Update on Project Prometheus 406
Aglassis writes "It appears that NASA is not backing down from their nuclear space initiative. Project Prometheus has recently started a new web page (under JPL) and NASA is finishing up a period of public comment (last session today). Currently Northrop Grumman is contracted to begin preliminary design of the spacecraft until 2008 for NASA (the reactor will be built by the Department of Energy's Division of Naval Reactors--the folks who control all US submarine and aircraft carrier nuclear reactors). Early specs are that it will be 60 meters long, have a 30,000 kg mass, use a 100 KW reactor using Brayton cycle gas turbines, be powered by ion thrusters with a 7000 second specific impulse, and have a science payload of 1500 kg. Early mission plans for Prometheus 1 (Jupiter Icy Moons Orbiter) indicate that the spacecraft would orbit Callisto, Ganymede, and Europa individually, and perhaps have a lifespan of about 20 years."
Northrop Grumman (Score:2, Informative)
Brayton cycle (Score:5, Interesting)
Disclaimer: I am not a rocket scientist.
Re:Brayton cycle (Score:5, Informative)
=Smidge=
Re:Brayton cycle (Score:3, Funny)
Re:Brayton cycle (Score:3, Informative)
http://www.grc.nasa.gov/WWW/RT2002/5000/549
Only 24% of the thermal heat from the reactor is converted to electricity, but then that's probably pretty good for a closed cycle unit.
No good heatsinks in space.
Re:Brayton cycle (Score:3, Insightful)
As for solar gain, that's simple... position your radiator so that it's parallel with the sun's rays. Let the sunshine hit the edge of the radiator, which would have a much smaller profile and would not be part of the heat transfer surface. You could even build a small sheild or use the craft itself to create a shadow.
=Smidge=
Re:Brayton cycle (Score:4, Funny)
Disclaimer: I am not a rocket scientist.
I am a rocket scientist, so I can anwser your questions. The key is to find planets rich in dylithium crystals. Or we can negotitate with other civilizations.
Seriously, with everything they will need to carry with them, I hope they find a power source that is plentiful everywhere.
And this is another reason why I hope we start colonizing other planets, building little self containted cities with mines and data reasearch centers. What will happen when the space ship runs out of fuel around pluto and nobody is there to help? I know.... it is all science fiction anyways. But maybe if someone can dream it, someone can build it.
Re:Brayton cycle (Score:2)
Cool, could you explain how you end an italics in HTML? Or how to spell answer?
For the humour challenged, Just kidding
Re:Brayton cycle (Score:2)
The PDF is embarrassing (Score:3, Insightful)
That was terrible. Cool project though
This is not un-typical for Gummint projects (Score:5, Informative)
Much of their computing equipment has been scrounged - and doesn't appear on any equipment manifests - because there was no budget for it. They have a Pentium-90 driving (pointing) their main 'scope with a backup P-90 literally sitting on the next shelf in case it dies.
The few pieces of gear that they do get grants for are typically extremely fancy. On the rare occasions when ThePowersThatBe say "yes, you can have a computer to process the incoming images," then the cost of that actual computer system and absolutely nothing else is almost immaterial as long as it fits certain criteria.
So... in the room to the left of the one housing the P-90 sits a you-beauty glow-in-the-dark (well, not literally, it would cause backscatter) state-of-the-art box with double overhead ThermalTakes and all the trimmings. Just one. And I bet they crammed memory and disks into that baby's purchasing spec until the chassis groaned under the weight.
When Mark Shuttleworth [markshuttleworth.com] gave his amazing talk at LCA2005 [linux.org.au], one of the things he mentioned was that the Yanks didn't want their astronauts (also going up in the Soyuz with Mark) flying to Baikonur in a rattly old Tupelov transport lest it unexpectedly drop out of the sky en route, but rather than come out and say so directly they came over all clever and simply pointed out that NASA regs forbade their astronauts to travel without seatbelts, which they knew the Tupelov wasn't fitted with. This was a mistake. On the day, the astronauts were marched out to the Tupelov, and aboard - and into a minibus in the cargo bay, where they sat and wore the minibus's seatbelts for the duration of the trip.
