I was listening to the Space Show interview Elon Musk.
I thought for all that effort to build the Falcon - how much more would it have taken to do a Nuclear SSTO.
Remember the Triton engine from PW - could that do it?
Hec - lets say the Goverment approved it - why wouldn't they? (oh yea it has the word Nuclear in it ... sigh avoiding the antinuclear culture would be hard but not impossible)
Has anyone really tried do a private Nuclear rocket?
From what I read here, you guys remind me that many of the problems have really been thought out. Such that a good starting point can be found to build a successful craft.
I would say, emphatically: Yes, it could be done by a private individual with sufficient financial resources.
However, going alone requires substantially more costs because it would still require a substantial infrastructure to be built, with exhaust scrubbing test stands, hot cells, fuel fabrication facilities etc. Going it alone--without any government assistance--would probably require atleast $15-20 billion and probably more, as well as the use of a cooperative country. Someone with the financial resources of Bill Gates or Warren Buffet could possibly accomplish this, but it would be an expensive enterprise.
With US government cooperation, a private citizen 'going it alone' (convincing the governement to use certain facilities) may be able to accomplish the same thing for substantially less. However, it would still take billions of dollars, and would likely employ the services of such companies as Boeing and Pratt and Whitney. Still I would imagine that a nuclear SSTO could probably be built using a cluster of afterburning Tritons for $15 billion dollars, maybe less. I am pulling this numbers out of thin air--so please don't give them too much weight. It is somewhat distressing to me at how much inflated the aerospace project costs tend to end up being--for instance the $15 billion International Space Station with a final price tag of nearly $100 billion! But I digress!
The nice thing about nuclear SSTO's is that they can remove some of the weight constraints that typically plague such a machine. For instance, instead of using graphite fiber propellant tanks, more or less standard lithium-aluminum alloys could be used. Instead of using space shuttle style thermal protection tiles, a heavier but more durable refractory metal skin with a silicon-carbide coating and undershell thermal SiO2 insulation could act as the heat shielding material.
A larger machine could deliver a substantial payload and return to Earth to fly again. The dream of any decent rocket scientist! Nuclear SSTO may be the wave of the future!
I don't think anyone has tried a private nuclear rocket because the technology needed to fly is challenging enough as it is without adding the nuclear tech to the equation. Several private groups have experimented with liquid fueled rocket engines, and one in particular as publically stated the goal of being the first ameteur group to orbit a sattelite (this would be the Reaction Research Organization, which can be found at www.rro.org ) But given the right circumstances, a private investor willing to accept ALL of the financial risks, and a Gung-Ho space oriented US administration--I think it could be done. There really isn't anything startlingly new about any of the technology needed. I see it as a technology integration problem--which is an order of magnitude less of a problem than developing the technologies needed from scratch.
I would agree with the above assessment -- except that it ignores regulatory realities.
Even if you had all the money in the world, you couldn't get yourself out of the corner that the US has painted itself into with regulations governing nuclear affairs.
The rules require that space nuclear reactors such as the PW Triton or a JIMO NEP must be delivered into orbit in a state in which its physically impossible for them to go critical in case of a launch accident, particularly one involving falling into the ocean.
This is possible to do with a reactor that only starts up once in orbit (or beyond), following final assembly or reconfiguration on-orbit.
But its not possible with a reactor that's powered up right from launch: Water in the ocean greatly increases neutron moderation and reflection. Normally a shutdown system could be designed with enough margin to counteract even this, but it cannot be counted on to work in an accident situation.
Of course the private developer could try to base his project in some other country. But that would likely result in a loss of much of his launch customer base (assuming he's in it for the business). In such a situation, the US would likely push other nations to embargo the host country.
Technically though, even the worst accident would not be that serious, because of the small size of the reactor and the short operating time (from launch to accident and ocean impact), hence low radioactive inventory. Upon impact, a large power burst would likely blow the reactor into several subcritical pieces, which would then harmlessly sink to the bottom of the ocean. Large pieces would have to be recovered, to avoid any possibility of diversion.
Anyway, these are some of the reasons I found it so bizarre that ESA actually funded a study of nuke SSTOs. If anything, their regulations (not to mention politics) are even more anti-nuke than those of the US. I guess they figure "no harm done," as long as the concept stays on paper
Involving nuclear materials will almost assuredly involve the government--probably no way around that..
