ROVER NERVA Nuclear Rocket Engine test stand #2

[fwgross]

What about the Boron cycle for an ion drive?

11B5 +p = 3(4He2) + 16MeV

Lots of energy produced . Exhause velocity 10000 kps with a specific impulse of a bit over a million.

[jibbi4one]

@fwgross Boron w/ exhaust velocity of 10,000 kps? What is kps?

When you express exhaust velocity it's in typical Specific Impulse (Isp) it's thrust force per unit propellant or fuel weight flow per second. An Isp of a million for Boron Ion Drive is not real. Studies of SEP (solar electric) or VASIMR or NEP are not BEST transport systems for intersellar transport. Real systems for solar system transport are Chemical & Nuclear Thermal. search&see video: Fusion Propulsion for Interstellar Travel

[ProjectFlashlight612]

Nuclear rockets are all well and good, but ion drives are clearly the way to go. Far less risk of rad leaks, vastly more efficient, and once you're in space, you can just kick out thrust forever and let momentum take you to the stars. Er, in about 20 years for somewhere like Alpha C....

[jibbi4one]

@ProjectFlashlight612 I don't want to offend here. REALLY you do need to put down comic books.

And do some science work if you feel the need to provide real energy for propulsion in space. Ion drives are a legitimate source of power but they DO NOT OPERATE in an energy vacuum they need a power source. Ion propulsion to A-Centauri, B-Centauri & Proxima is impossible! Now.

You need to go miniumun 1 C(speed of light) So far neutrinos might travel Faster Than Light (FTL).

So maybe FTL is real.

[MightyMike200]

@jibbi4one Why would you say you have to go a minimum of 1C? That's absurd based on our current understanding of physics. Ion drives are practical for interstellar travel yet but if you can maintain a constant acceleration of a significant fraction of G you can get to the stars in an acceptable duration according to the experience of the passenger.

[jibbi4one]

@MightyMike200 Yes, understand constant acceleration going 1 G principle. To provide this kind of propulsion requires massive energy w/ for example: FUSION.

We are roughly talking in orders of magnitude 63 terrajoules that's 96, 20 megaton A bombs exploding inside the fusion engine of a Nimitz Class aircraft carrier size spacecraft for over 31 million seconds!!!

Dude, that's insane power that human beings do not possess.

Utube search:FUSION PROPULSION FOR INTERSTELLAR TRAVEL-Bantokfomoki

[PimpMunkeh]

@ProjectFlashlight612 Ion Drives still need a fuel to "project" an exhaust for thrust. Thus we need a fuel cell to burn in space as space will provide no propellant. They're also slow as hell. The last Ion Engine we shot up into space took an equivalent of 4 days to go from 0 to 60 MPH. THAT'S How SLOW they accelerate. You need a BOOSTER to get you to a great speed, then the Ion Drive to keep that speed. Also, Solid Core Nuke Drives are not all that hazardous. NASA blew one up to test this.

[TheHotelMoxa]

@ProjectFlashlight612 actually Ion engines produce little thrust and it builds gradualy

a succesfull mission was Smart 1 and Dawn but it's not feasible for manned spaceflight

[normellow]

I love radiation .

[Xytan4]

Just imagine, we could have nuclear powered space planes. It'd be just like Star Wars, minus the faster than light travel.

[mdavies97131]

I should also note that the radioactivity issue will become null & void if we ever successfully master fusion energy or some other energy source as yet undiscovered.

[jibbi4one]

@mdavies97131 Sorry, but radioactivity is here to stay, I presume FOREVER since space radiation is typical for our region of the universe. It's literally OLDER THAN DIRT fortunately for Stellar Nucleosynthesis it's necessary for earthly existence and that goes for all of our stellar neighbors w/ earth like planets/moons.

So learn to love it and know your radiation limit before it becomes your poison.

[Perokneznik]

What speeds are nuclear thermal rockets capable of to reach?

[jibbi4one]

@Perokneznik 'speeds' don't know what this really means but a way to describe the efficiency of rocket and jet engines the Isp (Specific impulse) yielded specific impulses of about 850-1000 seconds (8,340 m/s), about more than twice that of the Space Shuttle engines.

The higher specific impulse (Isp), the less propellant is needed to gain a given amount of momentum.

[gogglesntophat]

is it true that nuclear engines are like the diesel of the rocket world? that they can use pretty mutch anything within reason as propellant?