BTW, when the video DVD from LCA2005 gets published, bend heaven and earth to get yourself a copy. It's well worth-while for Mark's presentation alone ("Welcome to Khazakstan!"), and there are many other excellent presentations on it (Keith Packard explaining the sport of Window Hurling [linux.org.au], for example, or E'dale demonstrating how to collapse a penguin's skull [linux.org.au]).
The point in that story which I wanted to use as an illustration here was that the minibus wasn't put aboard the transport for the astronauts' benefit. There was a budget for flying the Tupelov - pilots, fuel, landing fees and so on - but no budget for getting from the airport to where they were staying. So the van (which fell under the base's budget, so was financially covered) was fuelled up and driven aboard the Tupelov for use as a taxi while the transport 'plane was prepped for the return flight. In terms of working around bizarre regulations, NASA or not, the Americans really were amateurs playing in a professional field. (-:
I saw this before (Score:2, Funny)
ahhh they stabilized it (Score:5, Funny)
Re:ahhh they stabilized it (Score:4, Funny)
Re:ahhh they stabilized it (Score:3, Funny)
Oh, I get it - it's a reference to that TV show - "Wormhole Xtreme".
JIMO (Score:3, Informative)
Re:JIMO (Score:3, Insightful)
Wait, then what's all the JIMO stuff on NASA's Prometheus site for? Did they just forget to take it all down? Or haven't gotten to it yet?
http://prometheus.jpl.nasa.gov/index.cfm?pageL1
Re:JIMO (Score:3, Informative)
That said, every NASA visitor's center I've been in still has X-33/Venture Star still prominently displayed. Go figure.
Re:JIMO (Score:4, Informative)
Thank god (Score:5, Insightful)
Re:Thank god (Score:4, Insightful)
Yeah, but there's always the knee-jerk question about what would happen if a Columbia-esque accident occured with one of these. I'm not anti-nuclear, but I wouldn't blame somebody for pointing out that wreckage was found over a HUGE area.
Re:Thank god (Score:3, Insightful)
Re:Thank god (Score:2)
I hear ya, man. Don't forget the ignorant masses, though. I personally don't fear a serious accident by this, but I know people that'd suddenly go shopping for fallout shelters.
Heck, a member of my family actually thinks a microwave can go bad and cause a mushroom cloud. Ugh.
Re:Thank god (Score:3, Funny)
Uhhh...was it because they were by Madonna or as a protest of the lame outmoded audio cassette format? Inquiring minds want to know...
billy - damn, I just got used to 8 tracks
Re:Thank god (Score:4, Interesting)
The politics of why they even bothered to look, and what was actually found, are another subject/debate unto themselves...
Re:Thank god (Score:5, Insightful)
In other words the background radiation of the debris area was less than the natural background radiation of natural Uranium rich areas like Western Africa, or in fact many parts of Canada, which have higher radiation levels than the debris area.
Not exactly... (Score:3, Interesting)
It really doesn't work that way. Highly-radioactive chunks of metal of various sizes hit the ground after Cosmos 954 crashed. Several of them could have delivered a lethal dose to a person whio handled them without proper protection.
Here's one reference [www.jaxa.jp]
And another reference [space.com]
That talk about the potential lethality of some of the reco
At least three Russian RORSATs have fallen (Score:2, Interesting)
Not sure how big the Russian satellites are compared to this, though.
Re:Thank god (Score:3, Interesting)
Easy. We rename Project Prometheus to "Project Hubris".
Re:Thank god (Score:5, Insightful)
Coal is somewhere between one and thirteen parts per million Uranium. You can google and check the math but these numbers are not out of line:
We put twenty five *tons* of bomb grade Uranium 235 into the air each year with our current coal consumption. U235 is
http://greenwood.cr.usgs.gov/energy/factshts/16
Don't tell any tree hugging antinuclear activists, but our most common form of electricity production will *always* produce more radiation than the most horrific nuclear fuel accident. Changes the picture a bit, doesn't it?
