Tuesday, January 4, 2011

Nerva

I thought for sure that I'd written about this before on this very blog, but the Google search of this blog produced no hit for Nerva.   My page titled "Little Search Engine that Could" yielded a bunch of hits.  That plethora of hits may not include this page , but I know I have seen it before.

What drives my interest here is the possibility of using this technology with Ad Astra's VASIMR.  The thought of getting that much nuke power into space seemed daunting, yet this was within reach back in the Apollo days.  It got cancelled just before it could go operational.  Therefore, this is definitely not far-fetched.  It is feasible and nearly operational decades ago.  That should remain the case today.

There are questions, of course.  Could this be modified to work with VASIMR?  And should it be modified?  After all, VASIMR did not exist 40 years ago. Would this technology mated with VASIMR produce an even better propulsion system?  The possibility of sending a crew to Mars in 39 days with this does not seem so implausible after all.

Note:  I include this link in French because it appears to be discussing the Nerva program.  I don't know French, but maybe I can some of this translated.

Update:  Here it is, translated by a software add-on to Firefox


are purchases understand a on probation free membership in the club of pounds of the editor, in whom you can choose among more than a million works, without expenses. The book consists of articles Wikipedia on: Thermal Nuclear Propulsion, Orion plan, Nerva, Blown Nuclear Propulsion, Propulsion by Fragments of Fission, Radioisotopic Propulsion, Daedalus plan, collector Bussard, Longshot plan. Not illustrated. Online free updatings. Extract: Thermal or nucléo-thermal nuclear propulsion is a mode of propulsion of the missiles which uses a nuclear reactor to heat a propelling fluid. This one, as in the case of a motor - classical missile, is evicted via a blast pipe to provide the increase which projects the missile. This type of propulsion allows to attain in theory distinctly more well brought up speed of ejection of gas and therefore better output than chemical propulsion used on the actual pitchers. Different architectures were studied since the beginning of the space epoch of the simple solid heart (similar to that of a nuclear power station) up to more complex but more efficient concepts such as the gaseous hearts.
Although an archetype is tested on the soil by the United States (motor NERVA), any using missile this type of propulsion has still never flown. Important researches are still necessary between others to diminish the report weight / increase. If it is kept, nuclear propulsion will have to face up a party of the public opinion basically hostile to any launching of nuclear devices. Today, the appeal in nuclear propulsion is recalled only as part of program Constellation, for hypothetical lived missions towards march, in distant expiry date (after 2037). Schema of a thermal nuclear motor In a system of thermal or nucléo-thermal nuclear propulsion, a propelling fluid, in general some hydrogen, is heated


Comment:  Not much about Nerva.


Update: 1/4/2011: aprox 11:15 am cst

Upon "further review", it appears that using a Nerva system and VASIMR system together is not necessarily convenient.  Nerva heated the propellant directly.  Why reconfigure it to produce electricity for VASIMR so that it can heat propellant indirectly?  It is wasted energy, and adds complexity.   Hmm.

Yet the Nerva system shows ( I think) that you can get the energy equivalent up to VASIMR's needs.  If there is an advantage here, it could be two fold: 1) a longer lasting system in the VASIMR as opposed to the Nerva and 2) less propellant used than the Nerva.  The savings in propellant need to overcome the increase in hardware and complexity in order to make it worthwhile.

Update 1/5/2011: approx 7:20 am cst

I want to get into the habit of assessing odds of certain events.  I've written a bit about VASIMR lately.  In terms of getting to Mars, I want to predict that this is not likely with the VASIMR.  I see it as more of a space tug technology.

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