[jibbi4one]

@gogglesntophat Yes, U R correct. It is a 'work horse' for space access. I can be used over-and-over for trips to Mars and Moon and beyond within our solar system. It's like a long haul engine all you need is add fuel. The easiest fuel to EXTRA TERRA manufacture as fuel gases like: Hydrogen the most plentiful, Oxygen, Methane, Propane etc. to name a few.

[jibbi4one]

Yes, U R correct you know nuclear chemistry you can see pic of destroyed reactor at search google: Bifrostkärnan Corporation

[Xytan4]

I read these engines are very safe, because the actual nuclear fuel is contained in carbide rods. They purposely destroyed a nuclear rocket, and no nuclear fuel was released because it's buried deep in the carbide.

[Xytan4]

Did any one die from nuclear fallout when these engines were tested? Nope.

Sure SpaceX is making great progress as the first private space agency to lower costs, but it still costs over 20 million dollars to launch one of their big Falcon 9s. Space travel will continue to remain very expensive as long as we continue to use weak kneed chemical propellants.

[jibbi4one]

@Xytan4 Yes I agree. Also note that nuke rocket testing was a billion/yr. dollars for 10 years a lot of revenue was made when private business filed patents that gov't shops gave away FREE NERVA/ROVER was a incubator for many of the hight tech stuff we use today it generated a few trillion for private business shops in 80's, 90's, and present.In planetary or asteroid mining operations small reactors (SMR) nukes can work to provide power for undersea & space based operations & community.

[mdavies97131]

@Xytan4 Also bear in mind 2 reasons for noone being harmed by nuclear fallout. For nuclear thermal rockets, the reactor is merely used as a heat source, and is thus no risk as long as containment holds (no meltdown, basically). In the case of the nuclear pulse engines, it would be b/c noone was dumb enough to be close enough to find out :) That one, however, does send out radioactivity just like any other nuclear explosion, the main reason it was moved to space-only then scrapped.

[TV843]

Fascinating footage!

[stdavross666]

what is all the flashing lights for? and also on the post on the left too??

[jibbi4one]

@stdavross666 I don't know the purpose of lights. I could try and find an explanation.

[stdavross666]

@jibbi4one looks like binary, but the lights on the poles???

[Wanztnabel]

@jibbi4one Its a binary clock.

[TalksWithDirt]

@stdavross666 The right most column is counting in binary. With LSB on the bottom and MSB on the top. The sequence is ... 9, 14, 15, 2, 3, 4, 5, 6, 7, 8, 9, 14 ....... I think it'd be nifty to cook some sausages on that thing. Look at that heat plume!

[stdavross666]

@TalksWithDirt thanks for the reply mate

[SabaothChristou]

@stdavross666 Looks like a binary clock.  The right most column is single digit seconds, one beside it is tens of seconds, then hundreds of seconds, then thousands (watch the tens of seconds column.. it goes up to 9 instead of just 6). It's odd how after the single digit seconds hits 9 it appears to jump up to 14 and 15, then back down to 2...3...4... dunno why it does that.

[KohnanTB]

Why can't we do this? I have read books about this. I I talked with someone at NASA. I even asked a space lawyer. All I seem to find out is that it boils down to politics. Chemical rocket engineers will lose their jobs. Everyone else will want one. Canada is still paranoid because of the Russian nuclear-powered satellite that broke up over their airspace - stuff like that. You would think that none of these items would be insurmountable given the potential of this simple technology.

[jibbi4one]

@KohnanTB True...I totally agree w/ you. There's no real excuse not to use this technology. This debate has gone on for far too long. In fact like with the classical myths of 'Flat Earth'. But I'll say to you the times are changing. NASA & all space agencies + there space faring nations realise they have no other option IF they really want robust space programs and agenices. The new U.S. National Space policy does have strong language in favor of use. [do search] it's up to politics not science

[Weenchit]

@jibbi4one I did read the policy and I was initially excited about the language you mentioned. However, this kind of thing is usually thrown out the second the president says it so it doesn't give me much hope. Maybe someday...

[Alembic25]

@KohnanTB The problem was that the risks were too great. It was felt that using such an engine in the atmosphere was too risky and to examine a worst case scenario they actually blew up a Kiwi reactor while it was running at full power at Jackass Flats in 1970. The plume blew over San Fransisco and caused major political arguements to such an extent that NASA ditched the nuclear engine concept calling it "dirty tech". Quite rightly so.

[Weenchit]

@Alembic25 Engineers have designed a testing scheme that makes use of an underground facility that captures and scrubs the exhaust so this could be developed into something safe and reliable enough such that even a crash would not release radiation into the environment. I think the answer in the end is that there is no mission that requires something this powerful. If the gov't wanted to build a massive HLV or do deep space manned missions it would happen and happen fast.