Its all cold war BS that we don't have nuke powered space vessels to take advantage of the 1,000X energy density improvement over chemical fuels. I hope this comes to an end soon
Re:Thank god (Score:3, Insightful)
those 25 tons of uranium are spread over the whole globe, not just a small area. Chernobyl didn't realase that much radiation when it had its little boo-boo but that didn't stop a 30+ people from dying immediately, and another 200 or so being treated for radiation poisoning (not to mention varying degrees of contamination of the land, an increase in the thyroid cancer rate in the Ukraine, etc.)
You will never be able to convince pe
Selling nukes in space (Score:3, Insightful)
Permanently removing nuclear material from the Earth
Look at what a wonderful service is being provided, nuclear material is being made to Go Away Forever. The minor factor that it opens up exploration of the solar system is a minor side-effect, we don't need to talk about that. Just think of the nuclear material elimination aspects.
The hurdle is to convince skeptics that it's "Challenger-proof", not "Columbia-proo
JPL (Score:5, Funny)
Wow. Am I the only one that thought the JPL must be some license agreement like the GPL, and the wondered why the hell a web page needed to be released with a special license?
Jet Propulsion Labratory [nasa.gov]
Actually... (Score:2)
Actually, I was trying to figure out how a yet-to-be-built space craft has designed a web page. But, I suppose it isn't rocket-surgery.
Before you ask ... (Score:3, Informative)
It's a pleasant thought that the first software that aliens might encounter from Earth won't be from M$
Re:Before you ask ... (Score:4, Funny)
Re:Before you ask ... (Score:2)
On the other hand, if they made the USB key bootable and had the BIOS configured properly, they could (assuming the trajectory was precise enough
Re:Oh you mean W2k-style power management? (Score:3, Informative)
Re:Before you ask ... (Score:5, Funny)
Re:Before you ask ... (Score:2)
Based on comments, and icons, on /. (and from what I have seen), I think that the Borgs have already landed and have successfully installed their OS on our planet.
Re:Before you ask ... (Score:2, Insightful)
Re:Before you ask ... (Score:2)
Nuclear worries (Score:3, Interesting)
Re:Nuclear worries (Score:3, Insightful)
Re:Nuclear worries (Score:2, Funny)
Is this science fiction? (Score:5, Insightful)
http://prometheus.jpl.nasa.gov/contentImages/Blimp _over_Titan211_br.jpg [nasa.gov]
If that above picture happens in my lifetime, I will drop a load.
I hope they start with something more resonable than this. A big project will get bloated and is less likely to happen. Instead of going to Jupiter, how about getting to Mars with a little more reliability, with people?
Re:Is this science fiction? (Score:2)
Re:Is this science fiction? (Score:2)
Re:Is this science fiction? (Score:4, Informative)
Actually, the Bush administration explicitly gave the go-ahead [space.com] and requested funding for Project Prometheus. I dislike most of what Bush does, but this was one of the few things he did that I supported.
Of course, this made anti-nuclear folks like Bruce Gagnon [blogspot.com] quite spastic.
Re:Is this science fiction? (Score:4, Interesting)
Re:Is this science fiction? (Score:4, Insightful)
You think manned space flight to Mars is more reasonable and less bloated? It ain't a 3 day trip like it was to the moon.
Why, snails could move faster ... (Score:5, Interesting)
IMHO, it's a real shame projects like these aren't far more international in scope, open to all bidders, and funded from a futures type trust and traditional venture capital funding, as well as grants and taxes. Heck, most of these projects will pay back in spades if the new technologies were only properly licensed.
It simply amazes me how we have so many business geniuses, but not one of them has even considered space as the next new continent. What ever happened to good old American ingenuity and initiative, eh? Why have we apparently just given up our collective dreams of space exploration and development? Any one care to explain?
Re:Why, snails could move faster ... (Score:5, Insightful)
It simply amazes me how we have so many business geniuses, but not one of them has even considered space as the next new continent.
Because the vast majority of businessmen, "geniuses" or not (mostly not) are incapable of thinking past next quarter's results. The potential ROI on space travel is huge, but it's also very long-term. Interesting that you mention "new continent" as an example -- it's worth remembering that the early voyages of the Age of Exploration were done on government funding. I think the lesson here is pretty obvious.
