, it's not so easy to simply "switch fuels" in a rocket. Hydrocarbon fuels are very dense, while hydrogen is not. Hydrogen tanks are generally much larger than hydrocarbon fuel tanks in an equivalent rocket. Just compare the tanks in the Atlas V core (kerosene) and Delta IV core (hydrogen.)
I also came across an interesting tidbit on astronautix.com: mounting the payload on top of the rocket allows it to launch a heavier mass, but the stresses are quite different than those associated with lateral payloads, like the Energia payload and Shuttle Orbiter. This is one reason why NASA's "Magnum" concept dispenses with the Shuttle ET and goes with a new core rocket. It's just another factor to consider when talking about redesigning or improving Energia.
"I'm not much of a 'hands-on' evil scientist."--Dr. Evil, "Goldmember"
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Yes, the tanks would have to be redesigned and the engines modified. More thrust would be needed to lift the rocket off the ground also as the lower energy CH4 will amass more. I am just wondering about launch rates. Fueling up a rocket with LH2 is a big deal. The tanks actually contract due to the cold. Everything is checked out before the rocket is fueled up and checked again after fueling. LCH4 would also be cold. I must wonder if a shuttle burning kerosene and N2O4 or H2O2 would ever work for regular scheduled space flights for tourists let's say.
Yes, the ET would have to be redesigned for the Magnum or Ares. The Energia is designed to haul a 150 tons payload (I've also read 170 and 200 tons) mounted on top of the core with 8 Zenit boosters on the sides of the core. They call this configuration Vulkain. With 4 Zenit boosters 95 tons. Energia exists in reality. Magnum and Ares do not. The Russians need money, but would they offer a fair price? Would they deliver reliably. The only thing that seems to work in Russia these days is the mafia. I'm not cutting down Russians. It's just a sorry situation over there.
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I don't think that cryogenic propellant poses any significant problems regarding high flight rates. Liquid oxygen is handled routinely by enlistedmen who empty it into the breathing systems of military aircraft. Several reusable rockets were built using cryogenic fuels. These include the X-15, DC-X, and EZ-Rocket. The DC-X and EZ-Rocket have demonstrated quick turnarounds. They were not without problems, but such bugs are inevitable when developing new technologies and techniques.
"I'm not much of a 'hands-on' evil scientist."--Dr. Evil, "Goldmember"
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some good sites on it
http://members.lycos.co.uk/spaceproject … gialv.html
http://www.k26.com/buran/]http://www.k26.com/buran/
Energia is currently only really working on big projects for the ISS
'first steps are not for cheap, think about it...
did China build a great Wall in a day ?' ( Y L R newmars forum member )
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I'd like to see China work on an R-56 type HLLV. R-56 was to have four RD-270 engines--but if six were used, it would have nine million pounds of thrust.
Their new projects are converting to lox/kerosene or lox/hydrogen. They would have to scrap all their existing rockets and get new propellant handling capabilities. Best to go for a big R-56 Monoblock and a big pad for it--and keep the existing vehicles. They have solids coming along anyway.
To go to a whole new propellant regime and a whole line of rockets--which can take no more than 30 tons to LEO--seems a bit wasteful.
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Yet more on the heavy lift front:
http://www.space.com/businesstechnology … d_cev.html
http://images.spaceref.com/news/2005/il … go.med.jpg
http://images.spaceref.com/news/2005/ilc.chart.med.jpg
http://images.spaceref.com/news/2005/esmd.study.lrg.jpg
http://images.spaceref.com/news/2005/es … on.lrg.jpg
http://www.spaceref.com/news/viewnews.html?id=1057
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thanks for the links
'first steps are not for cheap, think about it...
did China build a great Wall in a day ?' ( Y L R newmars forum member )
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No problem.
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Just bringing this back up.
Hmmm, HLVs would be necessary for Shipyards, or at the very least the first one.
What is it with the public and irrational fears of nuclear? If an NTR was lauched in the middle of a desert, would it minimize the areas that would be effected if something did go wrong, or at the very least confine the really deadly stuff to the uninhabited areas?
Use what is abundant and build to last
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War in Ukraine: Destruction in wake of first strikes on Dnipro
https://www.bbc.com/news/av/world-europe-60706861
Russia hits Ukraine central city Dnipro with missile strikes
https://sports.yahoo.com/russia-hits-uk … 32748.html
The city of Dnipro, was once the heart of Ukrainian space industry, it has a mixed history and fallen to Ottoman Turk muslims in its historical past and fallen to Russians in the past, it has been known for its hundreds of schools and institutions. It has Arts and new theatres plus Opera the Dnipro Metro system and hydrofoils operating on water, winter games stadiums, religious Synagogue, majestic cathedral founded by order of Catherine the Great, it was one of the key centres of the nuclear, arms, and space industries of the Soviet Union and Ukraine.
If the Russian news reports that they will abandon Baikonur by 2005 are just bull shit attempts to pressure Kazakhstan to reduce their "rent", then we still have the Energia launch facilities.