[Puzzoozoo]

@Alembic25 It might be 'dirty tech' but we are never going to go any where without it.

[Alembic25]

@Puzzoozoo No one's going to be doing manned deep space missions for at least the next 100 years. The only ultra heavy lift application would be for asteroid deflection missions. A short timeframe would focus on easilly available equipment and I can't see Nerva being considered.

[TheHotelMoxa]

@Alembic25 100 years is a n optimistical figure,with curent budgets cuts at NASA and Roscosmos it is posible that even LEO manned missions and unmanned science probes will became a thing of the past.

Take for istance 2012 in spaceflight,NASA will only launch NUSTAR and Curiosity,if Curiosity fails there won't be any rover for the next Mars launch window in 2014.

[electrodes1300]

@Alembic25 -- Yes, cirica aprox 1968, have seen the pictures, long ago. No tax payer wanted low earth devolopment or to have their hair fall out. NASA the propoganda engine could not handle the political fallout provided by the Cold War era. The engine looked almost too simple, it was a semi-conical plate, with a long rod attached to the plate, along this rod were many big spherical shapes. The fission would take place such that the resultant ejection pushed forward on the plate. Been 30 years!

[diaflux]

Amazing technology

[jibbi4one]

@diaflux This is game changing technology right here-right now.

If only critics would stop wasting energy dismissing merits of this technology.

Or the polemic ruse that some super unobtainium fuel politically correct 'star trek source' can trump this technology in the short term.

[diaflux]

@jibbi4one For sure, for sure, it's just the public bias. A large number of people think anything nuclear related = Chernobyl. Never mind the advancements in technology, or the stringent safety standards in aeronautics. This looks like the only option we have at this point for interplanetary travel; manned exploration of the solar system. Amazing stuff.

[Membrane556]

NTR engines are pretty much the only propulsion technology that can allow a human mission to Mars any time soon.

It cut the transit time by 40% and nearly doubles the mass fraction of the mission.

The mas fraction for a BNTR mission is .5 which means over half is useful payload.

For chemical it's a pitiful .68 at best and much slower and there are no real abort options.

[jibbi4one]

Yea, I can relate to that.

Δv=-ve ln(mf/mo)

The example given a complete Space Shuttle system has:

-fueled weight at liftoff: 1,708,500 kg

-dry weight at liftoff: 342,100 kg

with the given numbers, the propellant mass fraction is .

1-(342,100/1,708,50)=0.8332

.5 is smaller (better)...

Now if only more people could realize the advantage of nuclear rocket engines.

[shk9664]

@jibbi4one

eln woudl just equal the contents. Can you clarify your equation and explain ur derivation.

[jibbi4one]

@shk9664 just equals what??? "In aerospace engineering, the propellant mass fraction is a measure of a vehicle's performance, determined as the portion of the vehicle's mass which does not reach the destination. In a spacecraft, this is an orbit, while for aircraft it is their landing location. A higher mass fraction represents less weight in a design."

When applied to a rocket as a whole, a low mass fraction is desirable.

Propellant Mass Fraction, wikipedia

[neogastropoda1]

Im not gd at maths but ye. almost all of an atoms energy lies in its nucleus, not some miniscule electron

Current reactor bits are made from forged arstenitic stainless stee. 8g per cubic CM Wheras titanium alloy are slightly tougher n harder but only weigh 5g per cubic CM. better stregnth to weight ratio.

I was talkin to metalurgist where i work n he said why it is hard to forge titanium components of the required size without defects, i cant remember y but oh well tech is always improving tho

[jibbi4one]

No that's anti-nuke BS.

There were only two incidences of reactor explosion one planned and the other was an accident. On both occasions the environment was cleaned and no one died or got sick from radiation poisoning, at most it cost $50K for clean up.

[jibbi4one]

Well...no NASA presently does not permit the use of nuclear propulsion and power in space. I believe there is a total ban on use for space commercial, public or exploration etc.

[KohnanTB]

@jibbi4one Not a 100% ban: Don't forget they do make use of radioisotope thermoelectric generators. Like in Voyager, Cassini and New Horizons. They are not useful for propulsion but they are reliable and long lasting. Maybe they will result in more support for nuclear. Then there is nuclear-electric propulsion which NASA seems to support. But what they don't mention is that a compact and powerful enough nuclear power source to make this as good as NTR won't exist for about 50 years.