Re:Why, snails could move faster ... (Score:4, Insightful)
Re:Why, snails could move faster ... (Score:2)
Actually you can blame this too on the general public. The funds needed to undertake such projects are such that you need public investment. It's the investors who don't look past the next quarter's return.
There are plenty of businessmen willing to gamble on it. But nobody will give them enough money to try.
Re:Why, snails could move faster ... (Score:2)
Re:Why, snails could move faster ... (Score:2)
However, I also don't dismiss the resposibility of the "People" either. In my opinion, we, as a society, have simply sold out.
Oh, and as to the government funding of the early American explorations. It is true the first few were, in part, funded by the respective crowns, however, that changed very quickly and the next centu
Re:Why, snails could move faster ... (Score:3, Interesting)
I am currently working on this - so perhaps I can give you some insights. The main problems are conflicting visions for the future, and people having problems basing business plans in th
Ehhh.. (Score:4, Interesting)
It'll still be lifted off the ground by chemical rockets. What happened to NERVA?
Isn't that quaint (Score:3, Funny)
Goofing around aside. This is cool. Dangerous but cool. Let's face it. This will be the mode of propulsion that will take spacecraft around our solar system for many years to come.
Re:Isn't that quaint (Score:3, Interesting)
Way O/T, but what the heck...
That model was always the odd one out. Most of the human ships and technologies in B5 are remarkably credible for a SF series; rumour has it the guys designing the Star Fury model talked to some guys from NASA about how they'd design such a ship for real, for example. But who in their right mind would design a carrier ship where the main egress for the small craft was right at the front, where all the incoming fire is going?
They'll be putting the bridge of a starship right o
Woah..... 7000 Seconds (Score:2, Interesting)
Re:Woah..... 7000 Seconds (Score:2, Insightful)
Prometheus, you say? (Score:2, Funny)
JIMO a no-go? (Score:2)
Looks like those "early mission plans" have been revised. See the second half of this article [spaceflightnow.com]. Here's the relevant paragraph:
Project Orion was cooler, though (Score:5, Interesting)
That said, I'm happy it never really materialized. Having a universe with a human population spreading effectively in it summons an eerie image on a spherically expanding brain-tumor to my mind...
http://isbndb.com/d/book/project_orion.html [isbndb.com]
Re:Project Orion was cooler, though (Score:3, Funny)
Gaseous Core Nuclear Reactor Rockets (Score:5, Interesting)
Here's a really interesting article [nuclearspace.com] that describes a design for a 100% reusable, non-polluting nuclear rocket based on the Saturn V form factor, capable of lifting 2 million pounds of cargo into orbit and returning to a soft landing. Just like in the old sci-fi movies. The design involves a gaseous core reactor, sometimes called a "nuclear lightbulb." It consists of a quartz bulb containing a cloud of uranium gas such as uranium hexafluoride, confined the center of the bulb by a buffer gas swirling around it. By adjusting the movement and pressure of the buffer gas, the compression of the UF6 can be finely regulated. When it is compressed to a critical state it heats up to about 25,000 degrees C, glowing intensely in the ultraviolet. Liquid hydrogen propellant pumped around the outside of the quartz bulb absorbs the ultraviolet light, becomes superheated, and shoots out of the nozzle. There is no leakage of radioactive fuel and no irradiation of the hydrogen. Completely clean burning. Such a rocket could burn for immensely longer times than any chemical rocket, providing the speed to get a manned mission to mars in a couple months. And not a skimpy mission, a spacious vehicle carrying 1000 tons of equipment, supplies and radiation shielding. Building a rocket like this wouldn't require any far-fetched technology, just some dedicated engineering.