This was an interesting bluff the Russians made many years ago but now they have lost acess to the European Spaceport in Kourou in French Guiana S.America.
Thankfully the commerical space industry has grown since these days and Musk is doing great with SpaceX.
Last edited by Mars_B4_Moon (2022-03-11 13:43:39)
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Araine won't launch ExoMars for some time yet...maybe another launcher?
The New Ariane 6 Heavy Lift Rocket is Finally on the Launch Pad, But Won’t Liftoff Until Late 2023
https://www.universetoday.com/158296/th … late-2023/
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Launch vehicle size comparison.
https://m.youtube.com/watch?v=fJ380rPYE4Q
Starship really is a monster.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Ukrainian government criticizes Vega C investigation
https://spacenews.com/ukrainian-governm … stigation/
The Ukrainian government claims that European investigators were “premature” in concluding that a component from a Ukrainian company was the blame for the failed Vega C launch last December.
In a March 6 statement, the State Space Agency of Ukraine took issue with the findings of an investigation published by the European Space Agency three days earlier, arguing that it “casts a shadow over the reputation of the space industry of Ukraine.”
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I think Private Commercial flight will take over from a lot of the old industries.
New companies are not always better and Many of the original big private space flight companies offering tourism are still sub-orbital. Europe seems to be in a strange place even though Ariane is a successful workhorse Europe is probably in a weaker position with the loss of a Vega rocket and sanction on the Soyuz in South America. Even if the USA lost a rocket they still have many choices, Space-X, SLS, Lockheed, Boeing, ULA - Delta, Atlas, Orbital ATK, Vulcan, years of experience and a growing Private Sector with RelativitySpace, FireflyAerospace, RocketLab. Japanese seem to have a vulnerability also and I'm surprised Japan only really had Mitsubishi doing big sucessful rockets later it starts to stagnate, India ISRO plans manned missions using the GSLV Mk.III LVM3 and S.Korea comes out of nowhere and starts having success.
The planned cargo or tests and used we have Cargo transport unmanned SpaceX Dragon, H-II with robot arm also called Kounotori, Cygnus enhanced and the Space Planes or Mini-Shuttle 'Dream Chaser' the Kliper Energia, the MiG-105, the ESA may have retired the ATV and there is the concept of 'Space Rider' I'm not sure if they planned to use it in LEO or Lunar Gateway? Joint missions only exist with Russia on the ISS and there have been sanctions after Russian invasion of Ukraine. Virgin Galactic, Space Adventures, Axiom Space hope to become Space-Liners, Blue Origin offered Space Stations, Space Liners, Space Mining, Spacecraft, Space Orbiters, other players arrive from Japan Hakuto ispace, tech demonstration, Landers, rovers and orbiters Planetary Transportation Systems from Germany and a Chinese private space launch group, China has a lot of private space rocket company startups upcoming. Eris from Australia links with Gilmour Space Technologies also known as Gilmour Space.
Space-X is the biggest game changer, also for Heavy Lift we have NASA's successful SLS launch and perhaps China coming, Firefly Aerospace has a Moon mission, Relativity Space and Rocket Lab are now offering 'GTO' and Deep Space.
Some news
'Rocket Lab Successfully Launches 34th Electron Rocket, Second Mission from Wallops Island'
https://www.wboc.com/news/rocket-lab-su … 30519.html
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Ariane 5 rocket from Europe's spaceport in Kourou, Jupiter Moons mission from French Guiana came after a previous attempt was called off due to the risk of lightning.
https://twitter.com/esaoperations/statu … 3660918784
We have received telemetry from ESAJuice!
ISRO news
'A great team effort. This achievement takes us one step closer to realising an Indian Reusable Launch Vehicle.'
https://twitter.com/narendramodi/status … 6363118594
SpaceX’s Starship Could Launch as Soon as Next Week, Elon Musk Says
https://news.yahoo.com/spacex-starship- … 00651.html
Last edited by Mars_B4_Moon (2023-04-14 09:13:20)
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There was a recent series of leaks and hacks
Russia's space program is crumbling because of US sanctions and the rise of SpaceX, but it's being replaced by China's rapid growth, leaked US intel says
https://www.businessinsider.com/russia- … tel-2023-4
3D-Printed Rocket Didn't Reach Orbit, but Relativity Space Is Already Building Its Successor
https://gizmodo.com/terran-space-opts-b … 1850328629
Last edited by Mars_B4_Moon (2023-04-27 14:19:17)
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Mars_B4_Moon,
Unless something else changed, NASA and ROSCOSMOS are supposed to be partners, war or no war. China wants to be an expansionist empire according to their own internal documents. China has no actual ties to Russia. Their governments once shared a political ideology that destroyed one of them and would've destroyed the other, had America allowed the Chinese government's insanity to run its course. China didn't lift a finger when millions of Russians were starving to death. The aid came from America- all three times during the 20th and 21st centuries. Russia needs to accept that nobody is coming to invade them. All of that was the death throes of colonialism. The old world is gone. It burnt to ashes during the World Wars.
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Arianespace CEO: Europe Won't Have Reusable Rockets For Another Decade
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