Agreed on the interaction of sea water with nuclear reactor components--a highly enrinched uranium reactor would almost certainly blow once the sea water gets in.
I am reminded of something that I once read concerning the Little Boy bomb, the uranium bomb dropped by the Enola Gay on the city of Hiroshima. Some of the miltary types had expressed concern that if the Enola Gay were shot down whether the bomb might be recovered intact by Japanese salvage crews. The phsycists concluded that once the bomb imacted the ocean and sank, then as the sea water forced its way inside, the neutrons would be moderated to the point that the bomb core would 'switch on' and begin a chain reaction. It wouldn't be long before the thing 'fizzled'--it was felt that the energy evolved would be enough to vaporize almost all of the bomb, even if it wasn't triggered by anything else. So no salvage would be possible....
It is true that in an SSTO several reactors, and in a large one perhaps ten or twelve--would be required to fly the vehicle. Having such a machine plummet into the ocean after an accident would definately create quite a mess. No doubt about that.
Still, it could be done.
Regulations are there for a reason--generally they're for safety. Operating nuclear vehicles should be held to the highest reasonable safety standards. Given a large number of launches, accidents are inevitable. Perhaps a design could be conceived to encapsulate the reactors in jettisoneable 'capsule' that has indipendent floatation of recovery beacons. I don't know, but this starts to sound a lot more complicated...
Thanks - you hired - as soon as I gather the billions, country and the permission of my wife.
Since trying to answers 10kBq jaro sad but true concerns leads me to the land of do-nothing. I think you are right to a point - but... I think there are changes in the world. For example this article from the Oregon
DAVID REINHARD
"T here is now a great deal of scientific evidence showing nuclear power to be an environmentally sound and safe choice. A doubling of nuclear energy production would make it possible to significantly reduce total [greenhouse gas] emissions nationwide. In order to create a better environmental and energy-secure future, the [United States] must once again renew its leadership in this area."
OK, guess which nuclear-energy champion made the statement above. Vice President Dick Cheney or a uranium cufflinked lobbyist for the nuclear industry?
OK, guess again. The pro-nukes manifesto came from Greenpeace founder Patrick Moore. The head of Greenspirit Strategies testified before Congress this past April, and he's not the only big-foot environmentalist who's rethinking nuclear power.
I also think that the lure of "real" engineering solution to build an effective SSTO won't stop other countries. The US Govt. won't do anything till after it's done else where and there are countries that can say 'so what'.
But ..... I rather build one.
On the engineer side, what was said was quite interesting. I think you are to high with the $15 B - but hey it's a SWAG as you said. Timeboxing it - I figure 7-14 years depending upons your starting point.
I had to go look at the liberty ship plans posted here, which gave me a thought.
Since I just produce $100Billion Virtual dollars for my imaginary space company - I'm just curious about the following thought experiment.
Mission : Fly to the moon and back, handle a 3 to 6 month duration for 8 people - and a respectable payload. Am I being to conservative? WAY to optimistic - I can print up more money?
The real # I'm curious is what would be the recurring cost of a Nuclear SSTO to a conventional SSTO.
Isn't it interesting how, once the enivironmental lobby calms down and logically rethinks some of its positions that nuclear power looks more like a friend than an enemy?
Intrinsicly safe high-temperature gas cooled pebble bed reactors built around a 'cookie cutter design' -- i.e., same design manufactured over and over again -- is a logical choice. The Chinese and South Africans are heavily invested in this technology and are codeveloping it--other countries like Germany are looking into it. Typically the US is lagging a quite a bit--hopefully we will get our collective behinds in gear and go for it. Nuclear power maybe one of the things that can save us from Petroleum Slavery--in my humble opinion!
Getting back on topic: recurring costs of an nuclear SSTO. I'm not sure. It would depend upon many factors, almost all would be hard to pin down until something like a finalized design was conceived. However, I can guess.
For something capable of a lunar round trip--that implies pretty high performance. The nuclear Liberty Ship conceptualization used gas core "Light Bulb' reactors--a technology not yet developed as far as I'm concerned. This implies a lot of R&D yet--and a lot more moeny.