I have never been a fan of nuclear reactors, but this thing sounds really good to me. The gaseous core has tremendous safety advantages over a solid core. The criticality of a cloud of gas is much easier to control and is to some extent self-regulating. For example, the problem of "hot spots" would not exist, because in gaseous form any part of the UF6 that overheated would expand, losing pressure and quenching itself instantly. The author describes several safety features, both active and passive, for letting the gas depressurize into a storage container extremely fast. Even if a gas core nuclear rocket exploded in the atmosphere, it would release a small fraction of the amount of nuclides from a single 1950s H-bomb test.
NASA must have told Bush there's oil on Titan! (Score:5, Funny)
Really efficient orbits using Lagrange points (Score:3, Informative)
It's much slower than traditional orbital transfers, but so much cheaper that it's worth using. It's already been used on SMART and Galileo:
http://www.sciencenews.org/articles/20050416/bob9. asp [sciencenews.org] (even mentions using it for Jupiter moon exploration!)
http://www.ufoindia.org/news_intsuperhighway.htm [ufoindia.org]
Re:Oh great (Score:5, Informative)
The first proposed mission within Prometheus Nuclear Systems and Technology would be a mission to Jupiter, the Jupiter Icy Moons Orbiter (JIMO), which represents a new class of mission capabilities far beyond those possible with current power and propulsion systems. Powered by a space nuclear reactor and propelled by electric ion engines, the spacecraft would make up-close, long-term orbiting visits to three of the solar system's most intriguing moons- Europa, Ganymede, and Callisto. Beneath their icy surfaces, these moons may contain oceans of water that could have provided an environment that may have harbored life."
http://prometheus.jpl.nasa.gov/index.cfm?pageL1
Beats the heck out of me what that has to do with militarizing space. Besides, IMO, nuclear power is a lot less environmentally dangerous than other power sources except maybe solar energy (which might not work when you're x billion miles from the sun).
Re:Oh great (Score:2)
Re:Oh great (Score:2)
Re:Oh great (Score:5, Informative)
Re:Oh great (Score:2)
Light is, of course, radiation. [n/t] (Score:3, Informative)
Re:Oh great (Score:2)
Not an insurmountable problem, the design of the engine will need to withstand an aborted take off and be launched over an unpopulated area like the sea.
Re:Oh great - It's a question of size really... (Score:2)
>earth? no, it radiation. Any radiation from a
> little spacecraft up in space is miniscule!
Not really... the sun puts out something like 1400 kiowatts/meter^2 before it gets to the surface... and that's mostly *not* in the form of gamma rays
A small 100kw nuclear reactor core puts out a lot more radiation in a smaller form factor (like a cubic meter or so)
Re:Oh great - It's a question of size really... (Score:3, Informative)
Re:Oh great (Score:3, Informative)
The current plan is for fission reactors to be used outside of an earth orbit. Earth is close enough to the sun that solar panels are still a good choice for energy, so reactors aren't needed. It's on the deep space probes, like the Jupiter Ice Moons Orbiter (if it ever happens) where this becomes useful. It could also potentially be used on a manned Mars mission since the extra power
Re:Oh great (Score:2)
Most of the immediate damage caused by a nuke, comes from the pressure wave from the blast. In space, no atmosphere, no pressure wave. So, the impact from the pressure wave doesn't exist, so not much is damaged immediately. The chain reaction also lets off a lot of heat, that would definitely effect things in the immediate vicinity, it may even melt them. There will be a localized concentration of radiation for a period, but, there's lots of var
Re:Oh great (Score:2)
The space craft I mentioned earlier in this post has neither distance or atmospheric shielding. But still, I have never heard of a reactor "Detonating" when it failed and melted down... at least recently. But ships and
Re:Oh great (Score:2)
Re:Oh great (Score:2)
Re:The U.S. has a good track record. (Score:4, Informative)
We used it in WWII.
And Iran would be pacifist if we never got involved in their history. They had a moderate government with some elements of capitalism. But then the USA decided to help Hussien, we sold him all the arms he needed to attack Iran for over a decade. And we let the Shah get expelled, for a very rigid Kohmeni.
Nuclear power is not relevant to this discussion (Score:2)
Some radioactive things are very good ideas.
Re:The U.S. has a good track record. (Score:3, Informative)
I think you are a bit confused about the particulars, though your general point is correct.
Act I: Iran has a popular, secular, western-educated leader, Mohammed Mossadegh [wikipedia.org]. Unfortunately this leader happen
Re:The U.S. has a good track record. (Score:2)
I'll believe that when the US stops manufacturing nuclear weapons. Until then, it's just a bunch of hypocritical pots hollering at the kettle....
Re:The U.S. has a good track record. (Score:4, Interesting)
Besides, when you already have several thousand fusion warheads, why build more?
Heat Sinks / Spreaders? (Score:5, Insightful)
I don't know the ins and outs but I'd imagine that if you have a nice chirpy nuclear-reactor to generate power, taking photovoltaics (solar panels) with you too would be rather pointless. - PVs would cost extra to put into space to start with and would also need trickery to align them with the sun.
Having glanced at the picture, I'd suggest it is more likely that the big flat panels are heat dissipators (heat-sinks) to get rid of the excess heat from the nuclear reactor. I presume that in space there is no conduction of heat away from the vehicle, only radiation. And that you improve the radiation of heat by increasing the surface area.
Re:Heat Sinks / Spreaders? (Score:5, Informative)
Re:Heat Sinks / Spreaders? (Score:5, Informative)
The move to fission is driven by a desire to get more power (even a large RTG will only produce a few hundred Watts, versus the kilowatts they expect to get from a reactor). I don't know exactly what the trade-offs are with using Brayton cycle vs thermoelectric (or thermionic) conversion. The Russians have flown a number of thermionic nuclear reactors (the Topaz series), and they seemed to work fairly well. I suppose it's possible that Brayton cycle reactors are more efficient than thermoelectric/thermionic conversion. But even if you assume a (highly unlikely) 90% conversion efficiency, a 100kW reactor would leave you with 10kW of thermal energy to dump. At this point it's probably worth noting that even the most high-power satellites we currently fly (the Boeing 702 comm-sat) operate on a mere 15kW of power. So you're talking about being able to radiate as much energy as most satellites generate in total. And as I said, that's based on some pretty optimistic assumptions about the efficiency of the Brayton cycle.
Re:Heat Sinks / Spreaders? (Score:5, Informative)
A good point. In fact, thermal design for spacecraft (at least at the preliminary stages) is typically carried out under the assumption that all of the electrical energy not leaving the spacecraft as RF radiation is converted into thermal energy.
The two energy expenditures I can think of that don't yield waste heat are the propulsion system (ideally), and the radios (again, ideally).
Unfortunately, both of those items are less than ideal. It's not uncommon for a spacecraft transponder to be on the order of 20% efficient (or worse). Likewise, the ion propulsion systems they are planning on using for Prometheus have an electrical->thermal conversion efficiency of around 70-80%. Which for a 20kW thruster (e.g. the proposed NEXIS thruster) means 4kW+ of waste heat.
Of course, I expect it would be possible to use a significant portion of that to heat the propulsion fuel.
The current proposals for Prometheus involve nuclear-electric propulsion rather than nuclear-thermal propulsion. I don't believe that heating the propellant in a NEP system helps (although I'm not really a propulsion expert, so I'm quite prepared to be corrected on this).
Re:Heat Sinks / Spreaders? (Score:2)
Re:The thing to do with Uranium (Score:2)
Re:The thing to do with Uranium (Score:5, Informative)
Re:The thing to do with Uranium (Score:3, Insightful)
How about all the steel in the world, too, to keep people from making knives?
Seriously--did you ever stop to think about the fact that nuclear fission might be a useful thing?
Some of us happen to think that nuclear fuels will help PREVENT wars over dwindling fossil fuel resources. Put that in your pipe and smoke it, hippie!
Re:Risk (Score:5, Insightful)
Re:Risk (Score:3, Insightful)
Re:Massive waste of money (Score:3, Insightful)
#2 - This propulsion system has everything to do with getting us to planets within our solar system. Up until the announcement of this project we have had chemical rockets to push us around the solar system. They are not suited to prolonged flights. This development is exceedingly important for getting us to destinations outside of lunar orbit.
#3 Consid