A more modest technological application--something using more conventional Tritons is much less a technological leap. However, performance will be satisfactory for achieving LEO in a SSTO configuration, I don't think it would be good enough without staging to achieve 'round trip lunar surface operations.' The delta-v requirements for such a mission--probably right around 20km/s minimum (without doing the math or looking numbers up, but this ought to be close) are such that without the ability to get 1500 sec of specific impulse, a single SSTO probably couldn't do it.
However a good SSTO could achieve Low Earth orbit and supply a depot. An intermediate waystation -- gee, wasn't the original International Space Station supposed to fill this role, hmmm? -- could be the launch point for many different kinds of missions, including trips to the moon, nearby comets and Earth Crossing Asteroids. Even Mars.
Current thinking is to go back to the moon, establish a base there, and then there is the 'vague' thinking of using it somehow as a base of operations for launching deep space missions. All fine and dandy, until you look at the numbers. Resupply and outfitting the lunar base with the stuff needed for deep space missions will consume almost as much delta-v as launching the deep space mission itself--so I don't see the moon as an advantage there. Eventually in the long term--once the infrastructure is built up there it makes sense, but nearer term I don't see it happening.
The recurring costs for a nuclear SSTO, if it is done right, could be fairly low. Obviously propellant costs: liquid hydrogen, a little liquid oxygen and some RCS propellants. Ground crew costs: if it is done right with onboard diagnostics and vehicle checkout, then thousands of people won't be needed. Maintenance of the engines and replacement of nozzles and throats as needed. Turbo pump maintenance. Complicated by some need for hot cell isolation if exposed to neutron flux from reactors, however as Jaro points out, the overall operation time is low compared to commercial reactors, so intensity of decay radiation ought to be proportionately lower. I'm thinking that such a vehicle ought to be capable of a fairly quick turn around with minimal costs--no more than $25 million I should think unless more major repairs are needed. Still, it's just a guess. A detailed engineering analysis is needed. But once a company has an established fleet of vehicles and the attending support infrastructure, the recuriring costs will amortize nicely so that individual per 'pound' payload costs will be pretty low. A fleet of 25 vehicles with support infrastructure will be able to supply an orbital depot with enough material and propellant to outfit some really nice missions--both to the moon and beyond.
Thanks for the write up - really appreciate your insights.
Isn't it interesting how, once the environmental lobby calms down and logically rethinks some of its positions that nuclear power looks more like a friend than an enemy?
Aye!
Nuclear power maybe one of the things that can save us from Petroleum Slavery--in my humble opinion!
And why not study radiation....learn push understand move forward... Some times I wonder how the first arguments for the usage of fire went.
Some hundred thousand years or so ago, An early engineer was playing with fire. A fellow tribe member walks, you know that stuff is dangerous, says one of the tribe - i saw it burn up the whole forest once. Hmm says' the other... But then that tribe member died early of food parasites while the engineer continue forward.
Oh yes, don't forget that the first Steam engine was built in ancient Greece. The sad joke goes, When Heron showed it to the governor, the governor said what would they do with all the slaves?
An interesting read of how society views engineers.. http://www.mlahanas.de/Greeks/HeroAndLoon.htm
Anyway..
If you guys go work for Blue Origin - tell us.
Back on track with the SSTO thread.
It’s not an engineer issue to build one – just that knowledge is cool.
So if one lined up the various SSTO and compared them from a business perspective and look at cost, performance. The best answer is a nuclear SSTO.
Another factor that I would add - is such a system would be one of the most effective space fleet.
These are very strong motivational forces. The counter force is only political, hence by aligning where the motivation is strong and the counter force is weak. One can find the most likely place for this type of construction.
So China or some other country could build the first one.
Unless one dealt with the political force. I think that is actually doable, especially if the public mellows out about nuclear with education. The Internet is helping.
I think you can contain this fear by where your spaceport is located. Working on the philosophy - Out of sight ...
I actually think the current political admin would buy into it - not that I like them. But they don't appear to have much fear about nuclear power.
Still given the momentum of people my guess is that we will see a nuclear rocket within 20 years. It will be the efficiency factor that will be the forcing function.
